diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..b857371
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,51 @@
+# C++ objects and libs
+*.slo
+*.lo
+*.o
+*.a
+*.la
+*.lai
+*.so
+*.dll
+*.dylib
+
+# Qt-es
+object_script.*.Release
+object_script.*.Debug
+*_plugin_import.cpp
+/.qmake.cache
+/.qmake.stash
+*.pro.user
+*.pro.user.*
+*.qbs.user
+*.qbs.user.*
+*.moc
+moc_*.cpp
+moc_*.h
+qrc_*.cpp
+ui_*.h
+*.qmlc
+*.jsc
+Makefile*
+*build-*
+*build_*
+
+# Qt unit tests
+target_wrapper.*
+
+# QtCreator
+*.autosave
+
+# QtCreator Qml
+*.qmlproject.user
+*.qmlproject.user.*
+
+# QtCreator CMake
+CMakeLists.txt.user*
+
+# My output files
+build
+
+# vs
+.vs
+.vscode
\ No newline at end of file
diff --git a/3rdparty/capo/make.hpp b/3rdparty/capo/make.hpp
new file mode 100644
index 0000000..908849c
--- /dev/null
+++ b/3rdparty/capo/make.hpp
@@ -0,0 +1,22 @@
+/*
+    The Capo Library
+    Code covered by the MIT License
+    Author: mutouyun (http://orzz.org)
+*/
+
+#pragma once
+
+#include <type_traits>  // std::decay
+#include <utility>      // std::forward
+
+namespace capo
+{
+    template <template <typename...> class Ret, typename... T>
+    using return_t = Ret<typename std::decay<T>::type...>;
+
+    template <template <typename...> class Ret, typename... T>
+    inline return_t<Ret, T...> make(T&&... args)
+    {
+        return return_t<Ret, T...>(std::forward<T>(args)...);
+    }
+}
\ No newline at end of file
diff --git a/3rdparty/capo/noncopyable.hpp b/3rdparty/capo/noncopyable.hpp
new file mode 100644
index 0000000..cb70a11
--- /dev/null
+++ b/3rdparty/capo/noncopyable.hpp
@@ -0,0 +1,25 @@
+/*
+    The Capo Library
+    Code covered by the MIT License
+    Author: mutouyun (http://orzz.org)
+*/
+
+#pragma once
+
+namespace capo {
+
+////////////////////////////////////////////////////////////////
+
+class noncopyable
+{
+protected:
+    noncopyable(void) = default;
+    ~noncopyable(void) = default;
+public:
+    noncopyable(const noncopyable&) = delete;
+    noncopyable& operator=(const noncopyable&) = delete;
+};
+
+////////////////////////////////////////////////////////////////
+
+} // namespace capo
\ No newline at end of file
diff --git a/3rdparty/capo/random.hpp b/3rdparty/capo/random.hpp
new file mode 100644
index 0000000..78f0e60
--- /dev/null
+++ b/3rdparty/capo/random.hpp
@@ -0,0 +1,52 @@
+/*
+    The Capo Library
+    Code covered by the MIT License
+
+    Author: mutouyun (http://orzz.org)
+*/
+
+#pragma once
+
+#include <random>   // std::default_random_engine, std::uniform_int_distribution
+#include <utility>  // std::forward
+
+namespace capo {
+
+////////////////////////////////////////////////////////////////
+/// Simple way of generating random numbers
+////////////////////////////////////////////////////////////////
+
+template <class Engine       = std::default_random_engine, 
+          class Distribution = std::uniform_int_distribution<>>
+class random : public Distribution
+{
+    using base_t = Distribution;
+
+public:
+    using engine_type       = Engine;
+    using distribution_type = Distribution;
+    using result_type       = typename distribution_type::result_type;
+    using param_type        = typename distribution_type::param_type;
+
+private:
+    engine_type engine_;
+
+public:
+    template <typename... T>
+    random(T&&... args)
+        : base_t (std::forward<T>(args)...)
+        , engine_(std::random_device{}())
+    {}
+
+    result_type operator()(void)
+    {
+        return base_t::operator()(engine_);
+    }
+
+    result_type operator()(const param_type& parm)
+    {
+        return base_t::operator()(engine_, parm);
+    }
+};
+
+} // namespace capo
diff --git a/3rdparty/capo/scope_guard.hpp b/3rdparty/capo/scope_guard.hpp
new file mode 100644
index 0000000..306b689
--- /dev/null
+++ b/3rdparty/capo/scope_guard.hpp
@@ -0,0 +1,103 @@
+/*
+    The Capo Library
+    Code covered by the MIT License
+    Author: mutouyun (http://orzz.org)
+*/
+
+#pragma once
+
+#include "capo/noncopyable.hpp"
+#include "capo/unused.hpp"
+#include "capo/make.hpp"
+
+#include <utility>      // std::forward, std::move
+#include <algorithm>    // std::swap
+#include <functional>   // std::function
+
+namespace capo {
+
+////////////////////////////////////////////////////////////////
+/// Execute guard function when the enclosing scope exits
+////////////////////////////////////////////////////////////////
+
+template <typename F = std::function<void()>>
+class scope_guard : capo::noncopyable
+{
+    F destructor_;
+    mutable bool dismiss_;
+
+public:
+    template <typename F_>
+    scope_guard(F_&& destructor)
+        : destructor_(std::forward<F_>(destructor))
+        , dismiss_(false)
+    {}
+
+    scope_guard(scope_guard&& rhs)
+        : destructor_(std::move(rhs.destructor_))
+        , dismiss_(true) // dismiss rhs
+    {
+        std::swap(dismiss_, rhs.dismiss_);
+    }
+
+    ~scope_guard(void)
+    {
+        try { do_exit(); }
+        /*
+            In the realm of exceptions, it is fundamental that you can do nothing
+            if your "undo/recover" action fails.
+        */
+        catch(...) { /* Do nothing */ }
+    }
+
+    void dismiss(void) const noexcept
+    {
+        dismiss_ = true;
+    }
+
+    void do_exit(void)
+    {
+        if (!dismiss_)
+        {
+            dismiss_ = true;
+            destructor_();
+        }
+    }
+
+    void swap(scope_guard& rhs)
+    {
+        std::swap(destructor_, rhs.destructor_);
+        std::swap(dismiss_,    rhs.dismiss_);
+    }
+};
+
+namespace detail_scope_guard {
+
+struct helper
+{
+    template <typename F>
+    auto operator=(F&& destructor) -> decltype(capo::make<scope_guard>(std::forward<F>(destructor)))
+    {
+        return capo::make<scope_guard>(std::forward<F>(destructor));
+    }
+};
+
+} // namespace detail_scope_guard
+
+#define CAPO_SCOPE_GUARD_V_(L)  CAPO_UNUSED_ scope_guard_##L##__
+#define CAPO_SCOPE_GUARD_L_(L)  auto CAPO_SCOPE_GUARD_V_(L) = capo::detail_scope_guard::helper{}
+
+/*
+    Do things like this:
+    -->
+    CAPO_SCOPE_GUARD_ = [ptr]
+    {
+        if (ptr) free(ptr);
+    };
+*/
+
+#define CAPO_SCOPE_GUARD_ CAPO_SCOPE_GUARD_L_(__LINE__)
+
+////////////////////////////////////////////////////////////////
+
+} // namespace capo
\ No newline at end of file
diff --git a/3rdparty/capo/spin_lock.hpp b/3rdparty/capo/spin_lock.hpp
new file mode 100644
index 0000000..8ca2635
--- /dev/null
+++ b/3rdparty/capo/spin_lock.hpp
@@ -0,0 +1,104 @@
+/*
+    The Capo Library
+    Code covered by the MIT License
+
+    Author: mutouyun (http://orzz.org)
+*/
+
+#pragma once
+
+#include <atomic>       // std::atomic_flag, std::atomic_signal_fence
+#include <thread>       // std::this_thread
+#include <chrono>       // std::chrono::milliseconds
+#if defined(_MSC_VER)
+#include <windows.h>    // YieldProcessor
+#endif/*_MSC_VER*/
+
+namespace capo {
+namespace detail_spin_lock {
+
+////////////////////////////////////////////////////////////////
+/// Gives hint to processor that improves performance of spin-wait loops.
+////////////////////////////////////////////////////////////////
+
+#if defined(_MSC_VER)
+/*
+    See: http://msdn.microsoft.com/en-us/library/windows/desktop/ms687419(v=vs.85).aspx
+    Not for intel c++ compiler, so ignore http://software.intel.com/en-us/forums/topic/296168
+*/
+#   define CAPO_SPIN_LOCK_PAUSE_() YieldProcessor()
+#elif defined(__GNUC__)
+#if defined(__i386__) || defined(__x86_64__)
+/*
+    See: Intel(R) 64 and IA-32 Architectures Software Developer's Manual V2
+         PAUSE-Spin Loop Hint, 4-57
+         http://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-instruction-set-reference-manual-325383.html?wapkw=instruction+set+reference
+*/
+#   define CAPO_SPIN_LOCK_PAUSE_() __asm__ __volatile__("pause")
+#elif defined(__ia64__) || defined(__ia64)
+/*
+    See: Intel(R) Itanium(R) Architecture Developer's Manual, Vol.3
+         hint - Performance Hint, 3:145
+         http://www.intel.com/content/www/us/en/processors/itanium/itanium-architecture-vol-3-manual.html
+*/
+#   define CAPO_SPIN_LOCK_PAUSE_() __asm__ __volatile__ ("hint @pause")
+#elif defined(__arm__)
+/*
+    See: ARM Architecture Reference Manuals (YIELD)
+         http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.subset.architecture.reference/index.html
+*/
+#   define CAPO_SPIN_LOCK_PAUSE_() __asm__ __volatile__ ("yield")
+#endif
+#endif/*compilers*/
+
+#if !defined(CAPO_SPIN_LOCK_PAUSE_)
+/*
+    Just use a compiler fence, prevent compiler from optimizing loop
+*/
+#   define CAPO_SPIN_LOCK_PAUSE_() std::atomic_signal_fence(std::memory_order_seq_cst)
+#endif/*!defined(CAPO_SPIN_LOCK_PAUSE_)*/
+
+////////////////////////////////////////////////////////////////
+/// Yield to other threads
+////////////////////////////////////////////////////////////////
+
+inline void yield(unsigned k)
+{
+    if (k < 4)  { /* Do nothing */ }
+    else
+    if (k < 16) { CAPO_SPIN_LOCK_PAUSE_(); }
+    else
+    if (k < 32) { std::this_thread::yield(); }
+    else
+    { std::this_thread::sleep_for(std::chrono::milliseconds(1)); }
+}
+
+} // namespace detail_spin_lock
+
+////////////////////////////////////////////////////////////////
+/// Spinlock
+////////////////////////////////////////////////////////////////
+
+class spin_lock
+{
+    std::atomic_flag lc_ = ATOMIC_FLAG_INIT;
+
+public:
+    bool try_lock(void)
+    {
+        return !lc_.test_and_set(std::memory_order_acquire);
+    }
+
+    void lock(void)
+    {
+        for (unsigned k = 0; lc_.test_and_set(std::memory_order_acquire); ++k)
+            detail_spin_lock::yield(k);
+    }
+
+    void unlock(void)
+    {
+        lc_.clear(std::memory_order_release);
+    }
+};
+
+} // namespace capo
diff --git a/3rdparty/capo/stopwatch.hpp b/3rdparty/capo/stopwatch.hpp
new file mode 100644
index 0000000..1e96dcb
--- /dev/null
+++ b/3rdparty/capo/stopwatch.hpp
@@ -0,0 +1,109 @@
+/*
+    The Capo Library
+    Code covered by the MIT License
+
+    Author: mutouyun (http://orzz.org)
+*/
+
+#pragma once
+
+#include <chrono>   // std::chrono
+#include <array>    // std::array
+#include <utility>  // std::pair, std::declval
+#include <cstddef>  // size_t
+
+namespace capo {
+
+////////////////////////////////////////////////////////////////
+/// Stopwatch - can store multiple sets of time
+////////////////////////////////////////////////////////////////
+
+template <size_t CountN = 1, class ClockT = std::chrono::steady_clock>
+class stopwatch : public ClockT
+{
+    using base_t = ClockT;
+
+    static_assert(CountN > 0, "The count must be greater than 0");
+
+public:
+    using rep        = typename ClockT::rep;
+    using period     = typename ClockT::period;
+    using duration   = typename ClockT::duration;
+    using time_point = typename ClockT::time_point;
+
+private:
+    using pair_t = std::pair<time_point/*start*/, time_point/*paused*/>;
+
+    std::array<pair_t, CountN> points_;
+    bool is_stopped_ = true;
+
+public:
+    stopwatch(bool start_watch = false)
+    {
+        if (start_watch) start();
+    }
+
+public:
+    bool is_stopped(void) const
+    {
+        return is_stopped_;
+    }
+
+    template <size_t N = 0>
+    bool is_paused(void) const
+    {
+        return (points_[N].second != points_[N].first);
+    }
+
+    template <size_t N = 0>
+    duration elapsed(void)
+    {
+        if (is_stopped())
+            return duration::zero();
+        else
+        if (is_paused<N>())
+            return (points_[N].second - points_[N].first);
+        else
+            return ClockT::now() - points_[N].first;
+    }
+
+    template <typename ToDur, size_t N = 0>
+    auto elapsed(void) -> decltype(std::declval<ToDur>().count())
+    {
+        return std::chrono::duration_cast<ToDur>(elapsed<N>()).count();
+    }
+
+    template <size_t N = 0>
+    void pause(void)
+    {
+        points_[N].second = ClockT::now();
+    }
+
+    template <size_t N = 0>
+    void restart(void)
+    {
+        points_[N].second = points_[N].first =
+            ClockT::now() - (points_[N].second - points_[N].first);
+    }
+
+    void start(void)
+    {
+        time_point now = ClockT::now();
+        for (auto& pt : points_)
+        {
+            pt.second = pt.first = now - (pt.second - pt.first);
+        }
+        is_stopped_ = false;
+    }
+
+    void stop(void)
+    {
+        for (auto& pt : points_)
+        {
+            pt.second = pt.first;
+        }
+        is_stopped_ = true;
+    }
+};
+
+} // namespace capo
diff --git a/3rdparty/capo/type_name.hpp b/3rdparty/capo/type_name.hpp
new file mode 100644
index 0000000..aee3033
--- /dev/null
+++ b/3rdparty/capo/type_name.hpp
@@ -0,0 +1,320 @@
+/*
+    The Capo Library
+    Code covered by the MIT License
+    Author: mutouyun (http://orzz.org)
+*/
+
+#pragma once
+
+#include "capo/scope_guard.hpp"
+
+#include <typeinfo>     // typeid
+#include <sstream>      // std::ostringstream, std::string
+#include <type_traits>  // std::is_array
+
+#if defined(__GNUC__)
+#   include <cxxabi.h>  // abi::__cxa_demangle
+#endif/*__GNUC__*/
+
+namespace capo {
+namespace detail_type_name {
+
+////////////////////////////////////////////////////////////////
+/// Ready for output
+////////////////////////////////////////////////////////////////
+
+// Forward declarations
+template <typename T, bool IsBase = false>
+struct check;
+
+/*
+    Output state management
+*/
+
+class output
+{
+    bool is_compact_ = true;
+
+    template <typename T>
+    bool check_empty(const T&) { return false; }
+    bool check_empty(const char* val)
+    {
+        return (!val) || (val[0] == 0);
+    }
+
+    template <typename T>
+    void out(const T& val)
+    {
+        if (check_empty(val)) return;
+        if (!is_compact_) sr_ += " ";
+        std::ostringstream ss;
+        ss << val;
+        sr_ += ss.str();
+        is_compact_ = false;
+    }
+
+    std::string& sr_;
+
+public:
+    output(std::string& sr) : sr_(sr) {}
+
+    output& operator()(void) { return (*this); }
+
+    template <typename T1, typename... T>
+    output& operator()(const T1& val, const T&... args)
+    {
+        out(val);
+        return operator()(args...);
+    }
+
+    output& compact(void)
+    {
+        is_compact_ = true;
+        return (*this);
+    }
+};
+
+// ()
+
+template <bool>
+struct bracket
+{
+    output& out_;
+
+    bracket(output& out, const char* = nullptr) : out_(out)
+    { out_("(").compact(); }
+
+    ~bracket(void)
+    { out_.compact()(")"); }
+};
+
+template <>
+struct bracket<false>
+{
+    bracket(output& out, const char* str = nullptr)
+    { out(str); }
+};
+
+// [N]
+
+template <size_t N = 0>
+struct bound
+{
+    output& out_;
+
+    bound(output& out) : out_(out) {}
+    ~bound(void)
+    {
+        if (N == 0) out_("[]");
+        else        out_("[").compact()
+                        ( N ).compact()
+                        ("]");
+    }
+};
+
+// (P1, P2, ...)
+
+template <bool, typename... P>
+struct parameter;
+
+template <bool IsStart>
+struct parameter<IsStart>
+{
+    output& out_;
+
+    parameter(output& out) : out_(out) {}
+    ~parameter(void)
+    { bracket<IsStart> { out_ }; }
+};
+
+template <bool IsStart, typename P1, typename... P>
+struct parameter<IsStart, P1, P...>
+{
+    output& out_;
+
+    parameter(output& out) : out_(out) {}
+    ~parameter(void)
+    {
+        [this](bracket<IsStart>&&)
+        {
+            check<P1> { out_ };
+            parameter<false, P...> { out_.compact() };
+        } (bracket<IsStart> { out_, "," });
+    }
+};
+
+////////////////////////////////////////////////////////////////
+/// Template specializations for checking
+////////////////////////////////////////////////////////////////
+
+/*
+    CV-qualifiers, references, pointers
+*/
+
+template <typename T, bool IsBase>
+struct check
+{
+    output out_;
+    check(const output& out) : out_(out)
+    {
+#   if defined(__GNUC__)
+        const char* typeid_name = typeid(T).name();
+        char* real_name = abi::__cxa_demangle(typeid_name, nullptr, nullptr, nullptr);
+        CAPO_SCOPE_GUARD_ = [real_name]
+        {
+            if (real_name) ::free(real_name);
+        };
+        out_(real_name ? real_name : typeid_name);
+#   else /*__GNUC__*/
+        out_(typeid(T).name());
+#   endif/*__GNUC__*/
+    }
+};
+
+#pragma push_macro("CAPO_CHECK_TYPE__")
+#undef  CAPO_CHECK_TYPE__
+#define CAPO_CHECK_TYPE__(OPT)                                 \
+    template <typename T, bool IsBase>                         \
+    struct check<T OPT, IsBase> : check<T, true>               \
+    {                                                          \
+        using base_t = check<T, true>;                         \
+        using base_t::out_;                                    \
+        check(const output& out) : base_t(out) { out_(#OPT); } \
+    };
+
+CAPO_CHECK_TYPE__(const)
+CAPO_CHECK_TYPE__(volatile)
+CAPO_CHECK_TYPE__(const volatile)
+CAPO_CHECK_TYPE__(&)
+CAPO_CHECK_TYPE__(&&)
+CAPO_CHECK_TYPE__(*)
+
+#pragma pop_macro("CAPO_CHECK_TYPE__")
+
+/*
+    Arrays
+*/
+
+#pragma push_macro("CAPO_CHECK_TYPE_ARRAY__")
+#pragma push_macro("CAPO_CHECK_TYPE_ARRAY_CV__")
+#pragma push_macro("CAPO_CHECK_TYPE_PLACEHOLDER__")
+
+#undef CAPO_CHECK_TYPE_ARRAY__
+#undef CAPO_CHECK_TYPE_ARRAY_CV__
+#undef CAPO_CHECK_TYPE_PLACEHOLDER__
+
+#define CAPO_CHECK_TYPE_ARRAY__(CV_OPT, BOUND_OPT, ...)                                    \
+    template <typename T, bool IsBase __VA_ARGS__>                                         \
+    struct check<T CV_OPT [BOUND_OPT], IsBase> : check<T CV_OPT, !std::is_array<T>::value> \
+    {                                                                                      \
+        using base_t = check<T CV_OPT, !std::is_array<T>::value>;                          \
+        using base_t::out_;                                                                \
+                                                                                           \
+        bound<BOUND_OPT> bound_   = out_;                                                  \
+        bracket<IsBase>  bracket_ = out_;                                                  \
+                                                                                           \
+        check(const output& out) : base_t(out) {}                                          \
+    };
+
+#define CAPO_CHECK_TYPE_ARRAY_CV__(BOUND_OPT, ...)               \
+    CAPO_CHECK_TYPE_ARRAY__(, BOUND_OPT, ,##__VA_ARGS__)         \
+    CAPO_CHECK_TYPE_ARRAY__(const, BOUND_OPT, ,##__VA_ARGS__)    \
+    CAPO_CHECK_TYPE_ARRAY__(volatile, BOUND_OPT, ,##__VA_ARGS__) \
+    CAPO_CHECK_TYPE_ARRAY__(const volatile, BOUND_OPT, ,##__VA_ARGS__)
+
+#define CAPO_CHECK_TYPE_PLACEHOLDER__
+
+CAPO_CHECK_TYPE_ARRAY_CV__(CAPO_CHECK_TYPE_PLACEHOLDER__)
+#if defined(__GNUC__)
+CAPO_CHECK_TYPE_ARRAY_CV__(0)
+#endif/*__GNUC__*/
+CAPO_CHECK_TYPE_ARRAY_CV__(N, size_t N)
+
+#pragma pop_macro("CAPO_CHECK_TYPE_PLACEHOLDER__")
+#pragma pop_macro("CAPO_CHECK_TYPE_ARRAY_CV__")
+#pragma pop_macro("CAPO_CHECK_TYPE_ARRAY__")
+
+/*
+    Functions
+*/
+
+template <typename T, bool IsBase, typename... P>
+struct check<T(P...), IsBase> : check<T, true>
+{
+    using base_t = check<T, true>;
+    using base_t::out_;
+
+    parameter<true, P...> parameter_ = out_;
+    bracket<IsBase>       bracket_   = out_;
+
+    check(const output& out) : base_t(out) {}
+};
+
+/*
+    Pointers to members
+*/
+
+template <typename T, bool IsBase, typename C>
+struct check<T C::*, IsBase> : check<T, true>
+{
+    using base_t = check<T, true>;
+    using base_t::out_;
+
+    check(const output& out) : base_t(out)
+    {
+        check<C> { out_ };
+        out_.compact()("::*");
+    }
+};
+
+/*
+    Pointers to member functions
+*/
+
+#pragma push_macro("CAPO_CHECK_TYPE_MEM_FUNC__")
+#undef  CAPO_CHECK_TYPE_MEM_FUNC__
+#define CAPO_CHECK_TYPE_MEM_FUNC__(...)                           \
+    template <typename T, bool IsBase, typename C, typename... P> \
+    struct check<T(C::*)(P...) __VA_ARGS__, IsBase>               \
+    {                                                             \
+        scope_guard<> at_destruct_cv_;                            \
+        check<T(P...), true> base_;                               \
+        output& out_ = base_.out_;                                \
+                                                                  \
+        check(const output& out)                                  \
+            : at_destruct_cv_([this]{ out_(#__VA_ARGS__); })      \
+            , base_(out)                                          \
+        {                                                         \
+            check<C> { out_ };                                    \
+            out_.compact()("::*");                                \
+        }                                                         \
+    };
+
+CAPO_CHECK_TYPE_MEM_FUNC__()
+CAPO_CHECK_TYPE_MEM_FUNC__(const)
+CAPO_CHECK_TYPE_MEM_FUNC__(volatile)
+CAPO_CHECK_TYPE_MEM_FUNC__(const volatile)
+
+#pragma pop_macro("CAPO_CHECK_TYPE_MEM_FUNC__")
+
+} // namespace detail_type_name
+
+////////////////////////////////////////////////////////////////
+/// Get the name of the given type
+////////////////////////////////////////////////////////////////
+
+/*
+    type_name<const volatile void *>()
+    -->
+    void const volatile *
+*/
+
+template <typename T>
+inline std::string type_name(void)
+{
+    std::string str;
+    detail_type_name::check<T> { str };
+    return str;
+}
+
+} // namespace capo
\ No newline at end of file
diff --git a/3rdparty/capo/unused.hpp b/3rdparty/capo/unused.hpp
new file mode 100644
index 0000000..b79d7ef
--- /dev/null
+++ b/3rdparty/capo/unused.hpp
@@ -0,0 +1,23 @@
+/*
+    The Capo Library
+    Code covered by the MIT License
+    Author: mutouyun (http://orzz.org)
+*/
+
+#pragma once
+
+////////////////////////////////////////////////////////////////
+
+#ifdef CAPO_UNUSED_
+#   error "CAPO_UNUSED_ has been defined."
+#endif
+
+#if defined(_MSC_VER)
+#   define CAPO_UNUSED_ __pragma(warning(suppress: 4100 4101 4189))
+#elif defined(__GNUC__)
+#   define CAPO_UNUSED_ __attribute__((__unused__))
+#else
+#   define CAPO_UNUSED_
+#endif
+
+////////////////////////////////////////////////////////////////
\ No newline at end of file
diff --git a/3rdparty/gperftools/libtcmalloc_minimal.so.4 b/3rdparty/gperftools/libtcmalloc_minimal.so.4
new file mode 100644
index 0000000..74cc460
--- /dev/null
+++ b/3rdparty/gperftools/libtcmalloc_minimal.so.4
@@ -0,0 +1 @@
+libtcmalloc_minimal.so
\ No newline at end of file
diff --git a/3rdparty/gperftools/libtcmalloc_minimal.so.4.5.3 b/3rdparty/gperftools/libtcmalloc_minimal.so.4.5.3
new file mode 100644
index 0000000..74cc460
--- /dev/null
+++ b/3rdparty/gperftools/libtcmalloc_minimal.so.4.5.3
@@ -0,0 +1 @@
+libtcmalloc_minimal.so
\ No newline at end of file
diff --git a/3rdparty/gperftools/tcmalloc.h b/3rdparty/gperftools/tcmalloc.h
new file mode 100644
index 0000000..7935081
--- /dev/null
+++ b/3rdparty/gperftools/tcmalloc.h
@@ -0,0 +1,163 @@
+// -*- Mode: C; c-basic-offset: 2; indent-tabs-mode: nil -*-
+/* Copyright (c) 2003, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ---
+ * Author: Sanjay Ghemawat <opensource@google.com>
+ *         .h file by Craig Silverstein <opensource@google.com>
+ */
+
+#ifndef TCMALLOC_TCMALLOC_H_
+#define TCMALLOC_TCMALLOC_H_
+
+#include <stddef.h>                     /* for size_t */
+#ifdef __cplusplus
+#include <new>                          /* for std::nothrow_t, std::align_val_t */
+#endif
+
+/* Define the version number so folks can check against it */
+#define TC_VERSION_MAJOR  2
+#define TC_VERSION_MINOR  7
+#define TC_VERSION_PATCH  ""
+#define TC_VERSION_STRING "gperftools 2.7"
+
+/* For struct mallinfo, if it's defined. */
+#if 1
+# include <malloc.h>
+#endif
+
+#ifndef PERFTOOLS_NOTHROW
+
+#if __cplusplus >= 201103L
+#define PERFTOOLS_NOTHROW noexcept
+#elif defined(__cplusplus)
+#define PERFTOOLS_NOTHROW throw()
+#else
+# ifdef __GNUC__
+#  define PERFTOOLS_NOTHROW __attribute__((__nothrow__))
+# else
+#  define PERFTOOLS_NOTHROW
+# endif
+#endif
+
+#endif
+
+#ifndef PERFTOOLS_DLL_DECL
+# ifdef _WIN32
+#   define PERFTOOLS_DLL_DECL  __declspec(dllimport)
+# else
+#   define PERFTOOLS_DLL_DECL
+# endif
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+  /*
+   * Returns a human-readable version string.  If major, minor,
+   * and/or patch are not NULL, they are set to the major version,
+   * minor version, and patch-code (a string, usually "").
+   */
+  PERFTOOLS_DLL_DECL const char* tc_version(int* major, int* minor,
+                                            const char** patch) PERFTOOLS_NOTHROW;
+
+  PERFTOOLS_DLL_DECL void* tc_malloc(size_t size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void* tc_malloc_skip_new_handler(size_t size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_free(void* ptr) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_free_sized(void *ptr, size_t size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void* tc_realloc(void* ptr, size_t size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void* tc_calloc(size_t nmemb, size_t size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_cfree(void* ptr) PERFTOOLS_NOTHROW;
+
+  PERFTOOLS_DLL_DECL void* tc_memalign(size_t __alignment,
+                                       size_t __size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL int tc_posix_memalign(void** ptr,
+                                           size_t align, size_t size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void* tc_valloc(size_t __size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void* tc_pvalloc(size_t __size) PERFTOOLS_NOTHROW;
+
+  PERFTOOLS_DLL_DECL void tc_malloc_stats(void) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL int tc_mallopt(int cmd, int value) PERFTOOLS_NOTHROW;
+#if 1
+  PERFTOOLS_DLL_DECL struct mallinfo tc_mallinfo(void) PERFTOOLS_NOTHROW;
+#endif
+
+  /*
+   * This is an alias for MallocExtension::instance()->GetAllocatedSize().
+   * It is equivalent to
+   *    OS X: malloc_size()
+   *    glibc: malloc_usable_size()
+   *    Windows: _msize()
+   */
+  PERFTOOLS_DLL_DECL size_t tc_malloc_size(void* ptr) PERFTOOLS_NOTHROW;
+
+#ifdef __cplusplus
+  PERFTOOLS_DLL_DECL int tc_set_new_mode(int flag) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void* tc_new(size_t size);
+  PERFTOOLS_DLL_DECL void* tc_new_nothrow(size_t size,
+                                          const std::nothrow_t&) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_delete(void* p) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_delete_sized(void* p, size_t size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_delete_nothrow(void* p,
+                                            const std::nothrow_t&) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void* tc_newarray(size_t size);
+  PERFTOOLS_DLL_DECL void* tc_newarray_nothrow(size_t size,
+                                               const std::nothrow_t&) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_deletearray(void* p) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_deletearray_sized(void* p, size_t size) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_deletearray_nothrow(void* p,
+                                                 const std::nothrow_t&) PERFTOOLS_NOTHROW;
+
+#if 1 && __cplusplus >= 201703L
+  PERFTOOLS_DLL_DECL void* tc_new_aligned(size_t size, std::align_val_t al);
+  PERFTOOLS_DLL_DECL void* tc_new_aligned_nothrow(size_t size, std::align_val_t al,
+                                          const std::nothrow_t&) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_delete_aligned(void* p, std::align_val_t al) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_delete_sized_aligned(void* p, size_t size, std::align_val_t al) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_delete_aligned_nothrow(void* p, std::align_val_t al,
+                                            const std::nothrow_t&) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void* tc_newarray_aligned(size_t size, std::align_val_t al);
+  PERFTOOLS_DLL_DECL void* tc_newarray_aligned_nothrow(size_t size, std::align_val_t al,
+                                               const std::nothrow_t&) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_deletearray_aligned(void* p, std::align_val_t al) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_deletearray_sized_aligned(void* p, size_t size, std::align_val_t al) PERFTOOLS_NOTHROW;
+  PERFTOOLS_DLL_DECL void tc_deletearray_aligned_nothrow(void* p, std::align_val_t al,
+                                                 const std::nothrow_t&) PERFTOOLS_NOTHROW;
+#endif
+}
+#endif
+
+/* We're only un-defining for public */
+#if !defined(GPERFTOOLS_CONFIG_H_)
+
+#undef PERFTOOLS_NOTHROW
+
+#endif /* GPERFTOOLS_CONFIG_H_ */
+
+#endif  /* #ifndef TCMALLOC_TCMALLOC_H_ */
diff --git a/3rdparty/gtest/CMakeLists.txt b/3rdparty/gtest/CMakeLists.txt
new file mode 100644
index 0000000..97af605
--- /dev/null
+++ b/3rdparty/gtest/CMakeLists.txt
@@ -0,0 +1,332 @@
+########################################################################
+# Note: CMake support is community-based. The maintainers do not use CMake
+# internally.
+#
+# CMake build script for Google Test.
+#
+# To run the tests for Google Test itself on Linux, use 'make test' or
+# ctest.  You can select which tests to run using 'ctest -R regex'.
+# For more options, run 'ctest --help'.
+
+if (POLICY CMP0077)
+  cmake_policy(SET CMP0077 NEW)
+endif (POLICY CMP0077)
+
+# When other libraries are using a shared version of runtime libraries,
+# Google Test also has to use one.
+option(
+  gtest_force_shared_crt
+  "Use shared (DLL) run-time lib even when Google Test is built as static lib."
+  OFF)
+
+option(gtest_build_tests "Build all of gtest's own tests." OFF)
+
+option(gtest_build_samples "Build gtest's sample programs." OFF)
+
+option(gtest_disable_pthreads "Disable uses of pthreads in gtest." OFF)
+
+option(
+  gtest_hide_internal_symbols
+  "Build gtest with internal symbols hidden in shared libraries."
+  OFF)
+
+# Defines pre_project_set_up_hermetic_build() and set_up_hermetic_build().
+include(cmake/hermetic_build.cmake OPTIONAL)
+
+if (COMMAND pre_project_set_up_hermetic_build)
+  pre_project_set_up_hermetic_build()
+endif()
+
+########################################################################
+#
+# Project-wide settings
+
+# Name of the project.
+#
+# CMake files in this project can refer to the root source directory
+# as ${gtest_SOURCE_DIR} and to the root binary directory as
+# ${gtest_BINARY_DIR}.
+# Language "C" is required for find_package(Threads).
+
+# Project version:
+
+if (CMAKE_VERSION VERSION_LESS 3.0)
+  project(gtest CXX C)
+  set(PROJECT_VERSION ${GOOGLETEST_VERSION})
+else()
+  cmake_policy(SET CMP0048 NEW)
+  project(gtest VERSION ${GOOGLETEST_VERSION} LANGUAGES CXX C)
+endif()
+cmake_minimum_required(VERSION 2.6.4)
+
+if (POLICY CMP0063) # Visibility
+  cmake_policy(SET CMP0063 NEW)
+endif (POLICY CMP0063)
+
+if (COMMAND set_up_hermetic_build)
+  set_up_hermetic_build()
+endif()
+
+# These commands only run if this is the main project
+if(CMAKE_PROJECT_NAME STREQUAL "gtest" OR CMAKE_PROJECT_NAME STREQUAL "googletest-distribution")
+
+  # BUILD_SHARED_LIBS is a standard CMake variable, but we declare it here to
+  # make it prominent in the GUI.
+  option(BUILD_SHARED_LIBS "Build shared libraries (DLLs)." OFF)
+
+else()
+
+  mark_as_advanced(
+    gtest_force_shared_crt
+    gtest_build_tests
+    gtest_build_samples
+    gtest_disable_pthreads
+    gtest_hide_internal_symbols)
+
+endif()
+
+
+if (gtest_hide_internal_symbols)
+  set(CMAKE_CXX_VISIBILITY_PRESET hidden)
+  set(CMAKE_VISIBILITY_INLINES_HIDDEN 1)
+endif()
+
+# Define helper functions and macros used by Google Test.
+include(cmake/internal_utils.cmake)
+
+config_compiler_and_linker()  # Defined in internal_utils.cmake.
+
+# Create the CMake package file descriptors.
+if (INSTALL_GTEST)
+  include(CMakePackageConfigHelpers)
+  set(cmake_package_name GTest)
+  set(targets_export_name ${cmake_package_name}Targets CACHE INTERNAL "")
+  set(generated_dir "${CMAKE_CURRENT_BINARY_DIR}/generated" CACHE INTERNAL "")
+  set(cmake_files_install_dir "${CMAKE_INSTALL_LIBDIR}/cmake/${cmake_package_name}")
+  set(version_file "${generated_dir}/${cmake_package_name}ConfigVersion.cmake")
+  write_basic_package_version_file(${version_file} VERSION ${GOOGLETEST_VERSION} COMPATIBILITY AnyNewerVersion)
+  install(EXPORT ${targets_export_name}
+    NAMESPACE ${cmake_package_name}::
+    DESTINATION ${cmake_files_install_dir})
+  set(config_file "${generated_dir}/${cmake_package_name}Config.cmake")
+  configure_package_config_file("${gtest_SOURCE_DIR}/cmake/Config.cmake.in"
+    "${config_file}" INSTALL_DESTINATION ${cmake_files_install_dir})
+  install(FILES ${version_file} ${config_file}
+    DESTINATION ${cmake_files_install_dir})
+endif()
+
+# Where Google Test's .h files can be found.
+set(gtest_build_include_dirs
+  "${gtest_SOURCE_DIR}/include"
+  "${gtest_SOURCE_DIR}")
+include_directories(${gtest_build_include_dirs})
+
+########################################################################
+#
+# Defines the gtest & gtest_main libraries.  User tests should link
+# with one of them.
+
+# Google Test libraries.  We build them using more strict warnings than what
+# are used for other targets, to ensure that gtest can be compiled by a user
+# aggressive about warnings.
+cxx_library(gtest "${cxx_strict}" src/gtest-all.cc)
+cxx_library(gtest_main "${cxx_strict}" src/gtest_main.cc)
+# If the CMake version supports it, attach header directory information
+# to the targets for when we are part of a parent build (ie being pulled
+# in via add_subdirectory() rather than being a standalone build).
+if (DEFINED CMAKE_VERSION AND NOT "${CMAKE_VERSION}" VERSION_LESS "2.8.11")
+  target_include_directories(gtest SYSTEM INTERFACE
+    "$<BUILD_INTERFACE:${gtest_build_include_dirs}>"
+    "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
+  target_include_directories(gtest_main SYSTEM INTERFACE
+    "$<BUILD_INTERFACE:${gtest_build_include_dirs}>"
+    "$<INSTALL_INTERFACE:$<INSTALL_PREFIX>/${CMAKE_INSTALL_INCLUDEDIR}>")
+endif()
+target_link_libraries(gtest_main PUBLIC gtest)
+
+########################################################################
+#
+# Install rules
+install_project(gtest gtest_main)
+
+########################################################################
+#
+# Samples on how to link user tests with gtest or gtest_main.
+#
+# They are not built by default.  To build them, set the
+# gtest_build_samples option to ON.  You can do it by running ccmake
+# or specifying the -Dgtest_build_samples=ON flag when running cmake.
+
+if (gtest_build_samples)
+  cxx_executable(sample1_unittest samples gtest_main samples/sample1.cc)
+  cxx_executable(sample2_unittest samples gtest_main samples/sample2.cc)
+  cxx_executable(sample3_unittest samples gtest_main)
+  cxx_executable(sample4_unittest samples gtest_main samples/sample4.cc)
+  cxx_executable(sample5_unittest samples gtest_main samples/sample1.cc)
+  cxx_executable(sample6_unittest samples gtest_main)
+  cxx_executable(sample7_unittest samples gtest_main)
+  cxx_executable(sample8_unittest samples gtest_main)
+  cxx_executable(sample9_unittest samples gtest)
+  cxx_executable(sample10_unittest samples gtest)
+endif()
+
+########################################################################
+#
+# Google Test's own tests.
+#
+# You can skip this section if you aren't interested in testing
+# Google Test itself.
+#
+# The tests are not built by default.  To build them, set the
+# gtest_build_tests option to ON.  You can do it by running ccmake
+# or specifying the -Dgtest_build_tests=ON flag when running cmake.
+
+if (gtest_build_tests)
+  # This must be set in the root directory for the tests to be run by
+  # 'make test' or ctest.
+  enable_testing()
+
+  if (WIN32)
+    file(GENERATE OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>/RunTest.ps1"
+         CONTENT
+"$project_bin = \"${CMAKE_BINARY_DIR}/bin/$<CONFIG>\"
+$env:Path = \"$project_bin;$env:Path\"
+& $args")
+  elseif (MINGW OR CYGWIN)
+    file(GENERATE OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/RunTest.ps1"
+         CONTENT
+"$project_bin = (cygpath --windows ${CMAKE_BINARY_DIR}/bin)
+$env:Path = \"$project_bin;$env:Path\"
+& $args")
+  endif()
+
+  ############################################################
+  # C++ tests built with standard compiler flags.
+
+  cxx_test(googletest-death-test-test gtest_main)
+  cxx_test(gtest_environment_test gtest)
+  cxx_test(googletest-filepath-test gtest_main)
+  cxx_test(googletest-listener-test gtest_main)
+  cxx_test(gtest_main_unittest gtest_main)
+  cxx_test(googletest-message-test gtest_main)
+  cxx_test(gtest_no_test_unittest gtest)
+  cxx_test(googletest-options-test gtest_main)
+  cxx_test(googletest-param-test-test gtest
+    test/googletest-param-test2-test.cc)
+  cxx_test(googletest-port-test gtest_main)
+  cxx_test(gtest_pred_impl_unittest gtest_main)
+  cxx_test(gtest_premature_exit_test gtest
+    test/gtest_premature_exit_test.cc)
+  cxx_test(googletest-printers-test gtest_main)
+  cxx_test(gtest_prod_test gtest_main
+    test/production.cc)
+  cxx_test(gtest_repeat_test gtest)
+  cxx_test(gtest_sole_header_test gtest_main)
+  cxx_test(gtest_stress_test gtest)
+  cxx_test(googletest-test-part-test gtest_main)
+  cxx_test(gtest_throw_on_failure_ex_test gtest)
+  cxx_test(gtest-typed-test_test gtest_main
+    test/gtest-typed-test2_test.cc)
+  cxx_test(gtest_unittest gtest_main)
+  cxx_test(gtest-unittest-api_test gtest)
+  cxx_test(gtest_skip_in_environment_setup_test gtest_main)
+  cxx_test(gtest_skip_test gtest_main)
+
+  ############################################################
+  # C++ tests built with non-standard compiler flags.
+
+  # MSVC 7.1 does not support STL with exceptions disabled.
+  if (NOT MSVC OR MSVC_VERSION GREATER 1310)
+    cxx_library(gtest_no_exception "${cxx_no_exception}"
+      src/gtest-all.cc)
+    cxx_library(gtest_main_no_exception "${cxx_no_exception}"
+      src/gtest-all.cc src/gtest_main.cc)
+  endif()
+  cxx_library(gtest_main_no_rtti "${cxx_no_rtti}"
+    src/gtest-all.cc src/gtest_main.cc)
+
+  cxx_test_with_flags(gtest-death-test_ex_nocatch_test
+    "${cxx_exception} -DGTEST_ENABLE_CATCH_EXCEPTIONS_=0"
+    gtest test/googletest-death-test_ex_test.cc)
+  cxx_test_with_flags(gtest-death-test_ex_catch_test
+    "${cxx_exception} -DGTEST_ENABLE_CATCH_EXCEPTIONS_=1"
+    gtest test/googletest-death-test_ex_test.cc)
+
+  cxx_test_with_flags(gtest_no_rtti_unittest "${cxx_no_rtti}"
+    gtest_main_no_rtti test/gtest_unittest.cc)
+
+  cxx_shared_library(gtest_dll "${cxx_default}"
+    src/gtest-all.cc src/gtest_main.cc)
+
+  cxx_executable_with_flags(gtest_dll_test_ "${cxx_default}"
+    gtest_dll test/gtest_all_test.cc)
+  set_target_properties(gtest_dll_test_
+                        PROPERTIES
+                        COMPILE_DEFINITIONS "GTEST_LINKED_AS_SHARED_LIBRARY=1")
+
+  ############################################################
+  # Python tests.
+
+  cxx_executable(googletest-break-on-failure-unittest_ test gtest)
+  py_test(googletest-break-on-failure-unittest)
+
+  py_test(gtest_skip_environment_check_output_test)
+
+  # Visual Studio .NET 2003 does not support STL with exceptions disabled.
+  if (NOT MSVC OR MSVC_VERSION GREATER 1310)  # 1310 is Visual Studio .NET 2003
+    cxx_executable_with_flags(
+      googletest-catch-exceptions-no-ex-test_
+      "${cxx_no_exception}"
+      gtest_main_no_exception
+      test/googletest-catch-exceptions-test_.cc)
+  endif()
+
+  cxx_executable_with_flags(
+    googletest-catch-exceptions-ex-test_
+    "${cxx_exception}"
+    gtest_main
+    test/googletest-catch-exceptions-test_.cc)
+  py_test(googletest-catch-exceptions-test)
+
+  cxx_executable(googletest-color-test_ test gtest)
+  py_test(googletest-color-test)
+
+  cxx_executable(googletest-env-var-test_ test gtest)
+  py_test(googletest-env-var-test)
+
+  cxx_executable(googletest-filter-unittest_ test gtest)
+  py_test(googletest-filter-unittest)
+
+  cxx_executable(gtest_help_test_ test gtest_main)
+  py_test(gtest_help_test)
+
+  cxx_executable(googletest-list-tests-unittest_ test gtest)
+  py_test(googletest-list-tests-unittest)
+
+  cxx_executable(googletest-output-test_ test gtest)
+  py_test(googletest-output-test --no_stacktrace_support)
+
+  cxx_executable(googletest-shuffle-test_ test gtest)
+  py_test(googletest-shuffle-test)
+
+  # MSVC 7.1 does not support STL with exceptions disabled.
+  if (NOT MSVC OR MSVC_VERSION GREATER 1310)
+    cxx_executable(googletest-throw-on-failure-test_ test gtest_no_exception)
+    set_target_properties(googletest-throw-on-failure-test_
+      PROPERTIES
+      COMPILE_FLAGS "${cxx_no_exception}")
+    py_test(googletest-throw-on-failure-test)
+  endif()
+
+  cxx_executable(googletest-uninitialized-test_ test gtest)
+  py_test(googletest-uninitialized-test)
+
+  cxx_executable(gtest_xml_outfile1_test_ test gtest_main)
+  cxx_executable(gtest_xml_outfile2_test_ test gtest_main)
+  py_test(gtest_xml_outfiles_test)
+  py_test(googletest-json-outfiles-test)
+
+  cxx_executable(gtest_xml_output_unittest_ test gtest)
+  py_test(gtest_xml_output_unittest --no_stacktrace_support)
+  py_test(googletest-json-output-unittest --no_stacktrace_support)
+endif()
diff --git a/3rdparty/gtest/CONTRIBUTORS b/3rdparty/gtest/CONTRIBUTORS
new file mode 100644
index 0000000..feae2fc
--- /dev/null
+++ b/3rdparty/gtest/CONTRIBUTORS
@@ -0,0 +1,37 @@
+# This file contains a list of people who've made non-trivial
+# contribution to the Google C++ Testing Framework project.  People
+# who commit code to the project are encouraged to add their names
+# here.  Please keep the list sorted by first names.
+
+Ajay Joshi <jaj@google.com>
+Balázs Dán <balazs.dan@gmail.com>
+Bharat Mediratta <bharat@menalto.com>
+Chandler Carruth <chandlerc@google.com>
+Chris Prince <cprince@google.com>
+Chris Taylor <taylorc@google.com>
+Dan Egnor <egnor@google.com>
+Eric Roman <eroman@chromium.org>
+Hady Zalek <hady.zalek@gmail.com>
+Jeffrey Yasskin <jyasskin@google.com>
+Jói Sigurðsson <joi@google.com>
+Keir Mierle <mierle@gmail.com>
+Keith Ray <keith.ray@gmail.com>
+Kenton Varda <kenton@google.com>
+Manuel Klimek <klimek@google.com>
+Markus Heule <markus.heule@gmail.com>
+Mika Raento <mikie@iki.fi>
+Miklós Fazekas <mfazekas@szemafor.com>
+Pasi Valminen <pasi.valminen@gmail.com>
+Patrick Hanna <phanna@google.com>
+Patrick Riley <pfr@google.com>
+Peter Kaminski <piotrk@google.com>
+Preston Jackson <preston.a.jackson@gmail.com>
+Rainer Klaffenboeck <rainer.klaffenboeck@dynatrace.com>
+Russ Cox <rsc@google.com>
+Russ Rufer <russ@pentad.com>
+Sean Mcafee <eefacm@gmail.com>
+Sigurður Ásgeirsson <siggi@google.com>
+Tracy Bialik <tracy@pentad.com>
+Vadim Berman <vadimb@google.com>
+Vlad Losev <vladl@google.com>
+Zhanyong Wan <wan@google.com>
diff --git a/3rdparty/gtest/LICENSE b/3rdparty/gtest/LICENSE
new file mode 100644
index 0000000..1941a11
--- /dev/null
+++ b/3rdparty/gtest/LICENSE
@@ -0,0 +1,28 @@
+Copyright 2008, Google Inc.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/3rdparty/gtest/README.md b/3rdparty/gtest/README.md
new file mode 100644
index 0000000..766ddc1
--- /dev/null
+++ b/3rdparty/gtest/README.md
@@ -0,0 +1,244 @@
+### Generic Build Instructions
+
+#### Setup
+
+To build Google Test and your tests that use it, you need to tell your build
+system where to find its headers and source files. The exact way to do it
+depends on which build system you use, and is usually straightforward.
+
+### Build with CMake
+
+Google Test comes with a CMake build script (
+[CMakeLists.txt](https://github.com/google/googletest/blob/master/CMakeLists.txt))
+that can be used on a wide range of platforms ("C" stands for cross-platform.).
+If you don't have CMake installed already, you can download it for free from
+<http://www.cmake.org/>.
+
+CMake works by generating native makefiles or build projects that can be used in
+the compiler environment of your choice. You can either build Google Test as a
+standalone project or it can be incorporated into an existing CMake build for
+another project.
+
+#### Standalone CMake Project
+
+When building Google Test as a standalone project, the typical workflow starts
+with:
+
+    mkdir mybuild       # Create a directory to hold the build output.
+    cd mybuild
+    cmake ${GTEST_DIR}  # Generate native build scripts.
+
+If you want to build Google Test's samples, you should replace the last command
+with
+
+    cmake -Dgtest_build_samples=ON ${GTEST_DIR}
+
+If you are on a \*nix system, you should now see a Makefile in the current
+directory. Just type 'make' to build gtest.
+
+If you use Windows and have Visual Studio installed, a `gtest.sln` file and
+several `.vcproj` files will be created. You can then build them using Visual
+Studio.
+
+On Mac OS X with Xcode installed, a `.xcodeproj` file will be generated.
+
+#### Incorporating Into An Existing CMake Project
+
+If you want to use gtest in a project which already uses CMake, then a more
+robust and flexible approach is to build gtest as part of that project directly.
+This is done by making the GoogleTest source code available to the main build
+and adding it using CMake's `add_subdirectory()` command. This has the
+significant advantage that the same compiler and linker settings are used
+between gtest and the rest of your project, so issues associated with using
+incompatible libraries (eg debug/release), etc. are avoided. This is
+particularly useful on Windows. Making GoogleTest's source code available to the
+main build can be done a few different ways:
+
+*   Download the GoogleTest source code manually and place it at a known
+    location. This is the least flexible approach and can make it more difficult
+    to use with continuous integration systems, etc.
+*   Embed the GoogleTest source code as a direct copy in the main project's
+    source tree. This is often the simplest approach, but is also the hardest to
+    keep up to date. Some organizations may not permit this method.
+*   Add GoogleTest as a git submodule or equivalent. This may not always be
+    possible or appropriate. Git submodules, for example, have their own set of
+    advantages and drawbacks.
+*   Use CMake to download GoogleTest as part of the build's configure step. This
+    is just a little more complex, but doesn't have the limitations of the other
+    methods.
+
+The last of the above methods is implemented with a small piece of CMake code in
+a separate file (e.g. `CMakeLists.txt.in`) which is copied to the build area and
+then invoked as a sub-build _during the CMake stage_. That directory is then
+pulled into the main build with `add_subdirectory()`. For example:
+
+New file `CMakeLists.txt.in`:
+
+```cmake
+cmake_minimum_required(VERSION 2.8.2)
+
+project(googletest-download NONE)
+
+include(ExternalProject)
+ExternalProject_Add(googletest
+  GIT_REPOSITORY    https://github.com/google/googletest.git
+  GIT_TAG           master
+  SOURCE_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-src"
+  BINARY_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-build"
+  CONFIGURE_COMMAND ""
+  BUILD_COMMAND     ""
+  INSTALL_COMMAND   ""
+  TEST_COMMAND      ""
+)
+```
+
+Existing build's `CMakeLists.txt`:
+
+```cmake
+# Download and unpack googletest at configure time
+configure_file(CMakeLists.txt.in googletest-download/CMakeLists.txt)
+execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
+  RESULT_VARIABLE result
+  WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download )
+if(result)
+  message(FATAL_ERROR "CMake step for googletest failed: ${result}")
+endif()
+execute_process(COMMAND ${CMAKE_COMMAND} --build .
+  RESULT_VARIABLE result
+  WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download )
+if(result)
+  message(FATAL_ERROR "Build step for googletest failed: ${result}")
+endif()
+
+# Prevent overriding the parent project's compiler/linker
+# settings on Windows
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+
+# Add googletest directly to our build. This defines
+# the gtest and gtest_main targets.
+add_subdirectory(${CMAKE_CURRENT_BINARY_DIR}/googletest-src
+                 ${CMAKE_CURRENT_BINARY_DIR}/googletest-build
+                 EXCLUDE_FROM_ALL)
+
+# The gtest/gtest_main targets carry header search path
+# dependencies automatically when using CMake 2.8.11 or
+# later. Otherwise we have to add them here ourselves.
+if (CMAKE_VERSION VERSION_LESS 2.8.11)
+  include_directories("${gtest_SOURCE_DIR}/include")
+endif()
+
+# Now simply link against gtest or gtest_main as needed. Eg
+add_executable(example example.cpp)
+target_link_libraries(example gtest_main)
+add_test(NAME example_test COMMAND example)
+```
+
+Note that this approach requires CMake 2.8.2 or later due to its use of the
+`ExternalProject_Add()` command. The above technique is discussed in more detail
+in [this separate article](http://crascit.com/2015/07/25/cmake-gtest/) which
+also contains a link to a fully generalized implementation of the technique.
+
+##### Visual Studio Dynamic vs Static Runtimes
+
+By default, new Visual Studio projects link the C runtimes dynamically but
+Google Test links them statically. This will generate an error that looks
+something like the following: gtest.lib(gtest-all.obj) : error LNK2038: mismatch
+detected for 'RuntimeLibrary': value 'MTd_StaticDebug' doesn't match value
+'MDd_DynamicDebug' in main.obj
+
+Google Test already has a CMake option for this: `gtest_force_shared_crt`
+
+Enabling this option will make gtest link the runtimes dynamically too, and
+match the project in which it is included.
+
+#### C++ Standard Version
+
+An environment that supports C++11 is required in order to successfully build
+Google Test. One way to ensure this is to specify the standard in the top-level
+project, for example by using the `set(CMAKE_CXX_STANDARD 11)` command. If this
+is not feasible, for example in a C project using Google Test for validation,
+then it can be specified by adding it to the options for cmake via the
+`DCMAKE_CXX_FLAGS` option.
+
+### Tweaking Google Test
+
+Google Test can be used in diverse environments. The default configuration may
+not work (or may not work well) out of the box in some environments. However,
+you can easily tweak Google Test by defining control macros on the compiler
+command line. Generally, these macros are named like `GTEST_XYZ` and you define
+them to either 1 or 0 to enable or disable a certain feature.
+
+We list the most frequently used macros below. For a complete list, see file
+[include/gtest/internal/gtest-port.h](https://github.com/google/googletest/blob/master/googletest/include/gtest/internal/gtest-port.h).
+
+### Multi-threaded Tests
+
+Google Test is thread-safe where the pthread library is available. After
+`#include "gtest/gtest.h"`, you can check the
+`GTEST_IS_THREADSAFE` macro to see whether this is the case (yes if the macro is
+`#defined` to 1, no if it's undefined.).
+
+If Google Test doesn't correctly detect whether pthread is available in your
+environment, you can force it with
+
+    -DGTEST_HAS_PTHREAD=1
+
+or
+
+    -DGTEST_HAS_PTHREAD=0
+
+When Google Test uses pthread, you may need to add flags to your compiler and/or
+linker to select the pthread library, or you'll get link errors. If you use the
+CMake script or the deprecated Autotools script, this is taken care of for you.
+If you use your own build script, you'll need to read your compiler and linker's
+manual to figure out what flags to add.
+
+### As a Shared Library (DLL)
+
+Google Test is compact, so most users can build and link it as a static library
+for the simplicity. You can choose to use Google Test as a shared library (known
+as a DLL on Windows) if you prefer.
+
+To compile *gtest* as a shared library, add
+
+    -DGTEST_CREATE_SHARED_LIBRARY=1
+
+to the compiler flags. You'll also need to tell the linker to produce a shared
+library instead - consult your linker's manual for how to do it.
+
+To compile your *tests* that use the gtest shared library, add
+
+    -DGTEST_LINKED_AS_SHARED_LIBRARY=1
+
+to the compiler flags.
+
+Note: while the above steps aren't technically necessary today when using some
+compilers (e.g. GCC), they may become necessary in the future, if we decide to
+improve the speed of loading the library (see
+<http://gcc.gnu.org/wiki/Visibility> for details). Therefore you are recommended
+to always add the above flags when using Google Test as a shared library.
+Otherwise a future release of Google Test may break your build script.
+
+### Avoiding Macro Name Clashes
+
+In C++, macros don't obey namespaces. Therefore two libraries that both define a
+macro of the same name will clash if you `#include` both definitions. In case a
+Google Test macro clashes with another library, you can force Google Test to
+rename its macro to avoid the conflict.
+
+Specifically, if both Google Test and some other code define macro FOO, you can
+add
+
+    -DGTEST_DONT_DEFINE_FOO=1
+
+to the compiler flags to tell Google Test to change the macro's name from `FOO`
+to `GTEST_FOO`. Currently `FOO` can be `FAIL`, `SUCCEED`, or `TEST`. For
+example, with `-DGTEST_DONT_DEFINE_TEST=1`, you'll need to write
+
+    GTEST_TEST(SomeTest, DoesThis) { ... }
+
+instead of
+
+    TEST(SomeTest, DoesThis) { ... }
+
+in order to define a test.
diff --git a/3rdparty/gtest/cmake/Config.cmake.in b/3rdparty/gtest/cmake/Config.cmake.in
new file mode 100644
index 0000000..12be449
--- /dev/null
+++ b/3rdparty/gtest/cmake/Config.cmake.in
@@ -0,0 +1,9 @@
+@PACKAGE_INIT@
+include(CMakeFindDependencyMacro)
+if (@GTEST_HAS_PTHREAD@)
+  set(THREADS_PREFER_PTHREAD_FLAG @THREADS_PREFER_PTHREAD_FLAG@)
+  find_dependency(Threads)
+endif()
+
+include("${CMAKE_CURRENT_LIST_DIR}/@targets_export_name@.cmake")
+check_required_components("@project_name@")
diff --git a/3rdparty/gtest/cmake/gtest.pc.in b/3rdparty/gtest/cmake/gtest.pc.in
new file mode 100644
index 0000000..9aae29e
--- /dev/null
+++ b/3rdparty/gtest/cmake/gtest.pc.in
@@ -0,0 +1,10 @@
+prefix=${pcfiledir}/../..
+libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
+includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
+
+Name: gtest
+Description: GoogleTest (without main() function)
+Version: @PROJECT_VERSION@
+URL: https://github.com/google/googletest
+Libs: -L${libdir} -lgtest @CMAKE_THREAD_LIBS_INIT@
+Cflags: -I${includedir} @GTEST_HAS_PTHREAD_MACRO@ @CMAKE_THREAD_LIBS_INIT@
diff --git a/3rdparty/gtest/cmake/gtest_main.pc.in b/3rdparty/gtest/cmake/gtest_main.pc.in
new file mode 100644
index 0000000..915f297
--- /dev/null
+++ b/3rdparty/gtest/cmake/gtest_main.pc.in
@@ -0,0 +1,11 @@
+prefix=${pcfiledir}/../..
+libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
+includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
+
+Name: gtest_main
+Description: GoogleTest (with main() function)
+Version: @PROJECT_VERSION@
+URL: https://github.com/google/googletest
+Requires: gtest
+Libs: -L${libdir} -lgtest_main @CMAKE_THREAD_LIBS_INIT@
+Cflags: -I${includedir} @GTEST_HAS_PTHREAD_MACRO@ @CMAKE_THREAD_LIBS_INIT@
diff --git a/3rdparty/gtest/cmake/internal_utils.cmake b/3rdparty/gtest/cmake/internal_utils.cmake
new file mode 100644
index 0000000..2f70f0b
--- /dev/null
+++ b/3rdparty/gtest/cmake/internal_utils.cmake
@@ -0,0 +1,358 @@
+# Defines functions and macros useful for building Google Test and
+# Google Mock.
+#
+# Note:
+#
+# - This file will be run twice when building Google Mock (once via
+#   Google Test's CMakeLists.txt, and once via Google Mock's).
+#   Therefore it shouldn't have any side effects other than defining
+#   the functions and macros.
+#
+# - The functions/macros defined in this file may depend on Google
+#   Test and Google Mock's option() definitions, and thus must be
+#   called *after* the options have been defined.
+
+if (POLICY CMP0054)
+  cmake_policy(SET CMP0054 NEW)
+endif (POLICY CMP0054)
+
+# Tweaks CMake's default compiler/linker settings to suit Google Test's needs.
+#
+# This must be a macro(), as inside a function string() can only
+# update variables in the function scope.
+macro(fix_default_compiler_settings_)
+  if (MSVC)
+    # For MSVC, CMake sets certain flags to defaults we want to override.
+    # This replacement code is taken from sample in the CMake Wiki at
+    # https://gitlab.kitware.com/cmake/community/wikis/FAQ#dynamic-replace.
+    foreach (flag_var
+             CMAKE_C_FLAGS CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_RELEASE
+             CMAKE_C_FLAGS_MINSIZEREL CMAKE_C_FLAGS_RELWITHDEBINFO
+             CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE
+             CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO)
+      if (NOT BUILD_SHARED_LIBS AND NOT gtest_force_shared_crt)
+        # When Google Test is built as a shared library, it should also use
+        # shared runtime libraries.  Otherwise, it may end up with multiple
+        # copies of runtime library data in different modules, resulting in
+        # hard-to-find crashes. When it is built as a static library, it is
+        # preferable to use CRT as static libraries, as we don't have to rely
+        # on CRT DLLs being available. CMake always defaults to using shared
+        # CRT libraries, so we override that default here.
+        string(REPLACE "/MD" "-MT" ${flag_var} "${${flag_var}}")
+      endif()
+
+      # We prefer more strict warning checking for building Google Test.
+      # Replaces /W3 with /W4 in defaults.
+      string(REPLACE "/W3" "/W4" ${flag_var} "${${flag_var}}")
+
+      # Prevent D9025 warning for targets that have exception handling
+      # turned off (/EHs-c- flag). Where required, exceptions are explicitly
+      # re-enabled using the cxx_exception_flags variable.
+      string(REPLACE "/EHsc" "" ${flag_var} "${${flag_var}}")
+    endforeach()
+  endif()
+endmacro()
+
+# Defines the compiler/linker flags used to build Google Test and
+# Google Mock.  You can tweak these definitions to suit your need.  A
+# variable's value is empty before it's explicitly assigned to.
+macro(config_compiler_and_linker)
+  # Note: pthreads on MinGW is not supported, even if available
+  # instead, we use windows threading primitives
+  unset(GTEST_HAS_PTHREAD)
+  if (NOT gtest_disable_pthreads AND NOT MINGW)
+    # Defines CMAKE_USE_PTHREADS_INIT and CMAKE_THREAD_LIBS_INIT.
+    find_package(Threads)
+    if (CMAKE_USE_PTHREADS_INIT)
+      set(GTEST_HAS_PTHREAD ON)
+    endif()
+  endif()
+
+  fix_default_compiler_settings_()
+  if (MSVC)
+    # Newlines inside flags variables break CMake's NMake generator.
+    # TODO(vladl@google.com): Add -RTCs and -RTCu to debug builds.
+    set(cxx_base_flags "-GS -W4 -WX -wd4251 -wd4275 -nologo -J -Zi")
+    set(cxx_base_flags "${cxx_base_flags} -D_UNICODE -DUNICODE -DWIN32 -D_WIN32")
+    set(cxx_base_flags "${cxx_base_flags} -DSTRICT -DWIN32_LEAN_AND_MEAN")
+    set(cxx_exception_flags "-EHsc -D_HAS_EXCEPTIONS=1")
+    set(cxx_no_exception_flags "-EHs-c- -D_HAS_EXCEPTIONS=0")
+    set(cxx_no_rtti_flags "-GR-")
+    # Suppress "unreachable code" warning
+    # http://stackoverflow.com/questions/3232669 explains the issue.
+    set(cxx_base_flags "${cxx_base_flags} -wd4702")
+  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    set(cxx_base_flags "-Wall -Wshadow -Werror -Wconversion")
+    set(cxx_exception_flags "-fexceptions")
+    set(cxx_no_exception_flags "-fno-exceptions")
+    set(cxx_strict_flags "-W -Wpointer-arith -Wreturn-type -Wcast-qual -Wwrite-strings -Wswitch -Wunused-parameter -Wcast-align -Wchar-subscripts -Winline -Wredundant-decls")
+    set(cxx_no_rtti_flags "-fno-rtti")
+  elseif (CMAKE_COMPILER_IS_GNUCXX)
+    set(cxx_base_flags "-Wall -Wshadow -Werror")
+    if(NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0.0)
+      set(cxx_base_flags "${cxx_base_flags} -Wno-error=dangling-else")
+    endif()
+    set(cxx_exception_flags "-fexceptions")
+    set(cxx_no_exception_flags "-fno-exceptions")
+    # Until version 4.3.2, GCC doesn't define a macro to indicate
+    # whether RTTI is enabled.  Therefore we define GTEST_HAS_RTTI
+    # explicitly.
+    set(cxx_no_rtti_flags "-fno-rtti -DGTEST_HAS_RTTI=0")
+    set(cxx_strict_flags
+      "-Wextra -Wno-unused-parameter -Wno-missing-field-initializers")
+  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "SunPro")
+    set(cxx_exception_flags "-features=except")
+    # Sun Pro doesn't provide macros to indicate whether exceptions and
+    # RTTI are enabled, so we define GTEST_HAS_* explicitly.
+    set(cxx_no_exception_flags "-features=no%except -DGTEST_HAS_EXCEPTIONS=0")
+    set(cxx_no_rtti_flags "-features=no%rtti -DGTEST_HAS_RTTI=0")
+  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "VisualAge" OR
+      CMAKE_CXX_COMPILER_ID STREQUAL "XL")
+    # CMake 2.8 changes Visual Age's compiler ID to "XL".
+    set(cxx_exception_flags "-qeh")
+    set(cxx_no_exception_flags "-qnoeh")
+    # Until version 9.0, Visual Age doesn't define a macro to indicate
+    # whether RTTI is enabled.  Therefore we define GTEST_HAS_RTTI
+    # explicitly.
+    set(cxx_no_rtti_flags "-qnortti -DGTEST_HAS_RTTI=0")
+  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "HP")
+    set(cxx_base_flags "-AA -mt")
+    set(cxx_exception_flags "-DGTEST_HAS_EXCEPTIONS=1")
+    set(cxx_no_exception_flags "+noeh -DGTEST_HAS_EXCEPTIONS=0")
+    # RTTI can not be disabled in HP aCC compiler.
+    set(cxx_no_rtti_flags "")
+  endif()
+
+  # The pthreads library is available and allowed?
+  if (DEFINED GTEST_HAS_PTHREAD)
+    set(GTEST_HAS_PTHREAD_MACRO "-DGTEST_HAS_PTHREAD=1")
+  else()
+    set(GTEST_HAS_PTHREAD_MACRO "-DGTEST_HAS_PTHREAD=0")
+  endif()
+  set(cxx_base_flags "${cxx_base_flags} ${GTEST_HAS_PTHREAD_MACRO}")
+
+  # For building gtest's own tests and samples.
+  set(cxx_exception "${cxx_base_flags} ${cxx_exception_flags}")
+  set(cxx_no_exception
+    "${CMAKE_CXX_FLAGS} ${cxx_base_flags} ${cxx_no_exception_flags}")
+  set(cxx_default "${cxx_exception}")
+  set(cxx_no_rtti "${cxx_default} ${cxx_no_rtti_flags}")
+
+  # For building the gtest libraries.
+  set(cxx_strict "${cxx_default} ${cxx_strict_flags}")
+endmacro()
+
+# Defines the gtest & gtest_main libraries.  User tests should link
+# with one of them.
+function(cxx_library_with_type name type cxx_flags)
+  # type can be either STATIC or SHARED to denote a static or shared library.
+  # ARGN refers to additional arguments after 'cxx_flags'.
+  add_library(${name} ${type} ${ARGN})
+  set_target_properties(${name}
+    PROPERTIES
+    COMPILE_FLAGS "${cxx_flags}")
+  # Generate debug library name with a postfix.
+  set_target_properties(${name}
+    PROPERTIES
+    DEBUG_POSTFIX "d")
+  # Set the output directory for build artifacts
+  set_target_properties(${name}
+    PROPERTIES
+    RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin"
+    LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+    ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+    PDB_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
+  # make PDBs match library name
+  get_target_property(pdb_debug_postfix ${name} DEBUG_POSTFIX)
+  set_target_properties(${name}
+    PROPERTIES
+    PDB_NAME "${name}"
+    PDB_NAME_DEBUG "${name}${pdb_debug_postfix}"
+    COMPILE_PDB_NAME "${name}"
+    COMPILE_PDB_NAME_DEBUG "${name}${pdb_debug_postfix}")
+
+  if (BUILD_SHARED_LIBS OR type STREQUAL "SHARED")
+    set_target_properties(${name}
+      PROPERTIES
+      COMPILE_DEFINITIONS "GTEST_CREATE_SHARED_LIBRARY=1")
+    if (NOT "${CMAKE_VERSION}" VERSION_LESS "2.8.11")
+      target_compile_definitions(${name} INTERFACE
+        $<INSTALL_INTERFACE:GTEST_LINKED_AS_SHARED_LIBRARY=1>)
+    endif()
+  endif()
+  if (DEFINED GTEST_HAS_PTHREAD)
+    if ("${CMAKE_VERSION}" VERSION_LESS "3.1.0")
+      set(threads_spec ${CMAKE_THREAD_LIBS_INIT})
+    else()
+      set(threads_spec Threads::Threads)
+    endif()
+    target_link_libraries(${name} PUBLIC ${threads_spec})
+  endif()
+endfunction()
+
+########################################################################
+#
+# Helper functions for creating build targets.
+
+function(cxx_shared_library name cxx_flags)
+  cxx_library_with_type(${name} SHARED "${cxx_flags}" ${ARGN})
+endfunction()
+
+function(cxx_library name cxx_flags)
+  cxx_library_with_type(${name} "" "${cxx_flags}" ${ARGN})
+endfunction()
+
+# cxx_executable_with_flags(name cxx_flags libs srcs...)
+#
+# creates a named C++ executable that depends on the given libraries and
+# is built from the given source files with the given compiler flags.
+function(cxx_executable_with_flags name cxx_flags libs)
+  add_executable(${name} ${ARGN})
+  if (MSVC)
+    # BigObj required for tests.
+    set(cxx_flags "${cxx_flags} -bigobj")
+  endif()
+  if (cxx_flags)
+    set_target_properties(${name}
+      PROPERTIES
+      COMPILE_FLAGS "${cxx_flags}")
+  endif()
+  if (BUILD_SHARED_LIBS)
+    set_target_properties(${name}
+      PROPERTIES
+      COMPILE_DEFINITIONS "GTEST_LINKED_AS_SHARED_LIBRARY=1")
+  endif()
+  # To support mixing linking in static and dynamic libraries, link each
+  # library in with an extra call to target_link_libraries.
+  foreach (lib "${libs}")
+    target_link_libraries(${name} ${lib})
+  endforeach()
+endfunction()
+
+# cxx_executable(name dir lib srcs...)
+#
+# creates a named target that depends on the given libs and is built
+# from the given source files.  dir/name.cc is implicitly included in
+# the source file list.
+function(cxx_executable name dir libs)
+  cxx_executable_with_flags(
+    ${name} "${cxx_default}" "${libs}" "${dir}/${name}.cc" ${ARGN})
+endfunction()
+
+# Sets PYTHONINTERP_FOUND and PYTHON_EXECUTABLE.
+find_package(PythonInterp)
+
+# cxx_test_with_flags(name cxx_flags libs srcs...)
+#
+# creates a named C++ test that depends on the given libs and is built
+# from the given source files with the given compiler flags.
+function(cxx_test_with_flags name cxx_flags libs)
+  cxx_executable_with_flags(${name} "${cxx_flags}" "${libs}" ${ARGN})
+  if (WIN32 OR MINGW)
+    add_test(NAME ${name}
+      COMMAND "powershell" "-Command" "${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>/RunTest.ps1" "$<TARGET_FILE:${name}>")
+  else()
+    add_test(NAME ${name}
+      COMMAND "$<TARGET_FILE:${name}>")
+  endif()
+endfunction()
+
+# cxx_test(name libs srcs...)
+#
+# creates a named test target that depends on the given libs and is
+# built from the given source files.  Unlike cxx_test_with_flags,
+# test/name.cc is already implicitly included in the source file list.
+function(cxx_test name libs)
+  cxx_test_with_flags("${name}" "${cxx_default}" "${libs}"
+    "test/${name}.cc" ${ARGN})
+endfunction()
+
+# py_test(name)
+#
+# creates a Python test with the given name whose main module is in
+# test/name.py.  It does nothing if Python is not installed.
+function(py_test name)
+  if (PYTHONINTERP_FOUND)
+    if ("${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}" VERSION_GREATER 3.1)
+      if (CMAKE_CONFIGURATION_TYPES)
+        # Multi-configuration build generators as for Visual Studio save
+        # output in a subdirectory of CMAKE_CURRENT_BINARY_DIR (Debug,
+        # Release etc.), so we have to provide it here.
+        if (WIN32 OR MINGW)
+          add_test(NAME ${name}
+            COMMAND powershell -Command ${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>/RunTest.ps1
+              ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/${name}.py
+              --build_dir=${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG> ${ARGN})
+        else()
+          add_test(NAME ${name}
+            COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/${name}.py
+              --build_dir=${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG> ${ARGN})
+        endif()
+      else (CMAKE_CONFIGURATION_TYPES)
+        # Single-configuration build generators like Makefile generators
+        # don't have subdirs below CMAKE_CURRENT_BINARY_DIR.
+        if (WIN32 OR MINGW)
+          add_test(NAME ${name}
+            COMMAND powershell -Command ${CMAKE_CURRENT_BINARY_DIR}/RunTest.ps1
+              ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/${name}.py
+              --build_dir=${CMAKE_CURRENT_BINARY_DIR} ${ARGN})
+        else()
+          add_test(NAME ${name}
+            COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/${name}.py
+              --build_dir=${CMAKE_CURRENT_BINARY_DIR} ${ARGN})
+        endif()
+      endif (CMAKE_CONFIGURATION_TYPES)
+    else()
+      # ${CMAKE_CURRENT_BINARY_DIR} is known at configuration time, so we can
+      # directly bind it from cmake. ${CTEST_CONFIGURATION_TYPE} is known
+      # only at ctest runtime (by calling ctest -c <Configuration>), so
+      # we have to escape $ to delay variable substitution here.
+      if (WIN32 OR MINGW)
+        add_test(NAME ${name}
+          COMMAND powershell -Command ${CMAKE_CURRENT_BINARY_DIR}/RunTest.ps1
+            ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/${name}.py
+            --build_dir=${CMAKE_CURRENT_BINARY_DIR}/\${CTEST_CONFIGURATION_TYPE} ${ARGN})
+      else()
+        add_test(NAME ${name}
+          COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/${name}.py
+            --build_dir=${CMAKE_CURRENT_BINARY_DIR}/\${CTEST_CONFIGURATION_TYPE} ${ARGN})
+      endif()
+    endif()
+  endif(PYTHONINTERP_FOUND)
+endfunction()
+
+# install_project(targets...)
+#
+# Installs the specified targets and configures the associated pkgconfig files.
+function(install_project)
+  if(INSTALL_GTEST)
+    install(DIRECTORY "${PROJECT_SOURCE_DIR}/include/"
+      DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+    # Install the project targets.
+    install(TARGETS ${ARGN}
+      EXPORT ${targets_export_name}
+      RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}"
+      ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}"
+      LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}")
+    if(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
+      # Install PDBs
+      foreach(t ${ARGN})
+        get_target_property(t_pdb_name ${t} COMPILE_PDB_NAME)
+        get_target_property(t_pdb_name_debug ${t} COMPILE_PDB_NAME_DEBUG)
+        get_target_property(t_pdb_output_directory ${t} PDB_OUTPUT_DIRECTORY)
+        install(FILES
+          "${t_pdb_output_directory}/\${CMAKE_INSTALL_CONFIG_NAME}/$<$<CONFIG:Debug>:${t_pdb_name_debug}>$<$<NOT:$<CONFIG:Debug>>:${t_pdb_name}>.pdb"
+          DESTINATION ${CMAKE_INSTALL_LIBDIR}
+          OPTIONAL)
+      endforeach()
+    endif()
+    # Configure and install pkgconfig files.
+    foreach(t ${ARGN})
+      set(configured_pc "${generated_dir}/${t}.pc")
+      configure_file("${PROJECT_SOURCE_DIR}/cmake/${t}.pc.in"
+        "${configured_pc}" @ONLY)
+      install(FILES "${configured_pc}"
+        DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
+    endforeach()
+  endif()
+endfunction()
diff --git a/3rdparty/gtest/cmake/libgtest.la.in b/3rdparty/gtest/cmake/libgtest.la.in
new file mode 100644
index 0000000..840c838
--- /dev/null
+++ b/3rdparty/gtest/cmake/libgtest.la.in
@@ -0,0 +1,21 @@
+# libgtest.la - a libtool library file
+# Generated by libtool (GNU libtool) 2.4.6
+
+# Please DO NOT delete this file!
+# It is necessary for linking the library.
+
+# Names of this library.
+library_names='libgtest.so'
+
+# Is this an already installed library?
+installed=yes
+
+# Should we warn about portability when linking against -modules?
+shouldnotlink=no
+
+# Files to dlopen/dlpreopen
+dlopen=''
+dlpreopen=''
+
+# Directory that this library needs to be installed in:
+libdir='@CMAKE_INSTALL_FULL_LIBDIR@'
diff --git a/3rdparty/gtest/docs/advanced.md b/3rdparty/gtest/docs/advanced.md
new file mode 100644
index 0000000..3e5f779
--- /dev/null
+++ b/3rdparty/gtest/docs/advanced.md
@@ -0,0 +1,2567 @@
+# Advanced googletest Topics
+
+<!-- GOOGLETEST_CM0016 DO NOT DELETE -->
+
+## Introduction
+
+Now that you have read the [googletest Primer](primer.md) and learned how to
+write tests using googletest, it's time to learn some new tricks. This document
+will show you more assertions as well as how to construct complex failure
+messages, propagate fatal failures, reuse and speed up your test fixtures, and
+use various flags with your tests.
+
+## More Assertions
+
+This section covers some less frequently used, but still significant,
+assertions.
+
+### Explicit Success and Failure
+
+These three assertions do not actually test a value or expression. Instead, they
+generate a success or failure directly. Like the macros that actually perform a
+test, you may stream a custom failure message into them.
+
+```c++
+SUCCEED();
+```
+
+Generates a success. This does **NOT** make the overall test succeed. A test is
+considered successful only if none of its assertions fail during its execution.
+
+NOTE: `SUCCEED()` is purely documentary and currently doesn't generate any
+user-visible output. However, we may add `SUCCEED()` messages to googletest's
+output in the future.
+
+```c++
+FAIL();
+ADD_FAILURE();
+ADD_FAILURE_AT("file_path", line_number);
+```
+
+`FAIL()` generates a fatal failure, while `ADD_FAILURE()` and `ADD_FAILURE_AT()`
+generate a nonfatal failure. These are useful when control flow, rather than a
+Boolean expression, determines the test's success or failure. For example, you
+might want to write something like:
+
+```c++
+switch(expression) {
+  case 1:
+     ... some checks ...
+  case 2:
+     ... some other checks ...
+  default:
+     FAIL() << "We shouldn't get here.";
+}
+```
+
+NOTE: you can only use `FAIL()` in functions that return `void`. See the
+[Assertion Placement section](#assertion-placement) for more information.
+
+### Exception Assertions
+
+These are for verifying that a piece of code throws (or does not throw) an
+exception of the given type:
+
+Fatal assertion                            | Nonfatal assertion                         | Verifies
+------------------------------------------ | ------------------------------------------ | --------
+`ASSERT_THROW(statement, exception_type);` | `EXPECT_THROW(statement, exception_type);` | `statement` throws an exception of the given type
+`ASSERT_ANY_THROW(statement);`             | `EXPECT_ANY_THROW(statement);`             | `statement` throws an exception of any type
+`ASSERT_NO_THROW(statement);`              | `EXPECT_NO_THROW(statement);`              | `statement` doesn't throw any exception
+
+Examples:
+
+```c++
+ASSERT_THROW(Foo(5), bar_exception);
+
+EXPECT_NO_THROW({
+  int n = 5;
+  Bar(&n);
+});
+```
+
+**Availability**: requires exceptions to be enabled in the build environment
+
+### Predicate Assertions for Better Error Messages
+
+Even though googletest has a rich set of assertions, they can never be complete,
+as it's impossible (nor a good idea) to anticipate all scenarios a user might
+run into. Therefore, sometimes a user has to use `EXPECT_TRUE()` to check a
+complex expression, for lack of a better macro. This has the problem of not
+showing you the values of the parts of the expression, making it hard to
+understand what went wrong. As a workaround, some users choose to construct the
+failure message by themselves, streaming it into `EXPECT_TRUE()`. However, this
+is awkward especially when the expression has side-effects or is expensive to
+evaluate.
+
+googletest gives you three different options to solve this problem:
+
+#### Using an Existing Boolean Function
+
+If you already have a function or functor that returns `bool` (or a type that
+can be implicitly converted to `bool`), you can use it in a *predicate
+assertion* to get the function arguments printed for free:
+
+<!-- mdformat off(github rendering does not support multiline tables) -->
+
+| Fatal assertion                   | Nonfatal assertion                | Verifies                    |
+| --------------------------------- | --------------------------------- | --------------------------- |
+| `ASSERT_PRED1(pred1, val1)`       | `EXPECT_PRED1(pred1, val1)`       | `pred1(val1)` is true       |
+| `ASSERT_PRED2(pred2, val1, val2)` | `EXPECT_PRED2(pred2, val1, val2)` | `pred1(val1, val2)` is true |
+| `...`                             | `...`                             | `...`                       |
+
+<!-- mdformat on-->
+In the above, `predn` is an `n`-ary predicate function or functor, where `val1`,
+`val2`, ..., and `valn` are its arguments. The assertion succeeds if the
+predicate returns `true` when applied to the given arguments, and fails
+otherwise. When the assertion fails, it prints the value of each argument. In
+either case, the arguments are evaluated exactly once.
+
+Here's an example. Given
+
+```c++
+// Returns true if m and n have no common divisors except 1.
+bool MutuallyPrime(int m, int n) { ... }
+
+const int a = 3;
+const int b = 4;
+const int c = 10;
+```
+
+the assertion
+
+```c++
+  EXPECT_PRED2(MutuallyPrime, a, b);
+```
+
+will succeed, while the assertion
+
+```c++
+  EXPECT_PRED2(MutuallyPrime, b, c);
+```
+
+will fail with the message
+
+```none
+MutuallyPrime(b, c) is false, where
+b is 4
+c is 10
+```
+
+> NOTE:
+>
+> 1.  If you see a compiler error "no matching function to call" when using
+>     `ASSERT_PRED*` or `EXPECT_PRED*`, please see
+>     [this](faq.md#the-compiler-complains-no-matching-function-to-call-when-i-use-assert-pred-how-do-i-fix-it)
+>     for how to resolve it.
+
+#### Using a Function That Returns an AssertionResult
+
+While `EXPECT_PRED*()` and friends are handy for a quick job, the syntax is not
+satisfactory: you have to use different macros for different arities, and it
+feels more like Lisp than C++. The `::testing::AssertionResult` class solves
+this problem.
+
+An `AssertionResult` object represents the result of an assertion (whether it's
+a success or a failure, and an associated message). You can create an
+`AssertionResult` using one of these factory functions:
+
+```c++
+namespace testing {
+
+// Returns an AssertionResult object to indicate that an assertion has
+// succeeded.
+AssertionResult AssertionSuccess();
+
+// Returns an AssertionResult object to indicate that an assertion has
+// failed.
+AssertionResult AssertionFailure();
+
+}
+```
+
+You can then use the `<<` operator to stream messages to the `AssertionResult`
+object.
+
+To provide more readable messages in Boolean assertions (e.g. `EXPECT_TRUE()`),
+write a predicate function that returns `AssertionResult` instead of `bool`. For
+example, if you define `IsEven()` as:
+
+```c++
+::testing::AssertionResult IsEven(int n) {
+  if ((n % 2) == 0)
+     return ::testing::AssertionSuccess();
+  else
+     return ::testing::AssertionFailure() << n << " is odd";
+}
+```
+
+instead of:
+
+```c++
+bool IsEven(int n) {
+  return (n % 2) == 0;
+}
+```
+
+the failed assertion `EXPECT_TRUE(IsEven(Fib(4)))` will print:
+
+```none
+Value of: IsEven(Fib(4))
+  Actual: false (3 is odd)
+Expected: true
+```
+
+instead of a more opaque
+
+```none
+Value of: IsEven(Fib(4))
+  Actual: false
+Expected: true
+```
+
+If you want informative messages in `EXPECT_FALSE` and `ASSERT_FALSE` as well
+(one third of Boolean assertions in the Google code base are negative ones), and
+are fine with making the predicate slower in the success case, you can supply a
+success message:
+
+```c++
+::testing::AssertionResult IsEven(int n) {
+  if ((n % 2) == 0)
+     return ::testing::AssertionSuccess() << n << " is even";
+  else
+     return ::testing::AssertionFailure() << n << " is odd";
+}
+```
+
+Then the statement `EXPECT_FALSE(IsEven(Fib(6)))` will print
+
+```none
+  Value of: IsEven(Fib(6))
+     Actual: true (8 is even)
+  Expected: false
+```
+
+#### Using a Predicate-Formatter
+
+If you find the default message generated by `(ASSERT|EXPECT)_PRED*` and
+`(ASSERT|EXPECT)_(TRUE|FALSE)` unsatisfactory, or some arguments to your
+predicate do not support streaming to `ostream`, you can instead use the
+following *predicate-formatter assertions* to *fully* customize how the message
+is formatted:
+
+Fatal assertion                                  | Nonfatal assertion                               | Verifies
+------------------------------------------------ | ------------------------------------------------ | --------
+`ASSERT_PRED_FORMAT1(pred_format1, val1);`       | `EXPECT_PRED_FORMAT1(pred_format1, val1);`       | `pred_format1(val1)` is successful
+`ASSERT_PRED_FORMAT2(pred_format2, val1, val2);` | `EXPECT_PRED_FORMAT2(pred_format2, val1, val2);` | `pred_format2(val1, val2)` is successful
+`...`                                            | `...`                                            | ...
+
+The difference between this and the previous group of macros is that instead of
+a predicate, `(ASSERT|EXPECT)_PRED_FORMAT*` take a *predicate-formatter*
+(`pred_formatn`), which is a function or functor with the signature:
+
+```c++
+::testing::AssertionResult PredicateFormattern(const char* expr1,
+                                               const char* expr2,
+                                               ...
+                                               const char* exprn,
+                                               T1 val1,
+                                               T2 val2,
+                                               ...
+                                               Tn valn);
+```
+
+where `val1`, `val2`, ..., and `valn` are the values of the predicate arguments,
+and `expr1`, `expr2`, ..., and `exprn` are the corresponding expressions as they
+appear in the source code. The types `T1`, `T2`, ..., and `Tn` can be either
+value types or reference types. For example, if an argument has type `Foo`, you
+can declare it as either `Foo` or `const Foo&`, whichever is appropriate.
+
+As an example, let's improve the failure message in `MutuallyPrime()`, which was
+used with `EXPECT_PRED2()`:
+
+```c++
+// Returns the smallest prime common divisor of m and n,
+// or 1 when m and n are mutually prime.
+int SmallestPrimeCommonDivisor(int m, int n) { ... }
+
+// A predicate-formatter for asserting that two integers are mutually prime.
+::testing::AssertionResult AssertMutuallyPrime(const char* m_expr,
+                                               const char* n_expr,
+                                               int m,
+                                               int n) {
+  if (MutuallyPrime(m, n)) return ::testing::AssertionSuccess();
+
+  return ::testing::AssertionFailure() << m_expr << " and " << n_expr
+      << " (" << m << " and " << n << ") are not mutually prime, "
+      << "as they have a common divisor " << SmallestPrimeCommonDivisor(m, n);
+}
+```
+
+With this predicate-formatter, we can use
+
+```c++
+  EXPECT_PRED_FORMAT2(AssertMutuallyPrime, b, c);
+```
+
+to generate the message
+
+```none
+b and c (4 and 10) are not mutually prime, as they have a common divisor 2.
+```
+
+As you may have realized, many of the built-in assertions we introduced earlier
+are special cases of `(EXPECT|ASSERT)_PRED_FORMAT*`. In fact, most of them are
+indeed defined using `(EXPECT|ASSERT)_PRED_FORMAT*`.
+
+### Floating-Point Comparison
+
+Comparing floating-point numbers is tricky. Due to round-off errors, it is very
+unlikely that two floating-points will match exactly. Therefore, `ASSERT_EQ` 's
+naive comparison usually doesn't work. And since floating-points can have a wide
+value range, no single fixed error bound works. It's better to compare by a
+fixed relative error bound, except for values close to 0 due to the loss of
+precision there.
+
+In general, for floating-point comparison to make sense, the user needs to
+carefully choose the error bound. If they don't want or care to, comparing in
+terms of Units in the Last Place (ULPs) is a good default, and googletest
+provides assertions to do this. Full details about ULPs are quite long; if you
+want to learn more, see
+[here](https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/).
+
+#### Floating-Point Macros
+
+<!-- mdformat off(github rendering does not support multiline tables) -->
+
+| Fatal assertion                 | Nonfatal assertion              | Verifies                                 |
+| ------------------------------- | ------------------------------- | ---------------------------------------- |
+| `ASSERT_FLOAT_EQ(val1, val2);`  | `EXPECT_FLOAT_EQ(val1, val2);`  | the two `float` values are almost equal  |
+| `ASSERT_DOUBLE_EQ(val1, val2);` | `EXPECT_DOUBLE_EQ(val1, val2);` | the two `double` values are almost equal |
+
+<!-- mdformat on-->
+
+By "almost equal" we mean the values are within 4 ULP's from each other.
+
+The following assertions allow you to choose the acceptable error bound:
+
+<!-- mdformat off(github rendering does not support multiline tables) -->
+
+| Fatal assertion                       | Nonfatal assertion                    | Verifies                                                                         |
+| ------------------------------------- | ------------------------------------- | -------------------------------------------------------------------------------- |
+| `ASSERT_NEAR(val1, val2, abs_error);` | `EXPECT_NEAR(val1, val2, abs_error);` | the difference between `val1` and `val2` doesn't exceed the given absolute error |
+
+<!-- mdformat on-->
+
+#### Floating-Point Predicate-Format Functions
+
+Some floating-point operations are useful, but not that often used. In order to
+avoid an explosion of new macros, we provide them as predicate-format functions
+that can be used in predicate assertion macros (e.g. `EXPECT_PRED_FORMAT2`,
+etc).
+
+```c++
+EXPECT_PRED_FORMAT2(::testing::FloatLE, val1, val2);
+EXPECT_PRED_FORMAT2(::testing::DoubleLE, val1, val2);
+```
+
+Verifies that `val1` is less than, or almost equal to, `val2`. You can replace
+`EXPECT_PRED_FORMAT2` in the above table with `ASSERT_PRED_FORMAT2`.
+
+### Asserting Using gMock Matchers
+
+[gMock](../../googlemock) comes with a library of matchers for validating
+arguments passed to mock objects. A gMock *matcher* is basically a predicate
+that knows how to describe itself. It can be used in these assertion macros:
+
+<!-- mdformat off(github rendering does not support multiline tables) -->
+
+| Fatal assertion                | Nonfatal assertion             | Verifies              |
+| ------------------------------ | ------------------------------ | --------------------- |
+| `ASSERT_THAT(value, matcher);` | `EXPECT_THAT(value, matcher);` | value matches matcher |
+
+<!-- mdformat on-->
+
+For example, `StartsWith(prefix)` is a matcher that matches a string starting
+with `prefix`, and you can write:
+
+```c++
+using ::testing::StartsWith;
+...
+    // Verifies that Foo() returns a string starting with "Hello".
+    EXPECT_THAT(Foo(), StartsWith("Hello"));
+```
+
+Read this
+[recipe](../../googlemock/docs/cook_book.md#using-matchers-in-googletest-assertions)
+in the gMock Cookbook for more details.
+
+gMock has a rich set of matchers. You can do many things googletest cannot do
+alone with them. For a list of matchers gMock provides, read
+[this](../../googlemock/docs/cook_book.md##using-matchers). It's easy to write
+your [own matchers](../../googlemock/docs/cook_book.md#NewMatchers) too.
+
+gMock is bundled with googletest, so you don't need to add any build dependency
+in order to take advantage of this. Just include `"testing/base/public/gmock.h"`
+and you're ready to go.
+
+### More String Assertions
+
+(Please read the [previous](#asserting-using-gmock-matchers) section first if
+you haven't.)
+
+You can use the gMock
+[string matchers](../../googlemock/docs/cheat_sheet.md#string-matchers) with
+`EXPECT_THAT()` or `ASSERT_THAT()` to do more string comparison tricks
+(sub-string, prefix, suffix, regular expression, and etc). For example,
+
+```c++
+using ::testing::HasSubstr;
+using ::testing::MatchesRegex;
+...
+  ASSERT_THAT(foo_string, HasSubstr("needle"));
+  EXPECT_THAT(bar_string, MatchesRegex("\\w*\\d+"));
+```
+
+If the string contains a well-formed HTML or XML document, you can check whether
+its DOM tree matches an
+[XPath expression](http://www.w3.org/TR/xpath/#contents):
+
+```c++
+// Currently still in //template/prototemplate/testing:xpath_matcher
+#include "template/prototemplate/testing/xpath_matcher.h"
+using prototemplate::testing::MatchesXPath;
+EXPECT_THAT(html_string, MatchesXPath("//a[text()='click here']"));
+```
+
+### Windows HRESULT assertions
+
+These assertions test for `HRESULT` success or failure.
+
+Fatal assertion                        | Nonfatal assertion                     | Verifies
+-------------------------------------- | -------------------------------------- | --------
+`ASSERT_HRESULT_SUCCEEDED(expression)` | `EXPECT_HRESULT_SUCCEEDED(expression)` | `expression` is a success `HRESULT`
+`ASSERT_HRESULT_FAILED(expression)`    | `EXPECT_HRESULT_FAILED(expression)`    | `expression` is a failure `HRESULT`
+
+The generated output contains the human-readable error message associated with
+the `HRESULT` code returned by `expression`.
+
+You might use them like this:
+
+```c++
+CComPtr<IShellDispatch2> shell;
+ASSERT_HRESULT_SUCCEEDED(shell.CoCreateInstance(L"Shell.Application"));
+CComVariant empty;
+ASSERT_HRESULT_SUCCEEDED(shell->ShellExecute(CComBSTR(url), empty, empty, empty, empty));
+```
+
+### Type Assertions
+
+You can call the function
+
+```c++
+::testing::StaticAssertTypeEq<T1, T2>();
+```
+
+to assert that types `T1` and `T2` are the same. The function does nothing if
+the assertion is satisfied. If the types are different, the function call will
+fail to compile, the compiler error message will say that
+`type1 and type2 are not the same type` and most likely (depending on the compiler)
+show you the actual values of `T1` and `T2`. This is mainly useful inside
+template code.
+
+**Caveat**: When used inside a member function of a class template or a function
+template, `StaticAssertTypeEq<T1, T2>()` is effective only if the function is
+instantiated. For example, given:
+
+```c++
+template <typename T> class Foo {
+ public:
+  void Bar() { ::testing::StaticAssertTypeEq<int, T>(); }
+};
+```
+
+the code:
+
+```c++
+void Test1() { Foo<bool> foo; }
+```
+
+will not generate a compiler error, as `Foo<bool>::Bar()` is never actually
+instantiated. Instead, you need:
+
+```c++
+void Test2() { Foo<bool> foo; foo.Bar(); }
+```
+
+to cause a compiler error.
+
+### Assertion Placement
+
+You can use assertions in any C++ function. In particular, it doesn't have to be
+a method of the test fixture class. The one constraint is that assertions that
+generate a fatal failure (`FAIL*` and `ASSERT_*`) can only be used in
+void-returning functions. This is a consequence of Google's not using
+exceptions. By placing it in a non-void function you'll get a confusing compile
+error like `"error: void value not ignored as it ought to be"` or `"cannot
+initialize return object of type 'bool' with an rvalue of type 'void'"` or
+`"error: no viable conversion from 'void' to 'string'"`.
+
+If you need to use fatal assertions in a function that returns non-void, one
+option is to make the function return the value in an out parameter instead. For
+example, you can rewrite `T2 Foo(T1 x)` to `void Foo(T1 x, T2* result)`. You
+need to make sure that `*result` contains some sensible value even when the
+function returns prematurely. As the function now returns `void`, you can use
+any assertion inside of it.
+
+If changing the function's type is not an option, you should just use assertions
+that generate non-fatal failures, such as `ADD_FAILURE*` and `EXPECT_*`.
+
+NOTE: Constructors and destructors are not considered void-returning functions,
+according to the C++ language specification, and so you may not use fatal
+assertions in them; you'll get a compilation error if you try. Instead, either
+call `abort` and crash the entire test executable, or put the fatal assertion in
+a `SetUp`/`TearDown` function; see
+[constructor/destructor vs. `SetUp`/`TearDown`](faq.md#CtorVsSetUp)
+
+WARNING: A fatal assertion in a helper function (private void-returning method)
+called from a constructor or destructor does not does not terminate the current
+test, as your intuition might suggest: it merely returns from the constructor or
+destructor early, possibly leaving your object in a partially-constructed or
+partially-destructed state! You almost certainly want to `abort` or use
+`SetUp`/`TearDown` instead.
+
+## Teaching googletest How to Print Your Values
+
+When a test assertion such as `EXPECT_EQ` fails, googletest prints the argument
+values to help you debug. It does this using a user-extensible value printer.
+
+This printer knows how to print built-in C++ types, native arrays, STL
+containers, and any type that supports the `<<` operator. For other types, it
+prints the raw bytes in the value and hopes that you the user can figure it out.
+
+As mentioned earlier, the printer is *extensible*. That means you can teach it
+to do a better job at printing your particular type than to dump the bytes. To
+do that, define `<<` for your type:
+
+```c++
+#include <ostream>
+
+namespace foo {
+
+class Bar {  // We want googletest to be able to print instances of this.
+...
+  // Create a free inline friend function.
+  friend std::ostream& operator<<(std::ostream& os, const Bar& bar) {
+    return os << bar.DebugString();  // whatever needed to print bar to os
+  }
+};
+
+// If you can't declare the function in the class it's important that the
+// << operator is defined in the SAME namespace that defines Bar.  C++'s look-up
+// rules rely on that.
+std::ostream& operator<<(std::ostream& os, const Bar& bar) {
+  return os << bar.DebugString();  // whatever needed to print bar to os
+}
+
+}  // namespace foo
+```
+
+Sometimes, this might not be an option: your team may consider it bad style to
+have a `<<` operator for `Bar`, or `Bar` may already have a `<<` operator that
+doesn't do what you want (and you cannot change it). If so, you can instead
+define a `PrintTo()` function like this:
+
+```c++
+#include <ostream>
+
+namespace foo {
+
+class Bar {
+  ...
+  friend void PrintTo(const Bar& bar, std::ostream* os) {
+    *os << bar.DebugString();  // whatever needed to print bar to os
+  }
+};
+
+// If you can't declare the function in the class it's important that PrintTo()
+// is defined in the SAME namespace that defines Bar.  C++'s look-up rules rely
+// on that.
+void PrintTo(const Bar& bar, std::ostream* os) {
+  *os << bar.DebugString();  // whatever needed to print bar to os
+}
+
+}  // namespace foo
+```
+
+If you have defined both `<<` and `PrintTo()`, the latter will be used when
+googletest is concerned. This allows you to customize how the value appears in
+googletest's output without affecting code that relies on the behavior of its
+`<<` operator.
+
+If you want to print a value `x` using googletest's value printer yourself, just
+call `::testing::PrintToString(x)`, which returns an `std::string`:
+
+```c++
+vector<pair<Bar, int> > bar_ints = GetBarIntVector();
+
+EXPECT_TRUE(IsCorrectBarIntVector(bar_ints))
+    << "bar_ints = " << ::testing::PrintToString(bar_ints);
+```
+
+## Death Tests
+
+In many applications, there are assertions that can cause application failure if
+a condition is not met. These sanity checks, which ensure that the program is in
+a known good state, are there to fail at the earliest possible time after some
+program state is corrupted. If the assertion checks the wrong condition, then
+the program may proceed in an erroneous state, which could lead to memory
+corruption, security holes, or worse. Hence it is vitally important to test that
+such assertion statements work as expected.
+
+Since these precondition checks cause the processes to die, we call such tests
+_death tests_. More generally, any test that checks that a program terminates
+(except by throwing an exception) in an expected fashion is also a death test.
+
+Note that if a piece of code throws an exception, we don't consider it "death"
+for the purpose of death tests, as the caller of the code could catch the
+exception and avoid the crash. If you want to verify exceptions thrown by your
+code, see [Exception Assertions](#ExceptionAssertions).
+
+If you want to test `EXPECT_*()/ASSERT_*()` failures in your test code, see
+Catching Failures
+
+### How to Write a Death Test
+
+googletest has the following macros to support death tests:
+
+Fatal assertion                                  | Nonfatal assertion                               | Verifies
+------------------------------------------------ | ------------------------------------------------ | --------
+`ASSERT_DEATH(statement, matcher);`              | `EXPECT_DEATH(statement, matcher);`              | `statement` crashes with the given error
+`ASSERT_DEATH_IF_SUPPORTED(statement, matcher);` | `EXPECT_DEATH_IF_SUPPORTED(statement, matcher);` | if death tests are supported, verifies that `statement` crashes with the given error; otherwise verifies nothing
+`ASSERT_EXIT(statement, predicate, matcher);`    | `EXPECT_EXIT(statement, predicate, matcher);`    | `statement` exits with the given error, and its exit code matches `predicate`
+
+where `statement` is a statement that is expected to cause the process to die,
+`predicate` is a function or function object that evaluates an integer exit
+status, and `matcher` is either a GMock matcher matching a `const std::string&`
+or a (Perl) regular expression - either of which is matched against the stderr
+output of `statement`. For legacy reasons, a bare string (i.e. with no matcher)
+is interpreted as `ContainsRegex(str)`, **not** `Eq(str)`. Note that `statement`
+can be *any valid statement* (including *compound statement*) and doesn't have
+to be an expression.
+
+As usual, the `ASSERT` variants abort the current test function, while the
+`EXPECT` variants do not.
+
+> NOTE: We use the word "crash" here to mean that the process terminates with a
+> *non-zero* exit status code. There are two possibilities: either the process
+> has called `exit()` or `_exit()` with a non-zero value, or it may be killed by
+> a signal.
+>
+> This means that if `*statement*` terminates the process with a 0 exit code, it
+> is *not* considered a crash by `EXPECT_DEATH`. Use `EXPECT_EXIT` instead if
+> this is the case, or if you want to restrict the exit code more precisely.
+
+A predicate here must accept an `int` and return a `bool`. The death test
+succeeds only if the predicate returns `true`. googletest defines a few
+predicates that handle the most common cases:
+
+```c++
+::testing::ExitedWithCode(exit_code)
+```
+
+This expression is `true` if the program exited normally with the given exit
+code.
+
+```c++
+::testing::KilledBySignal(signal_number)  // Not available on Windows.
+```
+
+This expression is `true` if the program was killed by the given signal.
+
+The `*_DEATH` macros are convenient wrappers for `*_EXIT` that use a predicate
+that verifies the process' exit code is non-zero.
+
+Note that a death test only cares about three things:
+
+1.  does `statement` abort or exit the process?
+2.  (in the case of `ASSERT_EXIT` and `EXPECT_EXIT`) does the exit status
+    satisfy `predicate`? Or (in the case of `ASSERT_DEATH` and `EXPECT_DEATH`)
+    is the exit status non-zero? And
+3.  does the stderr output match `regex`?
+
+In particular, if `statement` generates an `ASSERT_*` or `EXPECT_*` failure, it
+will **not** cause the death test to fail, as googletest assertions don't abort
+the process.
+
+To write a death test, simply use one of the above macros inside your test
+function. For example,
+
+```c++
+TEST(MyDeathTest, Foo) {
+  // This death test uses a compound statement.
+  ASSERT_DEATH({
+    int n = 5;
+    Foo(&n);
+  }, "Error on line .* of Foo()");
+}
+
+TEST(MyDeathTest, NormalExit) {
+  EXPECT_EXIT(NormalExit(), ::testing::ExitedWithCode(0), "Success");
+}
+
+TEST(MyDeathTest, KillMyself) {
+  EXPECT_EXIT(KillMyself(), ::testing::KilledBySignal(SIGKILL),
+              "Sending myself unblockable signal");
+}
+```
+
+verifies that:
+
+*   calling `Foo(5)` causes the process to die with the given error message,
+*   calling `NormalExit()` causes the process to print `"Success"` to stderr and
+    exit with exit code 0, and
+*   calling `KillMyself()` kills the process with signal `SIGKILL`.
+
+The test function body may contain other assertions and statements as well, if
+necessary.
+
+### Death Test Naming
+
+IMPORTANT: We strongly recommend you to follow the convention of naming your
+**test suite** (not test) `*DeathTest` when it contains a death test, as
+demonstrated in the above example. The
+[Death Tests And Threads](#death-tests-and-threads) section below explains why.
+
+If a test fixture class is shared by normal tests and death tests, you can use
+`using` or `typedef` to introduce an alias for the fixture class and avoid
+duplicating its code:
+
+```c++
+class FooTest : public ::testing::Test { ... };
+
+using FooDeathTest = FooTest;
+
+TEST_F(FooTest, DoesThis) {
+  // normal test
+}
+
+TEST_F(FooDeathTest, DoesThat) {
+  // death test
+}
+```
+
+### Regular Expression Syntax
+
+On POSIX systems (e.g. Linux, Cygwin, and Mac), googletest uses the
+[POSIX extended regular expression](http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap09.html#tag_09_04)
+syntax. To learn about this syntax, you may want to read this
+[Wikipedia entry](http://en.wikipedia.org/wiki/Regular_expression#POSIX_Extended_Regular_Expressions).
+
+On Windows, googletest uses its own simple regular expression implementation. It
+lacks many features. For example, we don't support union (`"x|y"`), grouping
+(`"(xy)"`), brackets (`"[xy]"`), and repetition count (`"x{5,7}"`), among
+others. Below is what we do support (`A` denotes a literal character, period
+(`.`), or a single `\\ ` escape sequence; `x` and `y` denote regular
+expressions.):
+
+Expression | Meaning
+---------- | --------------------------------------------------------------
+`c`        | matches any literal character `c`
+`\\d`      | matches any decimal digit
+`\\D`      | matches any character that's not a decimal digit
+`\\f`      | matches `\f`
+`\\n`      | matches `\n`
+`\\r`      | matches `\r`
+`\\s`      | matches any ASCII whitespace, including `\n`
+`\\S`      | matches any character that's not a whitespace
+`\\t`      | matches `\t`
+`\\v`      | matches `\v`
+`\\w`      | matches any letter, `_`, or decimal digit
+`\\W`      | matches any character that `\\w` doesn't match
+`\\c`      | matches any literal character `c`, which must be a punctuation
+`.`        | matches any single character except `\n`
+`A?`       | matches 0 or 1 occurrences of `A`
+`A*`       | matches 0 or many occurrences of `A`
+`A+`       | matches 1 or many occurrences of `A`
+`^`        | matches the beginning of a string (not that of each line)
+`$`        | matches the end of a string (not that of each line)
+`xy`       | matches `x` followed by `y`
+
+To help you determine which capability is available on your system, googletest
+defines macros to govern which regular expression it is using. The macros are:
+`GTEST_USES_SIMPLE_RE=1` or `GTEST_USES_POSIX_RE=1`. If you want your death
+tests to work in all cases, you can either `#if` on these macros or use the more
+limited syntax only.
+
+### How It Works
+
+Under the hood, `ASSERT_EXIT()` spawns a new process and executes the death test
+statement in that process. The details of how precisely that happens depend on
+the platform and the variable ::testing::GTEST_FLAG(death_test_style) (which is
+initialized from the command-line flag `--gtest_death_test_style`).
+
+*   On POSIX systems, `fork()` (or `clone()` on Linux) is used to spawn the
+    child, after which:
+    *   If the variable's value is `"fast"`, the death test statement is
+        immediately executed.
+    *   If the variable's value is `"threadsafe"`, the child process re-executes
+        the unit test binary just as it was originally invoked, but with some
+        extra flags to cause just the single death test under consideration to
+        be run.
+*   On Windows, the child is spawned using the `CreateProcess()` API, and
+    re-executes the binary to cause just the single death test under
+    consideration to be run - much like the `threadsafe` mode on POSIX.
+
+Other values for the variable are illegal and will cause the death test to fail.
+Currently, the flag's default value is **"fast"**
+
+1.  the child's exit status satisfies the predicate, and
+2.  the child's stderr matches the regular expression.
+
+If the death test statement runs to completion without dying, the child process
+will nonetheless terminate, and the assertion fails.
+
+### Death Tests And Threads
+
+The reason for the two death test styles has to do with thread safety. Due to
+well-known problems with forking in the presence of threads, death tests should
+be run in a single-threaded context. Sometimes, however, it isn't feasible to
+arrange that kind of environment. For example, statically-initialized modules
+may start threads before main is ever reached. Once threads have been created,
+it may be difficult or impossible to clean them up.
+
+googletest has three features intended to raise awareness of threading issues.
+
+1.  A warning is emitted if multiple threads are running when a death test is
+    encountered.
+2.  Test suites with a name ending in "DeathTest" are run before all other
+    tests.
+3.  It uses `clone()` instead of `fork()` to spawn the child process on Linux
+    (`clone()` is not available on Cygwin and Mac), as `fork()` is more likely
+    to cause the child to hang when the parent process has multiple threads.
+
+It's perfectly fine to create threads inside a death test statement; they are
+executed in a separate process and cannot affect the parent.
+
+### Death Test Styles
+
+The "threadsafe" death test style was introduced in order to help mitigate the
+risks of testing in a possibly multithreaded environment. It trades increased
+test execution time (potentially dramatically so) for improved thread safety.
+
+The automated testing framework does not set the style flag. You can choose a
+particular style of death tests by setting the flag programmatically:
+
+```c++
+testing::FLAGS_gtest_death_test_style="threadsafe"
+```
+
+You can do this in `main()` to set the style for all death tests in the binary,
+or in individual tests. Recall that flags are saved before running each test and
+restored afterwards, so you need not do that yourself. For example:
+
+```c++
+int main(int argc, char** argv) {
+  InitGoogle(argv[0], &argc, &argv, true);
+  ::testing::FLAGS_gtest_death_test_style = "fast";
+  return RUN_ALL_TESTS();
+}
+
+TEST(MyDeathTest, TestOne) {
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
+  // This test is run in the "threadsafe" style:
+  ASSERT_DEATH(ThisShouldDie(), "");
+}
+
+TEST(MyDeathTest, TestTwo) {
+  // This test is run in the "fast" style:
+  ASSERT_DEATH(ThisShouldDie(), "");
+}
+```
+
+### Caveats
+
+The `statement` argument of `ASSERT_EXIT()` can be any valid C++ statement. If
+it leaves the current function via a `return` statement or by throwing an
+exception, the death test is considered to have failed. Some googletest macros
+may return from the current function (e.g. `ASSERT_TRUE()`), so be sure to avoid
+them in `statement`.
+
+Since `statement` runs in the child process, any in-memory side effect (e.g.
+modifying a variable, releasing memory, etc) it causes will *not* be observable
+in the parent process. In particular, if you release memory in a death test,
+your program will fail the heap check as the parent process will never see the
+memory reclaimed. To solve this problem, you can
+
+1.  try not to free memory in a death test;
+2.  free the memory again in the parent process; or
+3.  do not use the heap checker in your program.
+
+Due to an implementation detail, you cannot place multiple death test assertions
+on the same line; otherwise, compilation will fail with an unobvious error
+message.
+
+Despite the improved thread safety afforded by the "threadsafe" style of death
+test, thread problems such as deadlock are still possible in the presence of
+handlers registered with `pthread_atfork(3)`.
+
+
+## Using Assertions in Sub-routines
+
+### Adding Traces to Assertions
+
+If a test sub-routine is called from several places, when an assertion inside it
+fails, it can be hard to tell which invocation of the sub-routine the failure is
+from. You can alleviate this problem using extra logging or custom failure
+messages, but that usually clutters up your tests. A better solution is to use
+the `SCOPED_TRACE` macro or the `ScopedTrace` utility:
+
+```c++
+SCOPED_TRACE(message);
+ScopedTrace trace("file_path", line_number, message);
+```
+
+where `message` can be anything streamable to `std::ostream`. `SCOPED_TRACE`
+macro will cause the current file name, line number, and the given message to be
+added in every failure message. `ScopedTrace` accepts explicit file name and
+line number in arguments, which is useful for writing test helpers. The effect
+will be undone when the control leaves the current lexical scope.
+
+For example,
+
+```c++
+10: void Sub1(int n) {
+11:   EXPECT_EQ(Bar(n), 1);
+12:   EXPECT_EQ(Bar(n + 1), 2);
+13: }
+14:
+15: TEST(FooTest, Bar) {
+16:   {
+17:     SCOPED_TRACE("A");  // This trace point will be included in
+18:                         // every failure in this scope.
+19:     Sub1(1);
+20:   }
+21:   // Now it won't.
+22:   Sub1(9);
+23: }
+```
+
+could result in messages like these:
+
+```none
+path/to/foo_test.cc:11: Failure
+Value of: Bar(n)
+Expected: 1
+  Actual: 2
+   Trace:
+path/to/foo_test.cc:17: A
+
+path/to/foo_test.cc:12: Failure
+Value of: Bar(n + 1)
+Expected: 2
+  Actual: 3
+```
+
+Without the trace, it would've been difficult to know which invocation of
+`Sub1()` the two failures come from respectively. (You could add an extra
+message to each assertion in `Sub1()` to indicate the value of `n`, but that's
+tedious.)
+
+Some tips on using `SCOPED_TRACE`:
+
+1.  With a suitable message, it's often enough to use `SCOPED_TRACE` at the
+    beginning of a sub-routine, instead of at each call site.
+2.  When calling sub-routines inside a loop, make the loop iterator part of the
+    message in `SCOPED_TRACE` such that you can know which iteration the failure
+    is from.
+3.  Sometimes the line number of the trace point is enough for identifying the
+    particular invocation of a sub-routine. In this case, you don't have to
+    choose a unique message for `SCOPED_TRACE`. You can simply use `""`.
+4.  You can use `SCOPED_TRACE` in an inner scope when there is one in the outer
+    scope. In this case, all active trace points will be included in the failure
+    messages, in reverse order they are encountered.
+5.  The trace dump is clickable in Emacs - hit `return` on a line number and
+    you'll be taken to that line in the source file!
+
+### Propagating Fatal Failures
+
+A common pitfall when using `ASSERT_*` and `FAIL*` is not understanding that
+when they fail they only abort the _current function_, not the entire test. For
+example, the following test will segfault:
+
+```c++
+void Subroutine() {
+  // Generates a fatal failure and aborts the current function.
+  ASSERT_EQ(1, 2);
+
+  // The following won't be executed.
+  ...
+}
+
+TEST(FooTest, Bar) {
+  Subroutine();  // The intended behavior is for the fatal failure
+                 // in Subroutine() to abort the entire test.
+
+  // The actual behavior: the function goes on after Subroutine() returns.
+  int* p = NULL;
+  *p = 3;  // Segfault!
+}
+```
+
+To alleviate this, googletest provides three different solutions. You could use
+either exceptions, the `(ASSERT|EXPECT)_NO_FATAL_FAILURE` assertions or the
+`HasFatalFailure()` function. They are described in the following two
+subsections.
+
+#### Asserting on Subroutines with an exception
+
+The following code can turn ASSERT-failure into an exception:
+
+```c++
+class ThrowListener : public testing::EmptyTestEventListener {
+  void OnTestPartResult(const testing::TestPartResult& result) override {
+    if (result.type() == testing::TestPartResult::kFatalFailure) {
+      throw testing::AssertionException(result);
+    }
+  }
+};
+int main(int argc, char** argv) {
+  ...
+  testing::UnitTest::GetInstance()->listeners().Append(new ThrowListener);
+  return RUN_ALL_TESTS();
+}
+```
+
+This listener should be added after other listeners if you have any, otherwise
+they won't see failed `OnTestPartResult`.
+
+#### Asserting on Subroutines
+
+As shown above, if your test calls a subroutine that has an `ASSERT_*` failure
+in it, the test will continue after the subroutine returns. This may not be what
+you want.
+
+Often people want fatal failures to propagate like exceptions. For that
+googletest offers the following macros:
+
+Fatal assertion                       | Nonfatal assertion                    | Verifies
+------------------------------------- | ------------------------------------- | --------
+`ASSERT_NO_FATAL_FAILURE(statement);` | `EXPECT_NO_FATAL_FAILURE(statement);` | `statement` doesn't generate any new fatal failures in the current thread.
+
+Only failures in the thread that executes the assertion are checked to determine
+the result of this type of assertions. If `statement` creates new threads,
+failures in these threads are ignored.
+
+Examples:
+
+```c++
+ASSERT_NO_FATAL_FAILURE(Foo());
+
+int i;
+EXPECT_NO_FATAL_FAILURE({
+  i = Bar();
+});
+```
+
+Assertions from multiple threads are currently not supported on Windows.
+
+#### Checking for Failures in the Current Test
+
+`HasFatalFailure()` in the `::testing::Test` class returns `true` if an
+assertion in the current test has suffered a fatal failure. This allows
+functions to catch fatal failures in a sub-routine and return early.
+
+```c++
+class Test {
+ public:
+  ...
+  static bool HasFatalFailure();
+};
+```
+
+The typical usage, which basically simulates the behavior of a thrown exception,
+is:
+
+```c++
+TEST(FooTest, Bar) {
+  Subroutine();
+  // Aborts if Subroutine() had a fatal failure.
+  if (HasFatalFailure()) return;
+
+  // The following won't be executed.
+  ...
+}
+```
+
+If `HasFatalFailure()` is used outside of `TEST()` , `TEST_F()` , or a test
+fixture, you must add the `::testing::Test::` prefix, as in:
+
+```c++
+if (::testing::Test::HasFatalFailure()) return;
+```
+
+Similarly, `HasNonfatalFailure()` returns `true` if the current test has at
+least one non-fatal failure, and `HasFailure()` returns `true` if the current
+test has at least one failure of either kind.
+
+## Logging Additional Information
+
+In your test code, you can call `RecordProperty("key", value)` to log additional
+information, where `value` can be either a string or an `int`. The *last* value
+recorded for a key will be emitted to the
+[XML output](#generating-an-xml-report) if you specify one. For example, the
+test
+
+```c++
+TEST_F(WidgetUsageTest, MinAndMaxWidgets) {
+  RecordProperty("MaximumWidgets", ComputeMaxUsage());
+  RecordProperty("MinimumWidgets", ComputeMinUsage());
+}
+```
+
+will output XML like this:
+
+```xml
+  ...
+    <testcase name="MinAndMaxWidgets" status="run" time="0.006" classname="WidgetUsageTest" MaximumWidgets="12" MinimumWidgets="9" />
+  ...
+```
+
+> NOTE:
+>
+> *   `RecordProperty()` is a static member of the `Test` class. Therefore it
+>     needs to be prefixed with `::testing::Test::` if used outside of the
+>     `TEST` body and the test fixture class.
+> *   `*key*` must be a valid XML attribute name, and cannot conflict with the
+>     ones already used by googletest (`name`, `status`, `time`, `classname`,
+>     `type_param`, and `value_param`).
+> *   Calling `RecordProperty()` outside of the lifespan of a test is allowed.
+>     If it's called outside of a test but between a test suite's
+>     `SetUpTestSuite()` and `TearDownTestSuite()` methods, it will be
+>     attributed to the XML element for the test suite. If it's called outside
+>     of all test suites (e.g. in a test environment), it will be attributed to
+>     the top-level XML element.
+
+## Sharing Resources Between Tests in the Same Test Suite
+
+googletest creates a new test fixture object for each test in order to make
+tests independent and easier to debug. However, sometimes tests use resources
+that are expensive to set up, making the one-copy-per-test model prohibitively
+expensive.
+
+If the tests don't change the resource, there's no harm in their sharing a
+single resource copy. So, in addition to per-test set-up/tear-down, googletest
+also supports per-test-suite set-up/tear-down. To use it:
+
+1.  In your test fixture class (say `FooTest` ), declare as `static` some member
+    variables to hold the shared resources.
+2.  Outside your test fixture class (typically just below it), define those
+    member variables, optionally giving them initial values.
+3.  In the same test fixture class, define a `static void SetUpTestSuite()`
+    function (remember not to spell it as **`SetupTestSuite`** with a small
+    `u`!) to set up the shared resources and a `static void TearDownTestSuite()`
+    function to tear them down.
+
+That's it! googletest automatically calls `SetUpTestSuite()` before running the
+*first test* in the `FooTest` test suite (i.e. before creating the first
+`FooTest` object), and calls `TearDownTestSuite()` after running the *last test*
+in it (i.e. after deleting the last `FooTest` object). In between, the tests can
+use the shared resources.
+
+Remember that the test order is undefined, so your code can't depend on a test
+preceding or following another. Also, the tests must either not modify the state
+of any shared resource, or, if they do modify the state, they must restore the
+state to its original value before passing control to the next test.
+
+Here's an example of per-test-suite set-up and tear-down:
+
+```c++
+class FooTest : public ::testing::Test {
+ protected:
+  // Per-test-suite set-up.
+  // Called before the first test in this test suite.
+  // Can be omitted if not needed.
+  static void SetUpTestSuite() {
+    shared_resource_ = new ...;
+  }
+
+  // Per-test-suite tear-down.
+  // Called after the last test in this test suite.
+  // Can be omitted if not needed.
+  static void TearDownTestSuite() {
+    delete shared_resource_;
+    shared_resource_ = NULL;
+  }
+
+  // You can define per-test set-up logic as usual.
+  virtual void SetUp() { ... }
+
+  // You can define per-test tear-down logic as usual.
+  virtual void TearDown() { ... }
+
+  // Some expensive resource shared by all tests.
+  static T* shared_resource_;
+};
+
+T* FooTest::shared_resource_ = NULL;
+
+TEST_F(FooTest, Test1) {
+  ... you can refer to shared_resource_ here ...
+}
+
+TEST_F(FooTest, Test2) {
+  ... you can refer to shared_resource_ here ...
+}
+```
+
+NOTE: Though the above code declares `SetUpTestSuite()` protected, it may
+sometimes be necessary to declare it public, such as when using it with
+`TEST_P`.
+
+## Global Set-Up and Tear-Down
+
+Just as you can do set-up and tear-down at the test level and the test suite
+level, you can also do it at the test program level. Here's how.
+
+First, you subclass the `::testing::Environment` class to define a test
+environment, which knows how to set-up and tear-down:
+
+```c++
+class Environment : public ::testing::Environment {
+ public:
+  virtual ~Environment() {}
+
+  // Override this to define how to set up the environment.
+  void SetUp() override {}
+
+  // Override this to define how to tear down the environment.
+  void TearDown() override {}
+};
+```
+
+Then, you register an instance of your environment class with googletest by
+calling the `::testing::AddGlobalTestEnvironment()` function:
+
+```c++
+Environment* AddGlobalTestEnvironment(Environment* env);
+```
+
+Now, when `RUN_ALL_TESTS()` is called, it first calls the `SetUp()` method of
+each environment object, then runs the tests if none of the environments
+reported fatal failures and `GTEST_SKIP()` was not called. `RUN_ALL_TESTS()`
+always calls `TearDown()` with each environment object, regardless of whether or
+not the tests were run.
+
+It's OK to register multiple environment objects. In this suite, their `SetUp()`
+will be called in the order they are registered, and their `TearDown()` will be
+called in the reverse order.
+
+Note that googletest takes ownership of the registered environment objects.
+Therefore **do not delete them** by yourself.
+
+You should call `AddGlobalTestEnvironment()` before `RUN_ALL_TESTS()` is called,
+probably in `main()`. If you use `gtest_main`, you need to call this before
+`main()` starts for it to take effect. One way to do this is to define a global
+variable like this:
+
+```c++
+::testing::Environment* const foo_env =
+    ::testing::AddGlobalTestEnvironment(new FooEnvironment);
+```
+
+However, we strongly recommend you to write your own `main()` and call
+`AddGlobalTestEnvironment()` there, as relying on initialization of global
+variables makes the code harder to read and may cause problems when you register
+multiple environments from different translation units and the environments have
+dependencies among them (remember that the compiler doesn't guarantee the order
+in which global variables from different translation units are initialized).
+
+## Value-Parameterized Tests
+
+*Value-parameterized tests* allow you to test your code with different
+parameters without writing multiple copies of the same test. This is useful in a
+number of situations, for example:
+
+*   You have a piece of code whose behavior is affected by one or more
+    command-line flags. You want to make sure your code performs correctly for
+    various values of those flags.
+*   You want to test different implementations of an OO interface.
+*   You want to test your code over various inputs (a.k.a. data-driven testing).
+    This feature is easy to abuse, so please exercise your good sense when doing
+    it!
+
+### How to Write Value-Parameterized Tests
+
+To write value-parameterized tests, first you should define a fixture class. It
+must be derived from both `testing::Test` and `testing::WithParamInterface<T>`
+(the latter is a pure interface), where `T` is the type of your parameter
+values. For convenience, you can just derive the fixture class from
+`testing::TestWithParam<T>`, which itself is derived from both `testing::Test`
+and `testing::WithParamInterface<T>`. `T` can be any copyable type. If it's a
+raw pointer, you are responsible for managing the lifespan of the pointed
+values.
+
+NOTE: If your test fixture defines `SetUpTestSuite()` or `TearDownTestSuite()`
+they must be declared **public** rather than **protected** in order to use
+`TEST_P`.
+
+```c++
+class FooTest :
+    public testing::TestWithParam<const char*> {
+  // You can implement all the usual fixture class members here.
+  // To access the test parameter, call GetParam() from class
+  // TestWithParam<T>.
+};
+
+// Or, when you want to add parameters to a pre-existing fixture class:
+class BaseTest : public testing::Test {
+  ...
+};
+class BarTest : public BaseTest,
+                public testing::WithParamInterface<const char*> {
+  ...
+};
+```
+
+Then, use the `TEST_P` macro to define as many test patterns using this fixture
+as you want. The `_P` suffix is for "parameterized" or "pattern", whichever you
+prefer to think.
+
+```c++
+TEST_P(FooTest, DoesBlah) {
+  // Inside a test, access the test parameter with the GetParam() method
+  // of the TestWithParam<T> class:
+  EXPECT_TRUE(foo.Blah(GetParam()));
+  ...
+}
+
+TEST_P(FooTest, HasBlahBlah) {
+  ...
+}
+```
+
+Finally, you can use `INSTANTIATE_TEST_SUITE_P` to instantiate the test suite
+with any set of parameters you want. googletest defines a number of functions
+for generating test parameters. They return what we call (surprise!) *parameter
+generators*. Here is a summary of them, which are all in the `testing`
+namespace:
+
+<!-- mdformat off(github rendering does not support multiline tables) -->
+
+| Parameter Generator                                                                       | Behavior                                                                                                          |
+| ----------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------- |
+| `Range(begin, end [, step])`                                                              | Yields values `{begin, begin+step, begin+step+step, ...}`. The values do not include `end`. `step` defaults to 1. |
+| `Values(v1, v2, ..., vN)`                                                                 | Yields values `{v1, v2, ..., vN}`.                                                                                |
+| `ValuesIn(container)` and  `ValuesIn(begin,end)`                                          | Yields values from a C-style array, an  STL-style container, or an iterator range `[begin, end)`                  |
+| `Bool()`                                                                                  | Yields sequence `{false, true}`.                                                                                  |
+| `Combine(g1, g2, ..., gN)`                                                                | Yields all combinations (Cartesian product) as std\:\:tuples of the values generated by the `N` generators.       |
+
+<!-- mdformat on-->
+
+For more details, see the comments at the definitions of these functions.
+
+The following statement will instantiate tests from the `FooTest` test suite
+each with parameter values `"meeny"`, `"miny"`, and `"moe"`.
+
+```c++
+INSTANTIATE_TEST_SUITE_P(InstantiationName,
+                         FooTest,
+                         testing::Values("meeny", "miny", "moe"));
+```
+
+NOTE: The code above must be placed at global or namespace scope, not at
+function scope.
+
+NOTE: Don't forget this step! If you do your test will silently pass, but none
+of its suites will ever run!
+
+To distinguish different instances of the pattern (yes, you can instantiate it
+more than once), the first argument to `INSTANTIATE_TEST_SUITE_P` is a prefix
+that will be added to the actual test suite name. Remember to pick unique
+prefixes for different instantiations. The tests from the instantiation above
+will have these names:
+
+*   `InstantiationName/FooTest.DoesBlah/0` for `"meeny"`
+*   `InstantiationName/FooTest.DoesBlah/1` for `"miny"`
+*   `InstantiationName/FooTest.DoesBlah/2` for `"moe"`
+*   `InstantiationName/FooTest.HasBlahBlah/0` for `"meeny"`
+*   `InstantiationName/FooTest.HasBlahBlah/1` for `"miny"`
+*   `InstantiationName/FooTest.HasBlahBlah/2` for `"moe"`
+
+You can use these names in [`--gtest_filter`](#running-a-subset-of-the-tests).
+
+This statement will instantiate all tests from `FooTest` again, each with
+parameter values `"cat"` and `"dog"`:
+
+```c++
+const char* pets[] = {"cat", "dog"};
+INSTANTIATE_TEST_SUITE_P(AnotherInstantiationName, FooTest,
+                         testing::ValuesIn(pets));
+```
+
+The tests from the instantiation above will have these names:
+
+*   `AnotherInstantiationName/FooTest.DoesBlah/0` for `"cat"`
+*   `AnotherInstantiationName/FooTest.DoesBlah/1` for `"dog"`
+*   `AnotherInstantiationName/FooTest.HasBlahBlah/0` for `"cat"`
+*   `AnotherInstantiationName/FooTest.HasBlahBlah/1` for `"dog"`
+
+Please note that `INSTANTIATE_TEST_SUITE_P` will instantiate *all* tests in the
+given test suite, whether their definitions come before or *after* the
+`INSTANTIATE_TEST_SUITE_P` statement.
+
+You can see [sample7_unittest.cc] and [sample8_unittest.cc] for more examples.
+
+[sample7_unittest.cc]: ../samples/sample7_unittest.cc "Parameterized Test example"
+[sample8_unittest.cc]: ../samples/sample8_unittest.cc "Parameterized Test example with multiple parameters"
+
+### Creating Value-Parameterized Abstract Tests
+
+In the above, we define and instantiate `FooTest` in the *same* source file.
+Sometimes you may want to define value-parameterized tests in a library and let
+other people instantiate them later. This pattern is known as *abstract tests*.
+As an example of its application, when you are designing an interface you can
+write a standard suite of abstract tests (perhaps using a factory function as
+the test parameter) that all implementations of the interface are expected to
+pass. When someone implements the interface, they can instantiate your suite to
+get all the interface-conformance tests for free.
+
+To define abstract tests, you should organize your code like this:
+
+1.  Put the definition of the parameterized test fixture class (e.g. `FooTest`)
+    in a header file, say `foo_param_test.h`. Think of this as *declaring* your
+    abstract tests.
+2.  Put the `TEST_P` definitions in `foo_param_test.cc`, which includes
+    `foo_param_test.h`. Think of this as *implementing* your abstract tests.
+
+Once they are defined, you can instantiate them by including `foo_param_test.h`,
+invoking `INSTANTIATE_TEST_SUITE_P()`, and depending on the library target that
+contains `foo_param_test.cc`. You can instantiate the same abstract test suite
+multiple times, possibly in different source files.
+
+### Specifying Names for Value-Parameterized Test Parameters
+
+The optional last argument to `INSTANTIATE_TEST_SUITE_P()` allows the user to
+specify a function or functor that generates custom test name suffixes based on
+the test parameters. The function should accept one argument of type
+`testing::TestParamInfo<class ParamType>`, and return `std::string`.
+
+`testing::PrintToStringParamName` is a builtin test suffix generator that
+returns the value of `testing::PrintToString(GetParam())`. It does not work for
+`std::string` or C strings.
+
+NOTE: test names must be non-empty, unique, and may only contain ASCII
+alphanumeric characters. In particular, they
+[should not contain underscores](faq.md#why-should-test-suite-names-and-test-names-not-contain-underscore)
+
+```c++
+class MyTestSuite : public testing::TestWithParam<int> {};
+
+TEST_P(MyTestSuite, MyTest)
+{
+  std::cout << "Example Test Param: " << GetParam() << std::endl;
+}
+
+INSTANTIATE_TEST_SUITE_P(MyGroup, MyTestSuite, testing::Range(0, 10),
+                         testing::PrintToStringParamName());
+```
+
+Providing a custom functor allows for more control over test parameter name
+generation, especially for types where the automatic conversion does not
+generate helpful parameter names (e.g. strings as demonstrated above). The
+following example illustrates this for multiple parameters, an enumeration type
+and a string, and also demonstrates how to combine generators. It uses a lambda
+for conciseness:
+
+```c++
+enum class MyType { MY_FOO = 0, MY_BAR = 1 };
+
+class MyTestSuite : public testing::TestWithParam<std::tuple<MyType, string>> {
+};
+
+INSTANTIATE_TEST_SUITE_P(
+    MyGroup, MyTestSuite,
+    testing::Combine(
+        testing::Values(MyType::VALUE_0, MyType::VALUE_1),
+        testing::ValuesIn("", "")),
+    [](const testing::TestParamInfo<MyTestSuite::ParamType>& info) {
+      string name = absl::StrCat(
+          std::get<0>(info.param) == MY_FOO ? "Foo" : "Bar", "_",
+          std::get<1>(info.param));
+      absl::c_replace_if(name, [](char c) { return !std::isalnum(c); }, '_');
+      return name;
+    });
+```
+
+## Typed Tests
+
+Suppose you have multiple implementations of the same interface and want to make
+sure that all of them satisfy some common requirements. Or, you may have defined
+several types that are supposed to conform to the same "concept" and you want to
+verify it. In both cases, you want the same test logic repeated for different
+types.
+
+While you can write one `TEST` or `TEST_F` for each type you want to test (and
+you may even factor the test logic into a function template that you invoke from
+the `TEST`), it's tedious and doesn't scale: if you want `m` tests over `n`
+types, you'll end up writing `m*n` `TEST`s.
+
+*Typed tests* allow you to repeat the same test logic over a list of types. You
+only need to write the test logic once, although you must know the type list
+when writing typed tests. Here's how you do it:
+
+First, define a fixture class template. It should be parameterized by a type.
+Remember to derive it from `::testing::Test`:
+
+```c++
+template <typename T>
+class FooTest : public ::testing::Test {
+ public:
+  ...
+  typedef std::list<T> List;
+  static T shared_;
+  T value_;
+};
+```
+
+Next, associate a list of types with the test suite, which will be repeated for
+each type in the list:
+
+```c++
+using MyTypes = ::testing::Types<char, int, unsigned int>;
+TYPED_TEST_SUITE(FooTest, MyTypes);
+```
+
+The type alias (`using` or `typedef`) is necessary for the `TYPED_TEST_SUITE`
+macro to parse correctly. Otherwise the compiler will think that each comma in
+the type list introduces a new macro argument.
+
+Then, use `TYPED_TEST()` instead of `TEST_F()` to define a typed test for this
+test suite. You can repeat this as many times as you want:
+
+```c++
+TYPED_TEST(FooTest, DoesBlah) {
+  // Inside a test, refer to the special name TypeParam to get the type
+  // parameter.  Since we are inside a derived class template, C++ requires
+  // us to visit the members of FooTest via 'this'.
+  TypeParam n = this->value_;
+
+  // To visit static members of the fixture, add the 'TestFixture::'
+  // prefix.
+  n += TestFixture::shared_;
+
+  // To refer to typedefs in the fixture, add the 'typename TestFixture::'
+  // prefix.  The 'typename' is required to satisfy the compiler.
+  typename TestFixture::List values;
+
+  values.push_back(n);
+  ...
+}
+
+TYPED_TEST(FooTest, HasPropertyA) { ... }
+```
+
+You can see [sample6_unittest.cc] for a complete example.
+
+[sample6_unittest.cc]: ../samples/sample6_unittest.cc "Typed Test example"
+
+## Type-Parameterized Tests
+
+*Type-parameterized tests* are like typed tests, except that they don't require
+you to know the list of types ahead of time. Instead, you can define the test
+logic first and instantiate it with different type lists later. You can even
+instantiate it more than once in the same program.
+
+If you are designing an interface or concept, you can define a suite of
+type-parameterized tests to verify properties that any valid implementation of
+the interface/concept should have. Then, the author of each implementation can
+just instantiate the test suite with their type to verify that it conforms to
+the requirements, without having to write similar tests repeatedly. Here's an
+example:
+
+First, define a fixture class template, as we did with typed tests:
+
+```c++
+template <typename T>
+class FooTest : public ::testing::Test {
+  ...
+};
+```
+
+Next, declare that you will define a type-parameterized test suite:
+
+```c++
+TYPED_TEST_SUITE_P(FooTest);
+```
+
+Then, use `TYPED_TEST_P()` to define a type-parameterized test. You can repeat
+this as many times as you want:
+
+```c++
+TYPED_TEST_P(FooTest, DoesBlah) {
+  // Inside a test, refer to TypeParam to get the type parameter.
+  TypeParam n = 0;
+  ...
+}
+
+TYPED_TEST_P(FooTest, HasPropertyA) { ... }
+```
+
+Now the tricky part: you need to register all test patterns using the
+`REGISTER_TYPED_TEST_SUITE_P` macro before you can instantiate them. The first
+argument of the macro is the test suite name; the rest are the names of the
+tests in this test suite:
+
+```c++
+REGISTER_TYPED_TEST_SUITE_P(FooTest,
+                            DoesBlah, HasPropertyA);
+```
+
+Finally, you are free to instantiate the pattern with the types you want. If you
+put the above code in a header file, you can `#include` it in multiple C++
+source files and instantiate it multiple times.
+
+```c++
+typedef ::testing::Types<char, int, unsigned int> MyTypes;
+INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, MyTypes);
+```
+
+To distinguish different instances of the pattern, the first argument to the
+`INSTANTIATE_TYPED_TEST_SUITE_P` macro is a prefix that will be added to the
+actual test suite name. Remember to pick unique prefixes for different
+instances.
+
+In the special case where the type list contains only one type, you can write
+that type directly without `::testing::Types<...>`, like this:
+
+```c++
+INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, int);
+```
+
+You can see [sample6_unittest.cc] for a complete example.
+
+## Testing Private Code
+
+If you change your software's internal implementation, your tests should not
+break as long as the change is not observable by users. Therefore, **per the
+black-box testing principle, most of the time you should test your code through
+its public interfaces.**
+
+**If you still find yourself needing to test internal implementation code,
+consider if there's a better design.** The desire to test internal
+implementation is often a sign that the class is doing too much. Consider
+extracting an implementation class, and testing it. Then use that implementation
+class in the original class.
+
+If you absolutely have to test non-public interface code though, you can. There
+are two cases to consider:
+
+*   Static functions ( *not* the same as static member functions!) or unnamed
+    namespaces, and
+*   Private or protected class members
+
+To test them, we use the following special techniques:
+
+*   Both static functions and definitions/declarations in an unnamed namespace
+    are only visible within the same translation unit. To test them, you can
+    `#include` the entire `.cc` file being tested in your `*_test.cc` file.
+    (#including `.cc` files is not a good way to reuse code - you should not do
+    this in production code!)
+
+    However, a better approach is to move the private code into the
+    `foo::internal` namespace, where `foo` is the namespace your project
+    normally uses, and put the private declarations in a `*-internal.h` file.
+    Your production `.cc` files and your tests are allowed to include this
+    internal header, but your clients are not. This way, you can fully test your
+    internal implementation without leaking it to your clients.
+
+*   Private class members are only accessible from within the class or by
+    friends. To access a class' private members, you can declare your test
+    fixture as a friend to the class and define accessors in your fixture. Tests
+    using the fixture can then access the private members of your production
+    class via the accessors in the fixture. Note that even though your fixture
+    is a friend to your production class, your tests are not automatically
+    friends to it, as they are technically defined in sub-classes of the
+    fixture.
+
+    Another way to test private members is to refactor them into an
+    implementation class, which is then declared in a `*-internal.h` file. Your
+    clients aren't allowed to include this header but your tests can. Such is
+    called the
+    [Pimpl](https://www.gamedev.net/articles/programming/general-and-gameplay-programming/the-c-pimpl-r1794/)
+    (Private Implementation) idiom.
+
+    Or, you can declare an individual test as a friend of your class by adding
+    this line in the class body:
+
+    ```c++
+        FRIEND_TEST(TestSuiteName, TestName);
+    ```
+
+    For example,
+
+    ```c++
+    // foo.h
+    class Foo {
+      ...
+     private:
+      FRIEND_TEST(FooTest, BarReturnsZeroOnNull);
+
+      int Bar(void* x);
+    };
+
+    // foo_test.cc
+    ...
+    TEST(FooTest, BarReturnsZeroOnNull) {
+      Foo foo;
+      EXPECT_EQ(foo.Bar(NULL), 0);  // Uses Foo's private member Bar().
+    }
+    ```
+
+    Pay special attention when your class is defined in a namespace, as you
+    should define your test fixtures and tests in the same namespace if you want
+    them to be friends of your class. For example, if the code to be tested
+    looks like:
+
+    ```c++
+    namespace my_namespace {
+
+    class Foo {
+      friend class FooTest;
+      FRIEND_TEST(FooTest, Bar);
+      FRIEND_TEST(FooTest, Baz);
+      ... definition of the class Foo ...
+    };
+
+    }  // namespace my_namespace
+    ```
+
+    Your test code should be something like:
+
+    ```c++
+    namespace my_namespace {
+
+    class FooTest : public ::testing::Test {
+     protected:
+      ...
+    };
+
+    TEST_F(FooTest, Bar) { ... }
+    TEST_F(FooTest, Baz) { ... }
+
+    }  // namespace my_namespace
+    ```
+
+## "Catching" Failures
+
+If you are building a testing utility on top of googletest, you'll want to test
+your utility. What framework would you use to test it? googletest, of course.
+
+The challenge is to verify that your testing utility reports failures correctly.
+In frameworks that report a failure by throwing an exception, you could catch
+the exception and assert on it. But googletest doesn't use exceptions, so how do
+we test that a piece of code generates an expected failure?
+
+gunit-spi.h contains some constructs to do this. After #including this header,
+you can use
+
+```c++
+  EXPECT_FATAL_FAILURE(statement, substring);
+```
+
+to assert that `statement` generates a fatal (e.g. `ASSERT_*`) failure in the
+current thread whose message contains the given `substring`, or use
+
+```c++
+  EXPECT_NONFATAL_FAILURE(statement, substring);
+```
+
+if you are expecting a non-fatal (e.g. `EXPECT_*`) failure.
+
+Only failures in the current thread are checked to determine the result of this
+type of expectations. If `statement` creates new threads, failures in these
+threads are also ignored. If you want to catch failures in other threads as
+well, use one of the following macros instead:
+
+```c++
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(statement, substring);
+  EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(statement, substring);
+```
+
+NOTE: Assertions from multiple threads are currently not supported on Windows.
+
+For technical reasons, there are some caveats:
+
+1.  You cannot stream a failure message to either macro.
+
+2.  `statement` in `EXPECT_FATAL_FAILURE{_ON_ALL_THREADS}()` cannot reference
+    local non-static variables or non-static members of `this` object.
+
+3.  `statement` in `EXPECT_FATAL_FAILURE{_ON_ALL_THREADS}()` cannot return a
+    value.
+
+## Registering tests programmatically
+
+The `TEST` macros handle the vast majority of all use cases, but there are few
+were runtime registration logic is required. For those cases, the framework
+provides the `::testing::RegisterTest` that allows callers to register arbitrary
+tests dynamically.
+
+This is an advanced API only to be used when the `TEST` macros are insufficient.
+The macros should be preferred when possible, as they avoid most of the
+complexity of calling this function.
+
+It provides the following signature:
+
+```c++
+template <typename Factory>
+TestInfo* RegisterTest(const char* test_suite_name, const char* test_name,
+                       const char* type_param, const char* value_param,
+                       const char* file, int line, Factory factory);
+```
+
+The `factory` argument is a factory callable (move-constructible) object or
+function pointer that creates a new instance of the Test object. It handles
+ownership to the caller. The signature of the callable is `Fixture*()`, where
+`Fixture` is the test fixture class for the test. All tests registered with the
+same `test_suite_name` must return the same fixture type. This is checked at
+runtime.
+
+The framework will infer the fixture class from the factory and will call the
+`SetUpTestSuite` and `TearDownTestSuite` for it.
+
+Must be called before `RUN_ALL_TESTS()` is invoked, otherwise behavior is
+undefined.
+
+Use case example:
+
+```c++
+class MyFixture : public ::testing::Test {
+ public:
+  // All of these optional, just like in regular macro usage.
+  static void SetUpTestSuite() { ... }
+  static void TearDownTestSuite() { ... }
+  void SetUp() override { ... }
+  void TearDown() override { ... }
+};
+
+class MyTest : public MyFixture {
+ public:
+  explicit MyTest(int data) : data_(data) {}
+  void TestBody() override { ... }
+
+ private:
+  int data_;
+};
+
+void RegisterMyTests(const std::vector<int>& values) {
+  for (int v : values) {
+    ::testing::RegisterTest(
+        "MyFixture", ("Test" + std::to_string(v)).c_str(), nullptr,
+        std::to_string(v).c_str(),
+        __FILE__, __LINE__,
+        // Important to use the fixture type as the return type here.
+        [=]() -> MyFixture* { return new MyTest(v); });
+  }
+}
+...
+int main(int argc, char** argv) {
+  std::vector<int> values_to_test = LoadValuesFromConfig();
+  RegisterMyTests(values_to_test);
+  ...
+  return RUN_ALL_TESTS();
+}
+```
+## Getting the Current Test's Name
+
+Sometimes a function may need to know the name of the currently running test.
+For example, you may be using the `SetUp()` method of your test fixture to set
+the golden file name based on which test is running. The `::testing::TestInfo`
+class has this information:
+
+```c++
+namespace testing {
+
+class TestInfo {
+ public:
+  // Returns the test suite name and the test name, respectively.
+  //
+  // Do NOT delete or free the return value - it's managed by the
+  // TestInfo class.
+  const char* test_suite_name() const;
+  const char* name() const;
+};
+
+}
+```
+
+To obtain a `TestInfo` object for the currently running test, call
+`current_test_info()` on the `UnitTest` singleton object:
+
+```c++
+  // Gets information about the currently running test.
+  // Do NOT delete the returned object - it's managed by the UnitTest class.
+  const ::testing::TestInfo* const test_info =
+    ::testing::UnitTest::GetInstance()->current_test_info();
+
+
+
+  printf("We are in test %s of test suite %s.\n",
+         test_info->name(),
+         test_info->test_suite_name());
+```
+
+`current_test_info()` returns a null pointer if no test is running. In
+particular, you cannot find the test suite name in `TestSuiteSetUp()`,
+`TestSuiteTearDown()` (where you know the test suite name implicitly), or
+functions called from them.
+
+## Extending googletest by Handling Test Events
+
+googletest provides an **event listener API** to let you receive notifications
+about the progress of a test program and test failures. The events you can
+listen to include the start and end of the test program, a test suite, or a test
+method, among others. You may use this API to augment or replace the standard
+console output, replace the XML output, or provide a completely different form
+of output, such as a GUI or a database. You can also use test events as
+checkpoints to implement a resource leak checker, for example.
+
+### Defining Event Listeners
+
+To define a event listener, you subclass either testing::TestEventListener or
+testing::EmptyTestEventListener The former is an (abstract) interface, where
+*each pure virtual method can be overridden to handle a test event* (For
+example, when a test starts, the `OnTestStart()` method will be called.). The
+latter provides an empty implementation of all methods in the interface, such
+that a subclass only needs to override the methods it cares about.
+
+When an event is fired, its context is passed to the handler function as an
+argument. The following argument types are used:
+
+*   UnitTest reflects the state of the entire test program,
+*   TestSuite has information about a test suite, which can contain one or more
+    tests,
+*   TestInfo contains the state of a test, and
+*   TestPartResult represents the result of a test assertion.
+
+An event handler function can examine the argument it receives to find out
+interesting information about the event and the test program's state.
+
+Here's an example:
+
+```c++
+  class MinimalistPrinter : public ::testing::EmptyTestEventListener {
+    // Called before a test starts.
+    virtual void OnTestStart(const ::testing::TestInfo& test_info) {
+      printf("*** Test %s.%s starting.\n",
+             test_info.test_suite_name(), test_info.name());
+    }
+
+    // Called after a failed assertion or a SUCCESS().
+    virtual void OnTestPartResult(const ::testing::TestPartResult& test_part_result) {
+      printf("%s in %s:%d\n%s\n",
+             test_part_result.failed() ? "*** Failure" : "Success",
+             test_part_result.file_name(),
+             test_part_result.line_number(),
+             test_part_result.summary());
+    }
+
+    // Called after a test ends.
+    virtual void OnTestEnd(const ::testing::TestInfo& test_info) {
+      printf("*** Test %s.%s ending.\n",
+             test_info.test_suite_name(), test_info.name());
+    }
+  };
+```
+
+### Using Event Listeners
+
+To use the event listener you have defined, add an instance of it to the
+googletest event listener list (represented by class TestEventListeners - note
+the "s" at the end of the name) in your `main()` function, before calling
+`RUN_ALL_TESTS()`:
+
+```c++
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  // Gets hold of the event listener list.
+  ::testing::TestEventListeners& listeners =
+        ::testing::UnitTest::GetInstance()->listeners();
+  // Adds a listener to the end.  googletest takes the ownership.
+  listeners.Append(new MinimalistPrinter);
+  return RUN_ALL_TESTS();
+}
+```
+
+There's only one problem: the default test result printer is still in effect, so
+its output will mingle with the output from your minimalist printer. To suppress
+the default printer, just release it from the event listener list and delete it.
+You can do so by adding one line:
+
+```c++
+  ...
+  delete listeners.Release(listeners.default_result_printer());
+  listeners.Append(new MinimalistPrinter);
+  return RUN_ALL_TESTS();
+```
+
+Now, sit back and enjoy a completely different output from your tests. For more
+details, see [sample9_unittest.cc].
+
+[sample9_unittest.cc]: ../samples/sample9_unittest.cc "Event listener example"
+
+You may append more than one listener to the list. When an `On*Start()` or
+`OnTestPartResult()` event is fired, the listeners will receive it in the order
+they appear in the list (since new listeners are added to the end of the list,
+the default text printer and the default XML generator will receive the event
+first). An `On*End()` event will be received by the listeners in the *reverse*
+order. This allows output by listeners added later to be framed by output from
+listeners added earlier.
+
+### Generating Failures in Listeners
+
+You may use failure-raising macros (`EXPECT_*()`, `ASSERT_*()`, `FAIL()`, etc)
+when processing an event. There are some restrictions:
+
+1.  You cannot generate any failure in `OnTestPartResult()` (otherwise it will
+    cause `OnTestPartResult()` to be called recursively).
+2.  A listener that handles `OnTestPartResult()` is not allowed to generate any
+    failure.
+
+When you add listeners to the listener list, you should put listeners that
+handle `OnTestPartResult()` *before* listeners that can generate failures. This
+ensures that failures generated by the latter are attributed to the right test
+by the former.
+
+See [sample10_unittest.cc] for an example of a failure-raising listener.
+
+[sample10_unittest.cc]: ../samples/sample10_unittest.cc "Failure-raising listener example"
+
+## Running Test Programs: Advanced Options
+
+googletest test programs are ordinary executables. Once built, you can run them
+directly and affect their behavior via the following environment variables
+and/or command line flags. For the flags to work, your programs must call
+`::testing::InitGoogleTest()` before calling `RUN_ALL_TESTS()`.
+
+To see a list of supported flags and their usage, please run your test program
+with the `--help` flag. You can also use `-h`, `-?`, or `/?` for short.
+
+If an option is specified both by an environment variable and by a flag, the
+latter takes precedence.
+
+### Selecting Tests
+
+#### Listing Test Names
+
+Sometimes it is necessary to list the available tests in a program before
+running them so that a filter may be applied if needed. Including the flag
+`--gtest_list_tests` overrides all other flags and lists tests in the following
+format:
+
+```none
+TestSuite1.
+  TestName1
+  TestName2
+TestSuite2.
+  TestName
+```
+
+None of the tests listed are actually run if the flag is provided. There is no
+corresponding environment variable for this flag.
+
+#### Running a Subset of the Tests
+
+By default, a googletest program runs all tests the user has defined. Sometimes,
+you want to run only a subset of the tests (e.g. for debugging or quickly
+verifying a change). If you set the `GTEST_FILTER` environment variable or the
+`--gtest_filter` flag to a filter string, googletest will only run the tests
+whose full names (in the form of `TestSuiteName.TestName`) match the filter.
+
+The format of a filter is a '`:`'-separated list of wildcard patterns (called
+the *positive patterns*) optionally followed by a '`-`' and another
+'`:`'-separated pattern list (called the *negative patterns*). A test matches
+the filter if and only if it matches any of the positive patterns but does not
+match any of the negative patterns.
+
+A pattern may contain `'*'` (matches any string) or `'?'` (matches any single
+character). For convenience, the filter `'*-NegativePatterns'` can be also
+written as `'-NegativePatterns'`.
+
+For example:
+
+*   `./foo_test` Has no flag, and thus runs all its tests.
+*   `./foo_test --gtest_filter=*` Also runs everything, due to the single
+    match-everything `*` value.
+*   `./foo_test --gtest_filter=FooTest.*` Runs everything in test suite
+    `FooTest` .
+*   `./foo_test --gtest_filter=*Null*:*Constructor*` Runs any test whose full
+    name contains either `"Null"` or `"Constructor"` .
+*   `./foo_test --gtest_filter=-*DeathTest.*` Runs all non-death tests.
+*   `./foo_test --gtest_filter=FooTest.*-FooTest.Bar` Runs everything in test
+    suite `FooTest` except `FooTest.Bar`.
+*   `./foo_test --gtest_filter=FooTest.*:BarTest.*-FooTest.Bar:BarTest.Foo` Runs
+    everything in test suite `FooTest` except `FooTest.Bar` and everything in
+    test suite `BarTest` except `BarTest.Foo`.
+
+#### Temporarily Disabling Tests
+
+If you have a broken test that you cannot fix right away, you can add the
+`DISABLED_` prefix to its name. This will exclude it from execution. This is
+better than commenting out the code or using `#if 0`, as disabled tests are
+still compiled (and thus won't rot).
+
+If you need to disable all tests in a test suite, you can either add `DISABLED_`
+to the front of the name of each test, or alternatively add it to the front of
+the test suite name.
+
+For example, the following tests won't be run by googletest, even though they
+will still be compiled:
+
+```c++
+// Tests that Foo does Abc.
+TEST(FooTest, DISABLED_DoesAbc) { ... }
+
+class DISABLED_BarTest : public ::testing::Test { ... };
+
+// Tests that Bar does Xyz.
+TEST_F(DISABLED_BarTest, DoesXyz) { ... }
+```
+
+NOTE: This feature should only be used for temporary pain-relief. You still have
+to fix the disabled tests at a later date. As a reminder, googletest will print
+a banner warning you if a test program contains any disabled tests.
+
+TIP: You can easily count the number of disabled tests you have using `gsearch`
+and/or `grep`. This number can be used as a metric for improving your test
+quality.
+
+#### Temporarily Enabling Disabled Tests
+
+To include disabled tests in test execution, just invoke the test program with
+the `--gtest_also_run_disabled_tests` flag or set the
+`GTEST_ALSO_RUN_DISABLED_TESTS` environment variable to a value other than `0`.
+You can combine this with the `--gtest_filter` flag to further select which
+disabled tests to run.
+
+### Repeating the Tests
+
+Once in a while you'll run into a test whose result is hit-or-miss. Perhaps it
+will fail only 1% of the time, making it rather hard to reproduce the bug under
+a debugger. This can be a major source of frustration.
+
+The `--gtest_repeat` flag allows you to repeat all (or selected) test methods in
+a program many times. Hopefully, a flaky test will eventually fail and give you
+a chance to debug. Here's how to use it:
+
+```none
+$ foo_test --gtest_repeat=1000
+Repeat foo_test 1000 times and don't stop at failures.
+
+$ foo_test --gtest_repeat=-1
+A negative count means repeating forever.
+
+$ foo_test --gtest_repeat=1000 --gtest_break_on_failure
+Repeat foo_test 1000 times, stopping at the first failure.  This
+is especially useful when running under a debugger: when the test
+fails, it will drop into the debugger and you can then inspect
+variables and stacks.
+
+$ foo_test --gtest_repeat=1000 --gtest_filter=FooBar.*
+Repeat the tests whose name matches the filter 1000 times.
+```
+
+If your test program contains
+[global set-up/tear-down](#global-set-up-and-tear-down) code, it will be
+repeated in each iteration as well, as the flakiness may be in it. You can also
+specify the repeat count by setting the `GTEST_REPEAT` environment variable.
+
+### Shuffling the Tests
+
+You can specify the `--gtest_shuffle` flag (or set the `GTEST_SHUFFLE`
+environment variable to `1`) to run the tests in a program in a random order.
+This helps to reveal bad dependencies between tests.
+
+By default, googletest uses a random seed calculated from the current time.
+Therefore you'll get a different order every time. The console output includes
+the random seed value, such that you can reproduce an order-related test failure
+later. To specify the random seed explicitly, use the `--gtest_random_seed=SEED`
+flag (or set the `GTEST_RANDOM_SEED` environment variable), where `SEED` is an
+integer in the range [0, 99999]. The seed value 0 is special: it tells
+googletest to do the default behavior of calculating the seed from the current
+time.
+
+If you combine this with `--gtest_repeat=N`, googletest will pick a different
+random seed and re-shuffle the tests in each iteration.
+
+### Controlling Test Output
+
+#### Colored Terminal Output
+
+googletest can use colors in its terminal output to make it easier to spot the
+important information:
+
+<code>
+...<br/>
+  <font color="green">[----------]</font><font color="black"> 1 test from
+  FooTest</font><br/>
+  <font color="green">[ RUN &nbsp; &nbsp; &nbsp;]</font><font color="black">
+  FooTest.DoesAbc</font><br/>
+  <font color="green">[ &nbsp; &nbsp; &nbsp; OK ]</font><font color="black">
+  FooTest.DoesAbc </font><br/>
+  <font color="green">[----------]</font><font color="black">
+  2 tests from BarTest</font><br/>
+  <font color="green">[ RUN &nbsp; &nbsp; &nbsp;]</font><font color="black">
+  BarTest.HasXyzProperty </font><br/>
+  <font color="green">[ &nbsp; &nbsp; &nbsp; OK ]</font><font color="black">
+  BarTest.HasXyzProperty</font><br/>
+  <font color="green">[ RUN &nbsp; &nbsp; &nbsp;]</font><font color="black">
+  BarTest.ReturnsTrueOnSuccess ... some error messages ...</font><br/>
+  <font color="red">[ &nbsp; FAILED ]</font><font color="black">
+  BarTest.ReturnsTrueOnSuccess ...</font><br/>
+  <font color="green">[==========]</font><font color="black">
+  30 tests from 14 test suites ran.</font><br/>
+  <font color="green">[ &nbsp; PASSED ]</font><font color="black">
+  28 tests.</font><br/>
+  <font color="red">[ &nbsp; FAILED ]</font><font color="black">
+  2 tests, listed below:</font><br/>
+  <font color="red">[ &nbsp; FAILED ]</font><font color="black">
+  BarTest.ReturnsTrueOnSuccess</font><br/>
+  <font color="red">[ &nbsp; FAILED ]</font><font color="black">
+  AnotherTest.DoesXyz<br/>
+<br/>
+  2 FAILED TESTS
+  </font>
+</code>
+
+You can set the `GTEST_COLOR` environment variable or the `--gtest_color`
+command line flag to `yes`, `no`, or `auto` (the default) to enable colors,
+disable colors, or let googletest decide. When the value is `auto`, googletest
+will use colors if and only if the output goes to a terminal and (on non-Windows
+platforms) the `TERM` environment variable is set to `xterm` or `xterm-color`.
+
+#### Suppressing the Elapsed Time
+
+By default, googletest prints the time it takes to run each test. To disable
+that, run the test program with the `--gtest_print_time=0` command line flag, or
+set the GTEST_PRINT_TIME environment variable to `0`.
+
+#### Suppressing UTF-8 Text Output
+
+In case of assertion failures, googletest prints expected and actual values of
+type `string` both as hex-encoded strings as well as in readable UTF-8 text if
+they contain valid non-ASCII UTF-8 characters. If you want to suppress the UTF-8
+text because, for example, you don't have an UTF-8 compatible output medium, run
+the test program with `--gtest_print_utf8=0` or set the `GTEST_PRINT_UTF8`
+environment variable to `0`.
+
+
+
+#### Generating an XML Report
+
+googletest can emit a detailed XML report to a file in addition to its normal
+textual output. The report contains the duration of each test, and thus can help
+you identify slow tests. The report is also used by the http://unittest
+dashboard to show per-test-method error messages.
+
+To generate the XML report, set the `GTEST_OUTPUT` environment variable or the
+`--gtest_output` flag to the string `"xml:path_to_output_file"`, which will
+create the file at the given location. You can also just use the string `"xml"`,
+in which case the output can be found in the `test_detail.xml` file in the
+current directory.
+
+If you specify a directory (for example, `"xml:output/directory/"` on Linux or
+`"xml:output\directory\"` on Windows), googletest will create the XML file in
+that directory, named after the test executable (e.g. `foo_test.xml` for test
+program `foo_test` or `foo_test.exe`). If the file already exists (perhaps left
+over from a previous run), googletest will pick a different name (e.g.
+`foo_test_1.xml`) to avoid overwriting it.
+
+The report is based on the `junitreport` Ant task. Since that format was
+originally intended for Java, a little interpretation is required to make it
+apply to googletest tests, as shown here:
+
+```xml
+<testsuites name="AllTests" ...>
+  <testsuite name="test_case_name" ...>
+    <testcase    name="test_name" ...>
+      <failure message="..."/>
+      <failure message="..."/>
+      <failure message="..."/>
+    </testcase>
+  </testsuite>
+</testsuites>
+```
+
+*   The root `<testsuites>` element corresponds to the entire test program.
+*   `<testsuite>` elements correspond to googletest test suites.
+*   `<testcase>` elements correspond to googletest test functions.
+
+For instance, the following program
+
+```c++
+TEST(MathTest, Addition) { ... }
+TEST(MathTest, Subtraction) { ... }
+TEST(LogicTest, NonContradiction) { ... }
+```
+
+could generate this report:
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<testsuites tests="3" failures="1" errors="0" time="0.035" timestamp="2011-10-31T18:52:42" name="AllTests">
+  <testsuite name="MathTest" tests="2" failures="1" errors="0" time="0.015">
+    <testcase name="Addition" status="run" time="0.007" classname="">
+      <failure message="Value of: add(1, 1)&#x0A;  Actual: 3&#x0A;Expected: 2" type="">...</failure>
+      <failure message="Value of: add(1, -1)&#x0A;  Actual: 1&#x0A;Expected: 0" type="">...</failure>
+    </testcase>
+    <testcase name="Subtraction" status="run" time="0.005" classname="">
+    </testcase>
+  </testsuite>
+  <testsuite name="LogicTest" tests="1" failures="0" errors="0" time="0.005">
+    <testcase name="NonContradiction" status="run" time="0.005" classname="">
+    </testcase>
+  </testsuite>
+</testsuites>
+```
+
+Things to note:
+
+*   The `tests` attribute of a `<testsuites>` or `<testsuite>` element tells how
+    many test functions the googletest program or test suite contains, while the
+    `failures` attribute tells how many of them failed.
+
+*   The `time` attribute expresses the duration of the test, test suite, or
+    entire test program in seconds.
+
+*   The `timestamp` attribute records the local date and time of the test
+    execution.
+
+*   Each `<failure>` element corresponds to a single failed googletest
+    assertion.
+
+#### Generating a JSON Report
+
+googletest can also emit a JSON report as an alternative format to XML. To
+generate the JSON report, set the `GTEST_OUTPUT` environment variable or the
+`--gtest_output` flag to the string `"json:path_to_output_file"`, which will
+create the file at the given location. You can also just use the string
+`"json"`, in which case the output can be found in the `test_detail.json` file
+in the current directory.
+
+The report format conforms to the following JSON Schema:
+
+```json
+{
+  "$schema": "http://json-schema.org/schema#",
+  "type": "object",
+  "definitions": {
+    "TestCase": {
+      "type": "object",
+      "properties": {
+        "name": { "type": "string" },
+        "tests": { "type": "integer" },
+        "failures": { "type": "integer" },
+        "disabled": { "type": "integer" },
+        "time": { "type": "string" },
+        "testsuite": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/TestInfo"
+          }
+        }
+      }
+    },
+    "TestInfo": {
+      "type": "object",
+      "properties": {
+        "name": { "type": "string" },
+        "status": {
+          "type": "string",
+          "enum": ["RUN", "NOTRUN"]
+        },
+        "time": { "type": "string" },
+        "classname": { "type": "string" },
+        "failures": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/Failure"
+          }
+        }
+      }
+    },
+    "Failure": {
+      "type": "object",
+      "properties": {
+        "failures": { "type": "string" },
+        "type": { "type": "string" }
+      }
+    }
+  },
+  "properties": {
+    "tests": { "type": "integer" },
+    "failures": { "type": "integer" },
+    "disabled": { "type": "integer" },
+    "errors": { "type": "integer" },
+    "timestamp": {
+      "type": "string",
+      "format": "date-time"
+    },
+    "time": { "type": "string" },
+    "name": { "type": "string" },
+    "testsuites": {
+      "type": "array",
+      "items": {
+        "$ref": "#/definitions/TestCase"
+      }
+    }
+  }
+}
+```
+
+The report uses the format that conforms to the following Proto3 using the
+[JSON encoding](https://developers.google.com/protocol-buffers/docs/proto3#json):
+
+```proto
+syntax = "proto3";
+
+package googletest;
+
+import "google/protobuf/timestamp.proto";
+import "google/protobuf/duration.proto";
+
+message UnitTest {
+  int32 tests = 1;
+  int32 failures = 2;
+  int32 disabled = 3;
+  int32 errors = 4;
+  google.protobuf.Timestamp timestamp = 5;
+  google.protobuf.Duration time = 6;
+  string name = 7;
+  repeated TestCase testsuites = 8;
+}
+
+message TestCase {
+  string name = 1;
+  int32 tests = 2;
+  int32 failures = 3;
+  int32 disabled = 4;
+  int32 errors = 5;
+  google.protobuf.Duration time = 6;
+  repeated TestInfo testsuite = 7;
+}
+
+message TestInfo {
+  string name = 1;
+  enum Status {
+    RUN = 0;
+    NOTRUN = 1;
+  }
+  Status status = 2;
+  google.protobuf.Duration time = 3;
+  string classname = 4;
+  message Failure {
+    string failures = 1;
+    string type = 2;
+  }
+  repeated Failure failures = 5;
+}
+```
+
+For instance, the following program
+
+```c++
+TEST(MathTest, Addition) { ... }
+TEST(MathTest, Subtraction) { ... }
+TEST(LogicTest, NonContradiction) { ... }
+```
+
+could generate this report:
+
+```json
+{
+  "tests": 3,
+  "failures": 1,
+  "errors": 0,
+  "time": "0.035s",
+  "timestamp": "2011-10-31T18:52:42Z",
+  "name": "AllTests",
+  "testsuites": [
+    {
+      "name": "MathTest",
+      "tests": 2,
+      "failures": 1,
+      "errors": 0,
+      "time": "0.015s",
+      "testsuite": [
+        {
+          "name": "Addition",
+          "status": "RUN",
+          "time": "0.007s",
+          "classname": "",
+          "failures": [
+            {
+              "message": "Value of: add(1, 1)\n  Actual: 3\nExpected: 2",
+              "type": ""
+            },
+            {
+              "message": "Value of: add(1, -1)\n  Actual: 1\nExpected: 0",
+              "type": ""
+            }
+          ]
+        },
+        {
+          "name": "Subtraction",
+          "status": "RUN",
+          "time": "0.005s",
+          "classname": ""
+        }
+      ]
+    },
+    {
+      "name": "LogicTest",
+      "tests": 1,
+      "failures": 0,
+      "errors": 0,
+      "time": "0.005s",
+      "testsuite": [
+        {
+          "name": "NonContradiction",
+          "status": "RUN",
+          "time": "0.005s",
+          "classname": ""
+        }
+      ]
+    }
+  ]
+}
+```
+
+IMPORTANT: The exact format of the JSON document is subject to change.
+
+### Controlling How Failures Are Reported
+
+#### Turning Assertion Failures into Break-Points
+
+When running test programs under a debugger, it's very convenient if the
+debugger can catch an assertion failure and automatically drop into interactive
+mode. googletest's *break-on-failure* mode supports this behavior.
+
+To enable it, set the `GTEST_BREAK_ON_FAILURE` environment variable to a value
+other than `0`. Alternatively, you can use the `--gtest_break_on_failure`
+command line flag.
+
+#### Disabling Catching Test-Thrown Exceptions
+
+googletest can be used either with or without exceptions enabled. If a test
+throws a C++ exception or (on Windows) a structured exception (SEH), by default
+googletest catches it, reports it as a test failure, and continues with the next
+test method. This maximizes the coverage of a test run. Also, on Windows an
+uncaught exception will cause a pop-up window, so catching the exceptions allows
+you to run the tests automatically.
+
+When debugging the test failures, however, you may instead want the exceptions
+to be handled by the debugger, such that you can examine the call stack when an
+exception is thrown. To achieve that, set the `GTEST_CATCH_EXCEPTIONS`
+environment variable to `0`, or use the `--gtest_catch_exceptions=0` flag when
+running the tests.
diff --git a/3rdparty/gtest/docs/faq.md b/3rdparty/gtest/docs/faq.md
new file mode 100644
index 0000000..960a827
--- /dev/null
+++ b/3rdparty/gtest/docs/faq.md
@@ -0,0 +1,753 @@
+# Googletest FAQ
+
+<!-- GOOGLETEST_CM0014 DO NOT DELETE -->
+
+## Why should test suite names and test names not contain underscore?
+
+Underscore (`_`) is special, as C++ reserves the following to be used by the
+compiler and the standard library:
+
+1.  any identifier that starts with an `_` followed by an upper-case letter, and
+2.  any identifier that contains two consecutive underscores (i.e. `__`)
+    *anywhere* in its name.
+
+User code is *prohibited* from using such identifiers.
+
+Now let's look at what this means for `TEST` and `TEST_F`.
+
+Currently `TEST(TestSuiteName, TestName)` generates a class named
+`TestSuiteName_TestName_Test`. What happens if `TestSuiteName` or `TestName`
+contains `_`?
+
+1.  If `TestSuiteName` starts with an `_` followed by an upper-case letter (say,
+    `_Foo`), we end up with `_Foo_TestName_Test`, which is reserved and thus
+    invalid.
+2.  If `TestSuiteName` ends with an `_` (say, `Foo_`), we get
+    `Foo__TestName_Test`, which is invalid.
+3.  If `TestName` starts with an `_` (say, `_Bar`), we get
+    `TestSuiteName__Bar_Test`, which is invalid.
+4.  If `TestName` ends with an `_` (say, `Bar_`), we get
+    `TestSuiteName_Bar__Test`, which is invalid.
+
+So clearly `TestSuiteName` and `TestName` cannot start or end with `_`
+(Actually, `TestSuiteName` can start with `_` -- as long as the `_` isn't
+followed by an upper-case letter. But that's getting complicated. So for
+simplicity we just say that it cannot start with `_`.).
+
+It may seem fine for `TestSuiteName` and `TestName` to contain `_` in the
+middle. However, consider this:
+
+```c++
+TEST(Time, Flies_Like_An_Arrow) { ... }
+TEST(Time_Flies, Like_An_Arrow) { ... }
+```
+
+Now, the two `TEST`s will both generate the same class
+(`Time_Flies_Like_An_Arrow_Test`). That's not good.
+
+So for simplicity, we just ask the users to avoid `_` in `TestSuiteName` and
+`TestName`. The rule is more constraining than necessary, but it's simple and
+easy to remember. It also gives googletest some wiggle room in case its
+implementation needs to change in the future.
+
+If you violate the rule, there may not be immediate consequences, but your test
+may (just may) break with a new compiler (or a new version of the compiler you
+are using) or with a new version of googletest. Therefore it's best to follow
+the rule.
+
+## Why does googletest support `EXPECT_EQ(NULL, ptr)` and `ASSERT_EQ(NULL, ptr)` but not `EXPECT_NE(NULL, ptr)` and `ASSERT_NE(NULL, ptr)`?
+
+First of all you can use `EXPECT_NE(nullptr, ptr)` and `ASSERT_NE(nullptr,
+ptr)`. This is the preferred syntax in the style guide because nullptr does not
+have the type problems that NULL does. Which is why NULL does not work.
+
+Due to some peculiarity of C++, it requires some non-trivial template meta
+programming tricks to support using `NULL` as an argument of the `EXPECT_XX()`
+and `ASSERT_XX()` macros. Therefore we only do it where it's most needed
+(otherwise we make the implementation of googletest harder to maintain and more
+error-prone than necessary).
+
+The `EXPECT_EQ()` macro takes the *expected* value as its first argument and the
+*actual* value as the second. It's reasonable that someone wants to write
+`EXPECT_EQ(NULL, some_expression)`, and this indeed was requested several times.
+Therefore we implemented it.
+
+The need for `EXPECT_NE(NULL, ptr)` isn't nearly as strong. When the assertion
+fails, you already know that `ptr` must be `NULL`, so it doesn't add any
+information to print `ptr` in this case. That means `EXPECT_TRUE(ptr != NULL)`
+works just as well.
+
+If we were to support `EXPECT_NE(NULL, ptr)`, for consistency we'll have to
+support `EXPECT_NE(ptr, NULL)` as well, as unlike `EXPECT_EQ`, we don't have a
+convention on the order of the two arguments for `EXPECT_NE`. This means using
+the template meta programming tricks twice in the implementation, making it even
+harder to understand and maintain. We believe the benefit doesn't justify the
+cost.
+
+Finally, with the growth of the gMock matcher library, we are encouraging people
+to use the unified `EXPECT_THAT(value, matcher)` syntax more often in tests. One
+significant advantage of the matcher approach is that matchers can be easily
+combined to form new matchers, while the `EXPECT_NE`, etc, macros cannot be
+easily combined. Therefore we want to invest more in the matchers than in the
+`EXPECT_XX()` macros.
+
+## I need to test that different implementations of an interface satisfy some common requirements. Should I use typed tests or value-parameterized tests?
+
+For testing various implementations of the same interface, either typed tests or
+value-parameterized tests can get it done. It's really up to you the user to
+decide which is more convenient for you, depending on your particular case. Some
+rough guidelines:
+
+*   Typed tests can be easier to write if instances of the different
+    implementations can be created the same way, modulo the type. For example,
+    if all these implementations have a public default constructor (such that
+    you can write `new TypeParam`), or if their factory functions have the same
+    form (e.g. `CreateInstance<TypeParam>()`).
+*   Value-parameterized tests can be easier to write if you need different code
+    patterns to create different implementations' instances, e.g. `new Foo` vs
+    `new Bar(5)`. To accommodate for the differences, you can write factory
+    function wrappers and pass these function pointers to the tests as their
+    parameters.
+*   When a typed test fails, the default output includes the name of the type,
+    which can help you quickly identify which implementation is wrong.
+    Value-parameterized tests only show the number of the failed iteration by
+    default. You will need to define a function that returns the iteration name
+    and pass it as the third parameter to INSTANTIATE_TEST_SUITE_P to have more
+    useful output.
+*   When using typed tests, you need to make sure you are testing against the
+    interface type, not the concrete types (in other words, you want to make
+    sure `implicit_cast<MyInterface*>(my_concrete_impl)` works, not just that
+    `my_concrete_impl` works). It's less likely to make mistakes in this area
+    when using value-parameterized tests.
+
+I hope I didn't confuse you more. :-) If you don't mind, I'd suggest you to give
+both approaches a try. Practice is a much better way to grasp the subtle
+differences between the two tools. Once you have some concrete experience, you
+can much more easily decide which one to use the next time.
+
+## I got some run-time errors about invalid proto descriptors when using `ProtocolMessageEquals`. Help!
+
+**Note:** `ProtocolMessageEquals` and `ProtocolMessageEquiv` are *deprecated*
+now. Please use `EqualsProto`, etc instead.
+
+`ProtocolMessageEquals` and `ProtocolMessageEquiv` were redefined recently and
+are now less tolerant of invalid protocol buffer definitions. In particular, if
+you have a `foo.proto` that doesn't fully qualify the type of a protocol message
+it references (e.g. `message<Bar>` where it should be `message<blah.Bar>`), you
+will now get run-time errors like:
+
+```
+... descriptor.cc:...] Invalid proto descriptor for file "path/to/foo.proto":
+... descriptor.cc:...]  blah.MyMessage.my_field: ".Bar" is not defined.
+```
+
+If you see this, your `.proto` file is broken and needs to be fixed by making
+the types fully qualified. The new definition of `ProtocolMessageEquals` and
+`ProtocolMessageEquiv` just happen to reveal your bug.
+
+## My death test modifies some state, but the change seems lost after the death test finishes. Why?
+
+Death tests (`EXPECT_DEATH`, etc) are executed in a sub-process s.t. the
+expected crash won't kill the test program (i.e. the parent process). As a
+result, any in-memory side effects they incur are observable in their respective
+sub-processes, but not in the parent process. You can think of them as running
+in a parallel universe, more or less.
+
+In particular, if you use mocking and the death test statement invokes some mock
+methods, the parent process will think the calls have never occurred. Therefore,
+you may want to move your `EXPECT_CALL` statements inside the `EXPECT_DEATH`
+macro.
+
+## EXPECT_EQ(htonl(blah), blah_blah) generates weird compiler errors in opt mode. Is this a googletest bug?
+
+Actually, the bug is in `htonl()`.
+
+According to `'man htonl'`, `htonl()` is a *function*, which means it's valid to
+use `htonl` as a function pointer. However, in opt mode `htonl()` is defined as
+a *macro*, which breaks this usage.
+
+Worse, the macro definition of `htonl()` uses a `gcc` extension and is *not*
+standard C++. That hacky implementation has some ad hoc limitations. In
+particular, it prevents you from writing `Foo<sizeof(htonl(x))>()`, where `Foo`
+is a template that has an integral argument.
+
+The implementation of `EXPECT_EQ(a, b)` uses `sizeof(... a ...)` inside a
+template argument, and thus doesn't compile in opt mode when `a` contains a call
+to `htonl()`. It is difficult to make `EXPECT_EQ` bypass the `htonl()` bug, as
+the solution must work with different compilers on various platforms.
+
+`htonl()` has some other problems as described in `//util/endian/endian.h`,
+which defines `ghtonl()` to replace it. `ghtonl()` does the same thing `htonl()`
+does, only without its problems. We suggest you to use `ghtonl()` instead of
+`htonl()`, both in your tests and production code.
+
+`//util/endian/endian.h` also defines `ghtons()`, which solves similar problems
+in `htons()`.
+
+Don't forget to add `//util/endian` to the list of dependencies in the `BUILD`
+file wherever `ghtonl()` and `ghtons()` are used. The library consists of a
+single header file and will not bloat your binary.
+
+## The compiler complains about "undefined references" to some static const member variables, but I did define them in the class body. What's wrong?
+
+If your class has a static data member:
+
+```c++
+// foo.h
+class Foo {
+  ...
+  static const int kBar = 100;
+};
+```
+
+You also need to define it *outside* of the class body in `foo.cc`:
+
+```c++
+const int Foo::kBar;  // No initializer here.
+```
+
+Otherwise your code is **invalid C++**, and may break in unexpected ways. In
+particular, using it in googletest comparison assertions (`EXPECT_EQ`, etc) will
+generate an "undefined reference" linker error. The fact that "it used to work"
+doesn't mean it's valid. It just means that you were lucky. :-)
+
+## Can I derive a test fixture from another?
+
+Yes.
+
+Each test fixture has a corresponding and same named test suite. This means only
+one test suite can use a particular fixture. Sometimes, however, multiple test
+cases may want to use the same or slightly different fixtures. For example, you
+may want to make sure that all of a GUI library's test suites don't leak
+important system resources like fonts and brushes.
+
+In googletest, you share a fixture among test suites by putting the shared logic
+in a base test fixture, then deriving from that base a separate fixture for each
+test suite that wants to use this common logic. You then use `TEST_F()` to write
+tests using each derived fixture.
+
+Typically, your code looks like this:
+
+```c++
+// Defines a base test fixture.
+class BaseTest : public ::testing::Test {
+ protected:
+  ...
+};
+
+// Derives a fixture FooTest from BaseTest.
+class FooTest : public BaseTest {
+ protected:
+  void SetUp() override {
+    BaseTest::SetUp();  // Sets up the base fixture first.
+    ... additional set-up work ...
+  }
+
+  void TearDown() override {
+    ... clean-up work for FooTest ...
+    BaseTest::TearDown();  // Remember to tear down the base fixture
+                           // after cleaning up FooTest!
+  }
+
+  ... functions and variables for FooTest ...
+};
+
+// Tests that use the fixture FooTest.
+TEST_F(FooTest, Bar) { ... }
+TEST_F(FooTest, Baz) { ... }
+
+... additional fixtures derived from BaseTest ...
+```
+
+If necessary, you can continue to derive test fixtures from a derived fixture.
+googletest has no limit on how deep the hierarchy can be.
+
+For a complete example using derived test fixtures, see
+[sample5_unittest.cc](../samples/sample5_unittest.cc).
+
+## My compiler complains "void value not ignored as it ought to be." What does this mean?
+
+You're probably using an `ASSERT_*()` in a function that doesn't return `void`.
+`ASSERT_*()` can only be used in `void` functions, due to exceptions being
+disabled by our build system. Please see more details
+[here](advanced.md#assertion-placement).
+
+## My death test hangs (or seg-faults). How do I fix it?
+
+In googletest, death tests are run in a child process and the way they work is
+delicate. To write death tests you really need to understand how they work.
+Please make sure you have read [this](advanced.md#how-it-works).
+
+In particular, death tests don't like having multiple threads in the parent
+process. So the first thing you can try is to eliminate creating threads outside
+of `EXPECT_DEATH()`. For example, you may want to use mocks or fake objects
+instead of real ones in your tests.
+
+Sometimes this is impossible as some library you must use may be creating
+threads before `main()` is even reached. In this case, you can try to minimize
+the chance of conflicts by either moving as many activities as possible inside
+`EXPECT_DEATH()` (in the extreme case, you want to move everything inside), or
+leaving as few things as possible in it. Also, you can try to set the death test
+style to `"threadsafe"`, which is safer but slower, and see if it helps.
+
+If you go with thread-safe death tests, remember that they rerun the test
+program from the beginning in the child process. Therefore make sure your
+program can run side-by-side with itself and is deterministic.
+
+In the end, this boils down to good concurrent programming. You have to make
+sure that there is no race conditions or dead locks in your program. No silver
+bullet - sorry!
+
+## Should I use the constructor/destructor of the test fixture or SetUp()/TearDown()? {#CtorVsSetUp}
+
+The first thing to remember is that googletest does **not** reuse the same test
+fixture object across multiple tests. For each `TEST_F`, googletest will create
+a **fresh** test fixture object, immediately call `SetUp()`, run the test body,
+call `TearDown()`, and then delete the test fixture object.
+
+When you need to write per-test set-up and tear-down logic, you have the choice
+between using the test fixture constructor/destructor or `SetUp()/TearDown()`.
+The former is usually preferred, as it has the following benefits:
+
+*   By initializing a member variable in the constructor, we have the option to
+    make it `const`, which helps prevent accidental changes to its value and
+    makes the tests more obviously correct.
+*   In case we need to subclass the test fixture class, the subclass'
+    constructor is guaranteed to call the base class' constructor *first*, and
+    the subclass' destructor is guaranteed to call the base class' destructor
+    *afterward*. With `SetUp()/TearDown()`, a subclass may make the mistake of
+    forgetting to call the base class' `SetUp()/TearDown()` or call them at the
+    wrong time.
+
+You may still want to use `SetUp()/TearDown()` in the following cases:
+
+*   C++ does not allow virtual function calls in constructors and destructors.
+    You can call a method declared as virtual, but it will not use dynamic
+    dispatch, it will use the definition from the class the constructor of which
+    is currently executing. This is because calling a virtual method before the
+    derived class constructor has a chance to run is very dangerous - the
+    virtual method might operate on uninitialized data. Therefore, if you need
+    to call a method that will be overridden in a derived class, you have to use
+    `SetUp()/TearDown()`.
+*   In the body of a constructor (or destructor), it's not possible to use the
+    `ASSERT_xx` macros. Therefore, if the set-up operation could cause a fatal
+    test failure that should prevent the test from running, it's necessary to
+    use `abort` <!-- GOOGLETEST_CM0015 DO NOT DELETE --> and abort the whole test executable,
+    or to use `SetUp()` instead of a constructor.
+*   If the tear-down operation could throw an exception, you must use
+    `TearDown()` as opposed to the destructor, as throwing in a destructor leads
+    to undefined behavior and usually will kill your program right away. Note
+    that many standard libraries (like STL) may throw when exceptions are
+    enabled in the compiler. Therefore you should prefer `TearDown()` if you
+    want to write portable tests that work with or without exceptions.
+*   The googletest team is considering making the assertion macros throw on
+    platforms where exceptions are enabled (e.g. Windows, Mac OS, and Linux
+    client-side), which will eliminate the need for the user to propagate
+    failures from a subroutine to its caller. Therefore, you shouldn't use
+    googletest assertions in a destructor if your code could run on such a
+    platform.
+
+## The compiler complains "no matching function to call" when I use ASSERT_PRED*. How do I fix it?
+
+If the predicate function you use in `ASSERT_PRED*` or `EXPECT_PRED*` is
+overloaded or a template, the compiler will have trouble figuring out which
+overloaded version it should use. `ASSERT_PRED_FORMAT*` and
+`EXPECT_PRED_FORMAT*` don't have this problem.
+
+If you see this error, you might want to switch to
+`(ASSERT|EXPECT)_PRED_FORMAT*`, which will also give you a better failure
+message. If, however, that is not an option, you can resolve the problem by
+explicitly telling the compiler which version to pick.
+
+For example, suppose you have
+
+```c++
+bool IsPositive(int n) {
+  return n > 0;
+}
+
+bool IsPositive(double x) {
+  return x > 0;
+}
+```
+
+you will get a compiler error if you write
+
+```c++
+EXPECT_PRED1(IsPositive, 5);
+```
+
+However, this will work:
+
+```c++
+EXPECT_PRED1(static_cast<bool (*)(int)>(IsPositive), 5);
+```
+
+(The stuff inside the angled brackets for the `static_cast` operator is the type
+of the function pointer for the `int`-version of `IsPositive()`.)
+
+As another example, when you have a template function
+
+```c++
+template <typename T>
+bool IsNegative(T x) {
+  return x < 0;
+}
+```
+
+you can use it in a predicate assertion like this:
+
+```c++
+ASSERT_PRED1(IsNegative<int>, -5);
+```
+
+Things are more interesting if your template has more than one parameters. The
+following won't compile:
+
+```c++
+ASSERT_PRED2(GreaterThan<int, int>, 5, 0);
+```
+
+as the C++ pre-processor thinks you are giving `ASSERT_PRED2` 4 arguments, which
+is one more than expected. The workaround is to wrap the predicate function in
+parentheses:
+
+```c++
+ASSERT_PRED2((GreaterThan<int, int>), 5, 0);
+```
+
+## My compiler complains about "ignoring return value" when I call RUN_ALL_TESTS(). Why?
+
+Some people had been ignoring the return value of `RUN_ALL_TESTS()`. That is,
+instead of
+
+```c++
+  return RUN_ALL_TESTS();
+```
+
+they write
+
+```c++
+  RUN_ALL_TESTS();
+```
+
+This is **wrong and dangerous**. The testing services needs to see the return
+value of `RUN_ALL_TESTS()` in order to determine if a test has passed. If your
+`main()` function ignores it, your test will be considered successful even if it
+has a googletest assertion failure. Very bad.
+
+We have decided to fix this (thanks to Michael Chastain for the idea). Now, your
+code will no longer be able to ignore `RUN_ALL_TESTS()` when compiled with
+`gcc`. If you do so, you'll get a compiler error.
+
+If you see the compiler complaining about you ignoring the return value of
+`RUN_ALL_TESTS()`, the fix is simple: just make sure its value is used as the
+return value of `main()`.
+
+But how could we introduce a change that breaks existing tests? Well, in this
+case, the code was already broken in the first place, so we didn't break it. :-)
+
+## My compiler complains that a constructor (or destructor) cannot return a value. What's going on?
+
+Due to a peculiarity of C++, in order to support the syntax for streaming
+messages to an `ASSERT_*`, e.g.
+
+```c++
+  ASSERT_EQ(1, Foo()) << "blah blah" << foo;
+```
+
+we had to give up using `ASSERT*` and `FAIL*` (but not `EXPECT*` and
+`ADD_FAILURE*`) in constructors and destructors. The workaround is to move the
+content of your constructor/destructor to a private void member function, or
+switch to `EXPECT_*()` if that works. This
+[section](advanced.md#assertion-placement) in the user's guide explains it.
+
+## My SetUp() function is not called. Why?
+
+C++ is case-sensitive. Did you spell it as `Setup()`?
+
+Similarly, sometimes people spell `SetUpTestSuite()` as `SetupTestSuite()` and
+wonder why it's never called.
+
+
+## I have several test suites which share the same test fixture logic, do I have to define a new test fixture class for each of them? This seems pretty tedious.
+
+You don't have to. Instead of
+
+```c++
+class FooTest : public BaseTest {};
+
+TEST_F(FooTest, Abc) { ... }
+TEST_F(FooTest, Def) { ... }
+
+class BarTest : public BaseTest {};
+
+TEST_F(BarTest, Abc) { ... }
+TEST_F(BarTest, Def) { ... }
+```
+
+you can simply `typedef` the test fixtures:
+
+```c++
+typedef BaseTest FooTest;
+
+TEST_F(FooTest, Abc) { ... }
+TEST_F(FooTest, Def) { ... }
+
+typedef BaseTest BarTest;
+
+TEST_F(BarTest, Abc) { ... }
+TEST_F(BarTest, Def) { ... }
+```
+
+## googletest output is buried in a whole bunch of LOG messages. What do I do?
+
+The googletest output is meant to be a concise and human-friendly report. If
+your test generates textual output itself, it will mix with the googletest
+output, making it hard to read. However, there is an easy solution to this
+problem.
+
+Since `LOG` messages go to stderr, we decided to let googletest output go to
+stdout. This way, you can easily separate the two using redirection. For
+example:
+
+```shell
+$ ./my_test > gtest_output.txt
+```
+
+## Why should I prefer test fixtures over global variables?
+
+There are several good reasons:
+
+1.  It's likely your test needs to change the states of its global variables.
+    This makes it difficult to keep side effects from escaping one test and
+    contaminating others, making debugging difficult. By using fixtures, each
+    test has a fresh set of variables that's different (but with the same
+    names). Thus, tests are kept independent of each other.
+2.  Global variables pollute the global namespace.
+3.  Test fixtures can be reused via subclassing, which cannot be done easily
+    with global variables. This is useful if many test suites have something in
+    common.
+
+## What can the statement argument in ASSERT_DEATH() be?
+
+`ASSERT_DEATH(*statement*, *regex*)` (or any death assertion macro) can be used
+wherever `*statement*` is valid. So basically `*statement*` can be any C++
+statement that makes sense in the current context. In particular, it can
+reference global and/or local variables, and can be:
+
+*   a simple function call (often the case),
+*   a complex expression, or
+*   a compound statement.
+
+Some examples are shown here:
+
+```c++
+// A death test can be a simple function call.
+TEST(MyDeathTest, FunctionCall) {
+  ASSERT_DEATH(Xyz(5), "Xyz failed");
+}
+
+// Or a complex expression that references variables and functions.
+TEST(MyDeathTest, ComplexExpression) {
+  const bool c = Condition();
+  ASSERT_DEATH((c ? Func1(0) : object2.Method("test")),
+               "(Func1|Method) failed");
+}
+
+// Death assertions can be used any where in a function.  In
+// particular, they can be inside a loop.
+TEST(MyDeathTest, InsideLoop) {
+  // Verifies that Foo(0), Foo(1), ..., and Foo(4) all die.
+  for (int i = 0; i < 5; i++) {
+    EXPECT_DEATH_M(Foo(i), "Foo has \\d+ errors",
+                   ::testing::Message() << "where i is " << i);
+  }
+}
+
+// A death assertion can contain a compound statement.
+TEST(MyDeathTest, CompoundStatement) {
+  // Verifies that at lease one of Bar(0), Bar(1), ..., and
+  // Bar(4) dies.
+  ASSERT_DEATH({
+    for (int i = 0; i < 5; i++) {
+      Bar(i);
+    }
+  },
+  "Bar has \\d+ errors");
+}
+```
+
+gtest-death-test_test.cc contains more examples if you are interested.
+
+## I have a fixture class `FooTest`, but `TEST_F(FooTest, Bar)` gives me error ``"no matching function for call to `FooTest::FooTest()'"``. Why?
+
+Googletest needs to be able to create objects of your test fixture class, so it
+must have a default constructor. Normally the compiler will define one for you.
+However, there are cases where you have to define your own:
+
+*   If you explicitly declare a non-default constructor for class `FooTest`
+    (`DISALLOW_EVIL_CONSTRUCTORS()` does this), then you need to define a
+    default constructor, even if it would be empty.
+*   If `FooTest` has a const non-static data member, then you have to define the
+    default constructor *and* initialize the const member in the initializer
+    list of the constructor. (Early versions of `gcc` doesn't force you to
+    initialize the const member. It's a bug that has been fixed in `gcc 4`.)
+
+## Why does ASSERT_DEATH complain about previous threads that were already joined?
+
+With the Linux pthread library, there is no turning back once you cross the line
+from single thread to multiple threads. The first time you create a thread, a
+manager thread is created in addition, so you get 3, not 2, threads. Later when
+the thread you create joins the main thread, the thread count decrements by 1,
+but the manager thread will never be killed, so you still have 2 threads, which
+means you cannot safely run a death test.
+
+The new NPTL thread library doesn't suffer from this problem, as it doesn't
+create a manager thread. However, if you don't control which machine your test
+runs on, you shouldn't depend on this.
+
+## Why does googletest require the entire test suite, instead of individual tests, to be named *DeathTest when it uses ASSERT_DEATH?
+
+googletest does not interleave tests from different test suites. That is, it
+runs all tests in one test suite first, and then runs all tests in the next test
+suite, and so on. googletest does this because it needs to set up a test suite
+before the first test in it is run, and tear it down afterwords. Splitting up
+the test case would require multiple set-up and tear-down processes, which is
+inefficient and makes the semantics unclean.
+
+If we were to determine the order of tests based on test name instead of test
+case name, then we would have a problem with the following situation:
+
+```c++
+TEST_F(FooTest, AbcDeathTest) { ... }
+TEST_F(FooTest, Uvw) { ... }
+
+TEST_F(BarTest, DefDeathTest) { ... }
+TEST_F(BarTest, Xyz) { ... }
+```
+
+Since `FooTest.AbcDeathTest` needs to run before `BarTest.Xyz`, and we don't
+interleave tests from different test suites, we need to run all tests in the
+`FooTest` case before running any test in the `BarTest` case. This contradicts
+with the requirement to run `BarTest.DefDeathTest` before `FooTest.Uvw`.
+
+## But I don't like calling my entire test suite \*DeathTest when it contains both death tests and non-death tests. What do I do?
+
+You don't have to, but if you like, you may split up the test suite into
+`FooTest` and `FooDeathTest`, where the names make it clear that they are
+related:
+
+```c++
+class FooTest : public ::testing::Test { ... };
+
+TEST_F(FooTest, Abc) { ... }
+TEST_F(FooTest, Def) { ... }
+
+using FooDeathTest = FooTest;
+
+TEST_F(FooDeathTest, Uvw) { ... EXPECT_DEATH(...) ... }
+TEST_F(FooDeathTest, Xyz) { ... ASSERT_DEATH(...) ... }
+```
+
+## googletest prints the LOG messages in a death test's child process only when the test fails. How can I see the LOG messages when the death test succeeds?
+
+Printing the LOG messages generated by the statement inside `EXPECT_DEATH()`
+makes it harder to search for real problems in the parent's log. Therefore,
+googletest only prints them when the death test has failed.
+
+If you really need to see such LOG messages, a workaround is to temporarily
+break the death test (e.g. by changing the regex pattern it is expected to
+match). Admittedly, this is a hack. We'll consider a more permanent solution
+after the fork-and-exec-style death tests are implemented.
+
+## The compiler complains about "no match for 'operator<<'" when I use an assertion. What gives?
+
+If you use a user-defined type `FooType` in an assertion, you must make sure
+there is an `std::ostream& operator<<(std::ostream&, const FooType&)` function
+defined such that we can print a value of `FooType`.
+
+In addition, if `FooType` is declared in a name space, the `<<` operator also
+needs to be defined in the *same* name space. See https://abseil.io/tips/49 for details.
+
+## How do I suppress the memory leak messages on Windows?
+
+Since the statically initialized googletest singleton requires allocations on
+the heap, the Visual C++ memory leak detector will report memory leaks at the
+end of the program run. The easiest way to avoid this is to use the
+`_CrtMemCheckpoint` and `_CrtMemDumpAllObjectsSince` calls to not report any
+statically initialized heap objects. See MSDN for more details and additional
+heap check/debug routines.
+
+## How can my code detect if it is running in a test?
+
+If you write code that sniffs whether it's running in a test and does different
+things accordingly, you are leaking test-only logic into production code and
+there is no easy way to ensure that the test-only code paths aren't run by
+mistake in production. Such cleverness also leads to
+[Heisenbugs](https://en.wikipedia.org/wiki/Heisenbug). Therefore we strongly
+advise against the practice, and googletest doesn't provide a way to do it.
+
+In general, the recommended way to cause the code to behave differently under
+test is [Dependency Injection](https://en.wikipedia.org/wiki/Dependency_injection). You can inject
+different functionality from the test and from the production code. Since your
+production code doesn't link in the for-test logic at all (the
+[`testonly`](https://docs.bazel.build/versions/master/be/common-definitions.html#common.testonly) attribute for BUILD targets helps to ensure
+that), there is no danger in accidentally running it.
+
+However, if you *really*, *really*, *really* have no choice, and if you follow
+the rule of ending your test program names with `_test`, you can use the
+*horrible* hack of sniffing your executable name (`argv[0]` in `main()`) to know
+whether the code is under test.
+
+## How do I temporarily disable a test?
+
+If you have a broken test that you cannot fix right away, you can add the
+DISABLED_ prefix to its name. This will exclude it from execution. This is
+better than commenting out the code or using #if 0, as disabled tests are still
+compiled (and thus won't rot).
+
+To include disabled tests in test execution, just invoke the test program with
+the --gtest_also_run_disabled_tests flag.
+
+## Is it OK if I have two separate `TEST(Foo, Bar)` test methods defined in different namespaces?
+
+Yes.
+
+The rule is **all test methods in the same test suite must use the same fixture
+class.** This means that the following is **allowed** because both tests use the
+same fixture class (`::testing::Test`).
+
+```c++
+namespace foo {
+TEST(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace foo
+
+namespace bar {
+TEST(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace bar
+```
+
+However, the following code is **not allowed** and will produce a runtime error
+from googletest because the test methods are using different test fixture
+classes with the same test suite name.
+
+```c++
+namespace foo {
+class CoolTest : public ::testing::Test {};  // Fixture foo::CoolTest
+TEST_F(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace foo
+
+namespace bar {
+class CoolTest : public ::testing::Test {};  // Fixture: bar::CoolTest
+TEST_F(CoolTest, DoSomething) {
+  SUCCEED();
+}
+}  // namespace bar
+```
diff --git a/3rdparty/gtest/docs/pkgconfig.md b/3rdparty/gtest/docs/pkgconfig.md
new file mode 100644
index 0000000..6dc0673
--- /dev/null
+++ b/3rdparty/gtest/docs/pkgconfig.md
@@ -0,0 +1,141 @@
+## Using GoogleTest from various build systems
+
+GoogleTest comes with pkg-config files that can be used to determine all
+necessary flags for compiling and linking to GoogleTest (and GoogleMock).
+Pkg-config is a standardised plain-text format containing
+
+*   the includedir (-I) path
+*   necessary macro (-D) definitions
+*   further required flags (-pthread)
+*   the library (-L) path
+*   the library (-l) to link to
+
+All current build systems support pkg-config in one way or another. For all
+examples here we assume you want to compile the sample
+`samples/sample3_unittest.cc`.
+
+### CMake
+
+Using `pkg-config` in CMake is fairly easy:
+
+```cmake
+cmake_minimum_required(VERSION 3.0)
+
+cmake_policy(SET CMP0048 NEW)
+project(my_gtest_pkgconfig VERSION 0.0.1 LANGUAGES CXX)
+
+find_package(PkgConfig)
+pkg_search_module(GTEST REQUIRED gtest_main)
+
+add_executable(testapp samples/sample3_unittest.cc)
+target_link_libraries(testapp ${GTEST_LDFLAGS})
+target_compile_options(testapp PUBLIC ${GTEST_CFLAGS})
+
+include(CTest)
+add_test(first_and_only_test testapp)
+```
+
+It is generally recommended that you use `target_compile_options` + `_CFLAGS`
+over `target_include_directories` + `_INCLUDE_DIRS` as the former includes not
+just -I flags (GoogleTest might require a macro indicating to internal headers
+that all libraries have been compiled with threading enabled. In addition,
+GoogleTest might also require `-pthread` in the compiling step, and as such
+splitting the pkg-config `Cflags` variable into include dirs and macros for
+`target_compile_definitions()` might still miss this). The same recommendation
+goes for using `_LDFLAGS` over the more commonplace `_LIBRARIES`, which happens
+to discard `-L` flags and `-pthread`.
+
+### Autotools
+
+Finding GoogleTest in Autoconf and using it from Automake is also fairly easy:
+
+In your `configure.ac`:
+
+```
+AC_PREREQ([2.69])
+AC_INIT([my_gtest_pkgconfig], [0.0.1])
+AC_CONFIG_SRCDIR([samples/sample3_unittest.cc])
+AC_PROG_CXX
+
+PKG_CHECK_MODULES([GTEST], [gtest_main])
+
+AM_INIT_AUTOMAKE([foreign subdir-objects])
+AC_CONFIG_FILES([Makefile])
+AC_OUTPUT
+```
+
+and in your `Makefile.am`:
+
+```
+check_PROGRAMS = testapp
+TESTS = $(check_PROGRAMS)
+
+testapp_SOURCES = samples/sample3_unittest.cc
+testapp_CXXFLAGS = $(GTEST_CFLAGS)
+testapp_LDADD = $(GTEST_LIBS)
+```
+
+### Meson
+
+Meson natively uses pkgconfig to query dependencies:
+
+```
+project('my_gtest_pkgconfig', 'cpp', version : '0.0.1')
+
+gtest_dep = dependency('gtest_main')
+
+testapp = executable(
+  'testapp',
+  files(['samples/sample3_unittest.cc']),
+  dependencies : gtest_dep,
+  install : false)
+
+test('first_and_only_test', testapp)
+```
+
+### Plain Makefiles
+
+Since `pkg-config` is a small Unix command-line utility, it can be used in
+handwritten `Makefile`s too:
+
+```makefile
+GTEST_CFLAGS = `pkg-config --cflags gtest_main`
+GTEST_LIBS = `pkg-config --libs gtest_main`
+
+.PHONY: tests all
+
+tests: all
+  ./testapp
+
+all: testapp
+
+testapp: testapp.o
+  $(CXX) $(CXXFLAGS) $(LDFLAGS) $< -o $@ $(GTEST_LIBS)
+
+testapp.o: samples/sample3_unittest.cc
+  $(CXX) $(CPPFLAGS) $(CXXFLAGS) $< -c -o $@ $(GTEST_CFLAGS)
+```
+
+### Help! pkg-config can't find GoogleTest!
+
+Let's say you have a `CMakeLists.txt` along the lines of the one in this
+tutorial and you try to run `cmake`. It is very possible that you get a failure
+along the lines of:
+
+```
+-- Checking for one of the modules 'gtest_main'
+CMake Error at /usr/share/cmake/Modules/FindPkgConfig.cmake:640 (message):
+  None of the required 'gtest_main' found
+```
+
+These failures are common if you installed GoogleTest yourself and have not
+sourced it from a distro or other package manager. If so, you need to tell
+pkg-config where it can find the `.pc` files containing the information. Say you
+installed GoogleTest to `/usr/local`, then it might be that the `.pc` files are
+installed under `/usr/local/lib64/pkgconfig`. If you set
+
+```
+export PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig
+```
+
+pkg-config will also try to look in `PKG_CONFIG_PATH` to find `gtest_main.pc`.
diff --git a/3rdparty/gtest/docs/primer.md b/3rdparty/gtest/docs/primer.md
new file mode 100644
index 0000000..0317692
--- /dev/null
+++ b/3rdparty/gtest/docs/primer.md
@@ -0,0 +1,567 @@
+# Googletest Primer
+
+## Introduction: Why googletest?
+
+*googletest* helps you write better C++ tests.
+
+googletest is a testing framework developed by the Testing Technology team with
+Google's specific requirements and constraints in mind. Whether you work on
+Linux, Windows, or a Mac, if you write C++ code, googletest can help you. And it
+supports *any* kind of tests, not just unit tests.
+
+So what makes a good test, and how does googletest fit in? We believe:
+
+1.  Tests should be *independent* and *repeatable*. It's a pain to debug a test
+    that succeeds or fails as a result of other tests. googletest isolates the
+    tests by running each of them on a different object. When a test fails,
+    googletest allows you to run it in isolation for quick debugging.
+2.  Tests should be well *organized* and reflect the structure of the tested
+    code. googletest groups related tests into test suites that can share data
+    and subroutines. This common pattern is easy to recognize and makes tests
+    easy to maintain. Such consistency is especially helpful when people switch
+    projects and start to work on a new code base.
+3.  Tests should be *portable* and *reusable*. Google has a lot of code that is
+    platform-neutral; its tests should also be platform-neutral. googletest
+    works on different OSes, with different compilers, with or without
+    exceptions, so googletest tests can work with a variety of configurations.
+4.  When tests fail, they should provide as much *information* about the problem
+    as possible. googletest doesn't stop at the first test failure. Instead, it
+    only stops the current test and continues with the next. You can also set up
+    tests that report non-fatal failures after which the current test continues.
+    Thus, you can detect and fix multiple bugs in a single run-edit-compile
+    cycle.
+5.  The testing framework should liberate test writers from housekeeping chores
+    and let them focus on the test *content*. googletest automatically keeps
+    track of all tests defined, and doesn't require the user to enumerate them
+    in order to run them.
+6.  Tests should be *fast*. With googletest, you can reuse shared resources
+    across tests and pay for the set-up/tear-down only once, without making
+    tests depend on each other.
+
+Since googletest is based on the popular xUnit architecture, you'll feel right
+at home if you've used JUnit or PyUnit before. If not, it will take you about 10
+minutes to learn the basics and get started. So let's go!
+
+## Beware of the nomenclature
+
+_Note:_ There might be some confusion arising from different definitions of the
+terms _Test_, _Test Case_ and _Test Suite_, so beware of misunderstanding these.
+
+Historically, googletest started to use the term _Test Case_ for grouping
+related tests, whereas current publications, including International Software
+Testing Qualifications Board ([ISTQB](http://www.istqb.org/)) materials and
+various textbooks on software quality, use the term
+_[Test Suite][istqb test suite]_ for this.
+
+The related term _Test_, as it is used in googletest, corresponds to the term
+_[Test Case][istqb test case]_ of ISTQB and others.
+
+The term _Test_ is commonly of broad enough sense, including ISTQB's definition
+of _Test Case_, so it's not much of a problem here. But the term _Test Case_ as
+was used in Google Test is of contradictory sense and thus confusing.
+
+googletest recently started replacing the term _Test Case_ with _Test Suite_.
+The preferred API is *TestSuite*. The older TestCase API is being slowly
+deprecated and refactored away.
+
+So please be aware of the different definitions of the terms:
+
+<!-- mdformat off(github rendering does not support multiline tables) -->
+
+Meaning                                                                              | googletest Term         | [ISTQB](http://www.istqb.org/) Term
+:----------------------------------------------------------------------------------- | :---------------------- | :----------------------------------
+Exercise a particular program path with specific input values and verify the results | [TEST()](#simple-tests) | [Test Case][istqb test case]
+
+<!-- mdformat on -->
+
+[istqb test case]: http://glossary.istqb.org/en/search/test%20case
+[istqb test suite]: http://glossary.istqb.org/en/search/test%20suite
+
+## Basic Concepts
+
+When using googletest, you start by writing *assertions*, which are statements
+that check whether a condition is true. An assertion's result can be *success*,
+*nonfatal failure*, or *fatal failure*. If a fatal failure occurs, it aborts the
+current function; otherwise the program continues normally.
+
+*Tests* use assertions to verify the tested code's behavior. If a test crashes
+or has a failed assertion, then it *fails*; otherwise it *succeeds*.
+
+A *test suite* contains one or many tests. You should group your tests into test
+suites that reflect the structure of the tested code. When multiple tests in a
+test suite need to share common objects and subroutines, you can put them into a
+*test fixture* class.
+
+A *test program* can contain multiple test suites.
+
+We'll now explain how to write a test program, starting at the individual
+assertion level and building up to tests and test suites.
+
+## Assertions
+
+googletest assertions are macros that resemble function calls. You test a class
+or function by making assertions about its behavior. When an assertion fails,
+googletest prints the assertion's source file and line number location, along
+with a failure message. You may also supply a custom failure message which will
+be appended to googletest's message.
+
+The assertions come in pairs that test the same thing but have different effects
+on the current function. `ASSERT_*` versions generate fatal failures when they
+fail, and **abort the current function**. `EXPECT_*` versions generate nonfatal
+failures, which don't abort the current function. Usually `EXPECT_*` are
+preferred, as they allow more than one failure to be reported in a test.
+However, you should use `ASSERT_*` if it doesn't make sense to continue when the
+assertion in question fails.
+
+Since a failed `ASSERT_*` returns from the current function immediately,
+possibly skipping clean-up code that comes after it, it may cause a space leak.
+Depending on the nature of the leak, it may or may not be worth fixing - so keep
+this in mind if you get a heap checker error in addition to assertion errors.
+
+To provide a custom failure message, simply stream it into the macro using the
+`<<` operator or a sequence of such operators. An example:
+
+```c++
+ASSERT_EQ(x.size(), y.size()) << "Vectors x and y are of unequal length";
+
+for (int i = 0; i < x.size(); ++i) {
+  EXPECT_EQ(x[i], y[i]) << "Vectors x and y differ at index " << i;
+}
+```
+
+Anything that can be streamed to an `ostream` can be streamed to an assertion
+macro--in particular, C strings and `string` objects. If a wide string
+(`wchar_t*`, `TCHAR*` in `UNICODE` mode on Windows, or `std::wstring`) is
+streamed to an assertion, it will be translated to UTF-8 when printed.
+
+### Basic Assertions
+
+These assertions do basic true/false condition testing.
+
+Fatal assertion            | Nonfatal assertion         | Verifies
+-------------------------- | -------------------------- | --------------------
+`ASSERT_TRUE(condition);`  | `EXPECT_TRUE(condition);`  | `condition` is true
+`ASSERT_FALSE(condition);` | `EXPECT_FALSE(condition);` | `condition` is false
+
+Remember, when they fail, `ASSERT_*` yields a fatal failure and returns from the
+current function, while `EXPECT_*` yields a nonfatal failure, allowing the
+function to continue running. In either case, an assertion failure means its
+containing test fails.
+
+**Availability**: Linux, Windows, Mac.
+
+### Binary Comparison
+
+This section describes assertions that compare two values.
+
+Fatal assertion          | Nonfatal assertion       | Verifies
+------------------------ | ------------------------ | --------------
+`ASSERT_EQ(val1, val2);` | `EXPECT_EQ(val1, val2);` | `val1 == val2`
+`ASSERT_NE(val1, val2);` | `EXPECT_NE(val1, val2);` | `val1 != val2`
+`ASSERT_LT(val1, val2);` | `EXPECT_LT(val1, val2);` | `val1 < val2`
+`ASSERT_LE(val1, val2);` | `EXPECT_LE(val1, val2);` | `val1 <= val2`
+`ASSERT_GT(val1, val2);` | `EXPECT_GT(val1, val2);` | `val1 > val2`
+`ASSERT_GE(val1, val2);` | `EXPECT_GE(val1, val2);` | `val1 >= val2`
+
+Value arguments must be comparable by the assertion's comparison operator or
+you'll get a compiler error. We used to require the arguments to support the
+`<<` operator for streaming to an `ostream`, but this is no longer necessary. If
+`<<` is supported, it will be called to print the arguments when the assertion
+fails; otherwise googletest will attempt to print them in the best way it can.
+For more details and how to customize the printing of the arguments, see the
+[documentation](../../googlemock/docs/cook_book.md#teaching-gmock-how-to-print-your-values).
+
+These assertions can work with a user-defined type, but only if you define the
+corresponding comparison operator (e.g., `==` or `<`). Since this is discouraged
+by the Google
+[C++ Style Guide](https://google.github.io/styleguide/cppguide.html#Operator_Overloading),
+you may need to use `ASSERT_TRUE()` or `EXPECT_TRUE()` to assert the equality of
+two objects of a user-defined type.
+
+However, when possible, `ASSERT_EQ(actual, expected)` is preferred to
+`ASSERT_TRUE(actual == expected)`, since it tells you `actual` and `expected`'s
+values on failure.
+
+Arguments are always evaluated exactly once. Therefore, it's OK for the
+arguments to have side effects. However, as with any ordinary C/C++ function,
+the arguments' evaluation order is undefined (i.e., the compiler is free to
+choose any order), and your code should not depend on any particular argument
+evaluation order.
+
+`ASSERT_EQ()` does pointer equality on pointers. If used on two C strings, it
+tests if they are in the same memory location, not if they have the same value.
+Therefore, if you want to compare C strings (e.g. `const char*`) by value, use
+`ASSERT_STREQ()`, which will be described later on. In particular, to assert
+that a C string is `NULL`, use `ASSERT_STREQ(c_string, NULL)`. Consider using
+`ASSERT_EQ(c_string, nullptr)` if c++11 is supported. To compare two `string`
+objects, you should use `ASSERT_EQ`.
+
+When doing pointer comparisons use `*_EQ(ptr, nullptr)` and `*_NE(ptr, nullptr)`
+instead of `*_EQ(ptr, NULL)` and `*_NE(ptr, NULL)`. This is because `nullptr` is
+typed, while `NULL` is not. See the [FAQ](faq.md) for more details.
+
+If you're working with floating point numbers, you may want to use the floating
+point variations of some of these macros in order to avoid problems caused by
+rounding. See [Advanced googletest Topics](advanced.md) for details.
+
+Macros in this section work with both narrow and wide string objects (`string`
+and `wstring`).
+
+**Availability**: Linux, Windows, Mac.
+
+**Historical note**: Before February 2016 `*_EQ` had a convention of calling it
+as `ASSERT_EQ(expected, actual)`, so lots of existing code uses this order. Now
+`*_EQ` treats both parameters in the same way.
+
+### String Comparison
+
+The assertions in this group compare two **C strings**. If you want to compare
+two `string` objects, use `EXPECT_EQ`, `EXPECT_NE`, and etc instead.
+
+<!-- mdformat off(github rendering does not support multiline tables) -->
+
+| Fatal assertion                | Nonfatal assertion             | Verifies                                                 |
+| --------------------------     | ------------------------------ | -------------------------------------------------------- |
+| `ASSERT_STREQ(str1,str2);`     | `EXPECT_STREQ(str1,str2);`     | the two C strings have the same content   		     |
+| `ASSERT_STRNE(str1,str2);`     | `EXPECT_STRNE(str1,str2);`     | the two C strings have different contents 		     |
+| `ASSERT_STRCASEEQ(str1,str2);` | `EXPECT_STRCASEEQ(str1,str2);` | the two C strings have the same content, ignoring case   |
+| `ASSERT_STRCASENE(str1,str2);` | `EXPECT_STRCASENE(str1,str2);` | the two C strings have different contents, ignoring case |
+
+<!-- mdformat on-->
+
+Note that "CASE" in an assertion name means that case is ignored. A `NULL`
+pointer and an empty string are considered *different*.
+
+`*STREQ*` and `*STRNE*` also accept wide C strings (`wchar_t*`). If a comparison
+of two wide strings fails, their values will be printed as UTF-8 narrow strings.
+
+**Availability**: Linux, Windows, Mac.
+
+**See also**: For more string comparison tricks (substring, prefix, suffix, and
+regular expression matching, for example), see [this](advanced.md) in the
+Advanced googletest Guide.
+
+## Simple Tests
+
+To create a test:
+
+1.  Use the `TEST()` macro to define and name a test function. These are
+    ordinary C++ functions that don't return a value.
+2.  In this function, along with any valid C++ statements you want to include,
+    use the various googletest assertions to check values.
+3.  The test's result is determined by the assertions; if any assertion in the
+    test fails (either fatally or non-fatally), or if the test crashes, the
+    entire test fails. Otherwise, it succeeds.
+
+```c++
+TEST(TestSuiteName, TestName) {
+  ... test body ...
+}
+```
+
+`TEST()` arguments go from general to specific. The *first* argument is the name
+of the test suite, and the *second* argument is the test's name within the test
+case. Both names must be valid C++ identifiers, and they should not contain
+any underscores (`_`). A test's *full name* consists of its containing test suite and
+its individual name. Tests from different test suites can have the same
+individual name.
+
+For example, let's take a simple integer function:
+
+```c++
+int Factorial(int n);  // Returns the factorial of n
+```
+
+A test suite for this function might look like:
+
+```c++
+// Tests factorial of 0.
+TEST(FactorialTest, HandlesZeroInput) {
+  EXPECT_EQ(Factorial(0), 1);
+}
+
+// Tests factorial of positive numbers.
+TEST(FactorialTest, HandlesPositiveInput) {
+  EXPECT_EQ(Factorial(1), 1);
+  EXPECT_EQ(Factorial(2), 2);
+  EXPECT_EQ(Factorial(3), 6);
+  EXPECT_EQ(Factorial(8), 40320);
+}
+```
+
+googletest groups the test results by test suites, so logically related tests
+should be in the same test suite; in other words, the first argument to their
+`TEST()` should be the same. In the above example, we have two tests,
+`HandlesZeroInput` and `HandlesPositiveInput`, that belong to the same test
+suite `FactorialTest`.
+
+When naming your test suites and tests, you should follow the same convention as
+for
+[naming functions and classes](https://google.github.io/styleguide/cppguide.html#Function_Names).
+
+**Availability**: Linux, Windows, Mac.
+
+## Test Fixtures: Using the Same Data Configuration for Multiple Tests {#same-data-multiple-tests}
+
+If you find yourself writing two or more tests that operate on similar data, you
+can use a *test fixture*. This allows you to reuse the same configuration of
+objects for several different tests.
+
+To create a fixture:
+
+1.  Derive a class from `::testing::Test` . Start its body with `protected:`, as
+    we'll want to access fixture members from sub-classes.
+2.  Inside the class, declare any objects you plan to use.
+3.  If necessary, write a default constructor or `SetUp()` function to prepare
+    the objects for each test. A common mistake is to spell `SetUp()` as
+    **`Setup()`** with a small `u` - Use `override` in C++11 to make sure you
+    spelled it correctly.
+4.  If necessary, write a destructor or `TearDown()` function to release any
+    resources you allocated in `SetUp()` . To learn when you should use the
+    constructor/destructor and when you should use `SetUp()/TearDown()`, read
+    the [FAQ](faq.md#CtorVsSetUp).
+5.  If needed, define subroutines for your tests to share.
+
+When using a fixture, use `TEST_F()` instead of `TEST()` as it allows you to
+access objects and subroutines in the test fixture:
+
+```c++
+TEST_F(TestFixtureName, TestName) {
+  ... test body ...
+}
+```
+
+Like `TEST()`, the first argument is the test suite name, but for `TEST_F()`
+this must be the name of the test fixture class. You've probably guessed: `_F`
+is for fixture.
+
+Unfortunately, the C++ macro system does not allow us to create a single macro
+that can handle both types of tests. Using the wrong macro causes a compiler
+error.
+
+Also, you must first define a test fixture class before using it in a
+`TEST_F()`, or you'll get the compiler error "`virtual outside class
+declaration`".
+
+For each test defined with `TEST_F()`, googletest will create a *fresh* test
+fixture at runtime, immediately initialize it via `SetUp()`, run the test,
+clean up by calling `TearDown()`, and then delete the test fixture. Note that
+different tests in the same test suite have different test fixture objects, and
+googletest always deletes a test fixture before it creates the next one.
+googletest does **not** reuse the same test fixture for multiple tests. Any
+changes one test makes to the fixture do not affect other tests.
+
+As an example, let's write tests for a FIFO queue class named `Queue`, which has
+the following interface:
+
+```c++
+template <typename E>  // E is the element type.
+class Queue {
+ public:
+  Queue();
+  void Enqueue(const E& element);
+  E* Dequeue();  // Returns NULL if the queue is empty.
+  size_t size() const;
+  ...
+};
+```
+
+First, define a fixture class. By convention, you should give it the name
+`FooTest` where `Foo` is the class being tested.
+
+```c++
+class QueueTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+     q1_.Enqueue(1);
+     q2_.Enqueue(2);
+     q2_.Enqueue(3);
+  }
+
+  // void TearDown() override {}
+
+  Queue<int> q0_;
+  Queue<int> q1_;
+  Queue<int> q2_;
+};
+```
+
+In this case, `TearDown()` is not needed since we don't have to clean up after
+each test, other than what's already done by the destructor.
+
+Now we'll write tests using `TEST_F()` and this fixture.
+
+```c++
+TEST_F(QueueTest, IsEmptyInitially) {
+  EXPECT_EQ(q0_.size(), 0);
+}
+
+TEST_F(QueueTest, DequeueWorks) {
+  int* n = q0_.Dequeue();
+  EXPECT_EQ(n, nullptr);
+
+  n = q1_.Dequeue();
+  ASSERT_NE(n, nullptr);
+  EXPECT_EQ(*n, 1);
+  EXPECT_EQ(q1_.size(), 0);
+  delete n;
+
+  n = q2_.Dequeue();
+  ASSERT_NE(n, nullptr);
+  EXPECT_EQ(*n, 2);
+  EXPECT_EQ(q2_.size(), 1);
+  delete n;
+}
+```
+
+The above uses both `ASSERT_*` and `EXPECT_*` assertions. The rule of thumb is
+to use `EXPECT_*` when you want the test to continue to reveal more errors after
+the assertion failure, and use `ASSERT_*` when continuing after failure doesn't
+make sense. For example, the second assertion in the `Dequeue` test is
+`ASSERT_NE(nullptr, n)`, as we need to dereference the pointer `n` later, which
+would lead to a segfault when `n` is `NULL`.
+
+When these tests run, the following happens:
+
+1.  googletest constructs a `QueueTest` object (let's call it `t1`).
+2.  `t1.SetUp()` initializes `t1`.
+3.  The first test (`IsEmptyInitially`) runs on `t1`.
+4.  `t1.TearDown()` cleans up after the test finishes.
+5.  `t1` is destructed.
+6.  The above steps are repeated on another `QueueTest` object, this time
+    running the `DequeueWorks` test.
+
+**Availability**: Linux, Windows, Mac.
+
+## Invoking the Tests
+
+`TEST()` and `TEST_F()` implicitly register their tests with googletest. So,
+unlike with many other C++ testing frameworks, you don't have to re-list all
+your defined tests in order to run them.
+
+After defining your tests, you can run them with `RUN_ALL_TESTS()`, which
+returns `0` if all the tests are successful, or `1` otherwise. Note that
+`RUN_ALL_TESTS()` runs *all tests* in your link unit--they can be from
+different test suites, or even different source files.
+
+When invoked, the `RUN_ALL_TESTS()` macro:
+
+*   Saves the state of all googletest flags.
+
+*   Creates a test fixture object for the first test.
+
+*   Initializes it via `SetUp()`.
+
+*   Runs the test on the fixture object.
+
+*   Cleans up the fixture via `TearDown()`.
+
+*   Deletes the fixture.
+
+*   Restores the state of all googletest flags.
+
+*   Repeats the above steps for the next test, until all tests have run.
+
+If a fatal failure happens the subsequent steps will be skipped.
+
+> IMPORTANT: You must **not** ignore the return value of `RUN_ALL_TESTS()`, or
+> you will get a compiler error. The rationale for this design is that the
+> automated testing service determines whether a test has passed based on its
+> exit code, not on its stdout/stderr output; thus your `main()` function must
+> return the value of `RUN_ALL_TESTS()`.
+>
+> Also, you should call `RUN_ALL_TESTS()` only **once**. Calling it more than
+> once conflicts with some advanced googletest features (e.g., thread-safe
+> [death tests](advanced.md#death-tests)) and thus is not supported.
+
+**Availability**: Linux, Windows, Mac.
+
+## Writing the main() Function
+
+Write your own main() function, which should return the value of
+`RUN_ALL_TESTS()`.
+
+You can start from this boilerplate:
+
+```c++
+#include "this/package/foo.h"
+#include "gtest/gtest.h"
+
+namespace {
+
+// The fixture for testing class Foo.
+class FooTest : public ::testing::Test {
+ protected:
+  // You can remove any or all of the following functions if its body
+  // is empty.
+
+  FooTest() {
+     // You can do set-up work for each test here.
+  }
+
+  ~FooTest() override {
+     // You can do clean-up work that doesn't throw exceptions here.
+  }
+
+  // If the constructor and destructor are not enough for setting up
+  // and cleaning up each test, you can define the following methods:
+
+  void SetUp() override {
+     // Code here will be called immediately after the constructor (right
+     // before each test).
+  }
+
+  void TearDown() override {
+     // Code here will be called immediately after each test (right
+     // before the destructor).
+  }
+
+  // Objects declared here can be used by all tests in the test suite for Foo.
+};
+
+// Tests that the Foo::Bar() method does Abc.
+TEST_F(FooTest, MethodBarDoesAbc) {
+  const std::string input_filepath = "this/package/testdata/myinputfile.dat";
+  const std::string output_filepath = "this/package/testdata/myoutputfile.dat";
+  Foo f;
+  EXPECT_EQ(f.Bar(input_filepath, output_filepath), 0);
+}
+
+// Tests that Foo does Xyz.
+TEST_F(FooTest, DoesXyz) {
+  // Exercises the Xyz feature of Foo.
+}
+
+}  // namespace
+
+int main(int argc, char **argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+```
+
+The `::testing::InitGoogleTest()` function parses the command line for
+googletest flags, and removes all recognized flags. This allows the user to
+control a test program's behavior via various flags, which we'll cover in
+the [AdvancedGuide](advanced.md). You **must** call this function before calling
+`RUN_ALL_TESTS()`, or the flags won't be properly initialized.
+
+On Windows, `InitGoogleTest()` also works with wide strings, so it can be used
+in programs compiled in `UNICODE` mode as well.
+
+But maybe you think that writing all those main() functions is too much work? We
+agree with you completely, and that's why Google Test provides a basic
+implementation of main(). If it fits your needs, then just link your test with
+gtest\_main library and you are good to go.
+
+NOTE: `ParseGUnitFlags()` is deprecated in favor of `InitGoogleTest()`.
+
+## Known Limitations
+
+*   Google Test is designed to be thread-safe. The implementation is thread-safe
+    on systems where the `pthreads` library is available. It is currently
+    _unsafe_ to use Google Test assertions from two threads concurrently on
+    other systems (e.g. Windows). In most tests this is not an issue as usually
+    the assertions are done in the main thread. If you want to help, you can
+    volunteer to implement the necessary synchronization primitives in
+    `gtest-port.h` for your platform.
diff --git a/3rdparty/gtest/docs/pump_manual.md b/3rdparty/gtest/docs/pump_manual.md
new file mode 100644
index 0000000..10b3c5f
--- /dev/null
+++ b/3rdparty/gtest/docs/pump_manual.md
@@ -0,0 +1,190 @@
+<b>P</b>ump is <b>U</b>seful for <b>M</b>eta <b>P</b>rogramming.
+
+# The Problem
+
+Template and macro libraries often need to define many classes, functions, or
+macros that vary only (or almost only) in the number of arguments they take.
+It's a lot of repetitive, mechanical, and error-prone work.
+
+Variadic templates and variadic macros can alleviate the problem. However, while
+both are being considered by the C++ committee, neither is in the standard yet
+or widely supported by compilers. Thus they are often not a good choice,
+especially when your code needs to be portable. And their capabilities are still
+limited.
+
+As a result, authors of such libraries often have to write scripts to generate
+their implementation. However, our experience is that it's tedious to write such
+scripts, which tend to reflect the structure of the generated code poorly and
+are often hard to read and edit. For example, a small change needed in the
+generated code may require some non-intuitive, non-trivial changes in the
+script. This is especially painful when experimenting with the code.
+
+# Our Solution
+
+Pump (for Pump is Useful for Meta Programming, Pretty Useful for Meta
+Programming, or Practical Utility for Meta Programming, whichever you prefer) is
+a simple meta-programming tool for C++. The idea is that a programmer writes a
+`foo.pump` file which contains C++ code plus meta code that manipulates the C++
+code. The meta code can handle iterations over a range, nested iterations, local
+meta variable definitions, simple arithmetic, and conditional expressions. You
+can view it as a small Domain-Specific Language. The meta language is designed
+to be non-intrusive (s.t. it won't confuse Emacs' C++ mode, for example) and
+concise, making Pump code intuitive and easy to maintain.
+
+## Highlights
+
+*   The implementation is in a single Python script and thus ultra portable: no
+    build or installation is needed and it works cross platforms.
+*   Pump tries to be smart with respect to
+    [Google's style guide](https://github.com/google/styleguide): it breaks long
+    lines (easy to have when they are generated) at acceptable places to fit
+    within 80 columns and indent the continuation lines correctly.
+*   The format is human-readable and more concise than XML.
+*   The format works relatively well with Emacs' C++ mode.
+
+## Examples
+
+The following Pump code (where meta keywords start with `$`, `[[` and `]]` are
+meta brackets, and `$$` starts a meta comment that ends with the line):
+
+```
+$var n = 3     $$ Defines a meta variable n.
+$range i 0..n  $$ Declares the range of meta iterator i (inclusive).
+$for i [[
+               $$ Meta loop.
+// Foo$i does blah for $i-ary predicates.
+$range j 1..i
+template <size_t N $for j [[, typename A$j]]>
+class Foo$i {
+$if i == 0 [[
+  blah a;
+]] $elif i <= 2 [[
+  blah b;
+]] $else [[
+  blah c;
+]]
+};
+
+]]
+```
+
+will be translated by the Pump compiler to:
+
+```cpp
+// Foo0 does blah for 0-ary predicates.
+template <size_t N>
+class Foo0 {
+  blah a;
+};
+
+// Foo1 does blah for 1-ary predicates.
+template <size_t N, typename A1>
+class Foo1 {
+  blah b;
+};
+
+// Foo2 does blah for 2-ary predicates.
+template <size_t N, typename A1, typename A2>
+class Foo2 {
+  blah b;
+};
+
+// Foo3 does blah for 3-ary predicates.
+template <size_t N, typename A1, typename A2, typename A3>
+class Foo3 {
+  blah c;
+};
+```
+
+In another example,
+
+```
+$range i 1..n
+Func($for i + [[a$i]]);
+$$ The text between i and [[ is the separator between iterations.
+```
+
+will generate one of the following lines (without the comments), depending on
+the value of `n`:
+
+```cpp
+Func();              // If n is 0.
+Func(a1);            // If n is 1.
+Func(a1 + a2);       // If n is 2.
+Func(a1 + a2 + a3);  // If n is 3.
+// And so on...
+```
+
+## Constructs
+
+We support the following meta programming constructs:
+
+| `$var id = exp`                  | Defines a named constant value. `$id` is |
+:                                  : valid util the end of the current meta   :
+:                                  : lexical block.                           :
+| :------------------------------- | :--------------------------------------- |
+| `$range id exp..exp`             | Sets the range of an iteration variable, |
+:                                  : which can be reused in multiple loops    :
+:                                  : later.                                   :
+| `$for id sep [[ code ]]`         | Iteration. The range of `id` must have   |
+:                                  : been defined earlier. `$id` is valid in  :
+:                                  : `code`.                                  :
+| `$($)`                           | Generates a single `$` character.        |
+| `$id`                            | Value of the named constant or iteration |
+:                                  : variable.                                :
+| `$(exp)`                         | Value of the expression.                 |
+| `$if exp [[ code ]] else_branch` | Conditional.                             |
+| `[[ code ]]`                     | Meta lexical block.                      |
+| `cpp_code`                       | Raw C++ code.                            |
+| `$$ comment`                     | Meta comment.                            |
+
+**Note:** To give the user some freedom in formatting the Pump source code, Pump
+ignores a new-line character if it's right after `$for foo` or next to `[[` or
+`]]`. Without this rule you'll often be forced to write very long lines to get
+the desired output. Therefore sometimes you may need to insert an extra new-line
+in such places for a new-line to show up in your output.
+
+## Grammar
+
+```ebnf
+code ::= atomic_code*
+atomic_code ::= $var id = exp
+    | $var id = [[ code ]]
+    | $range id exp..exp
+    | $for id sep [[ code ]]
+    | $($)
+    | $id
+    | $(exp)
+    | $if exp [[ code ]] else_branch
+    | [[ code ]]
+    | cpp_code
+sep ::= cpp_code | empty_string
+else_branch ::= $else [[ code ]]
+    | $elif exp [[ code ]] else_branch
+    | empty_string
+exp ::= simple_expression_in_Python_syntax
+```
+
+## Code
+
+You can find the source code of Pump in [scripts/pump.py](../scripts/pump.py).
+It is still very unpolished and lacks automated tests, although it has been
+successfully used many times. If you find a chance to use it in your project,
+please let us know what you think! We also welcome help on improving Pump.
+
+## Real Examples
+
+You can find real-world applications of Pump in
+[Google Test](https://github.com/google/googletest/tree/master/googletest) and
+[Google Mock](https://github.com/google/googletest/tree/master/googlemock). The
+source file `foo.h.pump` generates `foo.h`.
+
+## Tips
+
+*   If a meta variable is followed by a letter or digit, you can separate them
+    using `[[]]`, which inserts an empty string. For example `Foo$j[[]]Helper`
+    generate `Foo1Helper` when `j` is 1.
+*   To avoid extra-long Pump source lines, you can break a line anywhere you
+    want by inserting `[[]]` followed by a new line. Since any new-line
+    character next to `[[` or `]]` is ignored, the generated code won't contain
+    this new line.
diff --git a/3rdparty/gtest/docs/samples.md b/3rdparty/gtest/docs/samples.md
new file mode 100644
index 0000000..aaa5883
--- /dev/null
+++ b/3rdparty/gtest/docs/samples.md
@@ -0,0 +1,22 @@
+# Googletest Samples {#samples}
+
+If you're like us, you'd like to look at
+[googletest samples.](https://github.com/google/googletest/tree/master/googletest/samples)
+The sample directory has a number of well-commented samples showing how to use a
+variety of googletest features.
+
+*   Sample #1 shows the basic steps of using googletest to test C++ functions.
+*   Sample #2 shows a more complex unit test for a class with multiple member
+    functions.
+*   Sample #3 uses a test fixture.
+*   Sample #4 teaches you how to use googletest and `googletest.h` together to
+    get the best of both libraries.
+*   Sample #5 puts shared testing logic in a base test fixture, and reuses it in
+    derived fixtures.
+*   Sample #6 demonstrates type-parameterized tests.
+*   Sample #7 teaches the basics of value-parameterized tests.
+*   Sample #8 shows using `Combine()` in value-parameterized tests.
+*   Sample #9 shows use of the listener API to modify Google Test's console
+    output and the use of its reflection API to inspect test results.
+*   Sample #10 shows use of the listener API to implement a primitive memory
+    leak checker.
diff --git a/3rdparty/gtest/include/gtest/gtest-death-test.h b/3rdparty/gtest/include/gtest/gtest-death-test.h
new file mode 100644
index 0000000..dc878ff
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest-death-test.h
@@ -0,0 +1,343 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines the public API for death tests.  It is
+// #included by gtest.h so a user doesn't need to include this
+// directly.
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
+#define GTEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
+
+#include "gtest/internal/gtest-death-test-internal.h"
+
+namespace testing {
+
+// This flag controls the style of death tests.  Valid values are "threadsafe",
+// meaning that the death test child process will re-execute the test binary
+// from the start, running only a single death test, or "fast",
+// meaning that the child process will execute the test logic immediately
+// after forking.
+GTEST_DECLARE_string_(death_test_style);
+
+#if GTEST_HAS_DEATH_TEST
+
+namespace internal {
+
+// Returns a Boolean value indicating whether the caller is currently
+// executing in the context of the death test child process.  Tools such as
+// Valgrind heap checkers may need this to modify their behavior in death
+// tests.  IMPORTANT: This is an internal utility.  Using it may break the
+// implementation of death tests.  User code MUST NOT use it.
+GTEST_API_ bool InDeathTestChild();
+
+}  // namespace internal
+
+// The following macros are useful for writing death tests.
+
+// Here's what happens when an ASSERT_DEATH* or EXPECT_DEATH* is
+// executed:
+//
+//   1. It generates a warning if there is more than one active
+//   thread.  This is because it's safe to fork() or clone() only
+//   when there is a single thread.
+//
+//   2. The parent process clone()s a sub-process and runs the death
+//   test in it; the sub-process exits with code 0 at the end of the
+//   death test, if it hasn't exited already.
+//
+//   3. The parent process waits for the sub-process to terminate.
+//
+//   4. The parent process checks the exit code and error message of
+//   the sub-process.
+//
+// Examples:
+//
+//   ASSERT_DEATH(server.SendMessage(56, "Hello"), "Invalid port number");
+//   for (int i = 0; i < 5; i++) {
+//     EXPECT_DEATH(server.ProcessRequest(i),
+//                  "Invalid request .* in ProcessRequest()")
+//                  << "Failed to die on request " << i;
+//   }
+//
+//   ASSERT_EXIT(server.ExitNow(), ::testing::ExitedWithCode(0), "Exiting");
+//
+//   bool KilledBySIGHUP(int exit_code) {
+//     return WIFSIGNALED(exit_code) && WTERMSIG(exit_code) == SIGHUP;
+//   }
+//
+//   ASSERT_EXIT(client.HangUpServer(), KilledBySIGHUP, "Hanging up!");
+//
+// On the regular expressions used in death tests:
+//
+//   GOOGLETEST_CM0005 DO NOT DELETE
+//   On POSIX-compliant systems (*nix), we use the <regex.h> library,
+//   which uses the POSIX extended regex syntax.
+//
+//   On other platforms (e.g. Windows or Mac), we only support a simple regex
+//   syntax implemented as part of Google Test.  This limited
+//   implementation should be enough most of the time when writing
+//   death tests; though it lacks many features you can find in PCRE
+//   or POSIX extended regex syntax.  For example, we don't support
+//   union ("x|y"), grouping ("(xy)"), brackets ("[xy]"), and
+//   repetition count ("x{5,7}"), among others.
+//
+//   Below is the syntax that we do support.  We chose it to be a
+//   subset of both PCRE and POSIX extended regex, so it's easy to
+//   learn wherever you come from.  In the following: 'A' denotes a
+//   literal character, period (.), or a single \\ escape sequence;
+//   'x' and 'y' denote regular expressions; 'm' and 'n' are for
+//   natural numbers.
+//
+//     c     matches any literal character c
+//     \\d   matches any decimal digit
+//     \\D   matches any character that's not a decimal digit
+//     \\f   matches \f
+//     \\n   matches \n
+//     \\r   matches \r
+//     \\s   matches any ASCII whitespace, including \n
+//     \\S   matches any character that's not a whitespace
+//     \\t   matches \t
+//     \\v   matches \v
+//     \\w   matches any letter, _, or decimal digit
+//     \\W   matches any character that \\w doesn't match
+//     \\c   matches any literal character c, which must be a punctuation
+//     .     matches any single character except \n
+//     A?    matches 0 or 1 occurrences of A
+//     A*    matches 0 or many occurrences of A
+//     A+    matches 1 or many occurrences of A
+//     ^     matches the beginning of a string (not that of each line)
+//     $     matches the end of a string (not that of each line)
+//     xy    matches x followed by y
+//
+//   If you accidentally use PCRE or POSIX extended regex features
+//   not implemented by us, you will get a run-time failure.  In that
+//   case, please try to rewrite your regular expression within the
+//   above syntax.
+//
+//   This implementation is *not* meant to be as highly tuned or robust
+//   as a compiled regex library, but should perform well enough for a
+//   death test, which already incurs significant overhead by launching
+//   a child process.
+//
+// Known caveats:
+//
+//   A "threadsafe" style death test obtains the path to the test
+//   program from argv[0] and re-executes it in the sub-process.  For
+//   simplicity, the current implementation doesn't search the PATH
+//   when launching the sub-process.  This means that the user must
+//   invoke the test program via a path that contains at least one
+//   path separator (e.g. path/to/foo_test and
+//   /absolute/path/to/bar_test are fine, but foo_test is not).  This
+//   is rarely a problem as people usually don't put the test binary
+//   directory in PATH.
+//
+
+// Asserts that a given statement causes the program to exit, with an
+// integer exit status that satisfies predicate, and emitting error output
+// that matches regex.
+# define ASSERT_EXIT(statement, predicate, regex) \
+    GTEST_DEATH_TEST_(statement, predicate, regex, GTEST_FATAL_FAILURE_)
+
+// Like ASSERT_EXIT, but continues on to successive tests in the
+// test suite, if any:
+# define EXPECT_EXIT(statement, predicate, regex) \
+    GTEST_DEATH_TEST_(statement, predicate, regex, GTEST_NONFATAL_FAILURE_)
+
+// Asserts that a given statement causes the program to exit, either by
+// explicitly exiting with a nonzero exit code or being killed by a
+// signal, and emitting error output that matches regex.
+# define ASSERT_DEATH(statement, regex) \
+    ASSERT_EXIT(statement, ::testing::internal::ExitedUnsuccessfully, regex)
+
+// Like ASSERT_DEATH, but continues on to successive tests in the
+// test suite, if any:
+# define EXPECT_DEATH(statement, regex) \
+    EXPECT_EXIT(statement, ::testing::internal::ExitedUnsuccessfully, regex)
+
+// Two predicate classes that can be used in {ASSERT,EXPECT}_EXIT*:
+
+// Tests that an exit code describes a normal exit with a given exit code.
+class GTEST_API_ ExitedWithCode {
+ public:
+  explicit ExitedWithCode(int exit_code);
+  bool operator()(int exit_status) const;
+ private:
+  // No implementation - assignment is unsupported.
+  void operator=(const ExitedWithCode& other);
+
+  const int exit_code_;
+};
+
+# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+// Tests that an exit code describes an exit due to termination by a
+// given signal.
+// GOOGLETEST_CM0006 DO NOT DELETE
+class GTEST_API_ KilledBySignal {
+ public:
+  explicit KilledBySignal(int signum);
+  bool operator()(int exit_status) const;
+ private:
+  const int signum_;
+};
+# endif  // !GTEST_OS_WINDOWS
+
+// EXPECT_DEBUG_DEATH asserts that the given statements die in debug mode.
+// The death testing framework causes this to have interesting semantics,
+// since the sideeffects of the call are only visible in opt mode, and not
+// in debug mode.
+//
+// In practice, this can be used to test functions that utilize the
+// LOG(DFATAL) macro using the following style:
+//
+// int DieInDebugOr12(int* sideeffect) {
+//   if (sideeffect) {
+//     *sideeffect = 12;
+//   }
+//   LOG(DFATAL) << "death";
+//   return 12;
+// }
+//
+// TEST(TestSuite, TestDieOr12WorksInDgbAndOpt) {
+//   int sideeffect = 0;
+//   // Only asserts in dbg.
+//   EXPECT_DEBUG_DEATH(DieInDebugOr12(&sideeffect), "death");
+//
+// #ifdef NDEBUG
+//   // opt-mode has sideeffect visible.
+//   EXPECT_EQ(12, sideeffect);
+// #else
+//   // dbg-mode no visible sideeffect.
+//   EXPECT_EQ(0, sideeffect);
+// #endif
+// }
+//
+// This will assert that DieInDebugReturn12InOpt() crashes in debug
+// mode, usually due to a DCHECK or LOG(DFATAL), but returns the
+// appropriate fallback value (12 in this case) in opt mode. If you
+// need to test that a function has appropriate side-effects in opt
+// mode, include assertions against the side-effects.  A general
+// pattern for this is:
+//
+// EXPECT_DEBUG_DEATH({
+//   // Side-effects here will have an effect after this statement in
+//   // opt mode, but none in debug mode.
+//   EXPECT_EQ(12, DieInDebugOr12(&sideeffect));
+// }, "death");
+//
+# ifdef NDEBUG
+
+#  define EXPECT_DEBUG_DEATH(statement, regex) \
+  GTEST_EXECUTE_STATEMENT_(statement, regex)
+
+#  define ASSERT_DEBUG_DEATH(statement, regex) \
+  GTEST_EXECUTE_STATEMENT_(statement, regex)
+
+# else
+
+#  define EXPECT_DEBUG_DEATH(statement, regex) \
+  EXPECT_DEATH(statement, regex)
+
+#  define ASSERT_DEBUG_DEATH(statement, regex) \
+  ASSERT_DEATH(statement, regex)
+
+# endif  // NDEBUG for EXPECT_DEBUG_DEATH
+#endif  // GTEST_HAS_DEATH_TEST
+
+// This macro is used for implementing macros such as
+// EXPECT_DEATH_IF_SUPPORTED and ASSERT_DEATH_IF_SUPPORTED on systems where
+// death tests are not supported. Those macros must compile on such systems
+// if and only if EXPECT_DEATH and ASSERT_DEATH compile with the same parameters
+// on systems that support death tests. This allows one to write such a macro on
+// a system that does not support death tests and be sure that it will compile
+// on a death-test supporting system. It is exposed publicly so that systems
+// that have death-tests with stricter requirements than GTEST_HAS_DEATH_TEST
+// can write their own equivalent of EXPECT_DEATH_IF_SUPPORTED and
+// ASSERT_DEATH_IF_SUPPORTED.
+//
+// Parameters:
+//   statement -  A statement that a macro such as EXPECT_DEATH would test
+//                for program termination. This macro has to make sure this
+//                statement is compiled but not executed, to ensure that
+//                EXPECT_DEATH_IF_SUPPORTED compiles with a certain
+//                parameter if and only if EXPECT_DEATH compiles with it.
+//   regex     -  A regex that a macro such as EXPECT_DEATH would use to test
+//                the output of statement.  This parameter has to be
+//                compiled but not evaluated by this macro, to ensure that
+//                this macro only accepts expressions that a macro such as
+//                EXPECT_DEATH would accept.
+//   terminator - Must be an empty statement for EXPECT_DEATH_IF_SUPPORTED
+//                and a return statement for ASSERT_DEATH_IF_SUPPORTED.
+//                This ensures that ASSERT_DEATH_IF_SUPPORTED will not
+//                compile inside functions where ASSERT_DEATH doesn't
+//                compile.
+//
+//  The branch that has an always false condition is used to ensure that
+//  statement and regex are compiled (and thus syntactically correct) but
+//  never executed. The unreachable code macro protects the terminator
+//  statement from generating an 'unreachable code' warning in case
+//  statement unconditionally returns or throws. The Message constructor at
+//  the end allows the syntax of streaming additional messages into the
+//  macro, for compilational compatibility with EXPECT_DEATH/ASSERT_DEATH.
+# define GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, terminator) \
+    GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
+    if (::testing::internal::AlwaysTrue()) { \
+      GTEST_LOG_(WARNING) \
+          << "Death tests are not supported on this platform.\n" \
+          << "Statement '" #statement "' cannot be verified."; \
+    } else if (::testing::internal::AlwaysFalse()) { \
+      ::testing::internal::RE::PartialMatch(".*", (regex)); \
+      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
+      terminator; \
+    } else \
+      ::testing::Message()
+
+// EXPECT_DEATH_IF_SUPPORTED(statement, regex) and
+// ASSERT_DEATH_IF_SUPPORTED(statement, regex) expand to real death tests if
+// death tests are supported; otherwise they just issue a warning.  This is
+// useful when you are combining death test assertions with normal test
+// assertions in one test.
+#if GTEST_HAS_DEATH_TEST
+# define EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
+    EXPECT_DEATH(statement, regex)
+# define ASSERT_DEATH_IF_SUPPORTED(statement, regex) \
+    ASSERT_DEATH(statement, regex)
+#else
+# define EXPECT_DEATH_IF_SUPPORTED(statement, regex) \
+    GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, )
+# define ASSERT_DEATH_IF_SUPPORTED(statement, regex) \
+    GTEST_UNSUPPORTED_DEATH_TEST(statement, regex, return)
+#endif
+
+}  // namespace testing
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
diff --git a/3rdparty/gtest/include/gtest/gtest-matchers.h b/3rdparty/gtest/include/gtest/gtest-matchers.h
new file mode 100644
index 0000000..9de6c2e
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest-matchers.h
@@ -0,0 +1,750 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This file implements just enough of the matcher interface to allow
+// EXPECT_DEATH and friends to accept a matcher argument.
+
+// IWYU pragma: private, include "testing/base/public/gunit.h"
+// IWYU pragma: friend third_party/googletest/googlemock/.*
+// IWYU pragma: friend third_party/googletest/googletest/.*
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
+#define GTEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
+
+#include <memory>
+#include <ostream>
+#include <string>
+#include <type_traits>
+
+#include "gtest/gtest-printers.h"
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+
+// MSVC warning C5046 is new as of VS2017 version 15.8.
+#if defined(_MSC_VER) && _MSC_VER >= 1915
+#define GTEST_MAYBE_5046_ 5046
+#else
+#define GTEST_MAYBE_5046_
+#endif
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(
+    4251 GTEST_MAYBE_5046_ /* class A needs to have dll-interface to be used by
+                              clients of class B */
+    /* Symbol involving type with internal linkage not defined */)
+
+namespace testing {
+
+// To implement a matcher Foo for type T, define:
+//   1. a class FooMatcherImpl that implements the
+//      MatcherInterface<T> interface, and
+//   2. a factory function that creates a Matcher<T> object from a
+//      FooMatcherImpl*.
+//
+// The two-level delegation design makes it possible to allow a user
+// to write "v" instead of "Eq(v)" where a Matcher is expected, which
+// is impossible if we pass matchers by pointers.  It also eases
+// ownership management as Matcher objects can now be copied like
+// plain values.
+
+// MatchResultListener is an abstract class.  Its << operator can be
+// used by a matcher to explain why a value matches or doesn't match.
+//
+class MatchResultListener {
+ public:
+  // Creates a listener object with the given underlying ostream.  The
+  // listener does not own the ostream, and does not dereference it
+  // in the constructor or destructor.
+  explicit MatchResultListener(::std::ostream* os) : stream_(os) {}
+  virtual ~MatchResultListener() = 0;  // Makes this class abstract.
+
+  // Streams x to the underlying ostream; does nothing if the ostream
+  // is NULL.
+  template <typename T>
+  MatchResultListener& operator<<(const T& x) {
+    if (stream_ != nullptr) *stream_ << x;
+    return *this;
+  }
+
+  // Returns the underlying ostream.
+  ::std::ostream* stream() { return stream_; }
+
+  // Returns true if and only if the listener is interested in an explanation
+  // of the match result.  A matcher's MatchAndExplain() method can use
+  // this information to avoid generating the explanation when no one
+  // intends to hear it.
+  bool IsInterested() const { return stream_ != nullptr; }
+
+ private:
+  ::std::ostream* const stream_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(MatchResultListener);
+};
+
+inline MatchResultListener::~MatchResultListener() {
+}
+
+// An instance of a subclass of this knows how to describe itself as a
+// matcher.
+class MatcherDescriberInterface {
+ public:
+  virtual ~MatcherDescriberInterface() {}
+
+  // Describes this matcher to an ostream.  The function should print
+  // a verb phrase that describes the property a value matching this
+  // matcher should have.  The subject of the verb phrase is the value
+  // being matched.  For example, the DescribeTo() method of the Gt(7)
+  // matcher prints "is greater than 7".
+  virtual void DescribeTo(::std::ostream* os) const = 0;
+
+  // Describes the negation of this matcher to an ostream.  For
+  // example, if the description of this matcher is "is greater than
+  // 7", the negated description could be "is not greater than 7".
+  // You are not required to override this when implementing
+  // MatcherInterface, but it is highly advised so that your matcher
+  // can produce good error messages.
+  virtual void DescribeNegationTo(::std::ostream* os) const {
+    *os << "not (";
+    DescribeTo(os);
+    *os << ")";
+  }
+};
+
+// The implementation of a matcher.
+template <typename T>
+class MatcherInterface : public MatcherDescriberInterface {
+ public:
+  // Returns true if and only if the matcher matches x; also explains the
+  // match result to 'listener' if necessary (see the next paragraph), in
+  // the form of a non-restrictive relative clause ("which ...",
+  // "whose ...", etc) that describes x.  For example, the
+  // MatchAndExplain() method of the Pointee(...) matcher should
+  // generate an explanation like "which points to ...".
+  //
+  // Implementations of MatchAndExplain() should add an explanation of
+  // the match result *if and only if* they can provide additional
+  // information that's not already present (or not obvious) in the
+  // print-out of x and the matcher's description.  Whether the match
+  // succeeds is not a factor in deciding whether an explanation is
+  // needed, as sometimes the caller needs to print a failure message
+  // when the match succeeds (e.g. when the matcher is used inside
+  // Not()).
+  //
+  // For example, a "has at least 10 elements" matcher should explain
+  // what the actual element count is, regardless of the match result,
+  // as it is useful information to the reader; on the other hand, an
+  // "is empty" matcher probably only needs to explain what the actual
+  // size is when the match fails, as it's redundant to say that the
+  // size is 0 when the value is already known to be empty.
+  //
+  // You should override this method when defining a new matcher.
+  //
+  // It's the responsibility of the caller (Google Test) to guarantee
+  // that 'listener' is not NULL.  This helps to simplify a matcher's
+  // implementation when it doesn't care about the performance, as it
+  // can talk to 'listener' without checking its validity first.
+  // However, in order to implement dummy listeners efficiently,
+  // listener->stream() may be NULL.
+  virtual bool MatchAndExplain(T x, MatchResultListener* listener) const = 0;
+
+  // Inherits these methods from MatcherDescriberInterface:
+  //   virtual void DescribeTo(::std::ostream* os) const = 0;
+  //   virtual void DescribeNegationTo(::std::ostream* os) const;
+};
+
+namespace internal {
+
+// Converts a MatcherInterface<T> to a MatcherInterface<const T&>.
+template <typename T>
+class MatcherInterfaceAdapter : public MatcherInterface<const T&> {
+ public:
+  explicit MatcherInterfaceAdapter(const MatcherInterface<T>* impl)
+      : impl_(impl) {}
+  ~MatcherInterfaceAdapter() override { delete impl_; }
+
+  void DescribeTo(::std::ostream* os) const override { impl_->DescribeTo(os); }
+
+  void DescribeNegationTo(::std::ostream* os) const override {
+    impl_->DescribeNegationTo(os);
+  }
+
+  bool MatchAndExplain(const T& x,
+                       MatchResultListener* listener) const override {
+    return impl_->MatchAndExplain(x, listener);
+  }
+
+ private:
+  const MatcherInterface<T>* const impl_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(MatcherInterfaceAdapter);
+};
+
+struct AnyEq {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const { return a == b; }
+};
+struct AnyNe {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const { return a != b; }
+};
+struct AnyLt {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const { return a < b; }
+};
+struct AnyGt {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const { return a > b; }
+};
+struct AnyLe {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const { return a <= b; }
+};
+struct AnyGe {
+  template <typename A, typename B>
+  bool operator()(const A& a, const B& b) const { return a >= b; }
+};
+
+// A match result listener that ignores the explanation.
+class DummyMatchResultListener : public MatchResultListener {
+ public:
+  DummyMatchResultListener() : MatchResultListener(nullptr) {}
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(DummyMatchResultListener);
+};
+
+// A match result listener that forwards the explanation to a given
+// ostream.  The difference between this and MatchResultListener is
+// that the former is concrete.
+class StreamMatchResultListener : public MatchResultListener {
+ public:
+  explicit StreamMatchResultListener(::std::ostream* os)
+      : MatchResultListener(os) {}
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(StreamMatchResultListener);
+};
+
+// An internal class for implementing Matcher<T>, which will derive
+// from it.  We put functionalities common to all Matcher<T>
+// specializations here to avoid code duplication.
+template <typename T>
+class MatcherBase {
+ public:
+  // Returns true if and only if the matcher matches x; also explains the
+  // match result to 'listener'.
+  bool MatchAndExplain(const T& x, MatchResultListener* listener) const {
+    return impl_->MatchAndExplain(x, listener);
+  }
+
+  // Returns true if and only if this matcher matches x.
+  bool Matches(const T& x) const {
+    DummyMatchResultListener dummy;
+    return MatchAndExplain(x, &dummy);
+  }
+
+  // Describes this matcher to an ostream.
+  void DescribeTo(::std::ostream* os) const { impl_->DescribeTo(os); }
+
+  // Describes the negation of this matcher to an ostream.
+  void DescribeNegationTo(::std::ostream* os) const {
+    impl_->DescribeNegationTo(os);
+  }
+
+  // Explains why x matches, or doesn't match, the matcher.
+  void ExplainMatchResultTo(const T& x, ::std::ostream* os) const {
+    StreamMatchResultListener listener(os);
+    MatchAndExplain(x, &listener);
+  }
+
+  // Returns the describer for this matcher object; retains ownership
+  // of the describer, which is only guaranteed to be alive when
+  // this matcher object is alive.
+  const MatcherDescriberInterface* GetDescriber() const {
+    return impl_.get();
+  }
+
+ protected:
+  MatcherBase() {}
+
+  // Constructs a matcher from its implementation.
+  explicit MatcherBase(const MatcherInterface<const T&>* impl) : impl_(impl) {}
+
+  template <typename U>
+  explicit MatcherBase(
+      const MatcherInterface<U>* impl,
+      typename std::enable_if<!std::is_same<U, const U&>::value>::type* =
+          nullptr)
+      : impl_(new internal::MatcherInterfaceAdapter<U>(impl)) {}
+
+  MatcherBase(const MatcherBase&) = default;
+  MatcherBase& operator=(const MatcherBase&) = default;
+  MatcherBase(MatcherBase&&) = default;
+  MatcherBase& operator=(MatcherBase&&) = default;
+
+  virtual ~MatcherBase() {}
+
+ private:
+  std::shared_ptr<const MatcherInterface<const T&>> impl_;
+};
+
+}  // namespace internal
+
+// A Matcher<T> is a copyable and IMMUTABLE (except by assignment)
+// object that can check whether a value of type T matches.  The
+// implementation of Matcher<T> is just a std::shared_ptr to const
+// MatcherInterface<T>.  Don't inherit from Matcher!
+template <typename T>
+class Matcher : public internal::MatcherBase<T> {
+ public:
+  // Constructs a null matcher.  Needed for storing Matcher objects in STL
+  // containers.  A default-constructed matcher is not yet initialized.  You
+  // cannot use it until a valid value has been assigned to it.
+  explicit Matcher() {}  // NOLINT
+
+  // Constructs a matcher from its implementation.
+  explicit Matcher(const MatcherInterface<const T&>* impl)
+      : internal::MatcherBase<T>(impl) {}
+
+  template <typename U>
+  explicit Matcher(
+      const MatcherInterface<U>* impl,
+      typename std::enable_if<!std::is_same<U, const U&>::value>::type* =
+          nullptr)
+      : internal::MatcherBase<T>(impl) {}
+
+  // Implicit constructor here allows people to write
+  // EXPECT_CALL(foo, Bar(5)) instead of EXPECT_CALL(foo, Bar(Eq(5))) sometimes
+  Matcher(T value);  // NOLINT
+};
+
+// The following two specializations allow the user to write str
+// instead of Eq(str) and "foo" instead of Eq("foo") when a std::string
+// matcher is expected.
+template <>
+class GTEST_API_ Matcher<const std::string&>
+    : public internal::MatcherBase<const std::string&> {
+ public:
+  Matcher() {}
+
+  explicit Matcher(const MatcherInterface<const std::string&>* impl)
+      : internal::MatcherBase<const std::string&>(impl) {}
+
+  // Allows the user to write str instead of Eq(str) sometimes, where
+  // str is a std::string object.
+  Matcher(const std::string& s);  // NOLINT
+
+  // Allows the user to write "foo" instead of Eq("foo") sometimes.
+  Matcher(const char* s);  // NOLINT
+};
+
+template <>
+class GTEST_API_ Matcher<std::string>
+    : public internal::MatcherBase<std::string> {
+ public:
+  Matcher() {}
+
+  explicit Matcher(const MatcherInterface<const std::string&>* impl)
+      : internal::MatcherBase<std::string>(impl) {}
+  explicit Matcher(const MatcherInterface<std::string>* impl)
+      : internal::MatcherBase<std::string>(impl) {}
+
+  // Allows the user to write str instead of Eq(str) sometimes, where
+  // str is a string object.
+  Matcher(const std::string& s);  // NOLINT
+
+  // Allows the user to write "foo" instead of Eq("foo") sometimes.
+  Matcher(const char* s);  // NOLINT
+};
+
+#if GTEST_HAS_ABSL
+// The following two specializations allow the user to write str
+// instead of Eq(str) and "foo" instead of Eq("foo") when a absl::string_view
+// matcher is expected.
+template <>
+class GTEST_API_ Matcher<const absl::string_view&>
+    : public internal::MatcherBase<const absl::string_view&> {
+ public:
+  Matcher() {}
+
+  explicit Matcher(const MatcherInterface<const absl::string_view&>* impl)
+      : internal::MatcherBase<const absl::string_view&>(impl) {}
+
+  // Allows the user to write str instead of Eq(str) sometimes, where
+  // str is a std::string object.
+  Matcher(const std::string& s);  // NOLINT
+
+  // Allows the user to write "foo" instead of Eq("foo") sometimes.
+  Matcher(const char* s);  // NOLINT
+
+  // Allows the user to pass absl::string_views directly.
+  Matcher(absl::string_view s);  // NOLINT
+};
+
+template <>
+class GTEST_API_ Matcher<absl::string_view>
+    : public internal::MatcherBase<absl::string_view> {
+ public:
+  Matcher() {}
+
+  explicit Matcher(const MatcherInterface<const absl::string_view&>* impl)
+      : internal::MatcherBase<absl::string_view>(impl) {}
+  explicit Matcher(const MatcherInterface<absl::string_view>* impl)
+      : internal::MatcherBase<absl::string_view>(impl) {}
+
+  // Allows the user to write str instead of Eq(str) sometimes, where
+  // str is a std::string object.
+  Matcher(const std::string& s);  // NOLINT
+
+  // Allows the user to write "foo" instead of Eq("foo") sometimes.
+  Matcher(const char* s);  // NOLINT
+
+  // Allows the user to pass absl::string_views directly.
+  Matcher(absl::string_view s);  // NOLINT
+};
+#endif  // GTEST_HAS_ABSL
+
+// Prints a matcher in a human-readable format.
+template <typename T>
+std::ostream& operator<<(std::ostream& os, const Matcher<T>& matcher) {
+  matcher.DescribeTo(&os);
+  return os;
+}
+
+// The PolymorphicMatcher class template makes it easy to implement a
+// polymorphic matcher (i.e. a matcher that can match values of more
+// than one type, e.g. Eq(n) and NotNull()).
+//
+// To define a polymorphic matcher, a user should provide an Impl
+// class that has a DescribeTo() method and a DescribeNegationTo()
+// method, and define a member function (or member function template)
+//
+//   bool MatchAndExplain(const Value& value,
+//                        MatchResultListener* listener) const;
+//
+// See the definition of NotNull() for a complete example.
+template <class Impl>
+class PolymorphicMatcher {
+ public:
+  explicit PolymorphicMatcher(const Impl& an_impl) : impl_(an_impl) {}
+
+  // Returns a mutable reference to the underlying matcher
+  // implementation object.
+  Impl& mutable_impl() { return impl_; }
+
+  // Returns an immutable reference to the underlying matcher
+  // implementation object.
+  const Impl& impl() const { return impl_; }
+
+  template <typename T>
+  operator Matcher<T>() const {
+    return Matcher<T>(new MonomorphicImpl<const T&>(impl_));
+  }
+
+ private:
+  template <typename T>
+  class MonomorphicImpl : public MatcherInterface<T> {
+   public:
+    explicit MonomorphicImpl(const Impl& impl) : impl_(impl) {}
+
+    virtual void DescribeTo(::std::ostream* os) const { impl_.DescribeTo(os); }
+
+    virtual void DescribeNegationTo(::std::ostream* os) const {
+      impl_.DescribeNegationTo(os);
+    }
+
+    virtual bool MatchAndExplain(T x, MatchResultListener* listener) const {
+      return impl_.MatchAndExplain(x, listener);
+    }
+
+   private:
+    const Impl impl_;
+  };
+
+  Impl impl_;
+};
+
+// Creates a matcher from its implementation.
+// DEPRECATED: Especially in the generic code, prefer:
+//   Matcher<T>(new MyMatcherImpl<const T&>(...));
+//
+// MakeMatcher may create a Matcher that accepts its argument by value, which
+// leads to unnecessary copies & lack of support for non-copyable types.
+template <typename T>
+inline Matcher<T> MakeMatcher(const MatcherInterface<T>* impl) {
+  return Matcher<T>(impl);
+}
+
+// Creates a polymorphic matcher from its implementation.  This is
+// easier to use than the PolymorphicMatcher<Impl> constructor as it
+// doesn't require you to explicitly write the template argument, e.g.
+//
+//   MakePolymorphicMatcher(foo);
+// vs
+//   PolymorphicMatcher<TypeOfFoo>(foo);
+template <class Impl>
+inline PolymorphicMatcher<Impl> MakePolymorphicMatcher(const Impl& impl) {
+  return PolymorphicMatcher<Impl>(impl);
+}
+
+namespace internal {
+// Implements a matcher that compares a given value with a
+// pre-supplied value using one of the ==, <=, <, etc, operators.  The
+// two values being compared don't have to have the same type.
+//
+// The matcher defined here is polymorphic (for example, Eq(5) can be
+// used to match an int, a short, a double, etc).  Therefore we use
+// a template type conversion operator in the implementation.
+//
+// The following template definition assumes that the Rhs parameter is
+// a "bare" type (i.e. neither 'const T' nor 'T&').
+template <typename D, typename Rhs, typename Op>
+class ComparisonBase {
+ public:
+  explicit ComparisonBase(const Rhs& rhs) : rhs_(rhs) {}
+  template <typename Lhs>
+  operator Matcher<Lhs>() const {
+    return Matcher<Lhs>(new Impl<const Lhs&>(rhs_));
+  }
+
+ private:
+  template <typename T>
+  static const T& Unwrap(const T& v) { return v; }
+  template <typename T>
+  static const T& Unwrap(std::reference_wrapper<T> v) { return v; }
+
+  template <typename Lhs, typename = Rhs>
+  class Impl : public MatcherInterface<Lhs> {
+   public:
+    explicit Impl(const Rhs& rhs) : rhs_(rhs) {}
+    bool MatchAndExplain(Lhs lhs,
+                         MatchResultListener* /* listener */) const override {
+      return Op()(lhs, Unwrap(rhs_));
+    }
+    void DescribeTo(::std::ostream* os) const override {
+      *os << D::Desc() << " ";
+      UniversalPrint(Unwrap(rhs_), os);
+    }
+    void DescribeNegationTo(::std::ostream* os) const override {
+      *os << D::NegatedDesc() <<  " ";
+      UniversalPrint(Unwrap(rhs_), os);
+    }
+
+   private:
+    Rhs rhs_;
+  };
+  Rhs rhs_;
+};
+
+template <typename Rhs>
+class EqMatcher : public ComparisonBase<EqMatcher<Rhs>, Rhs, AnyEq> {
+ public:
+  explicit EqMatcher(const Rhs& rhs)
+      : ComparisonBase<EqMatcher<Rhs>, Rhs, AnyEq>(rhs) { }
+  static const char* Desc() { return "is equal to"; }
+  static const char* NegatedDesc() { return "isn't equal to"; }
+};
+template <typename Rhs>
+class NeMatcher : public ComparisonBase<NeMatcher<Rhs>, Rhs, AnyNe> {
+ public:
+  explicit NeMatcher(const Rhs& rhs)
+      : ComparisonBase<NeMatcher<Rhs>, Rhs, AnyNe>(rhs) { }
+  static const char* Desc() { return "isn't equal to"; }
+  static const char* NegatedDesc() { return "is equal to"; }
+};
+template <typename Rhs>
+class LtMatcher : public ComparisonBase<LtMatcher<Rhs>, Rhs, AnyLt> {
+ public:
+  explicit LtMatcher(const Rhs& rhs)
+      : ComparisonBase<LtMatcher<Rhs>, Rhs, AnyLt>(rhs) { }
+  static const char* Desc() { return "is <"; }
+  static const char* NegatedDesc() { return "isn't <"; }
+};
+template <typename Rhs>
+class GtMatcher : public ComparisonBase<GtMatcher<Rhs>, Rhs, AnyGt> {
+ public:
+  explicit GtMatcher(const Rhs& rhs)
+      : ComparisonBase<GtMatcher<Rhs>, Rhs, AnyGt>(rhs) { }
+  static const char* Desc() { return "is >"; }
+  static const char* NegatedDesc() { return "isn't >"; }
+};
+template <typename Rhs>
+class LeMatcher : public ComparisonBase<LeMatcher<Rhs>, Rhs, AnyLe> {
+ public:
+  explicit LeMatcher(const Rhs& rhs)
+      : ComparisonBase<LeMatcher<Rhs>, Rhs, AnyLe>(rhs) { }
+  static const char* Desc() { return "is <="; }
+  static const char* NegatedDesc() { return "isn't <="; }
+};
+template <typename Rhs>
+class GeMatcher : public ComparisonBase<GeMatcher<Rhs>, Rhs, AnyGe> {
+ public:
+  explicit GeMatcher(const Rhs& rhs)
+      : ComparisonBase<GeMatcher<Rhs>, Rhs, AnyGe>(rhs) { }
+  static const char* Desc() { return "is >="; }
+  static const char* NegatedDesc() { return "isn't >="; }
+};
+
+// Implements polymorphic matchers MatchesRegex(regex) and
+// ContainsRegex(regex), which can be used as a Matcher<T> as long as
+// T can be converted to a string.
+class MatchesRegexMatcher {
+ public:
+  MatchesRegexMatcher(const RE* regex, bool full_match)
+      : regex_(regex), full_match_(full_match) {}
+
+#if GTEST_HAS_ABSL
+  bool MatchAndExplain(const absl::string_view& s,
+                       MatchResultListener* listener) const {
+    return MatchAndExplain(std::string(s), listener);
+  }
+#endif  // GTEST_HAS_ABSL
+
+  // Accepts pointer types, particularly:
+  //   const char*
+  //   char*
+  //   const wchar_t*
+  //   wchar_t*
+  template <typename CharType>
+  bool MatchAndExplain(CharType* s, MatchResultListener* listener) const {
+    return s != nullptr && MatchAndExplain(std::string(s), listener);
+  }
+
+  // Matches anything that can convert to std::string.
+  //
+  // This is a template, not just a plain function with const std::string&,
+  // because absl::string_view has some interfering non-explicit constructors.
+  template <class MatcheeStringType>
+  bool MatchAndExplain(const MatcheeStringType& s,
+                       MatchResultListener* /* listener */) const {
+    const std::string& s2(s);
+    return full_match_ ? RE::FullMatch(s2, *regex_)
+                       : RE::PartialMatch(s2, *regex_);
+  }
+
+  void DescribeTo(::std::ostream* os) const {
+    *os << (full_match_ ? "matches" : "contains") << " regular expression ";
+    UniversalPrinter<std::string>::Print(regex_->pattern(), os);
+  }
+
+  void DescribeNegationTo(::std::ostream* os) const {
+    *os << "doesn't " << (full_match_ ? "match" : "contain")
+        << " regular expression ";
+    UniversalPrinter<std::string>::Print(regex_->pattern(), os);
+  }
+
+ private:
+  const std::shared_ptr<const RE> regex_;
+  const bool full_match_;
+};
+}  // namespace internal
+
+// Matches a string that fully matches regular expression 'regex'.
+// The matcher takes ownership of 'regex'.
+inline PolymorphicMatcher<internal::MatchesRegexMatcher> MatchesRegex(
+    const internal::RE* regex) {
+  return MakePolymorphicMatcher(internal::MatchesRegexMatcher(regex, true));
+}
+inline PolymorphicMatcher<internal::MatchesRegexMatcher> MatchesRegex(
+    const std::string& regex) {
+  return MatchesRegex(new internal::RE(regex));
+}
+
+// Matches a string that contains regular expression 'regex'.
+// The matcher takes ownership of 'regex'.
+inline PolymorphicMatcher<internal::MatchesRegexMatcher> ContainsRegex(
+    const internal::RE* regex) {
+  return MakePolymorphicMatcher(internal::MatchesRegexMatcher(regex, false));
+}
+inline PolymorphicMatcher<internal::MatchesRegexMatcher> ContainsRegex(
+    const std::string& regex) {
+  return ContainsRegex(new internal::RE(regex));
+}
+
+// Creates a polymorphic matcher that matches anything equal to x.
+// Note: if the parameter of Eq() were declared as const T&, Eq("foo")
+// wouldn't compile.
+template <typename T>
+inline internal::EqMatcher<T> Eq(T x) { return internal::EqMatcher<T>(x); }
+
+// Constructs a Matcher<T> from a 'value' of type T.  The constructed
+// matcher matches any value that's equal to 'value'.
+template <typename T>
+Matcher<T>::Matcher(T value) { *this = Eq(value); }
+
+// Creates a monomorphic matcher that matches anything with type Lhs
+// and equal to rhs.  A user may need to use this instead of Eq(...)
+// in order to resolve an overloading ambiguity.
+//
+// TypedEq<T>(x) is just a convenient short-hand for Matcher<T>(Eq(x))
+// or Matcher<T>(x), but more readable than the latter.
+//
+// We could define similar monomorphic matchers for other comparison
+// operations (e.g. TypedLt, TypedGe, and etc), but decided not to do
+// it yet as those are used much less than Eq() in practice.  A user
+// can always write Matcher<T>(Lt(5)) to be explicit about the type,
+// for example.
+template <typename Lhs, typename Rhs>
+inline Matcher<Lhs> TypedEq(const Rhs& rhs) { return Eq(rhs); }
+
+// Creates a polymorphic matcher that matches anything >= x.
+template <typename Rhs>
+inline internal::GeMatcher<Rhs> Ge(Rhs x) {
+  return internal::GeMatcher<Rhs>(x);
+}
+
+// Creates a polymorphic matcher that matches anything > x.
+template <typename Rhs>
+inline internal::GtMatcher<Rhs> Gt(Rhs x) {
+  return internal::GtMatcher<Rhs>(x);
+}
+
+// Creates a polymorphic matcher that matches anything <= x.
+template <typename Rhs>
+inline internal::LeMatcher<Rhs> Le(Rhs x) {
+  return internal::LeMatcher<Rhs>(x);
+}
+
+// Creates a polymorphic matcher that matches anything < x.
+template <typename Rhs>
+inline internal::LtMatcher<Rhs> Lt(Rhs x) {
+  return internal::LtMatcher<Rhs>(x);
+}
+
+// Creates a polymorphic matcher that matches anything != x.
+template <typename Rhs>
+inline internal::NeMatcher<Rhs> Ne(Rhs x) {
+  return internal::NeMatcher<Rhs>(x);
+}
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251 5046
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
diff --git a/3rdparty/gtest/include/gtest/gtest-message.h b/3rdparty/gtest/include/gtest/gtest-message.h
new file mode 100644
index 0000000..4a80e11
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest-message.h
@@ -0,0 +1,218 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines the Message class.
+//
+// IMPORTANT NOTE: Due to limitation of the C++ language, we have to
+// leave some internal implementation details in this header file.
+// They are clearly marked by comments like this:
+//
+//   // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+//
+// Such code is NOT meant to be used by a user directly, and is subject
+// to CHANGE WITHOUT NOTICE.  Therefore DO NOT DEPEND ON IT in a user
+// program!
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
+#define GTEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
+
+#include <limits>
+#include <memory>
+
+#include "gtest/internal/gtest-port.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+// Ensures that there is at least one operator<< in the global namespace.
+// See Message& operator<<(...) below for why.
+void operator<<(const testing::internal::Secret&, int);
+
+namespace testing {
+
+// The Message class works like an ostream repeater.
+//
+// Typical usage:
+//
+//   1. You stream a bunch of values to a Message object.
+//      It will remember the text in a stringstream.
+//   2. Then you stream the Message object to an ostream.
+//      This causes the text in the Message to be streamed
+//      to the ostream.
+//
+// For example;
+//
+//   testing::Message foo;
+//   foo << 1 << " != " << 2;
+//   std::cout << foo;
+//
+// will print "1 != 2".
+//
+// Message is not intended to be inherited from.  In particular, its
+// destructor is not virtual.
+//
+// Note that stringstream behaves differently in gcc and in MSVC.  You
+// can stream a NULL char pointer to it in the former, but not in the
+// latter (it causes an access violation if you do).  The Message
+// class hides this difference by treating a NULL char pointer as
+// "(null)".
+class GTEST_API_ Message {
+ private:
+  // The type of basic IO manipulators (endl, ends, and flush) for
+  // narrow streams.
+  typedef std::ostream& (*BasicNarrowIoManip)(std::ostream&);
+
+ public:
+  // Constructs an empty Message.
+  Message();
+
+  // Copy constructor.
+  Message(const Message& msg) : ss_(new ::std::stringstream) {  // NOLINT
+    *ss_ << msg.GetString();
+  }
+
+  // Constructs a Message from a C-string.
+  explicit Message(const char* str) : ss_(new ::std::stringstream) {
+    *ss_ << str;
+  }
+
+  // Streams a non-pointer value to this object.
+  template <typename T>
+  inline Message& operator <<(const T& val) {
+    // Some libraries overload << for STL containers.  These
+    // overloads are defined in the global namespace instead of ::std.
+    //
+    // C++'s symbol lookup rule (i.e. Koenig lookup) says that these
+    // overloads are visible in either the std namespace or the global
+    // namespace, but not other namespaces, including the testing
+    // namespace which Google Test's Message class is in.
+    //
+    // To allow STL containers (and other types that has a << operator
+    // defined in the global namespace) to be used in Google Test
+    // assertions, testing::Message must access the custom << operator
+    // from the global namespace.  With this using declaration,
+    // overloads of << defined in the global namespace and those
+    // visible via Koenig lookup are both exposed in this function.
+    using ::operator <<;
+    *ss_ << val;
+    return *this;
+  }
+
+  // Streams a pointer value to this object.
+  //
+  // This function is an overload of the previous one.  When you
+  // stream a pointer to a Message, this definition will be used as it
+  // is more specialized.  (The C++ Standard, section
+  // [temp.func.order].)  If you stream a non-pointer, then the
+  // previous definition will be used.
+  //
+  // The reason for this overload is that streaming a NULL pointer to
+  // ostream is undefined behavior.  Depending on the compiler, you
+  // may get "0", "(nil)", "(null)", or an access violation.  To
+  // ensure consistent result across compilers, we always treat NULL
+  // as "(null)".
+  template <typename T>
+  inline Message& operator <<(T* const& pointer) {  // NOLINT
+    if (pointer == nullptr) {
+      *ss_ << "(null)";
+    } else {
+      *ss_ << pointer;
+    }
+    return *this;
+  }
+
+  // Since the basic IO manipulators are overloaded for both narrow
+  // and wide streams, we have to provide this specialized definition
+  // of operator <<, even though its body is the same as the
+  // templatized version above.  Without this definition, streaming
+  // endl or other basic IO manipulators to Message will confuse the
+  // compiler.
+  Message& operator <<(BasicNarrowIoManip val) {
+    *ss_ << val;
+    return *this;
+  }
+
+  // Instead of 1/0, we want to see true/false for bool values.
+  Message& operator <<(bool b) {
+    return *this << (b ? "true" : "false");
+  }
+
+  // These two overloads allow streaming a wide C string to a Message
+  // using the UTF-8 encoding.
+  Message& operator <<(const wchar_t* wide_c_str);
+  Message& operator <<(wchar_t* wide_c_str);
+
+#if GTEST_HAS_STD_WSTRING
+  // Converts the given wide string to a narrow string using the UTF-8
+  // encoding, and streams the result to this Message object.
+  Message& operator <<(const ::std::wstring& wstr);
+#endif  // GTEST_HAS_STD_WSTRING
+
+  // Gets the text streamed to this object so far as an std::string.
+  // Each '\0' character in the buffer is replaced with "\\0".
+  //
+  // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+  std::string GetString() const;
+
+ private:
+  // We'll hold the text streamed to this object here.
+  const std::unique_ptr< ::std::stringstream> ss_;
+
+  // We declare (but don't implement) this to prevent the compiler
+  // from implementing the assignment operator.
+  void operator=(const Message&);
+};
+
+// Streams a Message to an ostream.
+inline std::ostream& operator <<(std::ostream& os, const Message& sb) {
+  return os << sb.GetString();
+}
+
+namespace internal {
+
+// Converts a streamable value to an std::string.  A NULL pointer is
+// converted to "(null)".  When the input value is a ::string,
+// ::std::string, ::wstring, or ::std::wstring object, each NUL
+// character in it is replaced with "\\0".
+template <typename T>
+std::string StreamableToString(const T& streamable) {
+  return (Message() << streamable).GetString();
+}
+
+}  // namespace internal
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
diff --git a/3rdparty/gtest/include/gtest/gtest-param-test.h b/3rdparty/gtest/include/gtest/gtest-param-test.h
new file mode 100644
index 0000000..c2e6eae
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest-param-test.h
@@ -0,0 +1,503 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Macros and functions for implementing parameterized tests
+// in Google C++ Testing and Mocking Framework (Google Test)
+//
+// This file is generated by a SCRIPT.  DO NOT EDIT BY HAND!
+//
+// GOOGLETEST_CM0001 DO NOT DELETE
+#ifndef GTEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
+#define GTEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
+
+
+// Value-parameterized tests allow you to test your code with different
+// parameters without writing multiple copies of the same test.
+//
+// Here is how you use value-parameterized tests:
+
+#if 0
+
+// To write value-parameterized tests, first you should define a fixture
+// class. It is usually derived from testing::TestWithParam<T> (see below for
+// another inheritance scheme that's sometimes useful in more complicated
+// class hierarchies), where the type of your parameter values.
+// TestWithParam<T> is itself derived from testing::Test. T can be any
+// copyable type. If it's a raw pointer, you are responsible for managing the
+// lifespan of the pointed values.
+
+class FooTest : public ::testing::TestWithParam<const char*> {
+  // You can implement all the usual class fixture members here.
+};
+
+// Then, use the TEST_P macro to define as many parameterized tests
+// for this fixture as you want. The _P suffix is for "parameterized"
+// or "pattern", whichever you prefer to think.
+
+TEST_P(FooTest, DoesBlah) {
+  // Inside a test, access the test parameter with the GetParam() method
+  // of the TestWithParam<T> class:
+  EXPECT_TRUE(foo.Blah(GetParam()));
+  ...
+}
+
+TEST_P(FooTest, HasBlahBlah) {
+  ...
+}
+
+// Finally, you can use INSTANTIATE_TEST_SUITE_P to instantiate the test
+// case with any set of parameters you want. Google Test defines a number
+// of functions for generating test parameters. They return what we call
+// (surprise!) parameter generators. Here is a summary of them, which
+// are all in the testing namespace:
+//
+//
+//  Range(begin, end [, step]) - Yields values {begin, begin+step,
+//                               begin+step+step, ...}. The values do not
+//                               include end. step defaults to 1.
+//  Values(v1, v2, ..., vN)    - Yields values {v1, v2, ..., vN}.
+//  ValuesIn(container)        - Yields values from a C-style array, an STL
+//  ValuesIn(begin,end)          container, or an iterator range [begin, end).
+//  Bool()                     - Yields sequence {false, true}.
+//  Combine(g1, g2, ..., gN)   - Yields all combinations (the Cartesian product
+//                               for the math savvy) of the values generated
+//                               by the N generators.
+//
+// For more details, see comments at the definitions of these functions below
+// in this file.
+//
+// The following statement will instantiate tests from the FooTest test suite
+// each with parameter values "meeny", "miny", and "moe".
+
+INSTANTIATE_TEST_SUITE_P(InstantiationName,
+                         FooTest,
+                         Values("meeny", "miny", "moe"));
+
+// To distinguish different instances of the pattern, (yes, you
+// can instantiate it more than once) the first argument to the
+// INSTANTIATE_TEST_SUITE_P macro is a prefix that will be added to the
+// actual test suite name. Remember to pick unique prefixes for different
+// instantiations. The tests from the instantiation above will have
+// these names:
+//
+//    * InstantiationName/FooTest.DoesBlah/0 for "meeny"
+//    * InstantiationName/FooTest.DoesBlah/1 for "miny"
+//    * InstantiationName/FooTest.DoesBlah/2 for "moe"
+//    * InstantiationName/FooTest.HasBlahBlah/0 for "meeny"
+//    * InstantiationName/FooTest.HasBlahBlah/1 for "miny"
+//    * InstantiationName/FooTest.HasBlahBlah/2 for "moe"
+//
+// You can use these names in --gtest_filter.
+//
+// This statement will instantiate all tests from FooTest again, each
+// with parameter values "cat" and "dog":
+
+const char* pets[] = {"cat", "dog"};
+INSTANTIATE_TEST_SUITE_P(AnotherInstantiationName, FooTest, ValuesIn(pets));
+
+// The tests from the instantiation above will have these names:
+//
+//    * AnotherInstantiationName/FooTest.DoesBlah/0 for "cat"
+//    * AnotherInstantiationName/FooTest.DoesBlah/1 for "dog"
+//    * AnotherInstantiationName/FooTest.HasBlahBlah/0 for "cat"
+//    * AnotherInstantiationName/FooTest.HasBlahBlah/1 for "dog"
+//
+// Please note that INSTANTIATE_TEST_SUITE_P will instantiate all tests
+// in the given test suite, whether their definitions come before or
+// AFTER the INSTANTIATE_TEST_SUITE_P statement.
+//
+// Please also note that generator expressions (including parameters to the
+// generators) are evaluated in InitGoogleTest(), after main() has started.
+// This allows the user on one hand, to adjust generator parameters in order
+// to dynamically determine a set of tests to run and on the other hand,
+// give the user a chance to inspect the generated tests with Google Test
+// reflection API before RUN_ALL_TESTS() is executed.
+//
+// You can see samples/sample7_unittest.cc and samples/sample8_unittest.cc
+// for more examples.
+//
+// In the future, we plan to publish the API for defining new parameter
+// generators. But for now this interface remains part of the internal
+// implementation and is subject to change.
+//
+//
+// A parameterized test fixture must be derived from testing::Test and from
+// testing::WithParamInterface<T>, where T is the type of the parameter
+// values. Inheriting from TestWithParam<T> satisfies that requirement because
+// TestWithParam<T> inherits from both Test and WithParamInterface. In more
+// complicated hierarchies, however, it is occasionally useful to inherit
+// separately from Test and WithParamInterface. For example:
+
+class BaseTest : public ::testing::Test {
+  // You can inherit all the usual members for a non-parameterized test
+  // fixture here.
+};
+
+class DerivedTest : public BaseTest, public ::testing::WithParamInterface<int> {
+  // The usual test fixture members go here too.
+};
+
+TEST_F(BaseTest, HasFoo) {
+  // This is an ordinary non-parameterized test.
+}
+
+TEST_P(DerivedTest, DoesBlah) {
+  // GetParam works just the same here as if you inherit from TestWithParam.
+  EXPECT_TRUE(foo.Blah(GetParam()));
+}
+
+#endif  // 0
+
+#include <iterator>
+#include <utility>
+
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-param-util.h"
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+
+// Functions producing parameter generators.
+//
+// Google Test uses these generators to produce parameters for value-
+// parameterized tests. When a parameterized test suite is instantiated
+// with a particular generator, Google Test creates and runs tests
+// for each element in the sequence produced by the generator.
+//
+// In the following sample, tests from test suite FooTest are instantiated
+// each three times with parameter values 3, 5, and 8:
+//
+// class FooTest : public TestWithParam<int> { ... };
+//
+// TEST_P(FooTest, TestThis) {
+// }
+// TEST_P(FooTest, TestThat) {
+// }
+// INSTANTIATE_TEST_SUITE_P(TestSequence, FooTest, Values(3, 5, 8));
+//
+
+// Range() returns generators providing sequences of values in a range.
+//
+// Synopsis:
+// Range(start, end)
+//   - returns a generator producing a sequence of values {start, start+1,
+//     start+2, ..., }.
+// Range(start, end, step)
+//   - returns a generator producing a sequence of values {start, start+step,
+//     start+step+step, ..., }.
+// Notes:
+//   * The generated sequences never include end. For example, Range(1, 5)
+//     returns a generator producing a sequence {1, 2, 3, 4}. Range(1, 9, 2)
+//     returns a generator producing {1, 3, 5, 7}.
+//   * start and end must have the same type. That type may be any integral or
+//     floating-point type or a user defined type satisfying these conditions:
+//     * It must be assignable (have operator=() defined).
+//     * It must have operator+() (operator+(int-compatible type) for
+//       two-operand version).
+//     * It must have operator<() defined.
+//     Elements in the resulting sequences will also have that type.
+//   * Condition start < end must be satisfied in order for resulting sequences
+//     to contain any elements.
+//
+template <typename T, typename IncrementT>
+internal::ParamGenerator<T> Range(T start, T end, IncrementT step) {
+  return internal::ParamGenerator<T>(
+      new internal::RangeGenerator<T, IncrementT>(start, end, step));
+}
+
+template <typename T>
+internal::ParamGenerator<T> Range(T start, T end) {
+  return Range(start, end, 1);
+}
+
+// ValuesIn() function allows generation of tests with parameters coming from
+// a container.
+//
+// Synopsis:
+// ValuesIn(const T (&array)[N])
+//   - returns a generator producing sequences with elements from
+//     a C-style array.
+// ValuesIn(const Container& container)
+//   - returns a generator producing sequences with elements from
+//     an STL-style container.
+// ValuesIn(Iterator begin, Iterator end)
+//   - returns a generator producing sequences with elements from
+//     a range [begin, end) defined by a pair of STL-style iterators. These
+//     iterators can also be plain C pointers.
+//
+// Please note that ValuesIn copies the values from the containers
+// passed in and keeps them to generate tests in RUN_ALL_TESTS().
+//
+// Examples:
+//
+// This instantiates tests from test suite StringTest
+// each with C-string values of "foo", "bar", and "baz":
+//
+// const char* strings[] = {"foo", "bar", "baz"};
+// INSTANTIATE_TEST_SUITE_P(StringSequence, StringTest, ValuesIn(strings));
+//
+// This instantiates tests from test suite StlStringTest
+// each with STL strings with values "a" and "b":
+//
+// ::std::vector< ::std::string> GetParameterStrings() {
+//   ::std::vector< ::std::string> v;
+//   v.push_back("a");
+//   v.push_back("b");
+//   return v;
+// }
+//
+// INSTANTIATE_TEST_SUITE_P(CharSequence,
+//                          StlStringTest,
+//                          ValuesIn(GetParameterStrings()));
+//
+//
+// This will also instantiate tests from CharTest
+// each with parameter values 'a' and 'b':
+//
+// ::std::list<char> GetParameterChars() {
+//   ::std::list<char> list;
+//   list.push_back('a');
+//   list.push_back('b');
+//   return list;
+// }
+// ::std::list<char> l = GetParameterChars();
+// INSTANTIATE_TEST_SUITE_P(CharSequence2,
+//                          CharTest,
+//                          ValuesIn(l.begin(), l.end()));
+//
+template <typename ForwardIterator>
+internal::ParamGenerator<
+    typename std::iterator_traits<ForwardIterator>::value_type>
+ValuesIn(ForwardIterator begin, ForwardIterator end) {
+  typedef typename std::iterator_traits<ForwardIterator>::value_type ParamType;
+  return internal::ParamGenerator<ParamType>(
+      new internal::ValuesInIteratorRangeGenerator<ParamType>(begin, end));
+}
+
+template <typename T, size_t N>
+internal::ParamGenerator<T> ValuesIn(const T (&array)[N]) {
+  return ValuesIn(array, array + N);
+}
+
+template <class Container>
+internal::ParamGenerator<typename Container::value_type> ValuesIn(
+    const Container& container) {
+  return ValuesIn(container.begin(), container.end());
+}
+
+// Values() allows generating tests from explicitly specified list of
+// parameters.
+//
+// Synopsis:
+// Values(T v1, T v2, ..., T vN)
+//   - returns a generator producing sequences with elements v1, v2, ..., vN.
+//
+// For example, this instantiates tests from test suite BarTest each
+// with values "one", "two", and "three":
+//
+// INSTANTIATE_TEST_SUITE_P(NumSequence,
+//                          BarTest,
+//                          Values("one", "two", "three"));
+//
+// This instantiates tests from test suite BazTest each with values 1, 2, 3.5.
+// The exact type of values will depend on the type of parameter in BazTest.
+//
+// INSTANTIATE_TEST_SUITE_P(FloatingNumbers, BazTest, Values(1, 2, 3.5));
+//
+//
+template <typename... T>
+internal::ValueArray<T...> Values(T... v) {
+  return internal::ValueArray<T...>(std::move(v)...);
+}
+
+// Bool() allows generating tests with parameters in a set of (false, true).
+//
+// Synopsis:
+// Bool()
+//   - returns a generator producing sequences with elements {false, true}.
+//
+// It is useful when testing code that depends on Boolean flags. Combinations
+// of multiple flags can be tested when several Bool()'s are combined using
+// Combine() function.
+//
+// In the following example all tests in the test suite FlagDependentTest
+// will be instantiated twice with parameters false and true.
+//
+// class FlagDependentTest : public testing::TestWithParam<bool> {
+//   virtual void SetUp() {
+//     external_flag = GetParam();
+//   }
+// }
+// INSTANTIATE_TEST_SUITE_P(BoolSequence, FlagDependentTest, Bool());
+//
+inline internal::ParamGenerator<bool> Bool() {
+  return Values(false, true);
+}
+
+// Combine() allows the user to combine two or more sequences to produce
+// values of a Cartesian product of those sequences' elements.
+//
+// Synopsis:
+// Combine(gen1, gen2, ..., genN)
+//   - returns a generator producing sequences with elements coming from
+//     the Cartesian product of elements from the sequences generated by
+//     gen1, gen2, ..., genN. The sequence elements will have a type of
+//     std::tuple<T1, T2, ..., TN> where T1, T2, ..., TN are the types
+//     of elements from sequences produces by gen1, gen2, ..., genN.
+//
+// Combine can have up to 10 arguments.
+//
+// Example:
+//
+// This will instantiate tests in test suite AnimalTest each one with
+// the parameter values tuple("cat", BLACK), tuple("cat", WHITE),
+// tuple("dog", BLACK), and tuple("dog", WHITE):
+//
+// enum Color { BLACK, GRAY, WHITE };
+// class AnimalTest
+//     : public testing::TestWithParam<std::tuple<const char*, Color> > {...};
+//
+// TEST_P(AnimalTest, AnimalLooksNice) {...}
+//
+// INSTANTIATE_TEST_SUITE_P(AnimalVariations, AnimalTest,
+//                          Combine(Values("cat", "dog"),
+//                                  Values(BLACK, WHITE)));
+//
+// This will instantiate tests in FlagDependentTest with all variations of two
+// Boolean flags:
+//
+// class FlagDependentTest
+//     : public testing::TestWithParam<std::tuple<bool, bool> > {
+//   virtual void SetUp() {
+//     // Assigns external_flag_1 and external_flag_2 values from the tuple.
+//     std::tie(external_flag_1, external_flag_2) = GetParam();
+//   }
+// };
+//
+// TEST_P(FlagDependentTest, TestFeature1) {
+//   // Test your code using external_flag_1 and external_flag_2 here.
+// }
+// INSTANTIATE_TEST_SUITE_P(TwoBoolSequence, FlagDependentTest,
+//                          Combine(Bool(), Bool()));
+//
+template <typename... Generator>
+internal::CartesianProductHolder<Generator...> Combine(const Generator&... g) {
+  return internal::CartesianProductHolder<Generator...>(g...);
+}
+
+#define TEST_P(test_suite_name, test_name)                                     \
+  class GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                     \
+      : public test_suite_name {                                               \
+   public:                                                                     \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)() {}                    \
+    virtual void TestBody();                                                   \
+                                                                               \
+   private:                                                                    \
+    static int AddToRegistry() {                                               \
+      ::testing::UnitTest::GetInstance()                                       \
+          ->parameterized_test_registry()                                      \
+          .GetTestSuitePatternHolder<test_suite_name>(                         \
+              #test_suite_name,                                                \
+              ::testing::internal::CodeLocation(__FILE__, __LINE__))           \
+          ->AddTestPattern(                                                    \
+              GTEST_STRINGIFY_(test_suite_name), GTEST_STRINGIFY_(test_name),  \
+              new ::testing::internal::TestMetaFactory<GTEST_TEST_CLASS_NAME_( \
+                  test_suite_name, test_name)>());                             \
+      return 0;                                                                \
+    }                                                                          \
+    static int gtest_registering_dummy_ GTEST_ATTRIBUTE_UNUSED_;               \
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(GTEST_TEST_CLASS_NAME_(test_suite_name,    \
+                                                           test_name));        \
+  };                                                                           \
+  int GTEST_TEST_CLASS_NAME_(test_suite_name,                                  \
+                             test_name)::gtest_registering_dummy_ =            \
+      GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::AddToRegistry();     \
+  void GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::TestBody()
+
+// The last argument to INSTANTIATE_TEST_SUITE_P allows the user to specify
+// generator and an optional function or functor that generates custom test name
+// suffixes based on the test parameters. Such a function or functor should
+// accept one argument of type testing::TestParamInfo<class ParamType>, and
+// return std::string.
+//
+// testing::PrintToStringParamName is a builtin test suffix generator that
+// returns the value of testing::PrintToString(GetParam()).
+//
+// Note: test names must be non-empty, unique, and may only contain ASCII
+// alphanumeric characters or underscore. Because PrintToString adds quotes
+// to std::string and C strings, it won't work for these types.
+
+#define GTEST_EXPAND_(arg) arg
+#define GTEST_GET_FIRST_(first, ...) first
+#define GTEST_GET_SECOND_(first, second, ...) second
+
+#define INSTANTIATE_TEST_SUITE_P(prefix, test_suite_name, ...)                \
+  static ::testing::internal::ParamGenerator<test_suite_name::ParamType>      \
+      gtest_##prefix##test_suite_name##_EvalGenerator_() {                    \
+    return GTEST_EXPAND_(GTEST_GET_FIRST_(__VA_ARGS__, DUMMY_PARAM_));        \
+  }                                                                           \
+  static ::std::string gtest_##prefix##test_suite_name##_EvalGenerateName_(   \
+      const ::testing::TestParamInfo<test_suite_name::ParamType>& info) {     \
+    if (::testing::internal::AlwaysFalse()) {                                 \
+      ::testing::internal::TestNotEmpty(GTEST_EXPAND_(GTEST_GET_SECOND_(      \
+          __VA_ARGS__,                                                        \
+          ::testing::internal::DefaultParamName<test_suite_name::ParamType>,  \
+          DUMMY_PARAM_)));                                                    \
+      auto t = std::make_tuple(__VA_ARGS__);                                  \
+      static_assert(std::tuple_size<decltype(t)>::value <= 2,                 \
+                    "Too Many Args!");                                        \
+    }                                                                         \
+    return ((GTEST_EXPAND_(GTEST_GET_SECOND_(                                 \
+        __VA_ARGS__,                                                          \
+        ::testing::internal::DefaultParamName<test_suite_name::ParamType>,    \
+        DUMMY_PARAM_))))(info);                                               \
+  }                                                                           \
+  static int gtest_##prefix##test_suite_name##_dummy_                         \
+      GTEST_ATTRIBUTE_UNUSED_ =                                               \
+          ::testing::UnitTest::GetInstance()                                  \
+              ->parameterized_test_registry()                                 \
+              .GetTestSuitePatternHolder<test_suite_name>(                    \
+                  #test_suite_name,                                           \
+                  ::testing::internal::CodeLocation(__FILE__, __LINE__))      \
+              ->AddTestSuiteInstantiation(                                    \
+                  #prefix, &gtest_##prefix##test_suite_name##_EvalGenerator_, \
+                  &gtest_##prefix##test_suite_name##_EvalGenerateName_,       \
+                  __FILE__, __LINE__)
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define INSTANTIATE_TEST_CASE_P                                            \
+  static_assert(::testing::internal::InstantiateTestCase_P_IsDeprecated(), \
+                "");                                                       \
+  INSTANTIATE_TEST_SUITE_P
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+}  // namespace testing
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
diff --git a/3rdparty/gtest/include/gtest/gtest-printers.h b/3rdparty/gtest/include/gtest/gtest-printers.h
new file mode 100644
index 0000000..56a0545
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest-printers.h
@@ -0,0 +1,928 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Google Test - The Google C++ Testing and Mocking Framework
+//
+// This file implements a universal value printer that can print a
+// value of any type T:
+//
+//   void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
+//
+// A user can teach this function how to print a class type T by
+// defining either operator<<() or PrintTo() in the namespace that
+// defines T.  More specifically, the FIRST defined function in the
+// following list will be used (assuming T is defined in namespace
+// foo):
+//
+//   1. foo::PrintTo(const T&, ostream*)
+//   2. operator<<(ostream&, const T&) defined in either foo or the
+//      global namespace.
+//
+// However if T is an STL-style container then it is printed element-wise
+// unless foo::PrintTo(const T&, ostream*) is defined. Note that
+// operator<<() is ignored for container types.
+//
+// If none of the above is defined, it will print the debug string of
+// the value if it is a protocol buffer, or print the raw bytes in the
+// value otherwise.
+//
+// To aid debugging: when T is a reference type, the address of the
+// value is also printed; when T is a (const) char pointer, both the
+// pointer value and the NUL-terminated string it points to are
+// printed.
+//
+// We also provide some convenient wrappers:
+//
+//   // Prints a value to a string.  For a (const or not) char
+//   // pointer, the NUL-terminated string (but not the pointer) is
+//   // printed.
+//   std::string ::testing::PrintToString(const T& value);
+//
+//   // Prints a value tersely: for a reference type, the referenced
+//   // value (but not the address) is printed; for a (const or not) char
+//   // pointer, the NUL-terminated string (but not the pointer) is
+//   // printed.
+//   void ::testing::internal::UniversalTersePrint(const T& value, ostream*);
+//
+//   // Prints value using the type inferred by the compiler.  The difference
+//   // from UniversalTersePrint() is that this function prints both the
+//   // pointer and the NUL-terminated string for a (const or not) char pointer.
+//   void ::testing::internal::UniversalPrint(const T& value, ostream*);
+//
+//   // Prints the fields of a tuple tersely to a string vector, one
+//   // element for each field. Tuple support must be enabled in
+//   // gtest-port.h.
+//   std::vector<string> UniversalTersePrintTupleFieldsToStrings(
+//       const Tuple& value);
+//
+// Known limitation:
+//
+// The print primitives print the elements of an STL-style container
+// using the compiler-inferred type of *iter where iter is a
+// const_iterator of the container.  When const_iterator is an input
+// iterator but not a forward iterator, this inferred type may not
+// match value_type, and the print output may be incorrect.  In
+// practice, this is rarely a problem as for most containers
+// const_iterator is a forward iterator.  We'll fix this if there's an
+// actual need for it.  Note that this fix cannot rely on value_type
+// being defined as many user-defined container types don't have
+// value_type.
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
+#define GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
+
+#include <functional>
+#include <ostream>  // NOLINT
+#include <sstream>
+#include <string>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <vector>
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+
+#if GTEST_HAS_ABSL
+#include "absl/strings/string_view.h"
+#include "absl/types/optional.h"
+#include "absl/types/variant.h"
+#endif  // GTEST_HAS_ABSL
+
+namespace testing {
+
+// Definitions in the 'internal' and 'internal2' name spaces are
+// subject to change without notice.  DO NOT USE THEM IN USER CODE!
+namespace internal2 {
+
+// Prints the given number of bytes in the given object to the given
+// ostream.
+GTEST_API_ void PrintBytesInObjectTo(const unsigned char* obj_bytes,
+                                     size_t count,
+                                     ::std::ostream* os);
+
+// For selecting which printer to use when a given type has neither <<
+// nor PrintTo().
+enum TypeKind {
+  kProtobuf,              // a protobuf type
+  kConvertibleToInteger,  // a type implicitly convertible to BiggestInt
+                          // (e.g. a named or unnamed enum type)
+#if GTEST_HAS_ABSL
+  kConvertibleToStringView,  // a type implicitly convertible to
+                             // absl::string_view
+#endif
+  kOtherType  // anything else
+};
+
+// TypeWithoutFormatter<T, kTypeKind>::PrintValue(value, os) is called
+// by the universal printer to print a value of type T when neither
+// operator<< nor PrintTo() is defined for T, where kTypeKind is the
+// "kind" of T as defined by enum TypeKind.
+template <typename T, TypeKind kTypeKind>
+class TypeWithoutFormatter {
+ public:
+  // This default version is called when kTypeKind is kOtherType.
+  static void PrintValue(const T& value, ::std::ostream* os) {
+    PrintBytesInObjectTo(
+        static_cast<const unsigned char*>(
+            reinterpret_cast<const void*>(std::addressof(value))),
+        sizeof(value), os);
+  }
+};
+
+// We print a protobuf using its ShortDebugString() when the string
+// doesn't exceed this many characters; otherwise we print it using
+// DebugString() for better readability.
+const size_t kProtobufOneLinerMaxLength = 50;
+
+template <typename T>
+class TypeWithoutFormatter<T, kProtobuf> {
+ public:
+  static void PrintValue(const T& value, ::std::ostream* os) {
+    std::string pretty_str = value.ShortDebugString();
+    if (pretty_str.length() > kProtobufOneLinerMaxLength) {
+      pretty_str = "\n" + value.DebugString();
+    }
+    *os << ("<" + pretty_str + ">");
+  }
+};
+
+template <typename T>
+class TypeWithoutFormatter<T, kConvertibleToInteger> {
+ public:
+  // Since T has no << operator or PrintTo() but can be implicitly
+  // converted to BiggestInt, we print it as a BiggestInt.
+  //
+  // Most likely T is an enum type (either named or unnamed), in which
+  // case printing it as an integer is the desired behavior.  In case
+  // T is not an enum, printing it as an integer is the best we can do
+  // given that it has no user-defined printer.
+  static void PrintValue(const T& value, ::std::ostream* os) {
+    const internal::BiggestInt kBigInt = value;
+    *os << kBigInt;
+  }
+};
+
+#if GTEST_HAS_ABSL
+template <typename T>
+class TypeWithoutFormatter<T, kConvertibleToStringView> {
+ public:
+  // Since T has neither operator<< nor PrintTo() but can be implicitly
+  // converted to absl::string_view, we print it as a absl::string_view.
+  //
+  // Note: the implementation is further below, as it depends on
+  // internal::PrintTo symbol which is defined later in the file.
+  static void PrintValue(const T& value, ::std::ostream* os);
+};
+#endif
+
+// Prints the given value to the given ostream.  If the value is a
+// protocol message, its debug string is printed; if it's an enum or
+// of a type implicitly convertible to BiggestInt, it's printed as an
+// integer; otherwise the bytes in the value are printed.  This is
+// what UniversalPrinter<T>::Print() does when it knows nothing about
+// type T and T has neither << operator nor PrintTo().
+//
+// A user can override this behavior for a class type Foo by defining
+// a << operator in the namespace where Foo is defined.
+//
+// We put this operator in namespace 'internal2' instead of 'internal'
+// to simplify the implementation, as much code in 'internal' needs to
+// use << in STL, which would conflict with our own << were it defined
+// in 'internal'.
+//
+// Note that this operator<< takes a generic std::basic_ostream<Char,
+// CharTraits> type instead of the more restricted std::ostream.  If
+// we define it to take an std::ostream instead, we'll get an
+// "ambiguous overloads" compiler error when trying to print a type
+// Foo that supports streaming to std::basic_ostream<Char,
+// CharTraits>, as the compiler cannot tell whether
+// operator<<(std::ostream&, const T&) or
+// operator<<(std::basic_stream<Char, CharTraits>, const Foo&) is more
+// specific.
+template <typename Char, typename CharTraits, typename T>
+::std::basic_ostream<Char, CharTraits>& operator<<(
+    ::std::basic_ostream<Char, CharTraits>& os, const T& x) {
+  TypeWithoutFormatter<T, (internal::IsAProtocolMessage<T>::value
+                               ? kProtobuf
+                               : std::is_convertible<
+                                     const T&, internal::BiggestInt>::value
+                                     ? kConvertibleToInteger
+                                     :
+#if GTEST_HAS_ABSL
+                                     std::is_convertible<
+                                         const T&, absl::string_view>::value
+                                         ? kConvertibleToStringView
+                                         :
+#endif
+                                         kOtherType)>::PrintValue(x, &os);
+  return os;
+}
+
+}  // namespace internal2
+}  // namespace testing
+
+// This namespace MUST NOT BE NESTED IN ::testing, or the name look-up
+// magic needed for implementing UniversalPrinter won't work.
+namespace testing_internal {
+
+// Used to print a value that is not an STL-style container when the
+// user doesn't define PrintTo() for it.
+template <typename T>
+void DefaultPrintNonContainerTo(const T& value, ::std::ostream* os) {
+  // With the following statement, during unqualified name lookup,
+  // testing::internal2::operator<< appears as if it was declared in
+  // the nearest enclosing namespace that contains both
+  // ::testing_internal and ::testing::internal2, i.e. the global
+  // namespace.  For more details, refer to the C++ Standard section
+  // 7.3.4-1 [namespace.udir].  This allows us to fall back onto
+  // testing::internal2::operator<< in case T doesn't come with a <<
+  // operator.
+  //
+  // We cannot write 'using ::testing::internal2::operator<<;', which
+  // gcc 3.3 fails to compile due to a compiler bug.
+  using namespace ::testing::internal2;  // NOLINT
+
+  // Assuming T is defined in namespace foo, in the next statement,
+  // the compiler will consider all of:
+  //
+  //   1. foo::operator<< (thanks to Koenig look-up),
+  //   2. ::operator<< (as the current namespace is enclosed in ::),
+  //   3. testing::internal2::operator<< (thanks to the using statement above).
+  //
+  // The operator<< whose type matches T best will be picked.
+  //
+  // We deliberately allow #2 to be a candidate, as sometimes it's
+  // impossible to define #1 (e.g. when foo is ::std, defining
+  // anything in it is undefined behavior unless you are a compiler
+  // vendor.).
+  *os << value;
+}
+
+}  // namespace testing_internal
+
+namespace testing {
+namespace internal {
+
+// FormatForComparison<ToPrint, OtherOperand>::Format(value) formats a
+// value of type ToPrint that is an operand of a comparison assertion
+// (e.g. ASSERT_EQ).  OtherOperand is the type of the other operand in
+// the comparison, and is used to help determine the best way to
+// format the value.  In particular, when the value is a C string
+// (char pointer) and the other operand is an STL string object, we
+// want to format the C string as a string, since we know it is
+// compared by value with the string object.  If the value is a char
+// pointer but the other operand is not an STL string object, we don't
+// know whether the pointer is supposed to point to a NUL-terminated
+// string, and thus want to print it as a pointer to be safe.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+
+// The default case.
+template <typename ToPrint, typename OtherOperand>
+class FormatForComparison {
+ public:
+  static ::std::string Format(const ToPrint& value) {
+    return ::testing::PrintToString(value);
+  }
+};
+
+// Array.
+template <typename ToPrint, size_t N, typename OtherOperand>
+class FormatForComparison<ToPrint[N], OtherOperand> {
+ public:
+  static ::std::string Format(const ToPrint* value) {
+    return FormatForComparison<const ToPrint*, OtherOperand>::Format(value);
+  }
+};
+
+// By default, print C string as pointers to be safe, as we don't know
+// whether they actually point to a NUL-terminated string.
+
+#define GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(CharType)                \
+  template <typename OtherOperand>                                      \
+  class FormatForComparison<CharType*, OtherOperand> {                  \
+   public:                                                              \
+    static ::std::string Format(CharType* value) {                      \
+      return ::testing::PrintToString(static_cast<const void*>(value)); \
+    }                                                                   \
+  }
+
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(wchar_t);
+GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const wchar_t);
+
+#undef GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_
+
+// If a C string is compared with an STL string object, we know it's meant
+// to point to a NUL-terminated string, and thus can print it as a string.
+
+#define GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(CharType, OtherStringType) \
+  template <>                                                           \
+  class FormatForComparison<CharType*, OtherStringType> {               \
+   public:                                                              \
+    static ::std::string Format(CharType* value) {                      \
+      return ::testing::PrintToString(value);                           \
+    }                                                                   \
+  }
+
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::std::string);
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::std::string);
+
+#if GTEST_HAS_STD_WSTRING
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::std::wstring);
+GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::std::wstring);
+#endif
+
+#undef GTEST_IMPL_FORMAT_C_STRING_AS_STRING_
+
+// Formats a comparison assertion (e.g. ASSERT_EQ, EXPECT_LT, and etc)
+// operand to be used in a failure message.  The type (but not value)
+// of the other operand may affect the format.  This allows us to
+// print a char* as a raw pointer when it is compared against another
+// char* or void*, and print it as a C string when it is compared
+// against an std::string object, for example.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+template <typename T1, typename T2>
+std::string FormatForComparisonFailureMessage(
+    const T1& value, const T2& /* other_operand */) {
+  return FormatForComparison<T1, T2>::Format(value);
+}
+
+// UniversalPrinter<T>::Print(value, ostream_ptr) prints the given
+// value to the given ostream.  The caller must ensure that
+// 'ostream_ptr' is not NULL, or the behavior is undefined.
+//
+// We define UniversalPrinter as a class template (as opposed to a
+// function template), as we need to partially specialize it for
+// reference types, which cannot be done with function templates.
+template <typename T>
+class UniversalPrinter;
+
+template <typename T>
+void UniversalPrint(const T& value, ::std::ostream* os);
+
+enum DefaultPrinterType {
+  kPrintContainer,
+  kPrintPointer,
+  kPrintFunctionPointer,
+  kPrintOther,
+};
+template <DefaultPrinterType type> struct WrapPrinterType {};
+
+// Used to print an STL-style container when the user doesn't define
+// a PrintTo() for it.
+template <typename C>
+void DefaultPrintTo(WrapPrinterType<kPrintContainer> /* dummy */,
+                    const C& container, ::std::ostream* os) {
+  const size_t kMaxCount = 32;  // The maximum number of elements to print.
+  *os << '{';
+  size_t count = 0;
+  for (typename C::const_iterator it = container.begin();
+       it != container.end(); ++it, ++count) {
+    if (count > 0) {
+      *os << ',';
+      if (count == kMaxCount) {  // Enough has been printed.
+        *os << " ...";
+        break;
+      }
+    }
+    *os << ' ';
+    // We cannot call PrintTo(*it, os) here as PrintTo() doesn't
+    // handle *it being a native array.
+    internal::UniversalPrint(*it, os);
+  }
+
+  if (count > 0) {
+    *os << ' ';
+  }
+  *os << '}';
+}
+
+// Used to print a pointer that is neither a char pointer nor a member
+// pointer, when the user doesn't define PrintTo() for it.  (A member
+// variable pointer or member function pointer doesn't really point to
+// a location in the address space.  Their representation is
+// implementation-defined.  Therefore they will be printed as raw
+// bytes.)
+template <typename T>
+void DefaultPrintTo(WrapPrinterType<kPrintPointer> /* dummy */,
+                    T* p, ::std::ostream* os) {
+  if (p == nullptr) {
+    *os << "NULL";
+  } else {
+    // T is not a function type.  We just call << to print p,
+    // relying on ADL to pick up user-defined << for their pointer
+    // types, if any.
+    *os << p;
+  }
+}
+template <typename T>
+void DefaultPrintTo(WrapPrinterType<kPrintFunctionPointer> /* dummy */,
+                    T* p, ::std::ostream* os) {
+  if (p == nullptr) {
+    *os << "NULL";
+  } else {
+    // T is a function type, so '*os << p' doesn't do what we want
+    // (it just prints p as bool).  We want to print p as a const
+    // void*.
+    *os << reinterpret_cast<const void*>(p);
+  }
+}
+
+// Used to print a non-container, non-pointer value when the user
+// doesn't define PrintTo() for it.
+template <typename T>
+void DefaultPrintTo(WrapPrinterType<kPrintOther> /* dummy */,
+                    const T& value, ::std::ostream* os) {
+  ::testing_internal::DefaultPrintNonContainerTo(value, os);
+}
+
+// Prints the given value using the << operator if it has one;
+// otherwise prints the bytes in it.  This is what
+// UniversalPrinter<T>::Print() does when PrintTo() is not specialized
+// or overloaded for type T.
+//
+// A user can override this behavior for a class type Foo by defining
+// an overload of PrintTo() in the namespace where Foo is defined.  We
+// give the user this option as sometimes defining a << operator for
+// Foo is not desirable (e.g. the coding style may prevent doing it,
+// or there is already a << operator but it doesn't do what the user
+// wants).
+template <typename T>
+void PrintTo(const T& value, ::std::ostream* os) {
+  // DefaultPrintTo() is overloaded.  The type of its first argument
+  // determines which version will be picked.
+  //
+  // Note that we check for container types here, prior to we check
+  // for protocol message types in our operator<<.  The rationale is:
+  //
+  // For protocol messages, we want to give people a chance to
+  // override Google Mock's format by defining a PrintTo() or
+  // operator<<.  For STL containers, other formats can be
+  // incompatible with Google Mock's format for the container
+  // elements; therefore we check for container types here to ensure
+  // that our format is used.
+  //
+  // Note that MSVC and clang-cl do allow an implicit conversion from
+  // pointer-to-function to pointer-to-object, but clang-cl warns on it.
+  // So don't use ImplicitlyConvertible if it can be helped since it will
+  // cause this warning, and use a separate overload of DefaultPrintTo for
+  // function pointers so that the `*os << p` in the object pointer overload
+  // doesn't cause that warning either.
+  DefaultPrintTo(
+      WrapPrinterType <
+                  (sizeof(IsContainerTest<T>(0)) == sizeof(IsContainer)) &&
+              !IsRecursiveContainer<T>::value
+          ? kPrintContainer
+          : !std::is_pointer<T>::value
+                ? kPrintOther
+                : std::is_function<typename std::remove_pointer<T>::type>::value
+                      ? kPrintFunctionPointer
+                      : kPrintPointer > (),
+      value, os);
+}
+
+// The following list of PrintTo() overloads tells
+// UniversalPrinter<T>::Print() how to print standard types (built-in
+// types, strings, plain arrays, and pointers).
+
+// Overloads for various char types.
+GTEST_API_ void PrintTo(unsigned char c, ::std::ostream* os);
+GTEST_API_ void PrintTo(signed char c, ::std::ostream* os);
+inline void PrintTo(char c, ::std::ostream* os) {
+  // When printing a plain char, we always treat it as unsigned.  This
+  // way, the output won't be affected by whether the compiler thinks
+  // char is signed or not.
+  PrintTo(static_cast<unsigned char>(c), os);
+}
+
+// Overloads for other simple built-in types.
+inline void PrintTo(bool x, ::std::ostream* os) {
+  *os << (x ? "true" : "false");
+}
+
+// Overload for wchar_t type.
+// Prints a wchar_t as a symbol if it is printable or as its internal
+// code otherwise and also as its decimal code (except for L'\0').
+// The L'\0' char is printed as "L'\\0'". The decimal code is printed
+// as signed integer when wchar_t is implemented by the compiler
+// as a signed type and is printed as an unsigned integer when wchar_t
+// is implemented as an unsigned type.
+GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os);
+
+// Overloads for C strings.
+GTEST_API_ void PrintTo(const char* s, ::std::ostream* os);
+inline void PrintTo(char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const char*>(s), os);
+}
+
+// signed/unsigned char is often used for representing binary data, so
+// we print pointers to it as void* to be safe.
+inline void PrintTo(const signed char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const void*>(s), os);
+}
+inline void PrintTo(signed char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const void*>(s), os);
+}
+inline void PrintTo(const unsigned char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const void*>(s), os);
+}
+inline void PrintTo(unsigned char* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const void*>(s), os);
+}
+
+// MSVC can be configured to define wchar_t as a typedef of unsigned
+// short.  It defines _NATIVE_WCHAR_T_DEFINED when wchar_t is a native
+// type.  When wchar_t is a typedef, defining an overload for const
+// wchar_t* would cause unsigned short* be printed as a wide string,
+// possibly causing invalid memory accesses.
+#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
+// Overloads for wide C strings
+GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os);
+inline void PrintTo(wchar_t* s, ::std::ostream* os) {
+  PrintTo(ImplicitCast_<const wchar_t*>(s), os);
+}
+#endif
+
+// Overload for C arrays.  Multi-dimensional arrays are printed
+// properly.
+
+// Prints the given number of elements in an array, without printing
+// the curly braces.
+template <typename T>
+void PrintRawArrayTo(const T a[], size_t count, ::std::ostream* os) {
+  UniversalPrint(a[0], os);
+  for (size_t i = 1; i != count; i++) {
+    *os << ", ";
+    UniversalPrint(a[i], os);
+  }
+}
+
+// Overloads for ::std::string.
+GTEST_API_ void PrintStringTo(const ::std::string&s, ::std::ostream* os);
+inline void PrintTo(const ::std::string& s, ::std::ostream* os) {
+  PrintStringTo(s, os);
+}
+
+// Overloads for ::std::wstring.
+#if GTEST_HAS_STD_WSTRING
+GTEST_API_ void PrintWideStringTo(const ::std::wstring&s, ::std::ostream* os);
+inline void PrintTo(const ::std::wstring& s, ::std::ostream* os) {
+  PrintWideStringTo(s, os);
+}
+#endif  // GTEST_HAS_STD_WSTRING
+
+#if GTEST_HAS_ABSL
+// Overload for absl::string_view.
+inline void PrintTo(absl::string_view sp, ::std::ostream* os) {
+  PrintTo(::std::string(sp), os);
+}
+#endif  // GTEST_HAS_ABSL
+
+inline void PrintTo(std::nullptr_t, ::std::ostream* os) { *os << "(nullptr)"; }
+
+template <typename T>
+void PrintTo(std::reference_wrapper<T> ref, ::std::ostream* os) {
+  UniversalPrinter<T&>::Print(ref.get(), os);
+}
+
+// Helper function for printing a tuple.  T must be instantiated with
+// a tuple type.
+template <typename T>
+void PrintTupleTo(const T&, std::integral_constant<size_t, 0>,
+                  ::std::ostream*) {}
+
+template <typename T, size_t I>
+void PrintTupleTo(const T& t, std::integral_constant<size_t, I>,
+                  ::std::ostream* os) {
+  PrintTupleTo(t, std::integral_constant<size_t, I - 1>(), os);
+  GTEST_INTENTIONAL_CONST_COND_PUSH_()
+  if (I > 1) {
+    GTEST_INTENTIONAL_CONST_COND_POP_()
+    *os << ", ";
+  }
+  UniversalPrinter<typename std::tuple_element<I - 1, T>::type>::Print(
+      std::get<I - 1>(t), os);
+}
+
+template <typename... Types>
+void PrintTo(const ::std::tuple<Types...>& t, ::std::ostream* os) {
+  *os << "(";
+  PrintTupleTo(t, std::integral_constant<size_t, sizeof...(Types)>(), os);
+  *os << ")";
+}
+
+// Overload for std::pair.
+template <typename T1, typename T2>
+void PrintTo(const ::std::pair<T1, T2>& value, ::std::ostream* os) {
+  *os << '(';
+  // We cannot use UniversalPrint(value.first, os) here, as T1 may be
+  // a reference type.  The same for printing value.second.
+  UniversalPrinter<T1>::Print(value.first, os);
+  *os << ", ";
+  UniversalPrinter<T2>::Print(value.second, os);
+  *os << ')';
+}
+
+// Implements printing a non-reference type T by letting the compiler
+// pick the right overload of PrintTo() for T.
+template <typename T>
+class UniversalPrinter {
+ public:
+  // MSVC warns about adding const to a function type, so we want to
+  // disable the warning.
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
+
+  // Note: we deliberately don't call this PrintTo(), as that name
+  // conflicts with ::testing::internal::PrintTo in the body of the
+  // function.
+  static void Print(const T& value, ::std::ostream* os) {
+    // By default, ::testing::internal::PrintTo() is used for printing
+    // the value.
+    //
+    // Thanks to Koenig look-up, if T is a class and has its own
+    // PrintTo() function defined in its namespace, that function will
+    // be visible here.  Since it is more specific than the generic ones
+    // in ::testing::internal, it will be picked by the compiler in the
+    // following statement - exactly what we want.
+    PrintTo(value, os);
+  }
+
+  GTEST_DISABLE_MSC_WARNINGS_POP_()
+};
+
+#if GTEST_HAS_ABSL
+
+// Printer for absl::optional
+
+template <typename T>
+class UniversalPrinter<::absl::optional<T>> {
+ public:
+  static void Print(const ::absl::optional<T>& value, ::std::ostream* os) {
+    *os << '(';
+    if (!value) {
+      *os << "nullopt";
+    } else {
+      UniversalPrint(*value, os);
+    }
+    *os << ')';
+  }
+};
+
+// Printer for absl::variant
+
+template <typename... T>
+class UniversalPrinter<::absl::variant<T...>> {
+ public:
+  static void Print(const ::absl::variant<T...>& value, ::std::ostream* os) {
+    *os << '(';
+    absl::visit(Visitor{os}, value);
+    *os << ')';
+  }
+
+ private:
+  struct Visitor {
+    template <typename U>
+    void operator()(const U& u) const {
+      *os << "'" << GetTypeName<U>() << "' with value ";
+      UniversalPrint(u, os);
+    }
+    ::std::ostream* os;
+  };
+};
+
+#endif  // GTEST_HAS_ABSL
+
+// UniversalPrintArray(begin, len, os) prints an array of 'len'
+// elements, starting at address 'begin'.
+template <typename T>
+void UniversalPrintArray(const T* begin, size_t len, ::std::ostream* os) {
+  if (len == 0) {
+    *os << "{}";
+  } else {
+    *os << "{ ";
+    const size_t kThreshold = 18;
+    const size_t kChunkSize = 8;
+    // If the array has more than kThreshold elements, we'll have to
+    // omit some details by printing only the first and the last
+    // kChunkSize elements.
+    if (len <= kThreshold) {
+      PrintRawArrayTo(begin, len, os);
+    } else {
+      PrintRawArrayTo(begin, kChunkSize, os);
+      *os << ", ..., ";
+      PrintRawArrayTo(begin + len - kChunkSize, kChunkSize, os);
+    }
+    *os << " }";
+  }
+}
+// This overload prints a (const) char array compactly.
+GTEST_API_ void UniversalPrintArray(
+    const char* begin, size_t len, ::std::ostream* os);
+
+// This overload prints a (const) wchar_t array compactly.
+GTEST_API_ void UniversalPrintArray(
+    const wchar_t* begin, size_t len, ::std::ostream* os);
+
+// Implements printing an array type T[N].
+template <typename T, size_t N>
+class UniversalPrinter<T[N]> {
+ public:
+  // Prints the given array, omitting some elements when there are too
+  // many.
+  static void Print(const T (&a)[N], ::std::ostream* os) {
+    UniversalPrintArray(a, N, os);
+  }
+};
+
+// Implements printing a reference type T&.
+template <typename T>
+class UniversalPrinter<T&> {
+ public:
+  // MSVC warns about adding const to a function type, so we want to
+  // disable the warning.
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
+
+  static void Print(const T& value, ::std::ostream* os) {
+    // Prints the address of the value.  We use reinterpret_cast here
+    // as static_cast doesn't compile when T is a function type.
+    *os << "@" << reinterpret_cast<const void*>(&value) << " ";
+
+    // Then prints the value itself.
+    UniversalPrint(value, os);
+  }
+
+  GTEST_DISABLE_MSC_WARNINGS_POP_()
+};
+
+// Prints a value tersely: for a reference type, the referenced value
+// (but not the address) is printed; for a (const) char pointer, the
+// NUL-terminated string (but not the pointer) is printed.
+
+template <typename T>
+class UniversalTersePrinter {
+ public:
+  static void Print(const T& value, ::std::ostream* os) {
+    UniversalPrint(value, os);
+  }
+};
+template <typename T>
+class UniversalTersePrinter<T&> {
+ public:
+  static void Print(const T& value, ::std::ostream* os) {
+    UniversalPrint(value, os);
+  }
+};
+template <typename T, size_t N>
+class UniversalTersePrinter<T[N]> {
+ public:
+  static void Print(const T (&value)[N], ::std::ostream* os) {
+    UniversalPrinter<T[N]>::Print(value, os);
+  }
+};
+template <>
+class UniversalTersePrinter<const char*> {
+ public:
+  static void Print(const char* str, ::std::ostream* os) {
+    if (str == nullptr) {
+      *os << "NULL";
+    } else {
+      UniversalPrint(std::string(str), os);
+    }
+  }
+};
+template <>
+class UniversalTersePrinter<char*> {
+ public:
+  static void Print(char* str, ::std::ostream* os) {
+    UniversalTersePrinter<const char*>::Print(str, os);
+  }
+};
+
+#if GTEST_HAS_STD_WSTRING
+template <>
+class UniversalTersePrinter<const wchar_t*> {
+ public:
+  static void Print(const wchar_t* str, ::std::ostream* os) {
+    if (str == nullptr) {
+      *os << "NULL";
+    } else {
+      UniversalPrint(::std::wstring(str), os);
+    }
+  }
+};
+#endif
+
+template <>
+class UniversalTersePrinter<wchar_t*> {
+ public:
+  static void Print(wchar_t* str, ::std::ostream* os) {
+    UniversalTersePrinter<const wchar_t*>::Print(str, os);
+  }
+};
+
+template <typename T>
+void UniversalTersePrint(const T& value, ::std::ostream* os) {
+  UniversalTersePrinter<T>::Print(value, os);
+}
+
+// Prints a value using the type inferred by the compiler.  The
+// difference between this and UniversalTersePrint() is that for a
+// (const) char pointer, this prints both the pointer and the
+// NUL-terminated string.
+template <typename T>
+void UniversalPrint(const T& value, ::std::ostream* os) {
+  // A workarond for the bug in VC++ 7.1 that prevents us from instantiating
+  // UniversalPrinter with T directly.
+  typedef T T1;
+  UniversalPrinter<T1>::Print(value, os);
+}
+
+typedef ::std::vector< ::std::string> Strings;
+
+  // Tersely prints the first N fields of a tuple to a string vector,
+  // one element for each field.
+template <typename Tuple>
+void TersePrintPrefixToStrings(const Tuple&, std::integral_constant<size_t, 0>,
+                               Strings*) {}
+template <typename Tuple, size_t I>
+void TersePrintPrefixToStrings(const Tuple& t,
+                               std::integral_constant<size_t, I>,
+                               Strings* strings) {
+  TersePrintPrefixToStrings(t, std::integral_constant<size_t, I - 1>(),
+                            strings);
+  ::std::stringstream ss;
+  UniversalTersePrint(std::get<I - 1>(t), &ss);
+  strings->push_back(ss.str());
+}
+
+// Prints the fields of a tuple tersely to a string vector, one
+// element for each field.  See the comment before
+// UniversalTersePrint() for how we define "tersely".
+template <typename Tuple>
+Strings UniversalTersePrintTupleFieldsToStrings(const Tuple& value) {
+  Strings result;
+  TersePrintPrefixToStrings(
+      value, std::integral_constant<size_t, std::tuple_size<Tuple>::value>(),
+      &result);
+  return result;
+}
+
+}  // namespace internal
+
+#if GTEST_HAS_ABSL
+namespace internal2 {
+template <typename T>
+void TypeWithoutFormatter<T, kConvertibleToStringView>::PrintValue(
+    const T& value, ::std::ostream* os) {
+  internal::PrintTo(absl::string_view(value), os);
+}
+}  // namespace internal2
+#endif
+
+template <typename T>
+::std::string PrintToString(const T& value) {
+  ::std::stringstream ss;
+  internal::UniversalTersePrinter<T>::Print(value, &ss);
+  return ss.str();
+}
+
+}  // namespace testing
+
+// Include any custom printer added by the local installation.
+// We must include this header at the end to make sure it can use the
+// declarations from this file.
+#include "gtest/internal/custom/gtest-printers.h"
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
diff --git a/3rdparty/gtest/include/gtest/gtest-spi.h b/3rdparty/gtest/include/gtest/gtest-spi.h
new file mode 100644
index 0000000..aa38870
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest-spi.h
@@ -0,0 +1,238 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Utilities for testing Google Test itself and code that uses Google Test
+// (e.g. frameworks built on top of Google Test).
+
+// GOOGLETEST_CM0004 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_SPI_H_
+#define GTEST_INCLUDE_GTEST_GTEST_SPI_H_
+
+#include "gtest/gtest.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+
+// This helper class can be used to mock out Google Test failure reporting
+// so that we can test Google Test or code that builds on Google Test.
+//
+// An object of this class appends a TestPartResult object to the
+// TestPartResultArray object given in the constructor whenever a Google Test
+// failure is reported. It can either intercept only failures that are
+// generated in the same thread that created this object or it can intercept
+// all generated failures. The scope of this mock object can be controlled with
+// the second argument to the two arguments constructor.
+class GTEST_API_ ScopedFakeTestPartResultReporter
+    : public TestPartResultReporterInterface {
+ public:
+  // The two possible mocking modes of this object.
+  enum InterceptMode {
+    INTERCEPT_ONLY_CURRENT_THREAD,  // Intercepts only thread local failures.
+    INTERCEPT_ALL_THREADS           // Intercepts all failures.
+  };
+
+  // The c'tor sets this object as the test part result reporter used
+  // by Google Test.  The 'result' parameter specifies where to report the
+  // results. This reporter will only catch failures generated in the current
+  // thread. DEPRECATED
+  explicit ScopedFakeTestPartResultReporter(TestPartResultArray* result);
+
+  // Same as above, but you can choose the interception scope of this object.
+  ScopedFakeTestPartResultReporter(InterceptMode intercept_mode,
+                                   TestPartResultArray* result);
+
+  // The d'tor restores the previous test part result reporter.
+  ~ScopedFakeTestPartResultReporter() override;
+
+  // Appends the TestPartResult object to the TestPartResultArray
+  // received in the constructor.
+  //
+  // This method is from the TestPartResultReporterInterface
+  // interface.
+  void ReportTestPartResult(const TestPartResult& result) override;
+
+ private:
+  void Init();
+
+  const InterceptMode intercept_mode_;
+  TestPartResultReporterInterface* old_reporter_;
+  TestPartResultArray* const result_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ScopedFakeTestPartResultReporter);
+};
+
+namespace internal {
+
+// A helper class for implementing EXPECT_FATAL_FAILURE() and
+// EXPECT_NONFATAL_FAILURE().  Its destructor verifies that the given
+// TestPartResultArray contains exactly one failure that has the given
+// type and contains the given substring.  If that's not the case, a
+// non-fatal failure will be generated.
+class GTEST_API_ SingleFailureChecker {
+ public:
+  // The constructor remembers the arguments.
+  SingleFailureChecker(const TestPartResultArray* results,
+                       TestPartResult::Type type, const std::string& substr);
+  ~SingleFailureChecker();
+ private:
+  const TestPartResultArray* const results_;
+  const TestPartResult::Type type_;
+  const std::string substr_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(SingleFailureChecker);
+};
+
+}  // namespace internal
+
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+// A set of macros for testing Google Test assertions or code that's expected
+// to generate Google Test fatal failures.  It verifies that the given
+// statement will cause exactly one fatal Google Test failure with 'substr'
+// being part of the failure message.
+//
+// There are two different versions of this macro. EXPECT_FATAL_FAILURE only
+// affects and considers failures generated in the current thread and
+// EXPECT_FATAL_FAILURE_ON_ALL_THREADS does the same but for all threads.
+//
+// The verification of the assertion is done correctly even when the statement
+// throws an exception or aborts the current function.
+//
+// Known restrictions:
+//   - 'statement' cannot reference local non-static variables or
+//     non-static members of the current object.
+//   - 'statement' cannot return a value.
+//   - You cannot stream a failure message to this macro.
+//
+// Note that even though the implementations of the following two
+// macros are much alike, we cannot refactor them to use a common
+// helper macro, due to some peculiarity in how the preprocessor
+// works.  The AcceptsMacroThatExpandsToUnprotectedComma test in
+// gtest_unittest.cc will fail to compile if we do that.
+#define EXPECT_FATAL_FAILURE(statement, substr) \
+  do { \
+    class GTestExpectFatalFailureHelper {\
+     public:\
+      static void Execute() { statement; }\
+    };\
+    ::testing::TestPartResultArray gtest_failures;\
+    ::testing::internal::SingleFailureChecker gtest_checker(\
+        &gtest_failures, ::testing::TestPartResult::kFatalFailure, (substr));\
+    {\
+      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(\
+          ::testing::ScopedFakeTestPartResultReporter:: \
+          INTERCEPT_ONLY_CURRENT_THREAD, &gtest_failures);\
+      GTestExpectFatalFailureHelper::Execute();\
+    }\
+  } while (::testing::internal::AlwaysFalse())
+
+#define EXPECT_FATAL_FAILURE_ON_ALL_THREADS(statement, substr) \
+  do { \
+    class GTestExpectFatalFailureHelper {\
+     public:\
+      static void Execute() { statement; }\
+    };\
+    ::testing::TestPartResultArray gtest_failures;\
+    ::testing::internal::SingleFailureChecker gtest_checker(\
+        &gtest_failures, ::testing::TestPartResult::kFatalFailure, (substr));\
+    {\
+      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(\
+          ::testing::ScopedFakeTestPartResultReporter:: \
+          INTERCEPT_ALL_THREADS, &gtest_failures);\
+      GTestExpectFatalFailureHelper::Execute();\
+    }\
+  } while (::testing::internal::AlwaysFalse())
+
+// A macro for testing Google Test assertions or code that's expected to
+// generate Google Test non-fatal failures.  It asserts that the given
+// statement will cause exactly one non-fatal Google Test failure with 'substr'
+// being part of the failure message.
+//
+// There are two different versions of this macro. EXPECT_NONFATAL_FAILURE only
+// affects and considers failures generated in the current thread and
+// EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS does the same but for all threads.
+//
+// 'statement' is allowed to reference local variables and members of
+// the current object.
+//
+// The verification of the assertion is done correctly even when the statement
+// throws an exception or aborts the current function.
+//
+// Known restrictions:
+//   - You cannot stream a failure message to this macro.
+//
+// Note that even though the implementations of the following two
+// macros are much alike, we cannot refactor them to use a common
+// helper macro, due to some peculiarity in how the preprocessor
+// works.  If we do that, the code won't compile when the user gives
+// EXPECT_NONFATAL_FAILURE() a statement that contains a macro that
+// expands to code containing an unprotected comma.  The
+// AcceptsMacroThatExpandsToUnprotectedComma test in gtest_unittest.cc
+// catches that.
+//
+// For the same reason, we have to write
+//   if (::testing::internal::AlwaysTrue()) { statement; }
+// instead of
+//   GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement)
+// to avoid an MSVC warning on unreachable code.
+#define EXPECT_NONFATAL_FAILURE(statement, substr) \
+  do {\
+    ::testing::TestPartResultArray gtest_failures;\
+    ::testing::internal::SingleFailureChecker gtest_checker(\
+        &gtest_failures, ::testing::TestPartResult::kNonFatalFailure, \
+        (substr));\
+    {\
+      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(\
+          ::testing::ScopedFakeTestPartResultReporter:: \
+          INTERCEPT_ONLY_CURRENT_THREAD, &gtest_failures);\
+      if (::testing::internal::AlwaysTrue()) { statement; }\
+    }\
+  } while (::testing::internal::AlwaysFalse())
+
+#define EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(statement, substr) \
+  do {\
+    ::testing::TestPartResultArray gtest_failures;\
+    ::testing::internal::SingleFailureChecker gtest_checker(\
+        &gtest_failures, ::testing::TestPartResult::kNonFatalFailure, \
+        (substr));\
+    {\
+      ::testing::ScopedFakeTestPartResultReporter gtest_reporter(\
+          ::testing::ScopedFakeTestPartResultReporter::INTERCEPT_ALL_THREADS, \
+          &gtest_failures);\
+      if (::testing::internal::AlwaysTrue()) { statement; }\
+    }\
+  } while (::testing::internal::AlwaysFalse())
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_SPI_H_
diff --git a/3rdparty/gtest/include/gtest/gtest-test-part.h b/3rdparty/gtest/include/gtest/gtest-test-part.h
new file mode 100644
index 0000000..05a7985
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest-test-part.h
@@ -0,0 +1,184 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
+#define GTEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
+
+#include <iosfwd>
+#include <vector>
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-string.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+
+// A copyable object representing the result of a test part (i.e. an
+// assertion or an explicit FAIL(), ADD_FAILURE(), or SUCCESS()).
+//
+// Don't inherit from TestPartResult as its destructor is not virtual.
+class GTEST_API_ TestPartResult {
+ public:
+  // The possible outcomes of a test part (i.e. an assertion or an
+  // explicit SUCCEED(), FAIL(), or ADD_FAILURE()).
+  enum Type {
+    kSuccess,          // Succeeded.
+    kNonFatalFailure,  // Failed but the test can continue.
+    kFatalFailure,     // Failed and the test should be terminated.
+    kSkip              // Skipped.
+  };
+
+  // C'tor.  TestPartResult does NOT have a default constructor.
+  // Always use this constructor (with parameters) to create a
+  // TestPartResult object.
+  TestPartResult(Type a_type, const char* a_file_name, int a_line_number,
+                 const char* a_message)
+      : type_(a_type),
+        file_name_(a_file_name == nullptr ? "" : a_file_name),
+        line_number_(a_line_number),
+        summary_(ExtractSummary(a_message)),
+        message_(a_message) {}
+
+  // Gets the outcome of the test part.
+  Type type() const { return type_; }
+
+  // Gets the name of the source file where the test part took place, or
+  // NULL if it's unknown.
+  const char* file_name() const {
+    return file_name_.empty() ? nullptr : file_name_.c_str();
+  }
+
+  // Gets the line in the source file where the test part took place,
+  // or -1 if it's unknown.
+  int line_number() const { return line_number_; }
+
+  // Gets the summary of the failure message.
+  const char* summary() const { return summary_.c_str(); }
+
+  // Gets the message associated with the test part.
+  const char* message() const { return message_.c_str(); }
+
+  // Returns true if and only if the test part was skipped.
+  bool skipped() const { return type_ == kSkip; }
+
+  // Returns true if and only if the test part passed.
+  bool passed() const { return type_ == kSuccess; }
+
+  // Returns true if and only if the test part non-fatally failed.
+  bool nonfatally_failed() const { return type_ == kNonFatalFailure; }
+
+  // Returns true if and only if the test part fatally failed.
+  bool fatally_failed() const { return type_ == kFatalFailure; }
+
+  // Returns true if and only if the test part failed.
+  bool failed() const { return fatally_failed() || nonfatally_failed(); }
+
+ private:
+  Type type_;
+
+  // Gets the summary of the failure message by omitting the stack
+  // trace in it.
+  static std::string ExtractSummary(const char* message);
+
+  // The name of the source file where the test part took place, or
+  // "" if the source file is unknown.
+  std::string file_name_;
+  // The line in the source file where the test part took place, or -1
+  // if the line number is unknown.
+  int line_number_;
+  std::string summary_;  // The test failure summary.
+  std::string message_;  // The test failure message.
+};
+
+// Prints a TestPartResult object.
+std::ostream& operator<<(std::ostream& os, const TestPartResult& result);
+
+// An array of TestPartResult objects.
+//
+// Don't inherit from TestPartResultArray as its destructor is not
+// virtual.
+class GTEST_API_ TestPartResultArray {
+ public:
+  TestPartResultArray() {}
+
+  // Appends the given TestPartResult to the array.
+  void Append(const TestPartResult& result);
+
+  // Returns the TestPartResult at the given index (0-based).
+  const TestPartResult& GetTestPartResult(int index) const;
+
+  // Returns the number of TestPartResult objects in the array.
+  int size() const;
+
+ private:
+  std::vector<TestPartResult> array_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestPartResultArray);
+};
+
+// This interface knows how to report a test part result.
+class GTEST_API_ TestPartResultReporterInterface {
+ public:
+  virtual ~TestPartResultReporterInterface() {}
+
+  virtual void ReportTestPartResult(const TestPartResult& result) = 0;
+};
+
+namespace internal {
+
+// This helper class is used by {ASSERT|EXPECT}_NO_FATAL_FAILURE to check if a
+// statement generates new fatal failures. To do so it registers itself as the
+// current test part result reporter. Besides checking if fatal failures were
+// reported, it only delegates the reporting to the former result reporter.
+// The original result reporter is restored in the destructor.
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+class GTEST_API_ HasNewFatalFailureHelper
+    : public TestPartResultReporterInterface {
+ public:
+  HasNewFatalFailureHelper();
+  ~HasNewFatalFailureHelper() override;
+  void ReportTestPartResult(const TestPartResult& result) override;
+  bool has_new_fatal_failure() const { return has_new_fatal_failure_; }
+ private:
+  bool has_new_fatal_failure_;
+  TestPartResultReporterInterface* original_reporter_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(HasNewFatalFailureHelper);
+};
+
+}  // namespace internal
+
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
diff --git a/3rdparty/gtest/include/gtest/gtest-typed-test.h b/3rdparty/gtest/include/gtest/gtest-typed-test.h
new file mode 100644
index 0000000..095ce05
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest-typed-test.h
@@ -0,0 +1,330 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
+#define GTEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
+
+// This header implements typed tests and type-parameterized tests.
+
+// Typed (aka type-driven) tests repeat the same test for types in a
+// list.  You must know which types you want to test with when writing
+// typed tests. Here's how you do it:
+
+#if 0
+
+// First, define a fixture class template.  It should be parameterized
+// by a type.  Remember to derive it from testing::Test.
+template <typename T>
+class FooTest : public testing::Test {
+ public:
+  ...
+  typedef std::list<T> List;
+  static T shared_;
+  T value_;
+};
+
+// Next, associate a list of types with the test suite, which will be
+// repeated for each type in the list.  The typedef is necessary for
+// the macro to parse correctly.
+typedef testing::Types<char, int, unsigned int> MyTypes;
+TYPED_TEST_SUITE(FooTest, MyTypes);
+
+// If the type list contains only one type, you can write that type
+// directly without Types<...>:
+//   TYPED_TEST_SUITE(FooTest, int);
+
+// Then, use TYPED_TEST() instead of TEST_F() to define as many typed
+// tests for this test suite as you want.
+TYPED_TEST(FooTest, DoesBlah) {
+  // Inside a test, refer to the special name TypeParam to get the type
+  // parameter.  Since we are inside a derived class template, C++ requires
+  // us to visit the members of FooTest via 'this'.
+  TypeParam n = this->value_;
+
+  // To visit static members of the fixture, add the TestFixture::
+  // prefix.
+  n += TestFixture::shared_;
+
+  // To refer to typedefs in the fixture, add the "typename
+  // TestFixture::" prefix.
+  typename TestFixture::List values;
+  values.push_back(n);
+  ...
+}
+
+TYPED_TEST(FooTest, HasPropertyA) { ... }
+
+// TYPED_TEST_SUITE takes an optional third argument which allows to specify a
+// class that generates custom test name suffixes based on the type. This should
+// be a class which has a static template function GetName(int index) returning
+// a string for each type. The provided integer index equals the index of the
+// type in the provided type list. In many cases the index can be ignored.
+//
+// For example:
+//   class MyTypeNames {
+//    public:
+//     template <typename T>
+//     static std::string GetName(int) {
+//       if (std::is_same<T, char>()) return "char";
+//       if (std::is_same<T, int>()) return "int";
+//       if (std::is_same<T, unsigned int>()) return "unsignedInt";
+//     }
+//   };
+//   TYPED_TEST_SUITE(FooTest, MyTypes, MyTypeNames);
+
+#endif  // 0
+
+// Type-parameterized tests are abstract test patterns parameterized
+// by a type.  Compared with typed tests, type-parameterized tests
+// allow you to define the test pattern without knowing what the type
+// parameters are.  The defined pattern can be instantiated with
+// different types any number of times, in any number of translation
+// units.
+//
+// If you are designing an interface or concept, you can define a
+// suite of type-parameterized tests to verify properties that any
+// valid implementation of the interface/concept should have.  Then,
+// each implementation can easily instantiate the test suite to verify
+// that it conforms to the requirements, without having to write
+// similar tests repeatedly.  Here's an example:
+
+#if 0
+
+// First, define a fixture class template.  It should be parameterized
+// by a type.  Remember to derive it from testing::Test.
+template <typename T>
+class FooTest : public testing::Test {
+  ...
+};
+
+// Next, declare that you will define a type-parameterized test suite
+// (the _P suffix is for "parameterized" or "pattern", whichever you
+// prefer):
+TYPED_TEST_SUITE_P(FooTest);
+
+// Then, use TYPED_TEST_P() to define as many type-parameterized tests
+// for this type-parameterized test suite as you want.
+TYPED_TEST_P(FooTest, DoesBlah) {
+  // Inside a test, refer to TypeParam to get the type parameter.
+  TypeParam n = 0;
+  ...
+}
+
+TYPED_TEST_P(FooTest, HasPropertyA) { ... }
+
+// Now the tricky part: you need to register all test patterns before
+// you can instantiate them.  The first argument of the macro is the
+// test suite name; the rest are the names of the tests in this test
+// case.
+REGISTER_TYPED_TEST_SUITE_P(FooTest,
+                            DoesBlah, HasPropertyA);
+
+// Finally, you are free to instantiate the pattern with the types you
+// want.  If you put the above code in a header file, you can #include
+// it in multiple C++ source files and instantiate it multiple times.
+//
+// To distinguish different instances of the pattern, the first
+// argument to the INSTANTIATE_* macro is a prefix that will be added
+// to the actual test suite name.  Remember to pick unique prefixes for
+// different instances.
+typedef testing::Types<char, int, unsigned int> MyTypes;
+INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, MyTypes);
+
+// If the type list contains only one type, you can write that type
+// directly without Types<...>:
+//   INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, int);
+//
+// Similar to the optional argument of TYPED_TEST_SUITE above,
+// INSTANTIATE_TEST_SUITE_P takes an optional fourth argument which allows to
+// generate custom names.
+//   INSTANTIATE_TYPED_TEST_SUITE_P(My, FooTest, MyTypes, MyTypeNames);
+
+#endif  // 0
+
+#include "gtest/internal/gtest-port.h"
+#include "gtest/internal/gtest-type-util.h"
+
+// Implements typed tests.
+
+#if GTEST_HAS_TYPED_TEST
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Expands to the name of the typedef for the type parameters of the
+// given test suite.
+#define GTEST_TYPE_PARAMS_(TestSuiteName) gtest_type_params_##TestSuiteName##_
+
+// Expands to the name of the typedef for the NameGenerator, responsible for
+// creating the suffixes of the name.
+#define GTEST_NAME_GENERATOR_(TestSuiteName) \
+  gtest_type_params_##TestSuiteName##_NameGenerator
+
+#define TYPED_TEST_SUITE(CaseName, Types, ...)                           \
+  typedef ::testing::internal::TypeList<Types>::type GTEST_TYPE_PARAMS_( \
+      CaseName);                                                         \
+  typedef ::testing::internal::NameGeneratorSelector<__VA_ARGS__>::type  \
+      GTEST_NAME_GENERATOR_(CaseName)
+
+# define TYPED_TEST(CaseName, TestName)                                       \
+  template <typename gtest_TypeParam_>                                        \
+  class GTEST_TEST_CLASS_NAME_(CaseName, TestName)                            \
+      : public CaseName<gtest_TypeParam_> {                                   \
+   private:                                                                   \
+    typedef CaseName<gtest_TypeParam_> TestFixture;                           \
+    typedef gtest_TypeParam_ TypeParam;                                       \
+    virtual void TestBody();                                                  \
+  };                                                                          \
+  static bool gtest_##CaseName##_##TestName##_registered_                     \
+        GTEST_ATTRIBUTE_UNUSED_ =                                             \
+      ::testing::internal::TypeParameterizedTest<                             \
+          CaseName,                                                           \
+          ::testing::internal::TemplateSel<GTEST_TEST_CLASS_NAME_(CaseName,   \
+                                                                  TestName)>, \
+          GTEST_TYPE_PARAMS_(                                                 \
+              CaseName)>::Register("",                                        \
+                                   ::testing::internal::CodeLocation(         \
+                                       __FILE__, __LINE__),                   \
+                                   #CaseName, #TestName, 0,                   \
+                                   ::testing::internal::GenerateNames<        \
+                                       GTEST_NAME_GENERATOR_(CaseName),       \
+                                       GTEST_TYPE_PARAMS_(CaseName)>());      \
+  template <typename gtest_TypeParam_>                                        \
+  void GTEST_TEST_CLASS_NAME_(CaseName,                                       \
+                              TestName)<gtest_TypeParam_>::TestBody()
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define TYPED_TEST_CASE                                                \
+  static_assert(::testing::internal::TypedTestCaseIsDeprecated(), ""); \
+  TYPED_TEST_SUITE
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+#endif  // GTEST_HAS_TYPED_TEST
+
+// Implements type-parameterized tests.
+
+#if GTEST_HAS_TYPED_TEST_P
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Expands to the namespace name that the type-parameterized tests for
+// the given type-parameterized test suite are defined in.  The exact
+// name of the namespace is subject to change without notice.
+#define GTEST_SUITE_NAMESPACE_(TestSuiteName) gtest_suite_##TestSuiteName##_
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Expands to the name of the variable used to remember the names of
+// the defined tests in the given test suite.
+#define GTEST_TYPED_TEST_SUITE_P_STATE_(TestSuiteName) \
+  gtest_typed_test_suite_p_state_##TestSuiteName##_
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE DIRECTLY.
+//
+// Expands to the name of the variable used to remember the names of
+// the registered tests in the given test suite.
+#define GTEST_REGISTERED_TEST_NAMES_(TestSuiteName) \
+  gtest_registered_test_names_##TestSuiteName##_
+
+// The variables defined in the type-parameterized test macros are
+// static as typically these macros are used in a .h file that can be
+// #included in multiple translation units linked together.
+#define TYPED_TEST_SUITE_P(SuiteName)              \
+  static ::testing::internal::TypedTestSuitePState \
+      GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName)
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define TYPED_TEST_CASE_P                                                 \
+  static_assert(::testing::internal::TypedTestCase_P_IsDeprecated(), ""); \
+  TYPED_TEST_SUITE_P
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+#define TYPED_TEST_P(SuiteName, TestName)                             \
+  namespace GTEST_SUITE_NAMESPACE_(SuiteName) {                       \
+    template <typename gtest_TypeParam_>                              \
+    class TestName : public SuiteName<gtest_TypeParam_> {             \
+     private:                                                         \
+      typedef SuiteName<gtest_TypeParam_> TestFixture;                \
+      typedef gtest_TypeParam_ TypeParam;                             \
+      virtual void TestBody();                                        \
+    };                                                                \
+    static bool gtest_##TestName##_defined_ GTEST_ATTRIBUTE_UNUSED_ = \
+        GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName).AddTestName(       \
+            __FILE__, __LINE__, #SuiteName, #TestName);               \
+  }                                                                   \
+  template <typename gtest_TypeParam_>                                \
+  void GTEST_SUITE_NAMESPACE_(                                        \
+      SuiteName)::TestName<gtest_TypeParam_>::TestBody()
+
+#define REGISTER_TYPED_TEST_SUITE_P(SuiteName, ...)                            \
+  namespace GTEST_SUITE_NAMESPACE_(SuiteName) {                                \
+    typedef ::testing::internal::Templates<__VA_ARGS__>::type gtest_AllTests_; \
+  }                                                                            \
+  static const char* const GTEST_REGISTERED_TEST_NAMES_(                       \
+      SuiteName) GTEST_ATTRIBUTE_UNUSED_ =                                     \
+      GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName).VerifyRegisteredTestNames(    \
+          __FILE__, __LINE__, #__VA_ARGS__)
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define REGISTER_TYPED_TEST_CASE_P                                           \
+  static_assert(::testing::internal::RegisterTypedTestCase_P_IsDeprecated(), \
+                "");                                                         \
+  REGISTER_TYPED_TEST_SUITE_P
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+#define INSTANTIATE_TYPED_TEST_SUITE_P(Prefix, SuiteName, Types, ...)       \
+  static bool gtest_##Prefix##_##SuiteName GTEST_ATTRIBUTE_UNUSED_ =        \
+      ::testing::internal::TypeParameterizedTestSuite<                      \
+          SuiteName, GTEST_SUITE_NAMESPACE_(SuiteName)::gtest_AllTests_,    \
+          ::testing::internal::TypeList<Types>::type>::                     \
+          Register(#Prefix,                                                 \
+                   ::testing::internal::CodeLocation(__FILE__, __LINE__),   \
+                   &GTEST_TYPED_TEST_SUITE_P_STATE_(SuiteName), #SuiteName, \
+                   GTEST_REGISTERED_TEST_NAMES_(SuiteName),                 \
+                   ::testing::internal::GenerateNames<                      \
+                       ::testing::internal::NameGeneratorSelector<          \
+                           __VA_ARGS__>::type,                              \
+                       ::testing::internal::TypeList<Types>::type>())
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+#define INSTANTIATE_TYPED_TEST_CASE_P                                      \
+  static_assert(                                                           \
+      ::testing::internal::InstantiateTypedTestCase_P_IsDeprecated(), ""); \
+  INSTANTIATE_TYPED_TEST_SUITE_P
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+#endif  // GTEST_HAS_TYPED_TEST_P
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
diff --git a/3rdparty/gtest/include/gtest/gtest.h b/3rdparty/gtest/include/gtest/gtest.h
new file mode 100644
index 0000000..dbe5b1c
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest.h
@@ -0,0 +1,2478 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines the public API for Google Test.  It should be
+// included by any test program that uses Google Test.
+//
+// IMPORTANT NOTE: Due to limitation of the C++ language, we have to
+// leave some internal implementation details in this header file.
+// They are clearly marked by comments like this:
+//
+//   // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+//
+// Such code is NOT meant to be used by a user directly, and is subject
+// to CHANGE WITHOUT NOTICE.  Therefore DO NOT DEPEND ON IT in a user
+// program!
+//
+// Acknowledgment: Google Test borrowed the idea of automatic test
+// registration from Barthelemy Dagenais' (barthelemy@prologique.com)
+// easyUnit framework.
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_H_
+#define GTEST_INCLUDE_GTEST_GTEST_H_
+
+#include <cstddef>
+#include <limits>
+#include <memory>
+#include <ostream>
+#include <type_traits>
+#include <vector>
+
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-string.h"
+#include "gtest/gtest-death-test.h"
+#include "gtest/gtest-matchers.h"
+#include "gtest/gtest-message.h"
+#include "gtest/gtest-param-test.h"
+#include "gtest/gtest-printers.h"
+#include "gtest/gtest_prod.h"
+#include "gtest/gtest-test-part.h"
+#include "gtest/gtest-typed-test.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+
+// Silence C4100 (unreferenced formal parameter) and 4805
+// unsafe mix of type 'const int' and type 'const bool'
+#ifdef _MSC_VER
+# pragma warning(push)
+# pragma warning(disable:4805)
+# pragma warning(disable:4100)
+#endif
+
+
+// Declares the flags.
+
+// This flag temporary enables the disabled tests.
+GTEST_DECLARE_bool_(also_run_disabled_tests);
+
+// This flag brings the debugger on an assertion failure.
+GTEST_DECLARE_bool_(break_on_failure);
+
+// This flag controls whether Google Test catches all test-thrown exceptions
+// and logs them as failures.
+GTEST_DECLARE_bool_(catch_exceptions);
+
+// This flag enables using colors in terminal output. Available values are
+// "yes" to enable colors, "no" (disable colors), or "auto" (the default)
+// to let Google Test decide.
+GTEST_DECLARE_string_(color);
+
+// This flag sets up the filter to select by name using a glob pattern
+// the tests to run. If the filter is not given all tests are executed.
+GTEST_DECLARE_string_(filter);
+
+// This flag controls whether Google Test installs a signal handler that dumps
+// debugging information when fatal signals are raised.
+GTEST_DECLARE_bool_(install_failure_signal_handler);
+
+// This flag causes the Google Test to list tests. None of the tests listed
+// are actually run if the flag is provided.
+GTEST_DECLARE_bool_(list_tests);
+
+// This flag controls whether Google Test emits a detailed XML report to a file
+// in addition to its normal textual output.
+GTEST_DECLARE_string_(output);
+
+// This flags control whether Google Test prints the elapsed time for each
+// test.
+GTEST_DECLARE_bool_(print_time);
+
+// This flags control whether Google Test prints UTF8 characters as text.
+GTEST_DECLARE_bool_(print_utf8);
+
+// This flag specifies the random number seed.
+GTEST_DECLARE_int32_(random_seed);
+
+// This flag sets how many times the tests are repeated. The default value
+// is 1. If the value is -1 the tests are repeating forever.
+GTEST_DECLARE_int32_(repeat);
+
+// This flag controls whether Google Test includes Google Test internal
+// stack frames in failure stack traces.
+GTEST_DECLARE_bool_(show_internal_stack_frames);
+
+// When this flag is specified, tests' order is randomized on every iteration.
+GTEST_DECLARE_bool_(shuffle);
+
+// This flag specifies the maximum number of stack frames to be
+// printed in a failure message.
+GTEST_DECLARE_int32_(stack_trace_depth);
+
+// When this flag is specified, a failed assertion will throw an
+// exception if exceptions are enabled, or exit the program with a
+// non-zero code otherwise. For use with an external test framework.
+GTEST_DECLARE_bool_(throw_on_failure);
+
+// When this flag is set with a "host:port" string, on supported
+// platforms test results are streamed to the specified port on
+// the specified host machine.
+GTEST_DECLARE_string_(stream_result_to);
+
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+GTEST_DECLARE_string_(flagfile);
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+
+// The upper limit for valid stack trace depths.
+const int kMaxStackTraceDepth = 100;
+
+namespace internal {
+
+class AssertHelper;
+class DefaultGlobalTestPartResultReporter;
+class ExecDeathTest;
+class NoExecDeathTest;
+class FinalSuccessChecker;
+class GTestFlagSaver;
+class StreamingListenerTest;
+class TestResultAccessor;
+class TestEventListenersAccessor;
+class TestEventRepeater;
+class UnitTestRecordPropertyTestHelper;
+class WindowsDeathTest;
+class FuchsiaDeathTest;
+class UnitTestImpl* GetUnitTestImpl();
+void ReportFailureInUnknownLocation(TestPartResult::Type result_type,
+                                    const std::string& message);
+
+}  // namespace internal
+
+// The friend relationship of some of these classes is cyclic.
+// If we don't forward declare them the compiler might confuse the classes
+// in friendship clauses with same named classes on the scope.
+class Test;
+class TestSuite;
+
+// Old API is still available but deprecated
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+using TestCase = TestSuite;
+#endif
+class TestInfo;
+class UnitTest;
+
+// A class for indicating whether an assertion was successful.  When
+// the assertion wasn't successful, the AssertionResult object
+// remembers a non-empty message that describes how it failed.
+//
+// To create an instance of this class, use one of the factory functions
+// (AssertionSuccess() and AssertionFailure()).
+//
+// This class is useful for two purposes:
+//   1. Defining predicate functions to be used with Boolean test assertions
+//      EXPECT_TRUE/EXPECT_FALSE and their ASSERT_ counterparts
+//   2. Defining predicate-format functions to be
+//      used with predicate assertions (ASSERT_PRED_FORMAT*, etc).
+//
+// For example, if you define IsEven predicate:
+//
+//   testing::AssertionResult IsEven(int n) {
+//     if ((n % 2) == 0)
+//       return testing::AssertionSuccess();
+//     else
+//       return testing::AssertionFailure() << n << " is odd";
+//   }
+//
+// Then the failed expectation EXPECT_TRUE(IsEven(Fib(5)))
+// will print the message
+//
+//   Value of: IsEven(Fib(5))
+//     Actual: false (5 is odd)
+//   Expected: true
+//
+// instead of a more opaque
+//
+//   Value of: IsEven(Fib(5))
+//     Actual: false
+//   Expected: true
+//
+// in case IsEven is a simple Boolean predicate.
+//
+// If you expect your predicate to be reused and want to support informative
+// messages in EXPECT_FALSE and ASSERT_FALSE (negative assertions show up
+// about half as often as positive ones in our tests), supply messages for
+// both success and failure cases:
+//
+//   testing::AssertionResult IsEven(int n) {
+//     if ((n % 2) == 0)
+//       return testing::AssertionSuccess() << n << " is even";
+//     else
+//       return testing::AssertionFailure() << n << " is odd";
+//   }
+//
+// Then a statement EXPECT_FALSE(IsEven(Fib(6))) will print
+//
+//   Value of: IsEven(Fib(6))
+//     Actual: true (8 is even)
+//   Expected: false
+//
+// NB: Predicates that support negative Boolean assertions have reduced
+// performance in positive ones so be careful not to use them in tests
+// that have lots (tens of thousands) of positive Boolean assertions.
+//
+// To use this class with EXPECT_PRED_FORMAT assertions such as:
+//
+//   // Verifies that Foo() returns an even number.
+//   EXPECT_PRED_FORMAT1(IsEven, Foo());
+//
+// you need to define:
+//
+//   testing::AssertionResult IsEven(const char* expr, int n) {
+//     if ((n % 2) == 0)
+//       return testing::AssertionSuccess();
+//     else
+//       return testing::AssertionFailure()
+//         << "Expected: " << expr << " is even\n  Actual: it's " << n;
+//   }
+//
+// If Foo() returns 5, you will see the following message:
+//
+//   Expected: Foo() is even
+//     Actual: it's 5
+//
+class GTEST_API_ AssertionResult {
+ public:
+  // Copy constructor.
+  // Used in EXPECT_TRUE/FALSE(assertion_result).
+  AssertionResult(const AssertionResult& other);
+
+#if defined(_MSC_VER) && _MSC_VER < 1910
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800 /* forcing value to bool */)
+#endif
+
+  // Used in the EXPECT_TRUE/FALSE(bool_expression).
+  //
+  // T must be contextually convertible to bool.
+  //
+  // The second parameter prevents this overload from being considered if
+  // the argument is implicitly convertible to AssertionResult. In that case
+  // we want AssertionResult's copy constructor to be used.
+  template <typename T>
+  explicit AssertionResult(
+      const T& success,
+      typename std::enable_if<
+          !std::is_convertible<T, AssertionResult>::value>::type*
+      /*enabler*/
+      = nullptr)
+      : success_(success) {}
+
+#if defined(_MSC_VER) && _MSC_VER < 1910
+  GTEST_DISABLE_MSC_WARNINGS_POP_()
+#endif
+
+  // Assignment operator.
+  AssertionResult& operator=(AssertionResult other) {
+    swap(other);
+    return *this;
+  }
+
+  // Returns true if and only if the assertion succeeded.
+  operator bool() const { return success_; }  // NOLINT
+
+  // Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
+  AssertionResult operator!() const;
+
+  // Returns the text streamed into this AssertionResult. Test assertions
+  // use it when they fail (i.e., the predicate's outcome doesn't match the
+  // assertion's expectation). When nothing has been streamed into the
+  // object, returns an empty string.
+  const char* message() const {
+    return message_.get() != nullptr ? message_->c_str() : "";
+  }
+  // Deprecated; please use message() instead.
+  const char* failure_message() const { return message(); }
+
+  // Streams a custom failure message into this object.
+  template <typename T> AssertionResult& operator<<(const T& value) {
+    AppendMessage(Message() << value);
+    return *this;
+  }
+
+  // Allows streaming basic output manipulators such as endl or flush into
+  // this object.
+  AssertionResult& operator<<(
+      ::std::ostream& (*basic_manipulator)(::std::ostream& stream)) {
+    AppendMessage(Message() << basic_manipulator);
+    return *this;
+  }
+
+ private:
+  // Appends the contents of message to message_.
+  void AppendMessage(const Message& a_message) {
+    if (message_.get() == nullptr) message_.reset(new ::std::string);
+    message_->append(a_message.GetString().c_str());
+  }
+
+  // Swap the contents of this AssertionResult with other.
+  void swap(AssertionResult& other);
+
+  // Stores result of the assertion predicate.
+  bool success_;
+  // Stores the message describing the condition in case the expectation
+  // construct is not satisfied with the predicate's outcome.
+  // Referenced via a pointer to avoid taking too much stack frame space
+  // with test assertions.
+  std::unique_ptr< ::std::string> message_;
+};
+
+// Makes a successful assertion result.
+GTEST_API_ AssertionResult AssertionSuccess();
+
+// Makes a failed assertion result.
+GTEST_API_ AssertionResult AssertionFailure();
+
+// Makes a failed assertion result with the given failure message.
+// Deprecated; use AssertionFailure() << msg.
+GTEST_API_ AssertionResult AssertionFailure(const Message& msg);
+
+}  // namespace testing
+
+// Includes the auto-generated header that implements a family of generic
+// predicate assertion macros. This include comes late because it relies on
+// APIs declared above.
+#include "gtest/gtest_pred_impl.h"
+
+namespace testing {
+
+// The abstract class that all tests inherit from.
+//
+// In Google Test, a unit test program contains one or many TestSuites, and
+// each TestSuite contains one or many Tests.
+//
+// When you define a test using the TEST macro, you don't need to
+// explicitly derive from Test - the TEST macro automatically does
+// this for you.
+//
+// The only time you derive from Test is when defining a test fixture
+// to be used in a TEST_F.  For example:
+//
+//   class FooTest : public testing::Test {
+//    protected:
+//     void SetUp() override { ... }
+//     void TearDown() override { ... }
+//     ...
+//   };
+//
+//   TEST_F(FooTest, Bar) { ... }
+//   TEST_F(FooTest, Baz) { ... }
+//
+// Test is not copyable.
+class GTEST_API_ Test {
+ public:
+  friend class TestInfo;
+
+  // The d'tor is virtual as we intend to inherit from Test.
+  virtual ~Test();
+
+  // Sets up the stuff shared by all tests in this test case.
+  //
+  // Google Test will call Foo::SetUpTestSuite() before running the first
+  // test in test case Foo.  Hence a sub-class can define its own
+  // SetUpTestSuite() method to shadow the one defined in the super
+  // class.
+  // Failures that happen during SetUpTestSuite are logged but otherwise
+  // ignored.
+  static void SetUpTestSuite() {}
+
+  // Tears down the stuff shared by all tests in this test suite.
+  //
+  // Google Test will call Foo::TearDownTestSuite() after running the last
+  // test in test case Foo.  Hence a sub-class can define its own
+  // TearDownTestSuite() method to shadow the one defined in the super
+  // class.
+  // Failures that happen during TearDownTestSuite are logged but otherwise
+  // ignored.
+  static void TearDownTestSuite() {}
+
+  // Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  static void TearDownTestCase() {}
+  static void SetUpTestCase() {}
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Returns true if and only if the current test has a fatal failure.
+  static bool HasFatalFailure();
+
+  // Returns true if and only if the current test has a non-fatal failure.
+  static bool HasNonfatalFailure();
+
+  // Returns true if and only if the current test was skipped.
+  static bool IsSkipped();
+
+  // Returns true if and only if the current test has a (either fatal or
+  // non-fatal) failure.
+  static bool HasFailure() { return HasFatalFailure() || HasNonfatalFailure(); }
+
+  // Logs a property for the current test, test suite, or for the entire
+  // invocation of the test program when used outside of the context of a
+  // test suite.  Only the last value for a given key is remembered.  These
+  // are public static so they can be called from utility functions that are
+  // not members of the test fixture.  Calls to RecordProperty made during
+  // lifespan of the test (from the moment its constructor starts to the
+  // moment its destructor finishes) will be output in XML as attributes of
+  // the <testcase> element.  Properties recorded from fixture's
+  // SetUpTestSuite or TearDownTestSuite are logged as attributes of the
+  // corresponding <testsuite> element.  Calls to RecordProperty made in the
+  // global context (before or after invocation of RUN_ALL_TESTS and from
+  // SetUp/TearDown method of Environment objects registered with Google
+  // Test) will be output as attributes of the <testsuites> element.
+  static void RecordProperty(const std::string& key, const std::string& value);
+  static void RecordProperty(const std::string& key, int value);
+
+ protected:
+  // Creates a Test object.
+  Test();
+
+  // Sets up the test fixture.
+  virtual void SetUp();
+
+  // Tears down the test fixture.
+  virtual void TearDown();
+
+ private:
+  // Returns true if and only if the current test has the same fixture class
+  // as the first test in the current test suite.
+  static bool HasSameFixtureClass();
+
+  // Runs the test after the test fixture has been set up.
+  //
+  // A sub-class must implement this to define the test logic.
+  //
+  // DO NOT OVERRIDE THIS FUNCTION DIRECTLY IN A USER PROGRAM.
+  // Instead, use the TEST or TEST_F macro.
+  virtual void TestBody() = 0;
+
+  // Sets up, executes, and tears down the test.
+  void Run();
+
+  // Deletes self.  We deliberately pick an unusual name for this
+  // internal method to avoid clashing with names used in user TESTs.
+  void DeleteSelf_() { delete this; }
+
+  const std::unique_ptr<GTEST_FLAG_SAVER_> gtest_flag_saver_;
+
+  // Often a user misspells SetUp() as Setup() and spends a long time
+  // wondering why it is never called by Google Test.  The declaration of
+  // the following method is solely for catching such an error at
+  // compile time:
+  //
+  //   - The return type is deliberately chosen to be not void, so it
+  //   will be a conflict if void Setup() is declared in the user's
+  //   test fixture.
+  //
+  //   - This method is private, so it will be another compiler error
+  //   if the method is called from the user's test fixture.
+  //
+  // DO NOT OVERRIDE THIS FUNCTION.
+  //
+  // If you see an error about overriding the following function or
+  // about it being private, you have mis-spelled SetUp() as Setup().
+  struct Setup_should_be_spelled_SetUp {};
+  virtual Setup_should_be_spelled_SetUp* Setup() { return nullptr; }
+
+  // We disallow copying Tests.
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(Test);
+};
+
+typedef internal::TimeInMillis TimeInMillis;
+
+// A copyable object representing a user specified test property which can be
+// output as a key/value string pair.
+//
+// Don't inherit from TestProperty as its destructor is not virtual.
+class TestProperty {
+ public:
+  // C'tor.  TestProperty does NOT have a default constructor.
+  // Always use this constructor (with parameters) to create a
+  // TestProperty object.
+  TestProperty(const std::string& a_key, const std::string& a_value) :
+    key_(a_key), value_(a_value) {
+  }
+
+  // Gets the user supplied key.
+  const char* key() const {
+    return key_.c_str();
+  }
+
+  // Gets the user supplied value.
+  const char* value() const {
+    return value_.c_str();
+  }
+
+  // Sets a new value, overriding the one supplied in the constructor.
+  void SetValue(const std::string& new_value) {
+    value_ = new_value;
+  }
+
+ private:
+  // The key supplied by the user.
+  std::string key_;
+  // The value supplied by the user.
+  std::string value_;
+};
+
+// The result of a single Test.  This includes a list of
+// TestPartResults, a list of TestProperties, a count of how many
+// death tests there are in the Test, and how much time it took to run
+// the Test.
+//
+// TestResult is not copyable.
+class GTEST_API_ TestResult {
+ public:
+  // Creates an empty TestResult.
+  TestResult();
+
+  // D'tor.  Do not inherit from TestResult.
+  ~TestResult();
+
+  // Gets the number of all test parts.  This is the sum of the number
+  // of successful test parts and the number of failed test parts.
+  int total_part_count() const;
+
+  // Returns the number of the test properties.
+  int test_property_count() const;
+
+  // Returns true if and only if the test passed (i.e. no test part failed).
+  bool Passed() const { return !Skipped() && !Failed(); }
+
+  // Returns true if and only if the test was skipped.
+  bool Skipped() const;
+
+  // Returns true if and only if the test failed.
+  bool Failed() const;
+
+  // Returns true if and only if the test fatally failed.
+  bool HasFatalFailure() const;
+
+  // Returns true if and only if the test has a non-fatal failure.
+  bool HasNonfatalFailure() const;
+
+  // Returns the elapsed time, in milliseconds.
+  TimeInMillis elapsed_time() const { return elapsed_time_; }
+
+  // Gets the time of the test case start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp() const { return start_timestamp_; }
+
+  // Returns the i-th test part result among all the results. i can range from 0
+  // to total_part_count() - 1. If i is not in that range, aborts the program.
+  const TestPartResult& GetTestPartResult(int i) const;
+
+  // Returns the i-th test property. i can range from 0 to
+  // test_property_count() - 1. If i is not in that range, aborts the
+  // program.
+  const TestProperty& GetTestProperty(int i) const;
+
+ private:
+  friend class TestInfo;
+  friend class TestSuite;
+  friend class UnitTest;
+  friend class internal::DefaultGlobalTestPartResultReporter;
+  friend class internal::ExecDeathTest;
+  friend class internal::TestResultAccessor;
+  friend class internal::UnitTestImpl;
+  friend class internal::WindowsDeathTest;
+  friend class internal::FuchsiaDeathTest;
+
+  // Gets the vector of TestPartResults.
+  const std::vector<TestPartResult>& test_part_results() const {
+    return test_part_results_;
+  }
+
+  // Gets the vector of TestProperties.
+  const std::vector<TestProperty>& test_properties() const {
+    return test_properties_;
+  }
+
+  // Sets the start time.
+  void set_start_timestamp(TimeInMillis start) { start_timestamp_ = start; }
+
+  // Sets the elapsed time.
+  void set_elapsed_time(TimeInMillis elapsed) { elapsed_time_ = elapsed; }
+
+  // Adds a test property to the list. The property is validated and may add
+  // a non-fatal failure if invalid (e.g., if it conflicts with reserved
+  // key names). If a property is already recorded for the same key, the
+  // value will be updated, rather than storing multiple values for the same
+  // key.  xml_element specifies the element for which the property is being
+  // recorded and is used for validation.
+  void RecordProperty(const std::string& xml_element,
+                      const TestProperty& test_property);
+
+  // Adds a failure if the key is a reserved attribute of Google Test
+  // testsuite tags.  Returns true if the property is valid.
+  // FIXME: Validate attribute names are legal and human readable.
+  static bool ValidateTestProperty(const std::string& xml_element,
+                                   const TestProperty& test_property);
+
+  // Adds a test part result to the list.
+  void AddTestPartResult(const TestPartResult& test_part_result);
+
+  // Returns the death test count.
+  int death_test_count() const { return death_test_count_; }
+
+  // Increments the death test count, returning the new count.
+  int increment_death_test_count() { return ++death_test_count_; }
+
+  // Clears the test part results.
+  void ClearTestPartResults();
+
+  // Clears the object.
+  void Clear();
+
+  // Protects mutable state of the property vector and of owned
+  // properties, whose values may be updated.
+  internal::Mutex test_properites_mutex_;
+
+  // The vector of TestPartResults
+  std::vector<TestPartResult> test_part_results_;
+  // The vector of TestProperties
+  std::vector<TestProperty> test_properties_;
+  // Running count of death tests.
+  int death_test_count_;
+  // The start time, in milliseconds since UNIX Epoch.
+  TimeInMillis start_timestamp_;
+  // The elapsed time, in milliseconds.
+  TimeInMillis elapsed_time_;
+
+  // We disallow copying TestResult.
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestResult);
+};  // class TestResult
+
+// A TestInfo object stores the following information about a test:
+//
+//   Test suite name
+//   Test name
+//   Whether the test should be run
+//   A function pointer that creates the test object when invoked
+//   Test result
+//
+// The constructor of TestInfo registers itself with the UnitTest
+// singleton such that the RUN_ALL_TESTS() macro knows which tests to
+// run.
+class GTEST_API_ TestInfo {
+ public:
+  // Destructs a TestInfo object.  This function is not virtual, so
+  // don't inherit from TestInfo.
+  ~TestInfo();
+
+  // Returns the test suite name.
+  const char* test_suite_name() const { return test_suite_name_.c_str(); }
+
+// Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  const char* test_case_name() const { return test_suite_name(); }
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Returns the test name.
+  const char* name() const { return name_.c_str(); }
+
+  // Returns the name of the parameter type, or NULL if this is not a typed
+  // or a type-parameterized test.
+  const char* type_param() const {
+    if (type_param_.get() != nullptr) return type_param_->c_str();
+    return nullptr;
+  }
+
+  // Returns the text representation of the value parameter, or NULL if this
+  // is not a value-parameterized test.
+  const char* value_param() const {
+    if (value_param_.get() != nullptr) return value_param_->c_str();
+    return nullptr;
+  }
+
+  // Returns the file name where this test is defined.
+  const char* file() const { return location_.file.c_str(); }
+
+  // Returns the line where this test is defined.
+  int line() const { return location_.line; }
+
+  // Return true if this test should not be run because it's in another shard.
+  bool is_in_another_shard() const { return is_in_another_shard_; }
+
+  // Returns true if this test should run, that is if the test is not
+  // disabled (or it is disabled but the also_run_disabled_tests flag has
+  // been specified) and its full name matches the user-specified filter.
+  //
+  // Google Test allows the user to filter the tests by their full names.
+  // The full name of a test Bar in test suite Foo is defined as
+  // "Foo.Bar".  Only the tests that match the filter will run.
+  //
+  // A filter is a colon-separated list of glob (not regex) patterns,
+  // optionally followed by a '-' and a colon-separated list of
+  // negative patterns (tests to exclude).  A test is run if it
+  // matches one of the positive patterns and does not match any of
+  // the negative patterns.
+  //
+  // For example, *A*:Foo.* is a filter that matches any string that
+  // contains the character 'A' or starts with "Foo.".
+  bool should_run() const { return should_run_; }
+
+  // Returns true if and only if this test will appear in the XML report.
+  bool is_reportable() const {
+    // The XML report includes tests matching the filter, excluding those
+    // run in other shards.
+    return matches_filter_ && !is_in_another_shard_;
+  }
+
+  // Returns the result of the test.
+  const TestResult* result() const { return &result_; }
+
+ private:
+#if GTEST_HAS_DEATH_TEST
+  friend class internal::DefaultDeathTestFactory;
+#endif  // GTEST_HAS_DEATH_TEST
+  friend class Test;
+  friend class TestSuite;
+  friend class internal::UnitTestImpl;
+  friend class internal::StreamingListenerTest;
+  friend TestInfo* internal::MakeAndRegisterTestInfo(
+      const char* test_suite_name, const char* name, const char* type_param,
+      const char* value_param, internal::CodeLocation code_location,
+      internal::TypeId fixture_class_id, internal::SetUpTestSuiteFunc set_up_tc,
+      internal::TearDownTestSuiteFunc tear_down_tc,
+      internal::TestFactoryBase* factory);
+
+  // Constructs a TestInfo object. The newly constructed instance assumes
+  // ownership of the factory object.
+  TestInfo(const std::string& test_suite_name, const std::string& name,
+           const char* a_type_param,   // NULL if not a type-parameterized test
+           const char* a_value_param,  // NULL if not a value-parameterized test
+           internal::CodeLocation a_code_location,
+           internal::TypeId fixture_class_id,
+           internal::TestFactoryBase* factory);
+
+  // Increments the number of death tests encountered in this test so
+  // far.
+  int increment_death_test_count() {
+    return result_.increment_death_test_count();
+  }
+
+  // Creates the test object, runs it, records its result, and then
+  // deletes it.
+  void Run();
+
+  static void ClearTestResult(TestInfo* test_info) {
+    test_info->result_.Clear();
+  }
+
+  // These fields are immutable properties of the test.
+  const std::string test_suite_name_;    // test suite name
+  const std::string name_;               // Test name
+  // Name of the parameter type, or NULL if this is not a typed or a
+  // type-parameterized test.
+  const std::unique_ptr<const ::std::string> type_param_;
+  // Text representation of the value parameter, or NULL if this is not a
+  // value-parameterized test.
+  const std::unique_ptr<const ::std::string> value_param_;
+  internal::CodeLocation location_;
+  const internal::TypeId fixture_class_id_;  // ID of the test fixture class
+  bool should_run_;           // True if and only if this test should run
+  bool is_disabled_;          // True if and only if this test is disabled
+  bool matches_filter_;       // True if this test matches the
+                              // user-specified filter.
+  bool is_in_another_shard_;  // Will be run in another shard.
+  internal::TestFactoryBase* const factory_;  // The factory that creates
+                                              // the test object
+
+  // This field is mutable and needs to be reset before running the
+  // test for the second time.
+  TestResult result_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestInfo);
+};
+
+// A test suite, which consists of a vector of TestInfos.
+//
+// TestSuite is not copyable.
+class GTEST_API_ TestSuite {
+ public:
+  // Creates a TestSuite with the given name.
+  //
+  // TestSuite does NOT have a default constructor.  Always use this
+  // constructor to create a TestSuite object.
+  //
+  // Arguments:
+  //
+  //   name:         name of the test suite
+  //   a_type_param: the name of the test's type parameter, or NULL if
+  //                 this is not a type-parameterized test.
+  //   set_up_tc:    pointer to the function that sets up the test suite
+  //   tear_down_tc: pointer to the function that tears down the test suite
+  TestSuite(const char* name, const char* a_type_param,
+            internal::SetUpTestSuiteFunc set_up_tc,
+            internal::TearDownTestSuiteFunc tear_down_tc);
+
+  // Destructor of TestSuite.
+  virtual ~TestSuite();
+
+  // Gets the name of the TestSuite.
+  const char* name() const { return name_.c_str(); }
+
+  // Returns the name of the parameter type, or NULL if this is not a
+  // type-parameterized test suite.
+  const char* type_param() const {
+    if (type_param_.get() != nullptr) return type_param_->c_str();
+    return nullptr;
+  }
+
+  // Returns true if any test in this test suite should run.
+  bool should_run() const { return should_run_; }
+
+  // Gets the number of successful tests in this test suite.
+  int successful_test_count() const;
+
+  // Gets the number of skipped tests in this test suite.
+  int skipped_test_count() const;
+
+  // Gets the number of failed tests in this test suite.
+  int failed_test_count() const;
+
+  // Gets the number of disabled tests that will be reported in the XML report.
+  int reportable_disabled_test_count() const;
+
+  // Gets the number of disabled tests in this test suite.
+  int disabled_test_count() const;
+
+  // Gets the number of tests to be printed in the XML report.
+  int reportable_test_count() const;
+
+  // Get the number of tests in this test suite that should run.
+  int test_to_run_count() const;
+
+  // Gets the number of all tests in this test suite.
+  int total_test_count() const;
+
+  // Returns true if and only if the test suite passed.
+  bool Passed() const { return !Failed(); }
+
+  // Returns true if and only if the test suite failed.
+  bool Failed() const { return failed_test_count() > 0; }
+
+  // Returns the elapsed time, in milliseconds.
+  TimeInMillis elapsed_time() const { return elapsed_time_; }
+
+  // Gets the time of the test suite start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp() const { return start_timestamp_; }
+
+  // Returns the i-th test among all the tests. i can range from 0 to
+  // total_test_count() - 1. If i is not in that range, returns NULL.
+  const TestInfo* GetTestInfo(int i) const;
+
+  // Returns the TestResult that holds test properties recorded during
+  // execution of SetUpTestSuite and TearDownTestSuite.
+  const TestResult& ad_hoc_test_result() const { return ad_hoc_test_result_; }
+
+ private:
+  friend class Test;
+  friend class internal::UnitTestImpl;
+
+  // Gets the (mutable) vector of TestInfos in this TestSuite.
+  std::vector<TestInfo*>& test_info_list() { return test_info_list_; }
+
+  // Gets the (immutable) vector of TestInfos in this TestSuite.
+  const std::vector<TestInfo*>& test_info_list() const {
+    return test_info_list_;
+  }
+
+  // Returns the i-th test among all the tests. i can range from 0 to
+  // total_test_count() - 1. If i is not in that range, returns NULL.
+  TestInfo* GetMutableTestInfo(int i);
+
+  // Sets the should_run member.
+  void set_should_run(bool should) { should_run_ = should; }
+
+  // Adds a TestInfo to this test suite.  Will delete the TestInfo upon
+  // destruction of the TestSuite object.
+  void AddTestInfo(TestInfo * test_info);
+
+  // Clears the results of all tests in this test suite.
+  void ClearResult();
+
+  // Clears the results of all tests in the given test suite.
+  static void ClearTestSuiteResult(TestSuite* test_suite) {
+    test_suite->ClearResult();
+  }
+
+  // Runs every test in this TestSuite.
+  void Run();
+
+  // Runs SetUpTestSuite() for this TestSuite.  This wrapper is needed
+  // for catching exceptions thrown from SetUpTestSuite().
+  void RunSetUpTestSuite() {
+    if (set_up_tc_ != nullptr) {
+      (*set_up_tc_)();
+    }
+  }
+
+  // Runs TearDownTestSuite() for this TestSuite.  This wrapper is
+  // needed for catching exceptions thrown from TearDownTestSuite().
+  void RunTearDownTestSuite() {
+    if (tear_down_tc_ != nullptr) {
+      (*tear_down_tc_)();
+    }
+  }
+
+  // Returns true if and only if test passed.
+  static bool TestPassed(const TestInfo* test_info) {
+    return test_info->should_run() && test_info->result()->Passed();
+  }
+
+  // Returns true if and only if test skipped.
+  static bool TestSkipped(const TestInfo* test_info) {
+    return test_info->should_run() && test_info->result()->Skipped();
+  }
+
+  // Returns true if and only if test failed.
+  static bool TestFailed(const TestInfo* test_info) {
+    return test_info->should_run() && test_info->result()->Failed();
+  }
+
+  // Returns true if and only if the test is disabled and will be reported in
+  // the XML report.
+  static bool TestReportableDisabled(const TestInfo* test_info) {
+    return test_info->is_reportable() && test_info->is_disabled_;
+  }
+
+  // Returns true if and only if test is disabled.
+  static bool TestDisabled(const TestInfo* test_info) {
+    return test_info->is_disabled_;
+  }
+
+  // Returns true if and only if this test will appear in the XML report.
+  static bool TestReportable(const TestInfo* test_info) {
+    return test_info->is_reportable();
+  }
+
+  // Returns true if the given test should run.
+  static bool ShouldRunTest(const TestInfo* test_info) {
+    return test_info->should_run();
+  }
+
+  // Shuffles the tests in this test suite.
+  void ShuffleTests(internal::Random* random);
+
+  // Restores the test order to before the first shuffle.
+  void UnshuffleTests();
+
+  // Name of the test suite.
+  std::string name_;
+  // Name of the parameter type, or NULL if this is not a typed or a
+  // type-parameterized test.
+  const std::unique_ptr<const ::std::string> type_param_;
+  // The vector of TestInfos in their original order.  It owns the
+  // elements in the vector.
+  std::vector<TestInfo*> test_info_list_;
+  // Provides a level of indirection for the test list to allow easy
+  // shuffling and restoring the test order.  The i-th element in this
+  // vector is the index of the i-th test in the shuffled test list.
+  std::vector<int> test_indices_;
+  // Pointer to the function that sets up the test suite.
+  internal::SetUpTestSuiteFunc set_up_tc_;
+  // Pointer to the function that tears down the test suite.
+  internal::TearDownTestSuiteFunc tear_down_tc_;
+  // True if and only if any test in this test suite should run.
+  bool should_run_;
+  // The start time, in milliseconds since UNIX Epoch.
+  TimeInMillis start_timestamp_;
+  // Elapsed time, in milliseconds.
+  TimeInMillis elapsed_time_;
+  // Holds test properties recorded during execution of SetUpTestSuite and
+  // TearDownTestSuite.
+  TestResult ad_hoc_test_result_;
+
+  // We disallow copying TestSuites.
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestSuite);
+};
+
+// An Environment object is capable of setting up and tearing down an
+// environment.  You should subclass this to define your own
+// environment(s).
+//
+// An Environment object does the set-up and tear-down in virtual
+// methods SetUp() and TearDown() instead of the constructor and the
+// destructor, as:
+//
+//   1. You cannot safely throw from a destructor.  This is a problem
+//      as in some cases Google Test is used where exceptions are enabled, and
+//      we may want to implement ASSERT_* using exceptions where they are
+//      available.
+//   2. You cannot use ASSERT_* directly in a constructor or
+//      destructor.
+class Environment {
+ public:
+  // The d'tor is virtual as we need to subclass Environment.
+  virtual ~Environment() {}
+
+  // Override this to define how to set up the environment.
+  virtual void SetUp() {}
+
+  // Override this to define how to tear down the environment.
+  virtual void TearDown() {}
+ private:
+  // If you see an error about overriding the following function or
+  // about it being private, you have mis-spelled SetUp() as Setup().
+  struct Setup_should_be_spelled_SetUp {};
+  virtual Setup_should_be_spelled_SetUp* Setup() { return nullptr; }
+};
+
+#if GTEST_HAS_EXCEPTIONS
+
+// Exception which can be thrown from TestEventListener::OnTestPartResult.
+class GTEST_API_ AssertionException
+    : public internal::GoogleTestFailureException {
+ public:
+  explicit AssertionException(const TestPartResult& result)
+      : GoogleTestFailureException(result) {}
+};
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// The interface for tracing execution of tests. The methods are organized in
+// the order the corresponding events are fired.
+class TestEventListener {
+ public:
+  virtual ~TestEventListener() {}
+
+  // Fired before any test activity starts.
+  virtual void OnTestProgramStart(const UnitTest& unit_test) = 0;
+
+  // Fired before each iteration of tests starts.  There may be more than
+  // one iteration if GTEST_FLAG(repeat) is set. iteration is the iteration
+  // index, starting from 0.
+  virtual void OnTestIterationStart(const UnitTest& unit_test,
+                                    int iteration) = 0;
+
+  // Fired before environment set-up for each iteration of tests starts.
+  virtual void OnEnvironmentsSetUpStart(const UnitTest& unit_test) = 0;
+
+  // Fired after environment set-up for each iteration of tests ends.
+  virtual void OnEnvironmentsSetUpEnd(const UnitTest& unit_test) = 0;
+
+  // Fired before the test suite starts.
+  virtual void OnTestSuiteStart(const TestSuite& /*test_suite*/) {}
+
+  //  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  virtual void OnTestCaseStart(const TestCase& /*test_case*/) {}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Fired before the test starts.
+  virtual void OnTestStart(const TestInfo& test_info) = 0;
+
+  // Fired after a failed assertion or a SUCCEED() invocation.
+  // If you want to throw an exception from this function to skip to the next
+  // TEST, it must be AssertionException defined above, or inherited from it.
+  virtual void OnTestPartResult(const TestPartResult& test_part_result) = 0;
+
+  // Fired after the test ends.
+  virtual void OnTestEnd(const TestInfo& test_info) = 0;
+
+  // Fired after the test suite ends.
+  virtual void OnTestSuiteEnd(const TestSuite& /*test_suite*/) {}
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  virtual void OnTestCaseEnd(const TestCase& /*test_case*/) {}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Fired before environment tear-down for each iteration of tests starts.
+  virtual void OnEnvironmentsTearDownStart(const UnitTest& unit_test) = 0;
+
+  // Fired after environment tear-down for each iteration of tests ends.
+  virtual void OnEnvironmentsTearDownEnd(const UnitTest& unit_test) = 0;
+
+  // Fired after each iteration of tests finishes.
+  virtual void OnTestIterationEnd(const UnitTest& unit_test,
+                                  int iteration) = 0;
+
+  // Fired after all test activities have ended.
+  virtual void OnTestProgramEnd(const UnitTest& unit_test) = 0;
+};
+
+// The convenience class for users who need to override just one or two
+// methods and are not concerned that a possible change to a signature of
+// the methods they override will not be caught during the build.  For
+// comments about each method please see the definition of TestEventListener
+// above.
+class EmptyTestEventListener : public TestEventListener {
+ public:
+  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationStart(const UnitTest& /*unit_test*/,
+                            int /*iteration*/) override {}
+  void OnEnvironmentsSetUpStart(const UnitTest& /*unit_test*/) override {}
+  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
+  void OnTestSuiteStart(const TestSuite& /*test_suite*/) override {}
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseStart(const TestCase& /*test_case*/) override {}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  void OnTestStart(const TestInfo& /*test_info*/) override {}
+  void OnTestPartResult(const TestPartResult& /*test_part_result*/) override {}
+  void OnTestEnd(const TestInfo& /*test_info*/) override {}
+  void OnTestSuiteEnd(const TestSuite& /*test_suite*/) override {}
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseEnd(const TestCase& /*test_case*/) override {}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  void OnEnvironmentsTearDownStart(const UnitTest& /*unit_test*/) override {}
+  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationEnd(const UnitTest& /*unit_test*/,
+                          int /*iteration*/) override {}
+  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
+};
+
+// TestEventListeners lets users add listeners to track events in Google Test.
+class GTEST_API_ TestEventListeners {
+ public:
+  TestEventListeners();
+  ~TestEventListeners();
+
+  // Appends an event listener to the end of the list. Google Test assumes
+  // the ownership of the listener (i.e. it will delete the listener when
+  // the test program finishes).
+  void Append(TestEventListener* listener);
+
+  // Removes the given event listener from the list and returns it.  It then
+  // becomes the caller's responsibility to delete the listener. Returns
+  // NULL if the listener is not found in the list.
+  TestEventListener* Release(TestEventListener* listener);
+
+  // Returns the standard listener responsible for the default console
+  // output.  Can be removed from the listeners list to shut down default
+  // console output.  Note that removing this object from the listener list
+  // with Release transfers its ownership to the caller and makes this
+  // function return NULL the next time.
+  TestEventListener* default_result_printer() const {
+    return default_result_printer_;
+  }
+
+  // Returns the standard listener responsible for the default XML output
+  // controlled by the --gtest_output=xml flag.  Can be removed from the
+  // listeners list by users who want to shut down the default XML output
+  // controlled by this flag and substitute it with custom one.  Note that
+  // removing this object from the listener list with Release transfers its
+  // ownership to the caller and makes this function return NULL the next
+  // time.
+  TestEventListener* default_xml_generator() const {
+    return default_xml_generator_;
+  }
+
+ private:
+  friend class TestSuite;
+  friend class TestInfo;
+  friend class internal::DefaultGlobalTestPartResultReporter;
+  friend class internal::NoExecDeathTest;
+  friend class internal::TestEventListenersAccessor;
+  friend class internal::UnitTestImpl;
+
+  // Returns repeater that broadcasts the TestEventListener events to all
+  // subscribers.
+  TestEventListener* repeater();
+
+  // Sets the default_result_printer attribute to the provided listener.
+  // The listener is also added to the listener list and previous
+  // default_result_printer is removed from it and deleted. The listener can
+  // also be NULL in which case it will not be added to the list. Does
+  // nothing if the previous and the current listener objects are the same.
+  void SetDefaultResultPrinter(TestEventListener* listener);
+
+  // Sets the default_xml_generator attribute to the provided listener.  The
+  // listener is also added to the listener list and previous
+  // default_xml_generator is removed from it and deleted. The listener can
+  // also be NULL in which case it will not be added to the list. Does
+  // nothing if the previous and the current listener objects are the same.
+  void SetDefaultXmlGenerator(TestEventListener* listener);
+
+  // Controls whether events will be forwarded by the repeater to the
+  // listeners in the list.
+  bool EventForwardingEnabled() const;
+  void SuppressEventForwarding();
+
+  // The actual list of listeners.
+  internal::TestEventRepeater* repeater_;
+  // Listener responsible for the standard result output.
+  TestEventListener* default_result_printer_;
+  // Listener responsible for the creation of the XML output file.
+  TestEventListener* default_xml_generator_;
+
+  // We disallow copying TestEventListeners.
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestEventListeners);
+};
+
+// A UnitTest consists of a vector of TestSuites.
+//
+// This is a singleton class.  The only instance of UnitTest is
+// created when UnitTest::GetInstance() is first called.  This
+// instance is never deleted.
+//
+// UnitTest is not copyable.
+//
+// This class is thread-safe as long as the methods are called
+// according to their specification.
+class GTEST_API_ UnitTest {
+ public:
+  // Gets the singleton UnitTest object.  The first time this method
+  // is called, a UnitTest object is constructed and returned.
+  // Consecutive calls will return the same object.
+  static UnitTest* GetInstance();
+
+  // Runs all tests in this UnitTest object and prints the result.
+  // Returns 0 if successful, or 1 otherwise.
+  //
+  // This method can only be called from the main thread.
+  //
+  // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+  int Run() GTEST_MUST_USE_RESULT_;
+
+  // Returns the working directory when the first TEST() or TEST_F()
+  // was executed.  The UnitTest object owns the string.
+  const char* original_working_dir() const;
+
+  // Returns the TestSuite object for the test that's currently running,
+  // or NULL if no test is running.
+  const TestSuite* current_test_suite() const GTEST_LOCK_EXCLUDED_(mutex_);
+
+// Legacy API is still available but deprecated
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  const TestCase* current_test_case() const GTEST_LOCK_EXCLUDED_(mutex_);
+#endif
+
+  // Returns the TestInfo object for the test that's currently running,
+  // or NULL if no test is running.
+  const TestInfo* current_test_info() const
+      GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Returns the random seed used at the start of the current test run.
+  int random_seed() const;
+
+  // Returns the ParameterizedTestSuiteRegistry object used to keep track of
+  // value-parameterized tests and instantiate and register them.
+  //
+  // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+  internal::ParameterizedTestSuiteRegistry& parameterized_test_registry()
+      GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Gets the number of successful test suites.
+  int successful_test_suite_count() const;
+
+  // Gets the number of failed test suites.
+  int failed_test_suite_count() const;
+
+  // Gets the number of all test suites.
+  int total_test_suite_count() const;
+
+  // Gets the number of all test suites that contain at least one test
+  // that should run.
+  int test_suite_to_run_count() const;
+
+  //  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  int successful_test_case_count() const;
+  int failed_test_case_count() const;
+  int total_test_case_count() const;
+  int test_case_to_run_count() const;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Gets the number of successful tests.
+  int successful_test_count() const;
+
+  // Gets the number of skipped tests.
+  int skipped_test_count() const;
+
+  // Gets the number of failed tests.
+  int failed_test_count() const;
+
+  // Gets the number of disabled tests that will be reported in the XML report.
+  int reportable_disabled_test_count() const;
+
+  // Gets the number of disabled tests.
+  int disabled_test_count() const;
+
+  // Gets the number of tests to be printed in the XML report.
+  int reportable_test_count() const;
+
+  // Gets the number of all tests.
+  int total_test_count() const;
+
+  // Gets the number of tests that should run.
+  int test_to_run_count() const;
+
+  // Gets the time of the test program start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp() const;
+
+  // Gets the elapsed time, in milliseconds.
+  TimeInMillis elapsed_time() const;
+
+  // Returns true if and only if the unit test passed (i.e. all test suites
+  // passed).
+  bool Passed() const;
+
+  // Returns true if and only if the unit test failed (i.e. some test suite
+  // failed or something outside of all tests failed).
+  bool Failed() const;
+
+  // Gets the i-th test suite among all the test suites. i can range from 0 to
+  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
+  const TestSuite* GetTestSuite(int i) const;
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  const TestCase* GetTestCase(int i) const;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Returns the TestResult containing information on test failures and
+  // properties logged outside of individual test suites.
+  const TestResult& ad_hoc_test_result() const;
+
+  // Returns the list of event listeners that can be used to track events
+  // inside Google Test.
+  TestEventListeners& listeners();
+
+ private:
+  // Registers and returns a global test environment.  When a test
+  // program is run, all global test environments will be set-up in
+  // the order they were registered.  After all tests in the program
+  // have finished, all global test environments will be torn-down in
+  // the *reverse* order they were registered.
+  //
+  // The UnitTest object takes ownership of the given environment.
+  //
+  // This method can only be called from the main thread.
+  Environment* AddEnvironment(Environment* env);
+
+  // Adds a TestPartResult to the current TestResult object.  All
+  // Google Test assertion macros (e.g. ASSERT_TRUE, EXPECT_EQ, etc)
+  // eventually call this to report their results.  The user code
+  // should use the assertion macros instead of calling this directly.
+  void AddTestPartResult(TestPartResult::Type result_type,
+                         const char* file_name,
+                         int line_number,
+                         const std::string& message,
+                         const std::string& os_stack_trace)
+      GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Adds a TestProperty to the current TestResult object when invoked from
+  // inside a test, to current TestSuite's ad_hoc_test_result_ when invoked
+  // from SetUpTestSuite or TearDownTestSuite, or to the global property set
+  // when invoked elsewhere.  If the result already contains a property with
+  // the same key, the value will be updated.
+  void RecordProperty(const std::string& key, const std::string& value);
+
+  // Gets the i-th test suite among all the test suites. i can range from 0 to
+  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
+  TestSuite* GetMutableTestSuite(int i);
+
+  // Accessors for the implementation object.
+  internal::UnitTestImpl* impl() { return impl_; }
+  const internal::UnitTestImpl* impl() const { return impl_; }
+
+  // These classes and functions are friends as they need to access private
+  // members of UnitTest.
+  friend class ScopedTrace;
+  friend class Test;
+  friend class internal::AssertHelper;
+  friend class internal::StreamingListenerTest;
+  friend class internal::UnitTestRecordPropertyTestHelper;
+  friend Environment* AddGlobalTestEnvironment(Environment* env);
+  friend internal::UnitTestImpl* internal::GetUnitTestImpl();
+  friend void internal::ReportFailureInUnknownLocation(
+      TestPartResult::Type result_type,
+      const std::string& message);
+
+  // Creates an empty UnitTest.
+  UnitTest();
+
+  // D'tor
+  virtual ~UnitTest();
+
+  // Pushes a trace defined by SCOPED_TRACE() on to the per-thread
+  // Google Test trace stack.
+  void PushGTestTrace(const internal::TraceInfo& trace)
+      GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Pops a trace from the per-thread Google Test trace stack.
+  void PopGTestTrace()
+      GTEST_LOCK_EXCLUDED_(mutex_);
+
+  // Protects mutable state in *impl_.  This is mutable as some const
+  // methods need to lock it too.
+  mutable internal::Mutex mutex_;
+
+  // Opaque implementation object.  This field is never changed once
+  // the object is constructed.  We don't mark it as const here, as
+  // doing so will cause a warning in the constructor of UnitTest.
+  // Mutable state in *impl_ is protected by mutex_.
+  internal::UnitTestImpl* impl_;
+
+  // We disallow copying UnitTest.
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(UnitTest);
+};
+
+// A convenient wrapper for adding an environment for the test
+// program.
+//
+// You should call this before RUN_ALL_TESTS() is called, probably in
+// main().  If you use gtest_main, you need to call this before main()
+// starts for it to take effect.  For example, you can define a global
+// variable like this:
+//
+//   testing::Environment* const foo_env =
+//       testing::AddGlobalTestEnvironment(new FooEnvironment);
+//
+// However, we strongly recommend you to write your own main() and
+// call AddGlobalTestEnvironment() there, as relying on initialization
+// of global variables makes the code harder to read and may cause
+// problems when you register multiple environments from different
+// translation units and the environments have dependencies among them
+// (remember that the compiler doesn't guarantee the order in which
+// global variables from different translation units are initialized).
+inline Environment* AddGlobalTestEnvironment(Environment* env) {
+  return UnitTest::GetInstance()->AddEnvironment(env);
+}
+
+// Initializes Google Test.  This must be called before calling
+// RUN_ALL_TESTS().  In particular, it parses a command line for the
+// flags that Google Test recognizes.  Whenever a Google Test flag is
+// seen, it is removed from argv, and *argc is decremented.
+//
+// No value is returned.  Instead, the Google Test flag variables are
+// updated.
+//
+// Calling the function for the second time has no user-visible effect.
+GTEST_API_ void InitGoogleTest(int* argc, char** argv);
+
+// This overloaded version can be used in Windows programs compiled in
+// UNICODE mode.
+GTEST_API_ void InitGoogleTest(int* argc, wchar_t** argv);
+
+// This overloaded version can be used on Arduino/embedded platforms where
+// there is no argc/argv.
+GTEST_API_ void InitGoogleTest();
+
+namespace internal {
+
+// Separate the error generating code from the code path to reduce the stack
+// frame size of CmpHelperEQ. This helps reduce the overhead of some sanitizers
+// when calling EXPECT_* in a tight loop.
+template <typename T1, typename T2>
+AssertionResult CmpHelperEQFailure(const char* lhs_expression,
+                                   const char* rhs_expression,
+                                   const T1& lhs, const T2& rhs) {
+  return EqFailure(lhs_expression,
+                   rhs_expression,
+                   FormatForComparisonFailureMessage(lhs, rhs),
+                   FormatForComparisonFailureMessage(rhs, lhs),
+                   false);
+}
+
+// This block of code defines operator==/!=
+// to block lexical scope lookup.
+// It prevents using invalid operator==/!= defined at namespace scope.
+struct faketype {};
+inline bool operator==(faketype, faketype) { return true; }
+inline bool operator!=(faketype, faketype) { return false; }
+
+// The helper function for {ASSERT|EXPECT}_EQ.
+template <typename T1, typename T2>
+AssertionResult CmpHelperEQ(const char* lhs_expression,
+                            const char* rhs_expression,
+                            const T1& lhs,
+                            const T2& rhs) {
+  if (lhs == rhs) {
+    return AssertionSuccess();
+  }
+
+  return CmpHelperEQFailure(lhs_expression, rhs_expression, lhs, rhs);
+}
+
+// With this overloaded version, we allow anonymous enums to be used
+// in {ASSERT|EXPECT}_EQ when compiled with gcc 4, as anonymous enums
+// can be implicitly cast to BiggestInt.
+GTEST_API_ AssertionResult CmpHelperEQ(const char* lhs_expression,
+                                       const char* rhs_expression,
+                                       BiggestInt lhs,
+                                       BiggestInt rhs);
+
+class EqHelper {
+ public:
+  // This templatized version is for the general case.
+  template <
+      typename T1, typename T2,
+      // Disable this overload for cases where one argument is a pointer
+      // and the other is the null pointer constant.
+      typename std::enable_if<!std::is_integral<T1>::value ||
+                              !std::is_pointer<T2>::value>::type* = nullptr>
+  static AssertionResult Compare(const char* lhs_expression,
+                                 const char* rhs_expression, const T1& lhs,
+                                 const T2& rhs) {
+    return CmpHelperEQ(lhs_expression, rhs_expression, lhs, rhs);
+  }
+
+  // With this overloaded version, we allow anonymous enums to be used
+  // in {ASSERT|EXPECT}_EQ when compiled with gcc 4, as anonymous
+  // enums can be implicitly cast to BiggestInt.
+  //
+  // Even though its body looks the same as the above version, we
+  // cannot merge the two, as it will make anonymous enums unhappy.
+  static AssertionResult Compare(const char* lhs_expression,
+                                 const char* rhs_expression,
+                                 BiggestInt lhs,
+                                 BiggestInt rhs) {
+    return CmpHelperEQ(lhs_expression, rhs_expression, lhs, rhs);
+  }
+
+  template <typename T>
+  static AssertionResult Compare(
+      const char* lhs_expression, const char* rhs_expression,
+      // Handle cases where '0' is used as a null pointer literal.
+      std::nullptr_t /* lhs */, T* rhs) {
+    // We already know that 'lhs' is a null pointer.
+    return CmpHelperEQ(lhs_expression, rhs_expression, static_cast<T*>(nullptr),
+                       rhs);
+  }
+};
+
+// Separate the error generating code from the code path to reduce the stack
+// frame size of CmpHelperOP. This helps reduce the overhead of some sanitizers
+// when calling EXPECT_OP in a tight loop.
+template <typename T1, typename T2>
+AssertionResult CmpHelperOpFailure(const char* expr1, const char* expr2,
+                                   const T1& val1, const T2& val2,
+                                   const char* op) {
+  return AssertionFailure()
+         << "Expected: (" << expr1 << ") " << op << " (" << expr2
+         << "), actual: " << FormatForComparisonFailureMessage(val1, val2)
+         << " vs " << FormatForComparisonFailureMessage(val2, val1);
+}
+
+// A macro for implementing the helper functions needed to implement
+// ASSERT_?? and EXPECT_??.  It is here just to avoid copy-and-paste
+// of similar code.
+//
+// For each templatized helper function, we also define an overloaded
+// version for BiggestInt in order to reduce code bloat and allow
+// anonymous enums to be used with {ASSERT|EXPECT}_?? when compiled
+// with gcc 4.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+
+#define GTEST_IMPL_CMP_HELPER_(op_name, op)\
+template <typename T1, typename T2>\
+AssertionResult CmpHelper##op_name(const char* expr1, const char* expr2, \
+                                   const T1& val1, const T2& val2) {\
+  if (val1 op val2) {\
+    return AssertionSuccess();\
+  } else {\
+    return CmpHelperOpFailure(expr1, expr2, val1, val2, #op);\
+  }\
+}\
+GTEST_API_ AssertionResult CmpHelper##op_name(\
+    const char* expr1, const char* expr2, BiggestInt val1, BiggestInt val2)
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+
+// Implements the helper function for {ASSERT|EXPECT}_NE
+GTEST_IMPL_CMP_HELPER_(NE, !=);
+// Implements the helper function for {ASSERT|EXPECT}_LE
+GTEST_IMPL_CMP_HELPER_(LE, <=);
+// Implements the helper function for {ASSERT|EXPECT}_LT
+GTEST_IMPL_CMP_HELPER_(LT, <);
+// Implements the helper function for {ASSERT|EXPECT}_GE
+GTEST_IMPL_CMP_HELPER_(GE, >=);
+// Implements the helper function for {ASSERT|EXPECT}_GT
+GTEST_IMPL_CMP_HELPER_(GT, >);
+
+#undef GTEST_IMPL_CMP_HELPER_
+
+// The helper function for {ASSERT|EXPECT}_STREQ.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTREQ(const char* s1_expression,
+                                          const char* s2_expression,
+                                          const char* s1,
+                                          const char* s2);
+
+// The helper function for {ASSERT|EXPECT}_STRCASEEQ.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTRCASEEQ(const char* s1_expression,
+                                              const char* s2_expression,
+                                              const char* s1,
+                                              const char* s2);
+
+// The helper function for {ASSERT|EXPECT}_STRNE.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTRNE(const char* s1_expression,
+                                          const char* s2_expression,
+                                          const char* s1,
+                                          const char* s2);
+
+// The helper function for {ASSERT|EXPECT}_STRCASENE.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTRCASENE(const char* s1_expression,
+                                              const char* s2_expression,
+                                              const char* s1,
+                                              const char* s2);
+
+
+// Helper function for *_STREQ on wide strings.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTREQ(const char* s1_expression,
+                                          const char* s2_expression,
+                                          const wchar_t* s1,
+                                          const wchar_t* s2);
+
+// Helper function for *_STRNE on wide strings.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult CmpHelperSTRNE(const char* s1_expression,
+                                          const char* s2_expression,
+                                          const wchar_t* s1,
+                                          const wchar_t* s2);
+
+}  // namespace internal
+
+// IsSubstring() and IsNotSubstring() are intended to be used as the
+// first argument to {EXPECT,ASSERT}_PRED_FORMAT2(), not by
+// themselves.  They check whether needle is a substring of haystack
+// (NULL is considered a substring of itself only), and return an
+// appropriate error message when they fail.
+//
+// The {needle,haystack}_expr arguments are the stringified
+// expressions that generated the two real arguments.
+GTEST_API_ AssertionResult IsSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const char* needle, const char* haystack);
+GTEST_API_ AssertionResult IsSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const wchar_t* needle, const wchar_t* haystack);
+GTEST_API_ AssertionResult IsNotSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const char* needle, const char* haystack);
+GTEST_API_ AssertionResult IsNotSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const wchar_t* needle, const wchar_t* haystack);
+GTEST_API_ AssertionResult IsSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const ::std::string& needle, const ::std::string& haystack);
+GTEST_API_ AssertionResult IsNotSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const ::std::string& needle, const ::std::string& haystack);
+
+#if GTEST_HAS_STD_WSTRING
+GTEST_API_ AssertionResult IsSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const ::std::wstring& needle, const ::std::wstring& haystack);
+GTEST_API_ AssertionResult IsNotSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const ::std::wstring& needle, const ::std::wstring& haystack);
+#endif  // GTEST_HAS_STD_WSTRING
+
+namespace internal {
+
+// Helper template function for comparing floating-points.
+//
+// Template parameter:
+//
+//   RawType: the raw floating-point type (either float or double)
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+template <typename RawType>
+AssertionResult CmpHelperFloatingPointEQ(const char* lhs_expression,
+                                         const char* rhs_expression,
+                                         RawType lhs_value,
+                                         RawType rhs_value) {
+  const FloatingPoint<RawType> lhs(lhs_value), rhs(rhs_value);
+
+  if (lhs.AlmostEquals(rhs)) {
+    return AssertionSuccess();
+  }
+
+  ::std::stringstream lhs_ss;
+  lhs_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
+         << lhs_value;
+
+  ::std::stringstream rhs_ss;
+  rhs_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
+         << rhs_value;
+
+  return EqFailure(lhs_expression,
+                   rhs_expression,
+                   StringStreamToString(&lhs_ss),
+                   StringStreamToString(&rhs_ss),
+                   false);
+}
+
+// Helper function for implementing ASSERT_NEAR.
+//
+// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
+GTEST_API_ AssertionResult DoubleNearPredFormat(const char* expr1,
+                                                const char* expr2,
+                                                const char* abs_error_expr,
+                                                double val1,
+                                                double val2,
+                                                double abs_error);
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+// A class that enables one to stream messages to assertion macros
+class GTEST_API_ AssertHelper {
+ public:
+  // Constructor.
+  AssertHelper(TestPartResult::Type type,
+               const char* file,
+               int line,
+               const char* message);
+  ~AssertHelper();
+
+  // Message assignment is a semantic trick to enable assertion
+  // streaming; see the GTEST_MESSAGE_ macro below.
+  void operator=(const Message& message) const;
+
+ private:
+  // We put our data in a struct so that the size of the AssertHelper class can
+  // be as small as possible.  This is important because gcc is incapable of
+  // re-using stack space even for temporary variables, so every EXPECT_EQ
+  // reserves stack space for another AssertHelper.
+  struct AssertHelperData {
+    AssertHelperData(TestPartResult::Type t,
+                     const char* srcfile,
+                     int line_num,
+                     const char* msg)
+        : type(t), file(srcfile), line(line_num), message(msg) { }
+
+    TestPartResult::Type const type;
+    const char* const file;
+    int const line;
+    std::string const message;
+
+   private:
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(AssertHelperData);
+  };
+
+  AssertHelperData* const data_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(AssertHelper);
+};
+
+enum GTestColor { COLOR_DEFAULT, COLOR_RED, COLOR_GREEN, COLOR_YELLOW };
+
+GTEST_API_ GTEST_ATTRIBUTE_PRINTF_(2, 3) void ColoredPrintf(GTestColor color,
+                                                            const char* fmt,
+                                                            ...);
+
+}  // namespace internal
+
+// The pure interface class that all value-parameterized tests inherit from.
+// A value-parameterized class must inherit from both ::testing::Test and
+// ::testing::WithParamInterface. In most cases that just means inheriting
+// from ::testing::TestWithParam, but more complicated test hierarchies
+// may need to inherit from Test and WithParamInterface at different levels.
+//
+// This interface has support for accessing the test parameter value via
+// the GetParam() method.
+//
+// Use it with one of the parameter generator defining functions, like Range(),
+// Values(), ValuesIn(), Bool(), and Combine().
+//
+// class FooTest : public ::testing::TestWithParam<int> {
+//  protected:
+//   FooTest() {
+//     // Can use GetParam() here.
+//   }
+//   ~FooTest() override {
+//     // Can use GetParam() here.
+//   }
+//   void SetUp() override {
+//     // Can use GetParam() here.
+//   }
+//   void TearDown override {
+//     // Can use GetParam() here.
+//   }
+// };
+// TEST_P(FooTest, DoesBar) {
+//   // Can use GetParam() method here.
+//   Foo foo;
+//   ASSERT_TRUE(foo.DoesBar(GetParam()));
+// }
+// INSTANTIATE_TEST_SUITE_P(OneToTenRange, FooTest, ::testing::Range(1, 10));
+
+template <typename T>
+class WithParamInterface {
+ public:
+  typedef T ParamType;
+  virtual ~WithParamInterface() {}
+
+  // The current parameter value. Is also available in the test fixture's
+  // constructor.
+  static const ParamType& GetParam() {
+    GTEST_CHECK_(parameter_ != nullptr)
+        << "GetParam() can only be called inside a value-parameterized test "
+        << "-- did you intend to write TEST_P instead of TEST_F?";
+    return *parameter_;
+  }
+
+ private:
+  // Sets parameter value. The caller is responsible for making sure the value
+  // remains alive and unchanged throughout the current test.
+  static void SetParam(const ParamType* parameter) {
+    parameter_ = parameter;
+  }
+
+  // Static value used for accessing parameter during a test lifetime.
+  static const ParamType* parameter_;
+
+  // TestClass must be a subclass of WithParamInterface<T> and Test.
+  template <class TestClass> friend class internal::ParameterizedTestFactory;
+};
+
+template <typename T>
+const T* WithParamInterface<T>::parameter_ = nullptr;
+
+// Most value-parameterized classes can ignore the existence of
+// WithParamInterface, and can just inherit from ::testing::TestWithParam.
+
+template <typename T>
+class TestWithParam : public Test, public WithParamInterface<T> {
+};
+
+// Macros for indicating success/failure in test code.
+
+// Skips test in runtime.
+// Skipping test aborts current function.
+// Skipped tests are neither successful nor failed.
+#define GTEST_SKIP() GTEST_SKIP_("Skipped")
+
+// ADD_FAILURE unconditionally adds a failure to the current test.
+// SUCCEED generates a success - it doesn't automatically make the
+// current test successful, as a test is only successful when it has
+// no failure.
+//
+// EXPECT_* verifies that a certain condition is satisfied.  If not,
+// it behaves like ADD_FAILURE.  In particular:
+//
+//   EXPECT_TRUE  verifies that a Boolean condition is true.
+//   EXPECT_FALSE verifies that a Boolean condition is false.
+//
+// FAIL and ASSERT_* are similar to ADD_FAILURE and EXPECT_*, except
+// that they will also abort the current function on failure.  People
+// usually want the fail-fast behavior of FAIL and ASSERT_*, but those
+// writing data-driven tests often find themselves using ADD_FAILURE
+// and EXPECT_* more.
+
+// Generates a nonfatal failure with a generic message.
+#define ADD_FAILURE() GTEST_NONFATAL_FAILURE_("Failed")
+
+// Generates a nonfatal failure at the given source file location with
+// a generic message.
+#define ADD_FAILURE_AT(file, line) \
+  GTEST_MESSAGE_AT_(file, line, "Failed", \
+                    ::testing::TestPartResult::kNonFatalFailure)
+
+// Generates a fatal failure with a generic message.
+#define GTEST_FAIL() GTEST_FATAL_FAILURE_("Failed")
+
+// Like GTEST_FAIL(), but at the given source file location.
+#define GTEST_FAIL_AT(file, line)         \
+  GTEST_MESSAGE_AT_(file, line, "Failed", \
+                    ::testing::TestPartResult::kFatalFailure)
+
+// Define this macro to 1 to omit the definition of FAIL(), which is a
+// generic name and clashes with some other libraries.
+#if !GTEST_DONT_DEFINE_FAIL
+# define FAIL() GTEST_FAIL()
+#endif
+
+// Generates a success with a generic message.
+#define GTEST_SUCCEED() GTEST_SUCCESS_("Succeeded")
+
+// Define this macro to 1 to omit the definition of SUCCEED(), which
+// is a generic name and clashes with some other libraries.
+#if !GTEST_DONT_DEFINE_SUCCEED
+# define SUCCEED() GTEST_SUCCEED()
+#endif
+
+// Macros for testing exceptions.
+//
+//    * {ASSERT|EXPECT}_THROW(statement, expected_exception):
+//         Tests that the statement throws the expected exception.
+//    * {ASSERT|EXPECT}_NO_THROW(statement):
+//         Tests that the statement doesn't throw any exception.
+//    * {ASSERT|EXPECT}_ANY_THROW(statement):
+//         Tests that the statement throws an exception.
+
+#define EXPECT_THROW(statement, expected_exception) \
+  GTEST_TEST_THROW_(statement, expected_exception, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_NO_THROW(statement) \
+  GTEST_TEST_NO_THROW_(statement, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_ANY_THROW(statement) \
+  GTEST_TEST_ANY_THROW_(statement, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_THROW(statement, expected_exception) \
+  GTEST_TEST_THROW_(statement, expected_exception, GTEST_FATAL_FAILURE_)
+#define ASSERT_NO_THROW(statement) \
+  GTEST_TEST_NO_THROW_(statement, GTEST_FATAL_FAILURE_)
+#define ASSERT_ANY_THROW(statement) \
+  GTEST_TEST_ANY_THROW_(statement, GTEST_FATAL_FAILURE_)
+
+// Boolean assertions. Condition can be either a Boolean expression or an
+// AssertionResult. For more information on how to use AssertionResult with
+// these macros see comments on that class.
+#define EXPECT_TRUE(condition) \
+  GTEST_TEST_BOOLEAN_(condition, #condition, false, true, \
+                      GTEST_NONFATAL_FAILURE_)
+#define EXPECT_FALSE(condition) \
+  GTEST_TEST_BOOLEAN_(!(condition), #condition, true, false, \
+                      GTEST_NONFATAL_FAILURE_)
+#define ASSERT_TRUE(condition) \
+  GTEST_TEST_BOOLEAN_(condition, #condition, false, true, \
+                      GTEST_FATAL_FAILURE_)
+#define ASSERT_FALSE(condition) \
+  GTEST_TEST_BOOLEAN_(!(condition), #condition, true, false, \
+                      GTEST_FATAL_FAILURE_)
+
+// Macros for testing equalities and inequalities.
+//
+//    * {ASSERT|EXPECT}_EQ(v1, v2): Tests that v1 == v2
+//    * {ASSERT|EXPECT}_NE(v1, v2): Tests that v1 != v2
+//    * {ASSERT|EXPECT}_LT(v1, v2): Tests that v1 < v2
+//    * {ASSERT|EXPECT}_LE(v1, v2): Tests that v1 <= v2
+//    * {ASSERT|EXPECT}_GT(v1, v2): Tests that v1 > v2
+//    * {ASSERT|EXPECT}_GE(v1, v2): Tests that v1 >= v2
+//
+// When they are not, Google Test prints both the tested expressions and
+// their actual values.  The values must be compatible built-in types,
+// or you will get a compiler error.  By "compatible" we mean that the
+// values can be compared by the respective operator.
+//
+// Note:
+//
+//   1. It is possible to make a user-defined type work with
+//   {ASSERT|EXPECT}_??(), but that requires overloading the
+//   comparison operators and is thus discouraged by the Google C++
+//   Usage Guide.  Therefore, you are advised to use the
+//   {ASSERT|EXPECT}_TRUE() macro to assert that two objects are
+//   equal.
+//
+//   2. The {ASSERT|EXPECT}_??() macros do pointer comparisons on
+//   pointers (in particular, C strings).  Therefore, if you use it
+//   with two C strings, you are testing how their locations in memory
+//   are related, not how their content is related.  To compare two C
+//   strings by content, use {ASSERT|EXPECT}_STR*().
+//
+//   3. {ASSERT|EXPECT}_EQ(v1, v2) is preferred to
+//   {ASSERT|EXPECT}_TRUE(v1 == v2), as the former tells you
+//   what the actual value is when it fails, and similarly for the
+//   other comparisons.
+//
+//   4. Do not depend on the order in which {ASSERT|EXPECT}_??()
+//   evaluate their arguments, which is undefined.
+//
+//   5. These macros evaluate their arguments exactly once.
+//
+// Examples:
+//
+//   EXPECT_NE(Foo(), 5);
+//   EXPECT_EQ(a_pointer, NULL);
+//   ASSERT_LT(i, array_size);
+//   ASSERT_GT(records.size(), 0) << "There is no record left.";
+
+#define EXPECT_EQ(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::EqHelper::Compare, val1, val2)
+#define EXPECT_NE(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperNE, val1, val2)
+#define EXPECT_LE(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperLE, val1, val2)
+#define EXPECT_LT(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperLT, val1, val2)
+#define EXPECT_GE(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperGE, val1, val2)
+#define EXPECT_GT(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperGT, val1, val2)
+
+#define GTEST_ASSERT_EQ(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::EqHelper::Compare, val1, val2)
+#define GTEST_ASSERT_NE(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperNE, val1, val2)
+#define GTEST_ASSERT_LE(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperLE, val1, val2)
+#define GTEST_ASSERT_LT(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperLT, val1, val2)
+#define GTEST_ASSERT_GE(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperGE, val1, val2)
+#define GTEST_ASSERT_GT(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperGT, val1, val2)
+
+// Define macro GTEST_DONT_DEFINE_ASSERT_XY to 1 to omit the definition of
+// ASSERT_XY(), which clashes with some users' own code.
+
+#if !GTEST_DONT_DEFINE_ASSERT_EQ
+# define ASSERT_EQ(val1, val2) GTEST_ASSERT_EQ(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_NE
+# define ASSERT_NE(val1, val2) GTEST_ASSERT_NE(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_LE
+# define ASSERT_LE(val1, val2) GTEST_ASSERT_LE(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_LT
+# define ASSERT_LT(val1, val2) GTEST_ASSERT_LT(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_GE
+# define ASSERT_GE(val1, val2) GTEST_ASSERT_GE(val1, val2)
+#endif
+
+#if !GTEST_DONT_DEFINE_ASSERT_GT
+# define ASSERT_GT(val1, val2) GTEST_ASSERT_GT(val1, val2)
+#endif
+
+// C-string Comparisons.  All tests treat NULL and any non-NULL string
+// as different.  Two NULLs are equal.
+//
+//    * {ASSERT|EXPECT}_STREQ(s1, s2):     Tests that s1 == s2
+//    * {ASSERT|EXPECT}_STRNE(s1, s2):     Tests that s1 != s2
+//    * {ASSERT|EXPECT}_STRCASEEQ(s1, s2): Tests that s1 == s2, ignoring case
+//    * {ASSERT|EXPECT}_STRCASENE(s1, s2): Tests that s1 != s2, ignoring case
+//
+// For wide or narrow string objects, you can use the
+// {ASSERT|EXPECT}_??() macros.
+//
+// Don't depend on the order in which the arguments are evaluated,
+// which is undefined.
+//
+// These macros evaluate their arguments exactly once.
+
+#define EXPECT_STREQ(s1, s2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTREQ, s1, s2)
+#define EXPECT_STRNE(s1, s2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRNE, s1, s2)
+#define EXPECT_STRCASEEQ(s1, s2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASEEQ, s1, s2)
+#define EXPECT_STRCASENE(s1, s2)\
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASENE, s1, s2)
+
+#define ASSERT_STREQ(s1, s2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTREQ, s1, s2)
+#define ASSERT_STRNE(s1, s2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRNE, s1, s2)
+#define ASSERT_STRCASEEQ(s1, s2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASEEQ, s1, s2)
+#define ASSERT_STRCASENE(s1, s2)\
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASENE, s1, s2)
+
+// Macros for comparing floating-point numbers.
+//
+//    * {ASSERT|EXPECT}_FLOAT_EQ(val1, val2):
+//         Tests that two float values are almost equal.
+//    * {ASSERT|EXPECT}_DOUBLE_EQ(val1, val2):
+//         Tests that two double values are almost equal.
+//    * {ASSERT|EXPECT}_NEAR(v1, v2, abs_error):
+//         Tests that v1 and v2 are within the given distance to each other.
+//
+// Google Test uses ULP-based comparison to automatically pick a default
+// error bound that is appropriate for the operands.  See the
+// FloatingPoint template class in gtest-internal.h if you are
+// interested in the implementation details.
+
+#define EXPECT_FLOAT_EQ(val1, val2)\
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<float>, \
+                      val1, val2)
+
+#define EXPECT_DOUBLE_EQ(val1, val2)\
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<double>, \
+                      val1, val2)
+
+#define ASSERT_FLOAT_EQ(val1, val2)\
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<float>, \
+                      val1, val2)
+
+#define ASSERT_DOUBLE_EQ(val1, val2)\
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<double>, \
+                      val1, val2)
+
+#define EXPECT_NEAR(val1, val2, abs_error)\
+  EXPECT_PRED_FORMAT3(::testing::internal::DoubleNearPredFormat, \
+                      val1, val2, abs_error)
+
+#define ASSERT_NEAR(val1, val2, abs_error)\
+  ASSERT_PRED_FORMAT3(::testing::internal::DoubleNearPredFormat, \
+                      val1, val2, abs_error)
+
+// These predicate format functions work on floating-point values, and
+// can be used in {ASSERT|EXPECT}_PRED_FORMAT2*(), e.g.
+//
+//   EXPECT_PRED_FORMAT2(testing::DoubleLE, Foo(), 5.0);
+
+// Asserts that val1 is less than, or almost equal to, val2.  Fails
+// otherwise.  In particular, it fails if either val1 or val2 is NaN.
+GTEST_API_ AssertionResult FloatLE(const char* expr1, const char* expr2,
+                                   float val1, float val2);
+GTEST_API_ AssertionResult DoubleLE(const char* expr1, const char* expr2,
+                                    double val1, double val2);
+
+
+#if GTEST_OS_WINDOWS
+
+// Macros that test for HRESULT failure and success, these are only useful
+// on Windows, and rely on Windows SDK macros and APIs to compile.
+//
+//    * {ASSERT|EXPECT}_HRESULT_{SUCCEEDED|FAILED}(expr)
+//
+// When expr unexpectedly fails or succeeds, Google Test prints the
+// expected result and the actual result with both a human-readable
+// string representation of the error, if available, as well as the
+// hex result code.
+# define EXPECT_HRESULT_SUCCEEDED(expr) \
+    EXPECT_PRED_FORMAT1(::testing::internal::IsHRESULTSuccess, (expr))
+
+# define ASSERT_HRESULT_SUCCEEDED(expr) \
+    ASSERT_PRED_FORMAT1(::testing::internal::IsHRESULTSuccess, (expr))
+
+# define EXPECT_HRESULT_FAILED(expr) \
+    EXPECT_PRED_FORMAT1(::testing::internal::IsHRESULTFailure, (expr))
+
+# define ASSERT_HRESULT_FAILED(expr) \
+    ASSERT_PRED_FORMAT1(::testing::internal::IsHRESULTFailure, (expr))
+
+#endif  // GTEST_OS_WINDOWS
+
+// Macros that execute statement and check that it doesn't generate new fatal
+// failures in the current thread.
+//
+//   * {ASSERT|EXPECT}_NO_FATAL_FAILURE(statement);
+//
+// Examples:
+//
+//   EXPECT_NO_FATAL_FAILURE(Process());
+//   ASSERT_NO_FATAL_FAILURE(Process()) << "Process() failed";
+//
+#define ASSERT_NO_FATAL_FAILURE(statement) \
+    GTEST_TEST_NO_FATAL_FAILURE_(statement, GTEST_FATAL_FAILURE_)
+#define EXPECT_NO_FATAL_FAILURE(statement) \
+    GTEST_TEST_NO_FATAL_FAILURE_(statement, GTEST_NONFATAL_FAILURE_)
+
+// Causes a trace (including the given source file path and line number,
+// and the given message) to be included in every test failure message generated
+// by code in the scope of the lifetime of an instance of this class. The effect
+// is undone with the destruction of the instance.
+//
+// The message argument can be anything streamable to std::ostream.
+//
+// Example:
+//   testing::ScopedTrace trace("file.cc", 123, "message");
+//
+class GTEST_API_ ScopedTrace {
+ public:
+  // The c'tor pushes the given source file location and message onto
+  // a trace stack maintained by Google Test.
+
+  // Template version. Uses Message() to convert the values into strings.
+  // Slow, but flexible.
+  template <typename T>
+  ScopedTrace(const char* file, int line, const T& message) {
+    PushTrace(file, line, (Message() << message).GetString());
+  }
+
+  // Optimize for some known types.
+  ScopedTrace(const char* file, int line, const char* message) {
+    PushTrace(file, line, message ? message : "(null)");
+  }
+
+  ScopedTrace(const char* file, int line, const std::string& message) {
+    PushTrace(file, line, message);
+  }
+
+  // The d'tor pops the info pushed by the c'tor.
+  //
+  // Note that the d'tor is not virtual in order to be efficient.
+  // Don't inherit from ScopedTrace!
+  ~ScopedTrace();
+
+ private:
+  void PushTrace(const char* file, int line, std::string message);
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ScopedTrace);
+} GTEST_ATTRIBUTE_UNUSED_;  // A ScopedTrace object does its job in its
+                            // c'tor and d'tor.  Therefore it doesn't
+                            // need to be used otherwise.
+
+// Causes a trace (including the source file path, the current line
+// number, and the given message) to be included in every test failure
+// message generated by code in the current scope.  The effect is
+// undone when the control leaves the current scope.
+//
+// The message argument can be anything streamable to std::ostream.
+//
+// In the implementation, we include the current line number as part
+// of the dummy variable name, thus allowing multiple SCOPED_TRACE()s
+// to appear in the same block - as long as they are on different
+// lines.
+//
+// Assuming that each thread maintains its own stack of traces.
+// Therefore, a SCOPED_TRACE() would (correctly) only affect the
+// assertions in its own thread.
+#define SCOPED_TRACE(message) \
+  ::testing::ScopedTrace GTEST_CONCAT_TOKEN_(gtest_trace_, __LINE__)(\
+    __FILE__, __LINE__, (message))
+
+// Compile-time assertion for type equality.
+// StaticAssertTypeEq<type1, type2>() compiles if and only if type1 and type2
+// are the same type.  The value it returns is not interesting.
+//
+// Instead of making StaticAssertTypeEq a class template, we make it a
+// function template that invokes a helper class template.  This
+// prevents a user from misusing StaticAssertTypeEq<T1, T2> by
+// defining objects of that type.
+//
+// CAVEAT:
+//
+// When used inside a method of a class template,
+// StaticAssertTypeEq<T1, T2>() is effective ONLY IF the method is
+// instantiated.  For example, given:
+//
+//   template <typename T> class Foo {
+//    public:
+//     void Bar() { testing::StaticAssertTypeEq<int, T>(); }
+//   };
+//
+// the code:
+//
+//   void Test1() { Foo<bool> foo; }
+//
+// will NOT generate a compiler error, as Foo<bool>::Bar() is never
+// actually instantiated.  Instead, you need:
+//
+//   void Test2() { Foo<bool> foo; foo.Bar(); }
+//
+// to cause a compiler error.
+template <typename T1, typename T2>
+constexpr bool StaticAssertTypeEq() noexcept {
+  static_assert(std::is_same<T1, T2>::value,
+                "type1 and type2 are not the same type");
+  return true;
+}
+
+// Defines a test.
+//
+// The first parameter is the name of the test suite, and the second
+// parameter is the name of the test within the test suite.
+//
+// The convention is to end the test suite name with "Test".  For
+// example, a test suite for the Foo class can be named FooTest.
+//
+// Test code should appear between braces after an invocation of
+// this macro.  Example:
+//
+//   TEST(FooTest, InitializesCorrectly) {
+//     Foo foo;
+//     EXPECT_TRUE(foo.StatusIsOK());
+//   }
+
+// Note that we call GetTestTypeId() instead of GetTypeId<
+// ::testing::Test>() here to get the type ID of testing::Test.  This
+// is to work around a suspected linker bug when using Google Test as
+// a framework on Mac OS X.  The bug causes GetTypeId<
+// ::testing::Test>() to return different values depending on whether
+// the call is from the Google Test framework itself or from user test
+// code.  GetTestTypeId() is guaranteed to always return the same
+// value, as it always calls GetTypeId<>() from the Google Test
+// framework.
+#define GTEST_TEST(test_suite_name, test_name)             \
+  GTEST_TEST_(test_suite_name, test_name, ::testing::Test, \
+              ::testing::internal::GetTestTypeId())
+
+// Define this macro to 1 to omit the definition of TEST(), which
+// is a generic name and clashes with some other libraries.
+#if !GTEST_DONT_DEFINE_TEST
+#define TEST(test_suite_name, test_name) GTEST_TEST(test_suite_name, test_name)
+#endif
+
+// Defines a test that uses a test fixture.
+//
+// The first parameter is the name of the test fixture class, which
+// also doubles as the test suite name.  The second parameter is the
+// name of the test within the test suite.
+//
+// A test fixture class must be declared earlier.  The user should put
+// the test code between braces after using this macro.  Example:
+//
+//   class FooTest : public testing::Test {
+//    protected:
+//     void SetUp() override { b_.AddElement(3); }
+//
+//     Foo a_;
+//     Foo b_;
+//   };
+//
+//   TEST_F(FooTest, InitializesCorrectly) {
+//     EXPECT_TRUE(a_.StatusIsOK());
+//   }
+//
+//   TEST_F(FooTest, ReturnsElementCountCorrectly) {
+//     EXPECT_EQ(a_.size(), 0);
+//     EXPECT_EQ(b_.size(), 1);
+//   }
+//
+// GOOGLETEST_CM0011 DO NOT DELETE
+#define TEST_F(test_fixture, test_name)\
+  GTEST_TEST_(test_fixture, test_name, test_fixture, \
+              ::testing::internal::GetTypeId<test_fixture>())
+
+// Returns a path to temporary directory.
+// Tries to determine an appropriate directory for the platform.
+GTEST_API_ std::string TempDir();
+
+#ifdef _MSC_VER
+#  pragma warning(pop)
+#endif
+
+// Dynamically registers a test with the framework.
+//
+// This is an advanced API only to be used when the `TEST` macros are
+// insufficient. The macros should be preferred when possible, as they avoid
+// most of the complexity of calling this function.
+//
+// The `factory` argument is a factory callable (move-constructible) object or
+// function pointer that creates a new instance of the Test object. It
+// handles ownership to the caller. The signature of the callable is
+// `Fixture*()`, where `Fixture` is the test fixture class for the test. All
+// tests registered with the same `test_suite_name` must return the same
+// fixture type. This is checked at runtime.
+//
+// The framework will infer the fixture class from the factory and will call
+// the `SetUpTestSuite` and `TearDownTestSuite` for it.
+//
+// Must be called before `RUN_ALL_TESTS()` is invoked, otherwise behavior is
+// undefined.
+//
+// Use case example:
+//
+// class MyFixture : public ::testing::Test {
+//  public:
+//   // All of these optional, just like in regular macro usage.
+//   static void SetUpTestSuite() { ... }
+//   static void TearDownTestSuite() { ... }
+//   void SetUp() override { ... }
+//   void TearDown() override { ... }
+// };
+//
+// class MyTest : public MyFixture {
+//  public:
+//   explicit MyTest(int data) : data_(data) {}
+//   void TestBody() override { ... }
+//
+//  private:
+//   int data_;
+// };
+//
+// void RegisterMyTests(const std::vector<int>& values) {
+//   for (int v : values) {
+//     ::testing::RegisterTest(
+//         "MyFixture", ("Test" + std::to_string(v)).c_str(), nullptr,
+//         std::to_string(v).c_str(),
+//         __FILE__, __LINE__,
+//         // Important to use the fixture type as the return type here.
+//         [=]() -> MyFixture* { return new MyTest(v); });
+//   }
+// }
+// ...
+// int main(int argc, char** argv) {
+//   std::vector<int> values_to_test = LoadValuesFromConfig();
+//   RegisterMyTests(values_to_test);
+//   ...
+//   return RUN_ALL_TESTS();
+// }
+//
+template <int&... ExplicitParameterBarrier, typename Factory>
+TestInfo* RegisterTest(const char* test_suite_name, const char* test_name,
+                       const char* type_param, const char* value_param,
+                       const char* file, int line, Factory factory) {
+  using TestT = typename std::remove_pointer<decltype(factory())>::type;
+
+  class FactoryImpl : public internal::TestFactoryBase {
+   public:
+    explicit FactoryImpl(Factory f) : factory_(std::move(f)) {}
+    Test* CreateTest() override { return factory_(); }
+
+   private:
+    Factory factory_;
+  };
+
+  return internal::MakeAndRegisterTestInfo(
+      test_suite_name, test_name, type_param, value_param,
+      internal::CodeLocation(file, line), internal::GetTypeId<TestT>(),
+      internal::SuiteApiResolver<TestT>::GetSetUpCaseOrSuite(file, line),
+      internal::SuiteApiResolver<TestT>::GetTearDownCaseOrSuite(file, line),
+      new FactoryImpl{std::move(factory)});
+}
+
+}  // namespace testing
+
+// Use this function in main() to run all tests.  It returns 0 if all
+// tests are successful, or 1 otherwise.
+//
+// RUN_ALL_TESTS() should be invoked after the command line has been
+// parsed by InitGoogleTest().
+//
+// This function was formerly a macro; thus, it is in the global
+// namespace and has an all-caps name.
+int RUN_ALL_TESTS() GTEST_MUST_USE_RESULT_;
+
+inline int RUN_ALL_TESTS() {
+  return ::testing::UnitTest::GetInstance()->Run();
+}
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_H_
diff --git a/3rdparty/gtest/include/gtest/gtest_pred_impl.h b/3rdparty/gtest/include/gtest/gtest_pred_impl.h
new file mode 100644
index 0000000..d514255
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest_pred_impl.h
@@ -0,0 +1,359 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// This file is AUTOMATICALLY GENERATED on 01/02/2019 by command
+// 'gen_gtest_pred_impl.py 5'.  DO NOT EDIT BY HAND!
+//
+// Implements a family of generic predicate assertion macros.
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
+#define GTEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
+
+#include "gtest/gtest.h"
+
+namespace testing {
+
+// This header implements a family of generic predicate assertion
+// macros:
+//
+//   ASSERT_PRED_FORMAT1(pred_format, v1)
+//   ASSERT_PRED_FORMAT2(pred_format, v1, v2)
+//   ...
+//
+// where pred_format is a function or functor that takes n (in the
+// case of ASSERT_PRED_FORMATn) values and their source expression
+// text, and returns a testing::AssertionResult.  See the definition
+// of ASSERT_EQ in gtest.h for an example.
+//
+// If you don't care about formatting, you can use the more
+// restrictive version:
+//
+//   ASSERT_PRED1(pred, v1)
+//   ASSERT_PRED2(pred, v1, v2)
+//   ...
+//
+// where pred is an n-ary function or functor that returns bool,
+// and the values v1, v2, ..., must support the << operator for
+// streaming to std::ostream.
+//
+// We also define the EXPECT_* variations.
+//
+// For now we only support predicates whose arity is at most 5.
+// Please email googletestframework@googlegroups.com if you need
+// support for higher arities.
+
+// GTEST_ASSERT_ is the basic statement to which all of the assertions
+// in this file reduce.  Don't use this in your code.
+
+#define GTEST_ASSERT_(expression, on_failure) \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
+  if (const ::testing::AssertionResult gtest_ar = (expression)) \
+    ; \
+  else \
+    on_failure(gtest_ar.failure_message())
+
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED1.  Don't use
+// this in your code.
+template <typename Pred,
+          typename T1>
+AssertionResult AssertPred1Helper(const char* pred_text,
+                                  const char* e1,
+                                  Pred pred,
+                                  const T1& v1) {
+  if (pred(v1)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT1.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT1_(pred_format, v1, on_failure)\
+  GTEST_ASSERT_(pred_format(#v1, v1), \
+                on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED1.  Don't use
+// this in your code.
+#define GTEST_PRED1_(pred, v1, on_failure)\
+  GTEST_ASSERT_(::testing::AssertPred1Helper(#pred, \
+                                             #v1, \
+                                             pred, \
+                                             v1), on_failure)
+
+// Unary predicate assertion macros.
+#define EXPECT_PRED_FORMAT1(pred_format, v1) \
+  GTEST_PRED_FORMAT1_(pred_format, v1, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED1(pred, v1) \
+  GTEST_PRED1_(pred, v1, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT1(pred_format, v1) \
+  GTEST_PRED_FORMAT1_(pred_format, v1, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED1(pred, v1) \
+  GTEST_PRED1_(pred, v1, GTEST_FATAL_FAILURE_)
+
+
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED2.  Don't use
+// this in your code.
+template <typename Pred,
+          typename T1,
+          typename T2>
+AssertionResult AssertPred2Helper(const char* pred_text,
+                                  const char* e1,
+                                  const char* e2,
+                                  Pred pred,
+                                  const T1& v1,
+                                  const T2& v2) {
+  if (pred(v1, v2)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ", " << e2
+         << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
+         << e2 << " evaluates to " << ::testing::PrintToString(v2);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT2.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT2_(pred_format, v1, v2, on_failure)\
+  GTEST_ASSERT_(pred_format(#v1, #v2, v1, v2), \
+                on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED2.  Don't use
+// this in your code.
+#define GTEST_PRED2_(pred, v1, v2, on_failure)\
+  GTEST_ASSERT_(::testing::AssertPred2Helper(#pred, \
+                                             #v1, \
+                                             #v2, \
+                                             pred, \
+                                             v1, \
+                                             v2), on_failure)
+
+// Binary predicate assertion macros.
+#define EXPECT_PRED_FORMAT2(pred_format, v1, v2) \
+  GTEST_PRED_FORMAT2_(pred_format, v1, v2, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED2(pred, v1, v2) \
+  GTEST_PRED2_(pred, v1, v2, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT2(pred_format, v1, v2) \
+  GTEST_PRED_FORMAT2_(pred_format, v1, v2, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED2(pred, v1, v2) \
+  GTEST_PRED2_(pred, v1, v2, GTEST_FATAL_FAILURE_)
+
+
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED3.  Don't use
+// this in your code.
+template <typename Pred,
+          typename T1,
+          typename T2,
+          typename T3>
+AssertionResult AssertPred3Helper(const char* pred_text,
+                                  const char* e1,
+                                  const char* e2,
+                                  const char* e3,
+                                  Pred pred,
+                                  const T1& v1,
+                                  const T2& v2,
+                                  const T3& v3) {
+  if (pred(v1, v2, v3)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ", " << e2 << ", " << e3
+         << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
+         << e2 << " evaluates to " << ::testing::PrintToString(v2) << "\n"
+         << e3 << " evaluates to " << ::testing::PrintToString(v3);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT3.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT3_(pred_format, v1, v2, v3, on_failure)\
+  GTEST_ASSERT_(pred_format(#v1, #v2, #v3, v1, v2, v3), \
+                on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED3.  Don't use
+// this in your code.
+#define GTEST_PRED3_(pred, v1, v2, v3, on_failure)\
+  GTEST_ASSERT_(::testing::AssertPred3Helper(#pred, \
+                                             #v1, \
+                                             #v2, \
+                                             #v3, \
+                                             pred, \
+                                             v1, \
+                                             v2, \
+                                             v3), on_failure)
+
+// Ternary predicate assertion macros.
+#define EXPECT_PRED_FORMAT3(pred_format, v1, v2, v3) \
+  GTEST_PRED_FORMAT3_(pred_format, v1, v2, v3, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED3(pred, v1, v2, v3) \
+  GTEST_PRED3_(pred, v1, v2, v3, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT3(pred_format, v1, v2, v3) \
+  GTEST_PRED_FORMAT3_(pred_format, v1, v2, v3, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED3(pred, v1, v2, v3) \
+  GTEST_PRED3_(pred, v1, v2, v3, GTEST_FATAL_FAILURE_)
+
+
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED4.  Don't use
+// this in your code.
+template <typename Pred,
+          typename T1,
+          typename T2,
+          typename T3,
+          typename T4>
+AssertionResult AssertPred4Helper(const char* pred_text,
+                                  const char* e1,
+                                  const char* e2,
+                                  const char* e3,
+                                  const char* e4,
+                                  Pred pred,
+                                  const T1& v1,
+                                  const T2& v2,
+                                  const T3& v3,
+                                  const T4& v4) {
+  if (pred(v1, v2, v3, v4)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ", " << e2 << ", " << e3 << ", " << e4
+         << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
+         << e2 << " evaluates to " << ::testing::PrintToString(v2) << "\n"
+         << e3 << " evaluates to " << ::testing::PrintToString(v3) << "\n"
+         << e4 << " evaluates to " << ::testing::PrintToString(v4);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT4.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT4_(pred_format, v1, v2, v3, v4, on_failure)\
+  GTEST_ASSERT_(pred_format(#v1, #v2, #v3, #v4, v1, v2, v3, v4), \
+                on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED4.  Don't use
+// this in your code.
+#define GTEST_PRED4_(pred, v1, v2, v3, v4, on_failure)\
+  GTEST_ASSERT_(::testing::AssertPred4Helper(#pred, \
+                                             #v1, \
+                                             #v2, \
+                                             #v3, \
+                                             #v4, \
+                                             pred, \
+                                             v1, \
+                                             v2, \
+                                             v3, \
+                                             v4), on_failure)
+
+// 4-ary predicate assertion macros.
+#define EXPECT_PRED_FORMAT4(pred_format, v1, v2, v3, v4) \
+  GTEST_PRED_FORMAT4_(pred_format, v1, v2, v3, v4, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED4(pred, v1, v2, v3, v4) \
+  GTEST_PRED4_(pred, v1, v2, v3, v4, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT4(pred_format, v1, v2, v3, v4) \
+  GTEST_PRED_FORMAT4_(pred_format, v1, v2, v3, v4, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED4(pred, v1, v2, v3, v4) \
+  GTEST_PRED4_(pred, v1, v2, v3, v4, GTEST_FATAL_FAILURE_)
+
+
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED5.  Don't use
+// this in your code.
+template <typename Pred,
+          typename T1,
+          typename T2,
+          typename T3,
+          typename T4,
+          typename T5>
+AssertionResult AssertPred5Helper(const char* pred_text,
+                                  const char* e1,
+                                  const char* e2,
+                                  const char* e3,
+                                  const char* e4,
+                                  const char* e5,
+                                  Pred pred,
+                                  const T1& v1,
+                                  const T2& v2,
+                                  const T3& v3,
+                                  const T4& v4,
+                                  const T5& v5) {
+  if (pred(v1, v2, v3, v4, v5)) return AssertionSuccess();
+
+  return AssertionFailure()
+         << pred_text << "(" << e1 << ", " << e2 << ", " << e3 << ", " << e4
+         << ", " << e5 << ") evaluates to false, where"
+         << "\n"
+         << e1 << " evaluates to " << ::testing::PrintToString(v1) << "\n"
+         << e2 << " evaluates to " << ::testing::PrintToString(v2) << "\n"
+         << e3 << " evaluates to " << ::testing::PrintToString(v3) << "\n"
+         << e4 << " evaluates to " << ::testing::PrintToString(v4) << "\n"
+         << e5 << " evaluates to " << ::testing::PrintToString(v5);
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT5.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT5_(pred_format, v1, v2, v3, v4, v5, on_failure)\
+  GTEST_ASSERT_(pred_format(#v1, #v2, #v3, #v4, #v5, v1, v2, v3, v4, v5), \
+                on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED5.  Don't use
+// this in your code.
+#define GTEST_PRED5_(pred, v1, v2, v3, v4, v5, on_failure)\
+  GTEST_ASSERT_(::testing::AssertPred5Helper(#pred, \
+                                             #v1, \
+                                             #v2, \
+                                             #v3, \
+                                             #v4, \
+                                             #v5, \
+                                             pred, \
+                                             v1, \
+                                             v2, \
+                                             v3, \
+                                             v4, \
+                                             v5), on_failure)
+
+// 5-ary predicate assertion macros.
+#define EXPECT_PRED_FORMAT5(pred_format, v1, v2, v3, v4, v5) \
+  GTEST_PRED_FORMAT5_(pred_format, v1, v2, v3, v4, v5, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED5(pred, v1, v2, v3, v4, v5) \
+  GTEST_PRED5_(pred, v1, v2, v3, v4, v5, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT5(pred_format, v1, v2, v3, v4, v5) \
+  GTEST_PRED_FORMAT5_(pred_format, v1, v2, v3, v4, v5, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED5(pred, v1, v2, v3, v4, v5) \
+  GTEST_PRED5_(pred, v1, v2, v3, v4, v5, GTEST_FATAL_FAILURE_)
+
+
+
+}  // namespace testing
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
diff --git a/3rdparty/gtest/include/gtest/gtest_prod.h b/3rdparty/gtest/include/gtest/gtest_prod.h
new file mode 100644
index 0000000..e651671
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/gtest_prod.h
@@ -0,0 +1,61 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Google C++ Testing and Mocking Framework definitions useful in production code.
+// GOOGLETEST_CM0003 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_PROD_H_
+#define GTEST_INCLUDE_GTEST_GTEST_PROD_H_
+
+// When you need to test the private or protected members of a class,
+// use the FRIEND_TEST macro to declare your tests as friends of the
+// class.  For example:
+//
+// class MyClass {
+//  private:
+//   void PrivateMethod();
+//   FRIEND_TEST(MyClassTest, PrivateMethodWorks);
+// };
+//
+// class MyClassTest : public testing::Test {
+//   // ...
+// };
+//
+// TEST_F(MyClassTest, PrivateMethodWorks) {
+//   // Can call MyClass::PrivateMethod() here.
+// }
+//
+// Note: The test class must be in the same namespace as the class being tested.
+// For example, putting MyClassTest in an anonymous namespace will not work.
+
+#define FRIEND_TEST(test_case_name, test_name)\
+friend class test_case_name##_##test_name##_Test
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_PROD_H_
diff --git a/3rdparty/gtest/include/gtest/internal/custom/README.md b/3rdparty/gtest/include/gtest/internal/custom/README.md
new file mode 100644
index 0000000..ff391fb
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/custom/README.md
@@ -0,0 +1,56 @@
+# Customization Points
+
+The custom directory is an injection point for custom user configurations.
+
+## Header `gtest.h`
+
+### The following macros can be defined:
+
+*   `GTEST_OS_STACK_TRACE_GETTER_` - The name of an implementation of
+    `OsStackTraceGetterInterface`.
+*   `GTEST_CUSTOM_TEMPDIR_FUNCTION_` - An override for `testing::TempDir()`. See
+    `testing::TempDir` for semantics and signature.
+
+## Header `gtest-port.h`
+
+The following macros can be defined:
+
+### Flag related macros:
+
+*   `GTEST_FLAG(flag_name)`
+*   `GTEST_USE_OWN_FLAGFILE_FLAG_` - Define to 0 when the system provides its
+    own flagfile flag parsing.
+*   `GTEST_DECLARE_bool_(name)`
+*   `GTEST_DECLARE_int32_(name)`
+*   `GTEST_DECLARE_string_(name)`
+*   `GTEST_DEFINE_bool_(name, default_val, doc)`
+*   `GTEST_DEFINE_int32_(name, default_val, doc)`
+*   `GTEST_DEFINE_string_(name, default_val, doc)`
+
+### Logging:
+
+*   `GTEST_LOG_(severity)`
+*   `GTEST_CHECK_(condition)`
+*   Functions `LogToStderr()` and `FlushInfoLog()` have to be provided too.
+
+### Threading:
+
+*   `GTEST_HAS_NOTIFICATION_` - Enabled if Notification is already provided.
+*   `GTEST_HAS_MUTEX_AND_THREAD_LOCAL_` - Enabled if `Mutex` and `ThreadLocal`
+    are already provided. Must also provide `GTEST_DECLARE_STATIC_MUTEX_(mutex)`
+    and `GTEST_DEFINE_STATIC_MUTEX_(mutex)`
+*   `GTEST_EXCLUSIVE_LOCK_REQUIRED_(locks)`
+*   `GTEST_LOCK_EXCLUDED_(locks)`
+
+### Underlying library support features
+
+*   `GTEST_HAS_CXXABI_H_`
+
+### Exporting API symbols:
+
+*   `GTEST_API_` - Specifier for exported symbols.
+
+## Header `gtest-printers.h`
+
+*   See documentation at `gtest/gtest-printers.h` for details on how to define a
+    custom printer.
diff --git a/3rdparty/gtest/include/gtest/internal/custom/gtest-port.h b/3rdparty/gtest/include/gtest/internal/custom/gtest-port.h
new file mode 100644
index 0000000..cd85d95
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/custom/gtest-port.h
@@ -0,0 +1,37 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Injection point for custom user configurations. See README for details
+//
+// ** Custom implementation starts here **
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PORT_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PORT_H_
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PORT_H_
diff --git a/3rdparty/gtest/include/gtest/internal/custom/gtest-printers.h b/3rdparty/gtest/include/gtest/internal/custom/gtest-printers.h
new file mode 100644
index 0000000..eb4467a
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/custom/gtest-printers.h
@@ -0,0 +1,42 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// This file provides an injection point for custom printers in a local
+// installation of gTest.
+// It will be included from gtest-printers.h and the overrides in this file
+// will be visible to everyone.
+//
+// Injection point for custom user configurations. See README for details
+//
+// ** Custom implementation starts here **
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PRINTERS_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PRINTERS_H_
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_PRINTERS_H_
diff --git a/3rdparty/gtest/include/gtest/internal/custom/gtest.h b/3rdparty/gtest/include/gtest/internal/custom/gtest.h
new file mode 100644
index 0000000..4c8e07b
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/custom/gtest.h
@@ -0,0 +1,37 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Injection point for custom user configurations. See README for details
+//
+// ** Custom implementation starts here **
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_H_
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_GTEST_H_
diff --git a/3rdparty/gtest/include/gtest/internal/gtest-death-test-internal.h b/3rdparty/gtest/include/gtest/internal/gtest-death-test-internal.h
new file mode 100644
index 0000000..68bd353
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/gtest-death-test-internal.h
@@ -0,0 +1,304 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines internal utilities needed for implementing
+// death tests.  They are subject to change without notice.
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
+
+#include "gtest/gtest-matchers.h"
+#include "gtest/internal/gtest-internal.h"
+
+#include <stdio.h>
+#include <memory>
+
+namespace testing {
+namespace internal {
+
+GTEST_DECLARE_string_(internal_run_death_test);
+
+// Names of the flags (needed for parsing Google Test flags).
+const char kDeathTestStyleFlag[] = "death_test_style";
+const char kDeathTestUseFork[] = "death_test_use_fork";
+const char kInternalRunDeathTestFlag[] = "internal_run_death_test";
+
+#if GTEST_HAS_DEATH_TEST
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+// DeathTest is a class that hides much of the complexity of the
+// GTEST_DEATH_TEST_ macro.  It is abstract; its static Create method
+// returns a concrete class that depends on the prevailing death test
+// style, as defined by the --gtest_death_test_style and/or
+// --gtest_internal_run_death_test flags.
+
+// In describing the results of death tests, these terms are used with
+// the corresponding definitions:
+//
+// exit status:  The integer exit information in the format specified
+//               by wait(2)
+// exit code:    The integer code passed to exit(3), _exit(2), or
+//               returned from main()
+class GTEST_API_ DeathTest {
+ public:
+  // Create returns false if there was an error determining the
+  // appropriate action to take for the current death test; for example,
+  // if the gtest_death_test_style flag is set to an invalid value.
+  // The LastMessage method will return a more detailed message in that
+  // case.  Otherwise, the DeathTest pointer pointed to by the "test"
+  // argument is set.  If the death test should be skipped, the pointer
+  // is set to NULL; otherwise, it is set to the address of a new concrete
+  // DeathTest object that controls the execution of the current test.
+  static bool Create(const char* statement, Matcher<const std::string&> matcher,
+                     const char* file, int line, DeathTest** test);
+  DeathTest();
+  virtual ~DeathTest() { }
+
+  // A helper class that aborts a death test when it's deleted.
+  class ReturnSentinel {
+   public:
+    explicit ReturnSentinel(DeathTest* test) : test_(test) { }
+    ~ReturnSentinel() { test_->Abort(TEST_ENCOUNTERED_RETURN_STATEMENT); }
+   private:
+    DeathTest* const test_;
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(ReturnSentinel);
+  } GTEST_ATTRIBUTE_UNUSED_;
+
+  // An enumeration of possible roles that may be taken when a death
+  // test is encountered.  EXECUTE means that the death test logic should
+  // be executed immediately.  OVERSEE means that the program should prepare
+  // the appropriate environment for a child process to execute the death
+  // test, then wait for it to complete.
+  enum TestRole { OVERSEE_TEST, EXECUTE_TEST };
+
+  // An enumeration of the three reasons that a test might be aborted.
+  enum AbortReason {
+    TEST_ENCOUNTERED_RETURN_STATEMENT,
+    TEST_THREW_EXCEPTION,
+    TEST_DID_NOT_DIE
+  };
+
+  // Assumes one of the above roles.
+  virtual TestRole AssumeRole() = 0;
+
+  // Waits for the death test to finish and returns its status.
+  virtual int Wait() = 0;
+
+  // Returns true if the death test passed; that is, the test process
+  // exited during the test, its exit status matches a user-supplied
+  // predicate, and its stderr output matches a user-supplied regular
+  // expression.
+  // The user-supplied predicate may be a macro expression rather
+  // than a function pointer or functor, or else Wait and Passed could
+  // be combined.
+  virtual bool Passed(bool exit_status_ok) = 0;
+
+  // Signals that the death test did not die as expected.
+  virtual void Abort(AbortReason reason) = 0;
+
+  // Returns a human-readable outcome message regarding the outcome of
+  // the last death test.
+  static const char* LastMessage();
+
+  static void set_last_death_test_message(const std::string& message);
+
+ private:
+  // A string containing a description of the outcome of the last death test.
+  static std::string last_death_test_message_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(DeathTest);
+};
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+// Factory interface for death tests.  May be mocked out for testing.
+class DeathTestFactory {
+ public:
+  virtual ~DeathTestFactory() { }
+  virtual bool Create(const char* statement,
+                      Matcher<const std::string&> matcher, const char* file,
+                      int line, DeathTest** test) = 0;
+};
+
+// A concrete DeathTestFactory implementation for normal use.
+class DefaultDeathTestFactory : public DeathTestFactory {
+ public:
+  bool Create(const char* statement, Matcher<const std::string&> matcher,
+              const char* file, int line, DeathTest** test) override;
+};
+
+// Returns true if exit_status describes a process that was terminated
+// by a signal, or exited normally with a nonzero exit code.
+GTEST_API_ bool ExitedUnsuccessfully(int exit_status);
+
+// A string passed to EXPECT_DEATH (etc.) is caught by one of these overloads
+// and interpreted as a regex (rather than an Eq matcher) for legacy
+// compatibility.
+inline Matcher<const ::std::string&> MakeDeathTestMatcher(
+    ::testing::internal::RE regex) {
+  return ContainsRegex(regex.pattern());
+}
+inline Matcher<const ::std::string&> MakeDeathTestMatcher(const char* regex) {
+  return ContainsRegex(regex);
+}
+inline Matcher<const ::std::string&> MakeDeathTestMatcher(
+    const ::std::string& regex) {
+  return ContainsRegex(regex);
+}
+
+// If a Matcher<const ::std::string&> is passed to EXPECT_DEATH (etc.), it's
+// used directly.
+inline Matcher<const ::std::string&> MakeDeathTestMatcher(
+    Matcher<const ::std::string&> matcher) {
+  return matcher;
+}
+
+// Traps C++ exceptions escaping statement and reports them as test
+// failures. Note that trapping SEH exceptions is not implemented here.
+# if GTEST_HAS_EXCEPTIONS
+#  define GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, death_test) \
+  try { \
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
+  } catch (const ::std::exception& gtest_exception) { \
+    fprintf(\
+        stderr, \
+        "\n%s: Caught std::exception-derived exception escaping the " \
+        "death test statement. Exception message: %s\n", \
+        ::testing::internal::FormatFileLocation(__FILE__, __LINE__).c_str(), \
+        gtest_exception.what()); \
+    fflush(stderr); \
+    death_test->Abort(::testing::internal::DeathTest::TEST_THREW_EXCEPTION); \
+  } catch (...) { \
+    death_test->Abort(::testing::internal::DeathTest::TEST_THREW_EXCEPTION); \
+  }
+
+# else
+#  define GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, death_test) \
+  GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement)
+
+# endif
+
+// This macro is for implementing ASSERT_DEATH*, EXPECT_DEATH*,
+// ASSERT_EXIT*, and EXPECT_EXIT*.
+#define GTEST_DEATH_TEST_(statement, predicate, regex_or_matcher, fail)        \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                                \
+  if (::testing::internal::AlwaysTrue()) {                                     \
+    ::testing::internal::DeathTest* gtest_dt;                                  \
+    if (!::testing::internal::DeathTest::Create(                               \
+            #statement,                                                        \
+            ::testing::internal::MakeDeathTestMatcher(regex_or_matcher),       \
+            __FILE__, __LINE__, &gtest_dt)) {                                  \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__);                        \
+    }                                                                          \
+    if (gtest_dt != nullptr) {                                                 \
+      std::unique_ptr< ::testing::internal::DeathTest> gtest_dt_ptr(gtest_dt); \
+      switch (gtest_dt->AssumeRole()) {                                        \
+        case ::testing::internal::DeathTest::OVERSEE_TEST:                     \
+          if (!gtest_dt->Passed(predicate(gtest_dt->Wait()))) {                \
+            goto GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__);                  \
+          }                                                                    \
+          break;                                                               \
+        case ::testing::internal::DeathTest::EXECUTE_TEST: {                   \
+          ::testing::internal::DeathTest::ReturnSentinel gtest_sentinel(       \
+              gtest_dt);                                                       \
+          GTEST_EXECUTE_DEATH_TEST_STATEMENT_(statement, gtest_dt);            \
+          gtest_dt->Abort(::testing::internal::DeathTest::TEST_DID_NOT_DIE);   \
+          break;                                                               \
+        }                                                                      \
+        default:                                                               \
+          break;                                                               \
+      }                                                                        \
+    }                                                                          \
+  } else                                                                       \
+    GTEST_CONCAT_TOKEN_(gtest_label_, __LINE__)                                \
+        : fail(::testing::internal::DeathTest::LastMessage())
+// The symbol "fail" here expands to something into which a message
+// can be streamed.
+
+// This macro is for implementing ASSERT/EXPECT_DEBUG_DEATH when compiled in
+// NDEBUG mode. In this case we need the statements to be executed and the macro
+// must accept a streamed message even though the message is never printed.
+// The regex object is not evaluated, but it is used to prevent "unused"
+// warnings and to avoid an expression that doesn't compile in debug mode.
+#define GTEST_EXECUTE_STATEMENT_(statement, regex_or_matcher)    \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_                                  \
+  if (::testing::internal::AlwaysTrue()) {                       \
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);   \
+  } else if (!::testing::internal::AlwaysTrue()) {               \
+    ::testing::internal::MakeDeathTestMatcher(regex_or_matcher); \
+  } else                                                         \
+    ::testing::Message()
+
+// A class representing the parsed contents of the
+// --gtest_internal_run_death_test flag, as it existed when
+// RUN_ALL_TESTS was called.
+class InternalRunDeathTestFlag {
+ public:
+  InternalRunDeathTestFlag(const std::string& a_file,
+                           int a_line,
+                           int an_index,
+                           int a_write_fd)
+      : file_(a_file), line_(a_line), index_(an_index),
+        write_fd_(a_write_fd) {}
+
+  ~InternalRunDeathTestFlag() {
+    if (write_fd_ >= 0)
+      posix::Close(write_fd_);
+  }
+
+  const std::string& file() const { return file_; }
+  int line() const { return line_; }
+  int index() const { return index_; }
+  int write_fd() const { return write_fd_; }
+
+ private:
+  std::string file_;
+  int line_;
+  int index_;
+  int write_fd_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(InternalRunDeathTestFlag);
+};
+
+// Returns a newly created InternalRunDeathTestFlag object with fields
+// initialized from the GTEST_FLAG(internal_run_death_test) flag if
+// the flag is specified; otherwise returns NULL.
+InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag();
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+}  // namespace internal
+}  // namespace testing
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
diff --git a/3rdparty/gtest/include/gtest/internal/gtest-filepath.h b/3rdparty/gtest/include/gtest/internal/gtest-filepath.h
new file mode 100644
index 0000000..c11b101
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/gtest-filepath.h
@@ -0,0 +1,211 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Google Test filepath utilities
+//
+// This header file declares classes and functions used internally by
+// Google Test.  They are subject to change without notice.
+//
+// This file is #included in gtest/internal/gtest-internal.h.
+// Do not include this header file separately!
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
+
+#include "gtest/internal/gtest-string.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+namespace internal {
+
+// FilePath - a class for file and directory pathname manipulation which
+// handles platform-specific conventions (like the pathname separator).
+// Used for helper functions for naming files in a directory for xml output.
+// Except for Set methods, all methods are const or static, which provides an
+// "immutable value object" -- useful for peace of mind.
+// A FilePath with a value ending in a path separator ("like/this/") represents
+// a directory, otherwise it is assumed to represent a file. In either case,
+// it may or may not represent an actual file or directory in the file system.
+// Names are NOT checked for syntax correctness -- no checking for illegal
+// characters, malformed paths, etc.
+
+class GTEST_API_ FilePath {
+ public:
+  FilePath() : pathname_("") { }
+  FilePath(const FilePath& rhs) : pathname_(rhs.pathname_) { }
+
+  explicit FilePath(const std::string& pathname) : pathname_(pathname) {
+    Normalize();
+  }
+
+  FilePath& operator=(const FilePath& rhs) {
+    Set(rhs);
+    return *this;
+  }
+
+  void Set(const FilePath& rhs) {
+    pathname_ = rhs.pathname_;
+  }
+
+  const std::string& string() const { return pathname_; }
+  const char* c_str() const { return pathname_.c_str(); }
+
+  // Returns the current working directory, or "" if unsuccessful.
+  static FilePath GetCurrentDir();
+
+  // Given directory = "dir", base_name = "test", number = 0,
+  // extension = "xml", returns "dir/test.xml". If number is greater
+  // than zero (e.g., 12), returns "dir/test_12.xml".
+  // On Windows platform, uses \ as the separator rather than /.
+  static FilePath MakeFileName(const FilePath& directory,
+                               const FilePath& base_name,
+                               int number,
+                               const char* extension);
+
+  // Given directory = "dir", relative_path = "test.xml",
+  // returns "dir/test.xml".
+  // On Windows, uses \ as the separator rather than /.
+  static FilePath ConcatPaths(const FilePath& directory,
+                              const FilePath& relative_path);
+
+  // Returns a pathname for a file that does not currently exist. The pathname
+  // will be directory/base_name.extension or
+  // directory/base_name_<number>.extension if directory/base_name.extension
+  // already exists. The number will be incremented until a pathname is found
+  // that does not already exist.
+  // Examples: 'dir/foo_test.xml' or 'dir/foo_test_1.xml'.
+  // There could be a race condition if two or more processes are calling this
+  // function at the same time -- they could both pick the same filename.
+  static FilePath GenerateUniqueFileName(const FilePath& directory,
+                                         const FilePath& base_name,
+                                         const char* extension);
+
+  // Returns true if and only if the path is "".
+  bool IsEmpty() const { return pathname_.empty(); }
+
+  // If input name has a trailing separator character, removes it and returns
+  // the name, otherwise return the name string unmodified.
+  // On Windows platform, uses \ as the separator, other platforms use /.
+  FilePath RemoveTrailingPathSeparator() const;
+
+  // Returns a copy of the FilePath with the directory part removed.
+  // Example: FilePath("path/to/file").RemoveDirectoryName() returns
+  // FilePath("file"). If there is no directory part ("just_a_file"), it returns
+  // the FilePath unmodified. If there is no file part ("just_a_dir/") it
+  // returns an empty FilePath ("").
+  // On Windows platform, '\' is the path separator, otherwise it is '/'.
+  FilePath RemoveDirectoryName() const;
+
+  // RemoveFileName returns the directory path with the filename removed.
+  // Example: FilePath("path/to/file").RemoveFileName() returns "path/to/".
+  // If the FilePath is "a_file" or "/a_file", RemoveFileName returns
+  // FilePath("./") or, on Windows, FilePath(".\\"). If the filepath does
+  // not have a file, like "just/a/dir/", it returns the FilePath unmodified.
+  // On Windows platform, '\' is the path separator, otherwise it is '/'.
+  FilePath RemoveFileName() const;
+
+  // Returns a copy of the FilePath with the case-insensitive extension removed.
+  // Example: FilePath("dir/file.exe").RemoveExtension("EXE") returns
+  // FilePath("dir/file"). If a case-insensitive extension is not
+  // found, returns a copy of the original FilePath.
+  FilePath RemoveExtension(const char* extension) const;
+
+  // Creates directories so that path exists. Returns true if successful or if
+  // the directories already exist; returns false if unable to create
+  // directories for any reason. Will also return false if the FilePath does
+  // not represent a directory (that is, it doesn't end with a path separator).
+  bool CreateDirectoriesRecursively() const;
+
+  // Create the directory so that path exists. Returns true if successful or
+  // if the directory already exists; returns false if unable to create the
+  // directory for any reason, including if the parent directory does not
+  // exist. Not named "CreateDirectory" because that's a macro on Windows.
+  bool CreateFolder() const;
+
+  // Returns true if FilePath describes something in the file-system,
+  // either a file, directory, or whatever, and that something exists.
+  bool FileOrDirectoryExists() const;
+
+  // Returns true if pathname describes a directory in the file-system
+  // that exists.
+  bool DirectoryExists() const;
+
+  // Returns true if FilePath ends with a path separator, which indicates that
+  // it is intended to represent a directory. Returns false otherwise.
+  // This does NOT check that a directory (or file) actually exists.
+  bool IsDirectory() const;
+
+  // Returns true if pathname describes a root directory. (Windows has one
+  // root directory per disk drive.)
+  bool IsRootDirectory() const;
+
+  // Returns true if pathname describes an absolute path.
+  bool IsAbsolutePath() const;
+
+ private:
+  // Replaces multiple consecutive separators with a single separator.
+  // For example, "bar///foo" becomes "bar/foo". Does not eliminate other
+  // redundancies that might be in a pathname involving "." or "..".
+  //
+  // A pathname with multiple consecutive separators may occur either through
+  // user error or as a result of some scripts or APIs that generate a pathname
+  // with a trailing separator. On other platforms the same API or script
+  // may NOT generate a pathname with a trailing "/". Then elsewhere that
+  // pathname may have another "/" and pathname components added to it,
+  // without checking for the separator already being there.
+  // The script language and operating system may allow paths like "foo//bar"
+  // but some of the functions in FilePath will not handle that correctly. In
+  // particular, RemoveTrailingPathSeparator() only removes one separator, and
+  // it is called in CreateDirectoriesRecursively() assuming that it will change
+  // a pathname from directory syntax (trailing separator) to filename syntax.
+  //
+  // On Windows this method also replaces the alternate path separator '/' with
+  // the primary path separator '\\', so that for example "bar\\/\\foo" becomes
+  // "bar\\foo".
+
+  void Normalize();
+
+  // Returns a pointer to the last occurence of a valid path separator in
+  // the FilePath. On Windows, for example, both '/' and '\' are valid path
+  // separators. Returns NULL if no path separator was found.
+  const char* FindLastPathSeparator() const;
+
+  std::string pathname_;
+};  // class FilePath
+
+}  // namespace internal
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
diff --git a/3rdparty/gtest/include/gtest/internal/gtest-internal.h b/3rdparty/gtest/include/gtest/internal/gtest-internal.h
new file mode 100644
index 0000000..94c816a
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/gtest-internal.h
@@ -0,0 +1,1380 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file declares functions and macros used internally by
+// Google Test.  They are subject to change without notice.
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
+
+#include "gtest/internal/gtest-port.h"
+
+#if GTEST_OS_LINUX
+# include <stdlib.h>
+# include <sys/types.h>
+# include <sys/wait.h>
+# include <unistd.h>
+#endif  // GTEST_OS_LINUX
+
+#if GTEST_HAS_EXCEPTIONS
+# include <stdexcept>
+#endif
+
+#include <ctype.h>
+#include <float.h>
+#include <string.h>
+#include <iomanip>
+#include <limits>
+#include <map>
+#include <set>
+#include <string>
+#include <type_traits>
+#include <vector>
+
+#include "gtest/gtest-message.h"
+#include "gtest/internal/gtest-filepath.h"
+#include "gtest/internal/gtest-string.h"
+#include "gtest/internal/gtest-type-util.h"
+
+// Due to C++ preprocessor weirdness, we need double indirection to
+// concatenate two tokens when one of them is __LINE__.  Writing
+//
+//   foo ## __LINE__
+//
+// will result in the token foo__LINE__, instead of foo followed by
+// the current line number.  For more details, see
+// http://www.parashift.com/c++-faq-lite/misc-technical-issues.html#faq-39.6
+#define GTEST_CONCAT_TOKEN_(foo, bar) GTEST_CONCAT_TOKEN_IMPL_(foo, bar)
+#define GTEST_CONCAT_TOKEN_IMPL_(foo, bar) foo ## bar
+
+// Stringifies its argument.
+#define GTEST_STRINGIFY_(name) #name
+
+namespace proto2 { class Message; }
+
+namespace testing {
+
+// Forward declarations.
+
+class AssertionResult;                 // Result of an assertion.
+class Message;                         // Represents a failure message.
+class Test;                            // Represents a test.
+class TestInfo;                        // Information about a test.
+class TestPartResult;                  // Result of a test part.
+class UnitTest;                        // A collection of test suites.
+
+template <typename T>
+::std::string PrintToString(const T& value);
+
+namespace internal {
+
+struct TraceInfo;                      // Information about a trace point.
+class TestInfoImpl;                    // Opaque implementation of TestInfo
+class UnitTestImpl;                    // Opaque implementation of UnitTest
+
+// The text used in failure messages to indicate the start of the
+// stack trace.
+GTEST_API_ extern const char kStackTraceMarker[];
+
+// An IgnoredValue object can be implicitly constructed from ANY value.
+class IgnoredValue {
+  struct Sink {};
+ public:
+  // This constructor template allows any value to be implicitly
+  // converted to IgnoredValue.  The object has no data member and
+  // doesn't try to remember anything about the argument.  We
+  // deliberately omit the 'explicit' keyword in order to allow the
+  // conversion to be implicit.
+  // Disable the conversion if T already has a magical conversion operator.
+  // Otherwise we get ambiguity.
+  template <typename T,
+            typename std::enable_if<!std::is_convertible<T, Sink>::value,
+                                    int>::type = 0>
+  IgnoredValue(const T& /* ignored */) {}  // NOLINT(runtime/explicit)
+};
+
+// Appends the user-supplied message to the Google-Test-generated message.
+GTEST_API_ std::string AppendUserMessage(
+    const std::string& gtest_msg, const Message& user_msg);
+
+#if GTEST_HAS_EXCEPTIONS
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4275 \
+/* an exported class was derived from a class that was not exported */)
+
+// This exception is thrown by (and only by) a failed Google Test
+// assertion when GTEST_FLAG(throw_on_failure) is true (if exceptions
+// are enabled).  We derive it from std::runtime_error, which is for
+// errors presumably detectable only at run time.  Since
+// std::runtime_error inherits from std::exception, many testing
+// frameworks know how to extract and print the message inside it.
+class GTEST_API_ GoogleTestFailureException : public ::std::runtime_error {
+ public:
+  explicit GoogleTestFailureException(const TestPartResult& failure);
+};
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4275
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+namespace edit_distance {
+// Returns the optimal edits to go from 'left' to 'right'.
+// All edits cost the same, with replace having lower priority than
+// add/remove.
+// Simple implementation of the Wagner-Fischer algorithm.
+// See http://en.wikipedia.org/wiki/Wagner-Fischer_algorithm
+enum EditType { kMatch, kAdd, kRemove, kReplace };
+GTEST_API_ std::vector<EditType> CalculateOptimalEdits(
+    const std::vector<size_t>& left, const std::vector<size_t>& right);
+
+// Same as above, but the input is represented as strings.
+GTEST_API_ std::vector<EditType> CalculateOptimalEdits(
+    const std::vector<std::string>& left,
+    const std::vector<std::string>& right);
+
+// Create a diff of the input strings in Unified diff format.
+GTEST_API_ std::string CreateUnifiedDiff(const std::vector<std::string>& left,
+                                         const std::vector<std::string>& right,
+                                         size_t context = 2);
+
+}  // namespace edit_distance
+
+// Calculate the diff between 'left' and 'right' and return it in unified diff
+// format.
+// If not null, stores in 'total_line_count' the total number of lines found
+// in left + right.
+GTEST_API_ std::string DiffStrings(const std::string& left,
+                                   const std::string& right,
+                                   size_t* total_line_count);
+
+// Constructs and returns the message for an equality assertion
+// (e.g. ASSERT_EQ, EXPECT_STREQ, etc) failure.
+//
+// The first four parameters are the expressions used in the assertion
+// and their values, as strings.  For example, for ASSERT_EQ(foo, bar)
+// where foo is 5 and bar is 6, we have:
+//
+//   expected_expression: "foo"
+//   actual_expression:   "bar"
+//   expected_value:      "5"
+//   actual_value:        "6"
+//
+// The ignoring_case parameter is true if and only if the assertion is a
+// *_STRCASEEQ*.  When it's true, the string " (ignoring case)" will
+// be inserted into the message.
+GTEST_API_ AssertionResult EqFailure(const char* expected_expression,
+                                     const char* actual_expression,
+                                     const std::string& expected_value,
+                                     const std::string& actual_value,
+                                     bool ignoring_case);
+
+// Constructs a failure message for Boolean assertions such as EXPECT_TRUE.
+GTEST_API_ std::string GetBoolAssertionFailureMessage(
+    const AssertionResult& assertion_result,
+    const char* expression_text,
+    const char* actual_predicate_value,
+    const char* expected_predicate_value);
+
+// This template class represents an IEEE floating-point number
+// (either single-precision or double-precision, depending on the
+// template parameters).
+//
+// The purpose of this class is to do more sophisticated number
+// comparison.  (Due to round-off error, etc, it's very unlikely that
+// two floating-points will be equal exactly.  Hence a naive
+// comparison by the == operation often doesn't work.)
+//
+// Format of IEEE floating-point:
+//
+//   The most-significant bit being the leftmost, an IEEE
+//   floating-point looks like
+//
+//     sign_bit exponent_bits fraction_bits
+//
+//   Here, sign_bit is a single bit that designates the sign of the
+//   number.
+//
+//   For float, there are 8 exponent bits and 23 fraction bits.
+//
+//   For double, there are 11 exponent bits and 52 fraction bits.
+//
+//   More details can be found at
+//   http://en.wikipedia.org/wiki/IEEE_floating-point_standard.
+//
+// Template parameter:
+//
+//   RawType: the raw floating-point type (either float or double)
+template <typename RawType>
+class FloatingPoint {
+ public:
+  // Defines the unsigned integer type that has the same size as the
+  // floating point number.
+  typedef typename TypeWithSize<sizeof(RawType)>::UInt Bits;
+
+  // Constants.
+
+  // # of bits in a number.
+  static const size_t kBitCount = 8*sizeof(RawType);
+
+  // # of fraction bits in a number.
+  static const size_t kFractionBitCount =
+    std::numeric_limits<RawType>::digits - 1;
+
+  // # of exponent bits in a number.
+  static const size_t kExponentBitCount = kBitCount - 1 - kFractionBitCount;
+
+  // The mask for the sign bit.
+  static const Bits kSignBitMask = static_cast<Bits>(1) << (kBitCount - 1);
+
+  // The mask for the fraction bits.
+  static const Bits kFractionBitMask =
+    ~static_cast<Bits>(0) >> (kExponentBitCount + 1);
+
+  // The mask for the exponent bits.
+  static const Bits kExponentBitMask = ~(kSignBitMask | kFractionBitMask);
+
+  // How many ULP's (Units in the Last Place) we want to tolerate when
+  // comparing two numbers.  The larger the value, the more error we
+  // allow.  A 0 value means that two numbers must be exactly the same
+  // to be considered equal.
+  //
+  // The maximum error of a single floating-point operation is 0.5
+  // units in the last place.  On Intel CPU's, all floating-point
+  // calculations are done with 80-bit precision, while double has 64
+  // bits.  Therefore, 4 should be enough for ordinary use.
+  //
+  // See the following article for more details on ULP:
+  // http://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
+  static const size_t kMaxUlps = 4;
+
+  // Constructs a FloatingPoint from a raw floating-point number.
+  //
+  // On an Intel CPU, passing a non-normalized NAN (Not a Number)
+  // around may change its bits, although the new value is guaranteed
+  // to be also a NAN.  Therefore, don't expect this constructor to
+  // preserve the bits in x when x is a NAN.
+  explicit FloatingPoint(const RawType& x) { u_.value_ = x; }
+
+  // Static methods
+
+  // Reinterprets a bit pattern as a floating-point number.
+  //
+  // This function is needed to test the AlmostEquals() method.
+  static RawType ReinterpretBits(const Bits bits) {
+    FloatingPoint fp(0);
+    fp.u_.bits_ = bits;
+    return fp.u_.value_;
+  }
+
+  // Returns the floating-point number that represent positive infinity.
+  static RawType Infinity() {
+    return ReinterpretBits(kExponentBitMask);
+  }
+
+  // Returns the maximum representable finite floating-point number.
+  static RawType Max();
+
+  // Non-static methods
+
+  // Returns the bits that represents this number.
+  const Bits &bits() const { return u_.bits_; }
+
+  // Returns the exponent bits of this number.
+  Bits exponent_bits() const { return kExponentBitMask & u_.bits_; }
+
+  // Returns the fraction bits of this number.
+  Bits fraction_bits() const { return kFractionBitMask & u_.bits_; }
+
+  // Returns the sign bit of this number.
+  Bits sign_bit() const { return kSignBitMask & u_.bits_; }
+
+  // Returns true if and only if this is NAN (not a number).
+  bool is_nan() const {
+    // It's a NAN if the exponent bits are all ones and the fraction
+    // bits are not entirely zeros.
+    return (exponent_bits() == kExponentBitMask) && (fraction_bits() != 0);
+  }
+
+  // Returns true if and only if this number is at most kMaxUlps ULP's away
+  // from rhs.  In particular, this function:
+  //
+  //   - returns false if either number is (or both are) NAN.
+  //   - treats really large numbers as almost equal to infinity.
+  //   - thinks +0.0 and -0.0 are 0 DLP's apart.
+  bool AlmostEquals(const FloatingPoint& rhs) const {
+    // The IEEE standard says that any comparison operation involving
+    // a NAN must return false.
+    if (is_nan() || rhs.is_nan()) return false;
+
+    return DistanceBetweenSignAndMagnitudeNumbers(u_.bits_, rhs.u_.bits_)
+        <= kMaxUlps;
+  }
+
+ private:
+  // The data type used to store the actual floating-point number.
+  union FloatingPointUnion {
+    RawType value_;  // The raw floating-point number.
+    Bits bits_;      // The bits that represent the number.
+  };
+
+  // Converts an integer from the sign-and-magnitude representation to
+  // the biased representation.  More precisely, let N be 2 to the
+  // power of (kBitCount - 1), an integer x is represented by the
+  // unsigned number x + N.
+  //
+  // For instance,
+  //
+  //   -N + 1 (the most negative number representable using
+  //          sign-and-magnitude) is represented by 1;
+  //   0      is represented by N; and
+  //   N - 1  (the biggest number representable using
+  //          sign-and-magnitude) is represented by 2N - 1.
+  //
+  // Read http://en.wikipedia.org/wiki/Signed_number_representations
+  // for more details on signed number representations.
+  static Bits SignAndMagnitudeToBiased(const Bits &sam) {
+    if (kSignBitMask & sam) {
+      // sam represents a negative number.
+      return ~sam + 1;
+    } else {
+      // sam represents a positive number.
+      return kSignBitMask | sam;
+    }
+  }
+
+  // Given two numbers in the sign-and-magnitude representation,
+  // returns the distance between them as an unsigned number.
+  static Bits DistanceBetweenSignAndMagnitudeNumbers(const Bits &sam1,
+                                                     const Bits &sam2) {
+    const Bits biased1 = SignAndMagnitudeToBiased(sam1);
+    const Bits biased2 = SignAndMagnitudeToBiased(sam2);
+    return (biased1 >= biased2) ? (biased1 - biased2) : (biased2 - biased1);
+  }
+
+  FloatingPointUnion u_;
+};
+
+// We cannot use std::numeric_limits<T>::max() as it clashes with the max()
+// macro defined by <windows.h>.
+template <>
+inline float FloatingPoint<float>::Max() { return FLT_MAX; }
+template <>
+inline double FloatingPoint<double>::Max() { return DBL_MAX; }
+
+// Typedefs the instances of the FloatingPoint template class that we
+// care to use.
+typedef FloatingPoint<float> Float;
+typedef FloatingPoint<double> Double;
+
+// In order to catch the mistake of putting tests that use different
+// test fixture classes in the same test suite, we need to assign
+// unique IDs to fixture classes and compare them.  The TypeId type is
+// used to hold such IDs.  The user should treat TypeId as an opaque
+// type: the only operation allowed on TypeId values is to compare
+// them for equality using the == operator.
+typedef const void* TypeId;
+
+template <typename T>
+class TypeIdHelper {
+ public:
+  // dummy_ must not have a const type.  Otherwise an overly eager
+  // compiler (e.g. MSVC 7.1 & 8.0) may try to merge
+  // TypeIdHelper<T>::dummy_ for different Ts as an "optimization".
+  static bool dummy_;
+};
+
+template <typename T>
+bool TypeIdHelper<T>::dummy_ = false;
+
+// GetTypeId<T>() returns the ID of type T.  Different values will be
+// returned for different types.  Calling the function twice with the
+// same type argument is guaranteed to return the same ID.
+template <typename T>
+TypeId GetTypeId() {
+  // The compiler is required to allocate a different
+  // TypeIdHelper<T>::dummy_ variable for each T used to instantiate
+  // the template.  Therefore, the address of dummy_ is guaranteed to
+  // be unique.
+  return &(TypeIdHelper<T>::dummy_);
+}
+
+// Returns the type ID of ::testing::Test.  Always call this instead
+// of GetTypeId< ::testing::Test>() to get the type ID of
+// ::testing::Test, as the latter may give the wrong result due to a
+// suspected linker bug when compiling Google Test as a Mac OS X
+// framework.
+GTEST_API_ TypeId GetTestTypeId();
+
+// Defines the abstract factory interface that creates instances
+// of a Test object.
+class TestFactoryBase {
+ public:
+  virtual ~TestFactoryBase() {}
+
+  // Creates a test instance to run. The instance is both created and destroyed
+  // within TestInfoImpl::Run()
+  virtual Test* CreateTest() = 0;
+
+ protected:
+  TestFactoryBase() {}
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestFactoryBase);
+};
+
+// This class provides implementation of TeastFactoryBase interface.
+// It is used in TEST and TEST_F macros.
+template <class TestClass>
+class TestFactoryImpl : public TestFactoryBase {
+ public:
+  Test* CreateTest() override { return new TestClass; }
+};
+
+#if GTEST_OS_WINDOWS
+
+// Predicate-formatters for implementing the HRESULT checking macros
+// {ASSERT|EXPECT}_HRESULT_{SUCCEEDED|FAILED}
+// We pass a long instead of HRESULT to avoid causing an
+// include dependency for the HRESULT type.
+GTEST_API_ AssertionResult IsHRESULTSuccess(const char* expr,
+                                            long hr);  // NOLINT
+GTEST_API_ AssertionResult IsHRESULTFailure(const char* expr,
+                                            long hr);  // NOLINT
+
+#endif  // GTEST_OS_WINDOWS
+
+// Types of SetUpTestSuite() and TearDownTestSuite() functions.
+using SetUpTestSuiteFunc = void (*)();
+using TearDownTestSuiteFunc = void (*)();
+
+struct CodeLocation {
+  CodeLocation(const std::string& a_file, int a_line)
+      : file(a_file), line(a_line) {}
+
+  std::string file;
+  int line;
+};
+
+//  Helper to identify which setup function for TestCase / TestSuite to call.
+//  Only one function is allowed, either TestCase or TestSute but not both.
+
+// Utility functions to help SuiteApiResolver
+using SetUpTearDownSuiteFuncType = void (*)();
+
+inline SetUpTearDownSuiteFuncType GetNotDefaultOrNull(
+    SetUpTearDownSuiteFuncType a, SetUpTearDownSuiteFuncType def) {
+  return a == def ? nullptr : a;
+}
+
+template <typename T>
+//  Note that SuiteApiResolver inherits from T because
+//  SetUpTestSuite()/TearDownTestSuite() could be protected. Ths way
+//  SuiteApiResolver can access them.
+struct SuiteApiResolver : T {
+  // testing::Test is only forward declared at this point. So we make it a
+  // dependend class for the compiler to be OK with it.
+  using Test =
+      typename std::conditional<sizeof(T) != 0, ::testing::Test, void>::type;
+
+  static SetUpTearDownSuiteFuncType GetSetUpCaseOrSuite(const char* filename,
+                                                        int line_num) {
+    SetUpTearDownSuiteFuncType test_case_fp =
+        GetNotDefaultOrNull(&T::SetUpTestCase, &Test::SetUpTestCase);
+    SetUpTearDownSuiteFuncType test_suite_fp =
+        GetNotDefaultOrNull(&T::SetUpTestSuite, &Test::SetUpTestSuite);
+
+    GTEST_CHECK_(!test_case_fp || !test_suite_fp)
+        << "Test can not provide both SetUpTestSuite and SetUpTestCase, please "
+           "make sure there is only one present at "
+        << filename << ":" << line_num;
+
+    return test_case_fp != nullptr ? test_case_fp : test_suite_fp;
+  }
+
+  static SetUpTearDownSuiteFuncType GetTearDownCaseOrSuite(const char* filename,
+                                                           int line_num) {
+    SetUpTearDownSuiteFuncType test_case_fp =
+        GetNotDefaultOrNull(&T::TearDownTestCase, &Test::TearDownTestCase);
+    SetUpTearDownSuiteFuncType test_suite_fp =
+        GetNotDefaultOrNull(&T::TearDownTestSuite, &Test::TearDownTestSuite);
+
+    GTEST_CHECK_(!test_case_fp || !test_suite_fp)
+        << "Test can not provide both TearDownTestSuite and TearDownTestCase,"
+           " please make sure there is only one present at"
+        << filename << ":" << line_num;
+
+    return test_case_fp != nullptr ? test_case_fp : test_suite_fp;
+  }
+};
+
+// Creates a new TestInfo object and registers it with Google Test;
+// returns the created object.
+//
+// Arguments:
+//
+//   test_suite_name:   name of the test suite
+//   name:             name of the test
+//   type_param        the name of the test's type parameter, or NULL if
+//                     this is not a typed or a type-parameterized test.
+//   value_param       text representation of the test's value parameter,
+//                     or NULL if this is not a type-parameterized test.
+//   code_location:    code location where the test is defined
+//   fixture_class_id: ID of the test fixture class
+//   set_up_tc:        pointer to the function that sets up the test suite
+//   tear_down_tc:     pointer to the function that tears down the test suite
+//   factory:          pointer to the factory that creates a test object.
+//                     The newly created TestInfo instance will assume
+//                     ownership of the factory object.
+GTEST_API_ TestInfo* MakeAndRegisterTestInfo(
+    const char* test_suite_name, const char* name, const char* type_param,
+    const char* value_param, CodeLocation code_location,
+    TypeId fixture_class_id, SetUpTestSuiteFunc set_up_tc,
+    TearDownTestSuiteFunc tear_down_tc, TestFactoryBase* factory);
+
+// If *pstr starts with the given prefix, modifies *pstr to be right
+// past the prefix and returns true; otherwise leaves *pstr unchanged
+// and returns false.  None of pstr, *pstr, and prefix can be NULL.
+GTEST_API_ bool SkipPrefix(const char* prefix, const char** pstr);
+
+#if GTEST_HAS_TYPED_TEST || GTEST_HAS_TYPED_TEST_P
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+// State of the definition of a type-parameterized test suite.
+class GTEST_API_ TypedTestSuitePState {
+ public:
+  TypedTestSuitePState() : registered_(false) {}
+
+  // Adds the given test name to defined_test_names_ and return true
+  // if the test suite hasn't been registered; otherwise aborts the
+  // program.
+  bool AddTestName(const char* file, int line, const char* case_name,
+                   const char* test_name) {
+    if (registered_) {
+      fprintf(stderr,
+              "%s Test %s must be defined before "
+              "REGISTER_TYPED_TEST_SUITE_P(%s, ...).\n",
+              FormatFileLocation(file, line).c_str(), test_name, case_name);
+      fflush(stderr);
+      posix::Abort();
+    }
+    registered_tests_.insert(
+        ::std::make_pair(test_name, CodeLocation(file, line)));
+    return true;
+  }
+
+  bool TestExists(const std::string& test_name) const {
+    return registered_tests_.count(test_name) > 0;
+  }
+
+  const CodeLocation& GetCodeLocation(const std::string& test_name) const {
+    RegisteredTestsMap::const_iterator it = registered_tests_.find(test_name);
+    GTEST_CHECK_(it != registered_tests_.end());
+    return it->second;
+  }
+
+  // Verifies that registered_tests match the test names in
+  // defined_test_names_; returns registered_tests if successful, or
+  // aborts the program otherwise.
+  const char* VerifyRegisteredTestNames(
+      const char* file, int line, const char* registered_tests);
+
+ private:
+  typedef ::std::map<std::string, CodeLocation> RegisteredTestsMap;
+
+  bool registered_;
+  RegisteredTestsMap registered_tests_;
+};
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+using TypedTestCasePState = TypedTestSuitePState;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+// Skips to the first non-space char after the first comma in 'str';
+// returns NULL if no comma is found in 'str'.
+inline const char* SkipComma(const char* str) {
+  const char* comma = strchr(str, ',');
+  if (comma == nullptr) {
+    return nullptr;
+  }
+  while (IsSpace(*(++comma))) {}
+  return comma;
+}
+
+// Returns the prefix of 'str' before the first comma in it; returns
+// the entire string if it contains no comma.
+inline std::string GetPrefixUntilComma(const char* str) {
+  const char* comma = strchr(str, ',');
+  return comma == nullptr ? str : std::string(str, comma);
+}
+
+// Splits a given string on a given delimiter, populating a given
+// vector with the fields.
+void SplitString(const ::std::string& str, char delimiter,
+                 ::std::vector< ::std::string>* dest);
+
+// The default argument to the template below for the case when the user does
+// not provide a name generator.
+struct DefaultNameGenerator {
+  template <typename T>
+  static std::string GetName(int i) {
+    return StreamableToString(i);
+  }
+};
+
+template <typename Provided = DefaultNameGenerator>
+struct NameGeneratorSelector {
+  typedef Provided type;
+};
+
+template <typename NameGenerator>
+void GenerateNamesRecursively(Types0, std::vector<std::string>*, int) {}
+
+template <typename NameGenerator, typename Types>
+void GenerateNamesRecursively(Types, std::vector<std::string>* result, int i) {
+  result->push_back(NameGenerator::template GetName<typename Types::Head>(i));
+  GenerateNamesRecursively<NameGenerator>(typename Types::Tail(), result,
+                                          i + 1);
+}
+
+template <typename NameGenerator, typename Types>
+std::vector<std::string> GenerateNames() {
+  std::vector<std::string> result;
+  GenerateNamesRecursively<NameGenerator>(Types(), &result, 0);
+  return result;
+}
+
+// TypeParameterizedTest<Fixture, TestSel, Types>::Register()
+// registers a list of type-parameterized tests with Google Test.  The
+// return value is insignificant - we just need to return something
+// such that we can call this function in a namespace scope.
+//
+// Implementation note: The GTEST_TEMPLATE_ macro declares a template
+// template parameter.  It's defined in gtest-type-util.h.
+template <GTEST_TEMPLATE_ Fixture, class TestSel, typename Types>
+class TypeParameterizedTest {
+ public:
+  // 'index' is the index of the test in the type list 'Types'
+  // specified in INSTANTIATE_TYPED_TEST_SUITE_P(Prefix, TestSuite,
+  // Types).  Valid values for 'index' are [0, N - 1] where N is the
+  // length of Types.
+  static bool Register(const char* prefix, const CodeLocation& code_location,
+                       const char* case_name, const char* test_names, int index,
+                       const std::vector<std::string>& type_names =
+                           GenerateNames<DefaultNameGenerator, Types>()) {
+    typedef typename Types::Head Type;
+    typedef Fixture<Type> FixtureClass;
+    typedef typename GTEST_BIND_(TestSel, Type) TestClass;
+
+    // First, registers the first type-parameterized test in the type
+    // list.
+    MakeAndRegisterTestInfo(
+        (std::string(prefix) + (prefix[0] == '\0' ? "" : "/") + case_name +
+         "/" + type_names[static_cast<size_t>(index)])
+            .c_str(),
+        StripTrailingSpaces(GetPrefixUntilComma(test_names)).c_str(),
+        GetTypeName<Type>().c_str(),
+        nullptr,  // No value parameter.
+        code_location, GetTypeId<FixtureClass>(),
+        SuiteApiResolver<TestClass>::GetSetUpCaseOrSuite(
+            code_location.file.c_str(), code_location.line),
+        SuiteApiResolver<TestClass>::GetTearDownCaseOrSuite(
+            code_location.file.c_str(), code_location.line),
+        new TestFactoryImpl<TestClass>);
+
+    // Next, recurses (at compile time) with the tail of the type list.
+    return TypeParameterizedTest<Fixture, TestSel,
+                                 typename Types::Tail>::Register(prefix,
+                                                                 code_location,
+                                                                 case_name,
+                                                                 test_names,
+                                                                 index + 1,
+                                                                 type_names);
+  }
+};
+
+// The base case for the compile time recursion.
+template <GTEST_TEMPLATE_ Fixture, class TestSel>
+class TypeParameterizedTest<Fixture, TestSel, Types0> {
+ public:
+  static bool Register(const char* /*prefix*/, const CodeLocation&,
+                       const char* /*case_name*/, const char* /*test_names*/,
+                       int /*index*/,
+                       const std::vector<std::string>& =
+                           std::vector<std::string>() /*type_names*/) {
+    return true;
+  }
+};
+
+// TypeParameterizedTestSuite<Fixture, Tests, Types>::Register()
+// registers *all combinations* of 'Tests' and 'Types' with Google
+// Test.  The return value is insignificant - we just need to return
+// something such that we can call this function in a namespace scope.
+template <GTEST_TEMPLATE_ Fixture, typename Tests, typename Types>
+class TypeParameterizedTestSuite {
+ public:
+  static bool Register(const char* prefix, CodeLocation code_location,
+                       const TypedTestSuitePState* state, const char* case_name,
+                       const char* test_names,
+                       const std::vector<std::string>& type_names =
+                           GenerateNames<DefaultNameGenerator, Types>()) {
+    std::string test_name = StripTrailingSpaces(
+        GetPrefixUntilComma(test_names));
+    if (!state->TestExists(test_name)) {
+      fprintf(stderr, "Failed to get code location for test %s.%s at %s.",
+              case_name, test_name.c_str(),
+              FormatFileLocation(code_location.file.c_str(),
+                                 code_location.line).c_str());
+      fflush(stderr);
+      posix::Abort();
+    }
+    const CodeLocation& test_location = state->GetCodeLocation(test_name);
+
+    typedef typename Tests::Head Head;
+
+    // First, register the first test in 'Test' for each type in 'Types'.
+    TypeParameterizedTest<Fixture, Head, Types>::Register(
+        prefix, test_location, case_name, test_names, 0, type_names);
+
+    // Next, recurses (at compile time) with the tail of the test list.
+    return TypeParameterizedTestSuite<Fixture, typename Tests::Tail,
+                                      Types>::Register(prefix, code_location,
+                                                       state, case_name,
+                                                       SkipComma(test_names),
+                                                       type_names);
+  }
+};
+
+// The base case for the compile time recursion.
+template <GTEST_TEMPLATE_ Fixture, typename Types>
+class TypeParameterizedTestSuite<Fixture, Templates0, Types> {
+ public:
+  static bool Register(const char* /*prefix*/, const CodeLocation&,
+                       const TypedTestSuitePState* /*state*/,
+                       const char* /*case_name*/, const char* /*test_names*/,
+                       const std::vector<std::string>& =
+                           std::vector<std::string>() /*type_names*/) {
+    return true;
+  }
+};
+
+#endif  // GTEST_HAS_TYPED_TEST || GTEST_HAS_TYPED_TEST_P
+
+// Returns the current OS stack trace as an std::string.
+//
+// The maximum number of stack frames to be included is specified by
+// the gtest_stack_trace_depth flag.  The skip_count parameter
+// specifies the number of top frames to be skipped, which doesn't
+// count against the number of frames to be included.
+//
+// For example, if Foo() calls Bar(), which in turn calls
+// GetCurrentOsStackTraceExceptTop(..., 1), Foo() will be included in
+// the trace but Bar() and GetCurrentOsStackTraceExceptTop() won't.
+GTEST_API_ std::string GetCurrentOsStackTraceExceptTop(
+    UnitTest* unit_test, int skip_count);
+
+// Helpers for suppressing warnings on unreachable code or constant
+// condition.
+
+// Always returns true.
+GTEST_API_ bool AlwaysTrue();
+
+// Always returns false.
+inline bool AlwaysFalse() { return !AlwaysTrue(); }
+
+// Helper for suppressing false warning from Clang on a const char*
+// variable declared in a conditional expression always being NULL in
+// the else branch.
+struct GTEST_API_ ConstCharPtr {
+  ConstCharPtr(const char* str) : value(str) {}
+  operator bool() const { return true; }
+  const char* value;
+};
+
+// A simple Linear Congruential Generator for generating random
+// numbers with a uniform distribution.  Unlike rand() and srand(), it
+// doesn't use global state (and therefore can't interfere with user
+// code).  Unlike rand_r(), it's portable.  An LCG isn't very random,
+// but it's good enough for our purposes.
+class GTEST_API_ Random {
+ public:
+  static const UInt32 kMaxRange = 1u << 31;
+
+  explicit Random(UInt32 seed) : state_(seed) {}
+
+  void Reseed(UInt32 seed) { state_ = seed; }
+
+  // Generates a random number from [0, range).  Crashes if 'range' is
+  // 0 or greater than kMaxRange.
+  UInt32 Generate(UInt32 range);
+
+ private:
+  UInt32 state_;
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(Random);
+};
+
+// Turns const U&, U&, const U, and U all into U.
+#define GTEST_REMOVE_REFERENCE_AND_CONST_(T) \
+  typename std::remove_const<typename std::remove_reference<T>::type>::type
+
+// IsAProtocolMessage<T>::value is a compile-time bool constant that's
+// true if and only if T is type proto2::Message or a subclass of it.
+template <typename T>
+struct IsAProtocolMessage
+    : public bool_constant<
+          std::is_convertible<const T*, const ::proto2::Message*>::value> {};
+
+// When the compiler sees expression IsContainerTest<C>(0), if C is an
+// STL-style container class, the first overload of IsContainerTest
+// will be viable (since both C::iterator* and C::const_iterator* are
+// valid types and NULL can be implicitly converted to them).  It will
+// be picked over the second overload as 'int' is a perfect match for
+// the type of argument 0.  If C::iterator or C::const_iterator is not
+// a valid type, the first overload is not viable, and the second
+// overload will be picked.  Therefore, we can determine whether C is
+// a container class by checking the type of IsContainerTest<C>(0).
+// The value of the expression is insignificant.
+//
+// In C++11 mode we check the existence of a const_iterator and that an
+// iterator is properly implemented for the container.
+//
+// For pre-C++11 that we look for both C::iterator and C::const_iterator.
+// The reason is that C++ injects the name of a class as a member of the
+// class itself (e.g. you can refer to class iterator as either
+// 'iterator' or 'iterator::iterator').  If we look for C::iterator
+// only, for example, we would mistakenly think that a class named
+// iterator is an STL container.
+//
+// Also note that the simpler approach of overloading
+// IsContainerTest(typename C::const_iterator*) and
+// IsContainerTest(...) doesn't work with Visual Age C++ and Sun C++.
+typedef int IsContainer;
+template <class C,
+          class Iterator = decltype(::std::declval<const C&>().begin()),
+          class = decltype(::std::declval<const C&>().end()),
+          class = decltype(++::std::declval<Iterator&>()),
+          class = decltype(*::std::declval<Iterator>()),
+          class = typename C::const_iterator>
+IsContainer IsContainerTest(int /* dummy */) {
+  return 0;
+}
+
+typedef char IsNotContainer;
+template <class C>
+IsNotContainer IsContainerTest(long /* dummy */) { return '\0'; }
+
+// Trait to detect whether a type T is a hash table.
+// The heuristic used is that the type contains an inner type `hasher` and does
+// not contain an inner type `reverse_iterator`.
+// If the container is iterable in reverse, then order might actually matter.
+template <typename T>
+struct IsHashTable {
+ private:
+  template <typename U>
+  static char test(typename U::hasher*, typename U::reverse_iterator*);
+  template <typename U>
+  static int test(typename U::hasher*, ...);
+  template <typename U>
+  static char test(...);
+
+ public:
+  static const bool value = sizeof(test<T>(nullptr, nullptr)) == sizeof(int);
+};
+
+template <typename T>
+const bool IsHashTable<T>::value;
+
+template <typename C,
+          bool = sizeof(IsContainerTest<C>(0)) == sizeof(IsContainer)>
+struct IsRecursiveContainerImpl;
+
+template <typename C>
+struct IsRecursiveContainerImpl<C, false> : public std::false_type {};
+
+// Since the IsRecursiveContainerImpl depends on the IsContainerTest we need to
+// obey the same inconsistencies as the IsContainerTest, namely check if
+// something is a container is relying on only const_iterator in C++11 and
+// is relying on both const_iterator and iterator otherwise
+template <typename C>
+struct IsRecursiveContainerImpl<C, true> {
+  using value_type = decltype(*std::declval<typename C::const_iterator>());
+  using type =
+      std::is_same<typename std::remove_const<
+                       typename std::remove_reference<value_type>::type>::type,
+                   C>;
+};
+
+// IsRecursiveContainer<Type> is a unary compile-time predicate that
+// evaluates whether C is a recursive container type. A recursive container
+// type is a container type whose value_type is equal to the container type
+// itself. An example for a recursive container type is
+// boost::filesystem::path, whose iterator has a value_type that is equal to
+// boost::filesystem::path.
+template <typename C>
+struct IsRecursiveContainer : public IsRecursiveContainerImpl<C>::type {};
+
+// Utilities for native arrays.
+
+// ArrayEq() compares two k-dimensional native arrays using the
+// elements' operator==, where k can be any integer >= 0.  When k is
+// 0, ArrayEq() degenerates into comparing a single pair of values.
+
+template <typename T, typename U>
+bool ArrayEq(const T* lhs, size_t size, const U* rhs);
+
+// This generic version is used when k is 0.
+template <typename T, typename U>
+inline bool ArrayEq(const T& lhs, const U& rhs) { return lhs == rhs; }
+
+// This overload is used when k >= 1.
+template <typename T, typename U, size_t N>
+inline bool ArrayEq(const T(&lhs)[N], const U(&rhs)[N]) {
+  return internal::ArrayEq(lhs, N, rhs);
+}
+
+// This helper reduces code bloat.  If we instead put its logic inside
+// the previous ArrayEq() function, arrays with different sizes would
+// lead to different copies of the template code.
+template <typename T, typename U>
+bool ArrayEq(const T* lhs, size_t size, const U* rhs) {
+  for (size_t i = 0; i != size; i++) {
+    if (!internal::ArrayEq(lhs[i], rhs[i]))
+      return false;
+  }
+  return true;
+}
+
+// Finds the first element in the iterator range [begin, end) that
+// equals elem.  Element may be a native array type itself.
+template <typename Iter, typename Element>
+Iter ArrayAwareFind(Iter begin, Iter end, const Element& elem) {
+  for (Iter it = begin; it != end; ++it) {
+    if (internal::ArrayEq(*it, elem))
+      return it;
+  }
+  return end;
+}
+
+// CopyArray() copies a k-dimensional native array using the elements'
+// operator=, where k can be any integer >= 0.  When k is 0,
+// CopyArray() degenerates into copying a single value.
+
+template <typename T, typename U>
+void CopyArray(const T* from, size_t size, U* to);
+
+// This generic version is used when k is 0.
+template <typename T, typename U>
+inline void CopyArray(const T& from, U* to) { *to = from; }
+
+// This overload is used when k >= 1.
+template <typename T, typename U, size_t N>
+inline void CopyArray(const T(&from)[N], U(*to)[N]) {
+  internal::CopyArray(from, N, *to);
+}
+
+// This helper reduces code bloat.  If we instead put its logic inside
+// the previous CopyArray() function, arrays with different sizes
+// would lead to different copies of the template code.
+template <typename T, typename U>
+void CopyArray(const T* from, size_t size, U* to) {
+  for (size_t i = 0; i != size; i++) {
+    internal::CopyArray(from[i], to + i);
+  }
+}
+
+// The relation between an NativeArray object (see below) and the
+// native array it represents.
+// We use 2 different structs to allow non-copyable types to be used, as long
+// as RelationToSourceReference() is passed.
+struct RelationToSourceReference {};
+struct RelationToSourceCopy {};
+
+// Adapts a native array to a read-only STL-style container.  Instead
+// of the complete STL container concept, this adaptor only implements
+// members useful for Google Mock's container matchers.  New members
+// should be added as needed.  To simplify the implementation, we only
+// support Element being a raw type (i.e. having no top-level const or
+// reference modifier).  It's the client's responsibility to satisfy
+// this requirement.  Element can be an array type itself (hence
+// multi-dimensional arrays are supported).
+template <typename Element>
+class NativeArray {
+ public:
+  // STL-style container typedefs.
+  typedef Element value_type;
+  typedef Element* iterator;
+  typedef const Element* const_iterator;
+
+  // Constructs from a native array. References the source.
+  NativeArray(const Element* array, size_t count, RelationToSourceReference) {
+    InitRef(array, count);
+  }
+
+  // Constructs from a native array. Copies the source.
+  NativeArray(const Element* array, size_t count, RelationToSourceCopy) {
+    InitCopy(array, count);
+  }
+
+  // Copy constructor.
+  NativeArray(const NativeArray& rhs) {
+    (this->*rhs.clone_)(rhs.array_, rhs.size_);
+  }
+
+  ~NativeArray() {
+    if (clone_ != &NativeArray::InitRef)
+      delete[] array_;
+  }
+
+  // STL-style container methods.
+  size_t size() const { return size_; }
+  const_iterator begin() const { return array_; }
+  const_iterator end() const { return array_ + size_; }
+  bool operator==(const NativeArray& rhs) const {
+    return size() == rhs.size() &&
+        ArrayEq(begin(), size(), rhs.begin());
+  }
+
+ private:
+  static_assert(!std::is_const<Element>::value, "Type must not be const");
+  static_assert(!std::is_reference<Element>::value,
+                "Type must not be a reference");
+
+  // Initializes this object with a copy of the input.
+  void InitCopy(const Element* array, size_t a_size) {
+    Element* const copy = new Element[a_size];
+    CopyArray(array, a_size, copy);
+    array_ = copy;
+    size_ = a_size;
+    clone_ = &NativeArray::InitCopy;
+  }
+
+  // Initializes this object with a reference of the input.
+  void InitRef(const Element* array, size_t a_size) {
+    array_ = array;
+    size_ = a_size;
+    clone_ = &NativeArray::InitRef;
+  }
+
+  const Element* array_;
+  size_t size_;
+  void (NativeArray::*clone_)(const Element*, size_t);
+
+  GTEST_DISALLOW_ASSIGN_(NativeArray);
+};
+
+// Backport of std::index_sequence.
+template <size_t... Is>
+struct IndexSequence {
+  using type = IndexSequence;
+};
+
+// Double the IndexSequence, and one if plus_one is true.
+template <bool plus_one, typename T, size_t sizeofT>
+struct DoubleSequence;
+template <size_t... I, size_t sizeofT>
+struct DoubleSequence<true, IndexSequence<I...>, sizeofT> {
+  using type = IndexSequence<I..., (sizeofT + I)..., 2 * sizeofT>;
+};
+template <size_t... I, size_t sizeofT>
+struct DoubleSequence<false, IndexSequence<I...>, sizeofT> {
+  using type = IndexSequence<I..., (sizeofT + I)...>;
+};
+
+// Backport of std::make_index_sequence.
+// It uses O(ln(N)) instantiation depth.
+template <size_t N>
+struct MakeIndexSequence
+    : DoubleSequence<N % 2 == 1, typename MakeIndexSequence<N / 2>::type,
+                     N / 2>::type {};
+
+template <>
+struct MakeIndexSequence<0> : IndexSequence<> {};
+
+// FIXME: This implementation of ElemFromList is O(1) in instantiation depth,
+// but it is O(N^2) in total instantiations. Not sure if this is the best
+// tradeoff, as it will make it somewhat slow to compile.
+template <typename T, size_t, size_t>
+struct ElemFromListImpl {};
+
+template <typename T, size_t I>
+struct ElemFromListImpl<T, I, I> {
+  using type = T;
+};
+
+// Get the Nth element from T...
+// It uses O(1) instantiation depth.
+template <size_t N, typename I, typename... T>
+struct ElemFromList;
+
+template <size_t N, size_t... I, typename... T>
+struct ElemFromList<N, IndexSequence<I...>, T...>
+    : ElemFromListImpl<T, N, I>... {};
+
+template <typename... T>
+class FlatTuple;
+
+template <typename Derived, size_t I>
+struct FlatTupleElemBase;
+
+template <typename... T, size_t I>
+struct FlatTupleElemBase<FlatTuple<T...>, I> {
+  using value_type =
+      typename ElemFromList<I, typename MakeIndexSequence<sizeof...(T)>::type,
+                            T...>::type;
+  FlatTupleElemBase() = default;
+  explicit FlatTupleElemBase(value_type t) : value(std::move(t)) {}
+  value_type value;
+};
+
+template <typename Derived, typename Idx>
+struct FlatTupleBase;
+
+template <size_t... Idx, typename... T>
+struct FlatTupleBase<FlatTuple<T...>, IndexSequence<Idx...>>
+    : FlatTupleElemBase<FlatTuple<T...>, Idx>... {
+  using Indices = IndexSequence<Idx...>;
+  FlatTupleBase() = default;
+  explicit FlatTupleBase(T... t)
+      : FlatTupleElemBase<FlatTuple<T...>, Idx>(std::move(t))... {}
+};
+
+// Analog to std::tuple but with different tradeoffs.
+// This class minimizes the template instantiation depth, thus allowing more
+// elements that std::tuple would. std::tuple has been seen to require an
+// instantiation depth of more than 10x the number of elements in some
+// implementations.
+// FlatTuple and ElemFromList are not recursive and have a fixed depth
+// regardless of T...
+// MakeIndexSequence, on the other hand, it is recursive but with an
+// instantiation depth of O(ln(N)).
+template <typename... T>
+class FlatTuple
+    : private FlatTupleBase<FlatTuple<T...>,
+                            typename MakeIndexSequence<sizeof...(T)>::type> {
+  using Indices = typename FlatTuple::FlatTupleBase::Indices;
+
+ public:
+  FlatTuple() = default;
+  explicit FlatTuple(T... t) : FlatTuple::FlatTupleBase(std::move(t)...) {}
+
+  template <size_t I>
+  const typename ElemFromList<I, Indices, T...>::type& Get() const {
+    return static_cast<const FlatTupleElemBase<FlatTuple, I>*>(this)->value;
+  }
+
+  template <size_t I>
+  typename ElemFromList<I, Indices, T...>::type& Get() {
+    return static_cast<FlatTupleElemBase<FlatTuple, I>*>(this)->value;
+  }
+};
+
+// Utility functions to be called with static_assert to induce deprecation
+// warnings.
+GTEST_INTERNAL_DEPRECATED(
+    "INSTANTIATE_TEST_CASE_P is deprecated, please use "
+    "INSTANTIATE_TEST_SUITE_P")
+constexpr bool InstantiateTestCase_P_IsDeprecated() { return true; }
+
+GTEST_INTERNAL_DEPRECATED(
+    "TYPED_TEST_CASE_P is deprecated, please use "
+    "TYPED_TEST_SUITE_P")
+constexpr bool TypedTestCase_P_IsDeprecated() { return true; }
+
+GTEST_INTERNAL_DEPRECATED(
+    "TYPED_TEST_CASE is deprecated, please use "
+    "TYPED_TEST_SUITE")
+constexpr bool TypedTestCaseIsDeprecated() { return true; }
+
+GTEST_INTERNAL_DEPRECATED(
+    "REGISTER_TYPED_TEST_CASE_P is deprecated, please use "
+    "REGISTER_TYPED_TEST_SUITE_P")
+constexpr bool RegisterTypedTestCase_P_IsDeprecated() { return true; }
+
+GTEST_INTERNAL_DEPRECATED(
+    "INSTANTIATE_TYPED_TEST_CASE_P is deprecated, please use "
+    "INSTANTIATE_TYPED_TEST_SUITE_P")
+constexpr bool InstantiateTypedTestCase_P_IsDeprecated() { return true; }
+
+}  // namespace internal
+}  // namespace testing
+
+#define GTEST_MESSAGE_AT_(file, line, message, result_type) \
+  ::testing::internal::AssertHelper(result_type, file, line, message) \
+    = ::testing::Message()
+
+#define GTEST_MESSAGE_(message, result_type) \
+  GTEST_MESSAGE_AT_(__FILE__, __LINE__, message, result_type)
+
+#define GTEST_FATAL_FAILURE_(message) \
+  return GTEST_MESSAGE_(message, ::testing::TestPartResult::kFatalFailure)
+
+#define GTEST_NONFATAL_FAILURE_(message) \
+  GTEST_MESSAGE_(message, ::testing::TestPartResult::kNonFatalFailure)
+
+#define GTEST_SUCCESS_(message) \
+  GTEST_MESSAGE_(message, ::testing::TestPartResult::kSuccess)
+
+#define GTEST_SKIP_(message) \
+  return GTEST_MESSAGE_(message, ::testing::TestPartResult::kSkip)
+
+// Suppress MSVC warning 4072 (unreachable code) for the code following
+// statement if it returns or throws (or doesn't return or throw in some
+// situations).
+#define GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement) \
+  if (::testing::internal::AlwaysTrue()) { statement; }
+
+#define GTEST_TEST_THROW_(statement, expected_exception, fail) \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
+  if (::testing::internal::ConstCharPtr gtest_msg = "") { \
+    bool gtest_caught_expected = false; \
+    try { \
+      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
+    } \
+    catch (expected_exception const&) { \
+      gtest_caught_expected = true; \
+    } \
+    catch (...) { \
+      gtest_msg.value = \
+          "Expected: " #statement " throws an exception of type " \
+          #expected_exception ".\n  Actual: it throws a different type."; \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__); \
+    } \
+    if (!gtest_caught_expected) { \
+      gtest_msg.value = \
+          "Expected: " #statement " throws an exception of type " \
+          #expected_exception ".\n  Actual: it throws nothing."; \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__); \
+    } \
+  } else \
+    GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__): \
+      fail(gtest_msg.value)
+
+#define GTEST_TEST_NO_THROW_(statement, fail) \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
+  if (::testing::internal::AlwaysTrue()) { \
+    try { \
+      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
+    } \
+    catch (...) { \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__); \
+    } \
+  } else \
+    GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__): \
+      fail("Expected: " #statement " doesn't throw an exception.\n" \
+           "  Actual: it throws.")
+
+#define GTEST_TEST_ANY_THROW_(statement, fail) \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
+  if (::testing::internal::AlwaysTrue()) { \
+    bool gtest_caught_any = false; \
+    try { \
+      GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
+    } \
+    catch (...) { \
+      gtest_caught_any = true; \
+    } \
+    if (!gtest_caught_any) { \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testanythrow_, __LINE__); \
+    } \
+  } else \
+    GTEST_CONCAT_TOKEN_(gtest_label_testanythrow_, __LINE__): \
+      fail("Expected: " #statement " throws an exception.\n" \
+           "  Actual: it doesn't.")
+
+
+// Implements Boolean test assertions such as EXPECT_TRUE. expression can be
+// either a boolean expression or an AssertionResult. text is a textual
+// represenation of expression as it was passed into the EXPECT_TRUE.
+#define GTEST_TEST_BOOLEAN_(expression, text, actual, expected, fail) \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
+  if (const ::testing::AssertionResult gtest_ar_ = \
+      ::testing::AssertionResult(expression)) \
+    ; \
+  else \
+    fail(::testing::internal::GetBoolAssertionFailureMessage(\
+        gtest_ar_, text, #actual, #expected).c_str())
+
+#define GTEST_TEST_NO_FATAL_FAILURE_(statement, fail) \
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
+  if (::testing::internal::AlwaysTrue()) { \
+    ::testing::internal::HasNewFatalFailureHelper gtest_fatal_failure_checker; \
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
+    if (gtest_fatal_failure_checker.has_new_fatal_failure()) { \
+      goto GTEST_CONCAT_TOKEN_(gtest_label_testnofatal_, __LINE__); \
+    } \
+  } else \
+    GTEST_CONCAT_TOKEN_(gtest_label_testnofatal_, __LINE__): \
+      fail("Expected: " #statement " doesn't generate new fatal " \
+           "failures in the current thread.\n" \
+           "  Actual: it does.")
+
+// Expands to the name of the class that implements the given test.
+#define GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) \
+  test_suite_name##_##test_name##_Test
+
+// Helper macro for defining tests.
+#define GTEST_TEST_(test_suite_name, test_name, parent_class, parent_id)      \
+  static_assert(sizeof(GTEST_STRINGIFY_(test_suite_name)) > 1,                \
+                "test_suite_name must not be empty");                         \
+  static_assert(sizeof(GTEST_STRINGIFY_(test_name)) > 1,                      \
+                "test_name must not be empty");                               \
+  class GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                    \
+      : public parent_class {                                                 \
+   public:                                                                    \
+    GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)() {}                   \
+                                                                              \
+   private:                                                                   \
+    virtual void TestBody();                                                  \
+    static ::testing::TestInfo* const test_info_ GTEST_ATTRIBUTE_UNUSED_;     \
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(GTEST_TEST_CLASS_NAME_(test_suite_name,   \
+                                                           test_name));       \
+  };                                                                          \
+                                                                              \
+  ::testing::TestInfo* const GTEST_TEST_CLASS_NAME_(test_suite_name,          \
+                                                    test_name)::test_info_ =  \
+      ::testing::internal::MakeAndRegisterTestInfo(                           \
+          #test_suite_name, #test_name, nullptr, nullptr,                     \
+          ::testing::internal::CodeLocation(__FILE__, __LINE__), (parent_id), \
+          ::testing::internal::SuiteApiResolver<                              \
+              parent_class>::GetSetUpCaseOrSuite(__FILE__, __LINE__),         \
+          ::testing::internal::SuiteApiResolver<                              \
+              parent_class>::GetTearDownCaseOrSuite(__FILE__, __LINE__),      \
+          new ::testing::internal::TestFactoryImpl<GTEST_TEST_CLASS_NAME_(    \
+              test_suite_name, test_name)>);                                  \
+  void GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::TestBody()
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
diff --git a/3rdparty/gtest/include/gtest/internal/gtest-param-util.h b/3rdparty/gtest/include/gtest/internal/gtest-param-util.h
new file mode 100644
index 0000000..9753399
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/gtest-param-util.h
@@ -0,0 +1,883 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Type and function utilities for implementing parameterized tests.
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
+
+#include <ctype.h>
+
+#include <cassert>
+#include <iterator>
+#include <memory>
+#include <set>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+#include "gtest/gtest-printers.h"
+
+namespace testing {
+// Input to a parameterized test name generator, describing a test parameter.
+// Consists of the parameter value and the integer parameter index.
+template <class ParamType>
+struct TestParamInfo {
+  TestParamInfo(const ParamType& a_param, size_t an_index) :
+    param(a_param),
+    index(an_index) {}
+  ParamType param;
+  size_t index;
+};
+
+// A builtin parameterized test name generator which returns the result of
+// testing::PrintToString.
+struct PrintToStringParamName {
+  template <class ParamType>
+  std::string operator()(const TestParamInfo<ParamType>& info) const {
+    return PrintToString(info.param);
+  }
+};
+
+namespace internal {
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+// Utility Functions
+
+// Outputs a message explaining invalid registration of different
+// fixture class for the same test suite. This may happen when
+// TEST_P macro is used to define two tests with the same name
+// but in different namespaces.
+GTEST_API_ void ReportInvalidTestSuiteType(const char* test_suite_name,
+                                           CodeLocation code_location);
+
+template <typename> class ParamGeneratorInterface;
+template <typename> class ParamGenerator;
+
+// Interface for iterating over elements provided by an implementation
+// of ParamGeneratorInterface<T>.
+template <typename T>
+class ParamIteratorInterface {
+ public:
+  virtual ~ParamIteratorInterface() {}
+  // A pointer to the base generator instance.
+  // Used only for the purposes of iterator comparison
+  // to make sure that two iterators belong to the same generator.
+  virtual const ParamGeneratorInterface<T>* BaseGenerator() const = 0;
+  // Advances iterator to point to the next element
+  // provided by the generator. The caller is responsible
+  // for not calling Advance() on an iterator equal to
+  // BaseGenerator()->End().
+  virtual void Advance() = 0;
+  // Clones the iterator object. Used for implementing copy semantics
+  // of ParamIterator<T>.
+  virtual ParamIteratorInterface* Clone() const = 0;
+  // Dereferences the current iterator and provides (read-only) access
+  // to the pointed value. It is the caller's responsibility not to call
+  // Current() on an iterator equal to BaseGenerator()->End().
+  // Used for implementing ParamGenerator<T>::operator*().
+  virtual const T* Current() const = 0;
+  // Determines whether the given iterator and other point to the same
+  // element in the sequence generated by the generator.
+  // Used for implementing ParamGenerator<T>::operator==().
+  virtual bool Equals(const ParamIteratorInterface& other) const = 0;
+};
+
+// Class iterating over elements provided by an implementation of
+// ParamGeneratorInterface<T>. It wraps ParamIteratorInterface<T>
+// and implements the const forward iterator concept.
+template <typename T>
+class ParamIterator {
+ public:
+  typedef T value_type;
+  typedef const T& reference;
+  typedef ptrdiff_t difference_type;
+
+  // ParamIterator assumes ownership of the impl_ pointer.
+  ParamIterator(const ParamIterator& other) : impl_(other.impl_->Clone()) {}
+  ParamIterator& operator=(const ParamIterator& other) {
+    if (this != &other)
+      impl_.reset(other.impl_->Clone());
+    return *this;
+  }
+
+  const T& operator*() const { return *impl_->Current(); }
+  const T* operator->() const { return impl_->Current(); }
+  // Prefix version of operator++.
+  ParamIterator& operator++() {
+    impl_->Advance();
+    return *this;
+  }
+  // Postfix version of operator++.
+  ParamIterator operator++(int /*unused*/) {
+    ParamIteratorInterface<T>* clone = impl_->Clone();
+    impl_->Advance();
+    return ParamIterator(clone);
+  }
+  bool operator==(const ParamIterator& other) const {
+    return impl_.get() == other.impl_.get() || impl_->Equals(*other.impl_);
+  }
+  bool operator!=(const ParamIterator& other) const {
+    return !(*this == other);
+  }
+
+ private:
+  friend class ParamGenerator<T>;
+  explicit ParamIterator(ParamIteratorInterface<T>* impl) : impl_(impl) {}
+  std::unique_ptr<ParamIteratorInterface<T> > impl_;
+};
+
+// ParamGeneratorInterface<T> is the binary interface to access generators
+// defined in other translation units.
+template <typename T>
+class ParamGeneratorInterface {
+ public:
+  typedef T ParamType;
+
+  virtual ~ParamGeneratorInterface() {}
+
+  // Generator interface definition
+  virtual ParamIteratorInterface<T>* Begin() const = 0;
+  virtual ParamIteratorInterface<T>* End() const = 0;
+};
+
+// Wraps ParamGeneratorInterface<T> and provides general generator syntax
+// compatible with the STL Container concept.
+// This class implements copy initialization semantics and the contained
+// ParamGeneratorInterface<T> instance is shared among all copies
+// of the original object. This is possible because that instance is immutable.
+template<typename T>
+class ParamGenerator {
+ public:
+  typedef ParamIterator<T> iterator;
+
+  explicit ParamGenerator(ParamGeneratorInterface<T>* impl) : impl_(impl) {}
+  ParamGenerator(const ParamGenerator& other) : impl_(other.impl_) {}
+
+  ParamGenerator& operator=(const ParamGenerator& other) {
+    impl_ = other.impl_;
+    return *this;
+  }
+
+  iterator begin() const { return iterator(impl_->Begin()); }
+  iterator end() const { return iterator(impl_->End()); }
+
+ private:
+  std::shared_ptr<const ParamGeneratorInterface<T> > impl_;
+};
+
+// Generates values from a range of two comparable values. Can be used to
+// generate sequences of user-defined types that implement operator+() and
+// operator<().
+// This class is used in the Range() function.
+template <typename T, typename IncrementT>
+class RangeGenerator : public ParamGeneratorInterface<T> {
+ public:
+  RangeGenerator(T begin, T end, IncrementT step)
+      : begin_(begin), end_(end),
+        step_(step), end_index_(CalculateEndIndex(begin, end, step)) {}
+  ~RangeGenerator() override {}
+
+  ParamIteratorInterface<T>* Begin() const override {
+    return new Iterator(this, begin_, 0, step_);
+  }
+  ParamIteratorInterface<T>* End() const override {
+    return new Iterator(this, end_, end_index_, step_);
+  }
+
+ private:
+  class Iterator : public ParamIteratorInterface<T> {
+   public:
+    Iterator(const ParamGeneratorInterface<T>* base, T value, int index,
+             IncrementT step)
+        : base_(base), value_(value), index_(index), step_(step) {}
+    ~Iterator() override {}
+
+    const ParamGeneratorInterface<T>* BaseGenerator() const override {
+      return base_;
+    }
+    void Advance() override {
+      value_ = static_cast<T>(value_ + step_);
+      index_++;
+    }
+    ParamIteratorInterface<T>* Clone() const override {
+      return new Iterator(*this);
+    }
+    const T* Current() const override { return &value_; }
+    bool Equals(const ParamIteratorInterface<T>& other) const override {
+      // Having the same base generator guarantees that the other
+      // iterator is of the same type and we can downcast.
+      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
+          << "The program attempted to compare iterators "
+          << "from different generators." << std::endl;
+      const int other_index =
+          CheckedDowncastToActualType<const Iterator>(&other)->index_;
+      return index_ == other_index;
+    }
+
+   private:
+    Iterator(const Iterator& other)
+        : ParamIteratorInterface<T>(),
+          base_(other.base_), value_(other.value_), index_(other.index_),
+          step_(other.step_) {}
+
+    // No implementation - assignment is unsupported.
+    void operator=(const Iterator& other);
+
+    const ParamGeneratorInterface<T>* const base_;
+    T value_;
+    int index_;
+    const IncrementT step_;
+  };  // class RangeGenerator::Iterator
+
+  static int CalculateEndIndex(const T& begin,
+                               const T& end,
+                               const IncrementT& step) {
+    int end_index = 0;
+    for (T i = begin; i < end; i = static_cast<T>(i + step))
+      end_index++;
+    return end_index;
+  }
+
+  // No implementation - assignment is unsupported.
+  void operator=(const RangeGenerator& other);
+
+  const T begin_;
+  const T end_;
+  const IncrementT step_;
+  // The index for the end() iterator. All the elements in the generated
+  // sequence are indexed (0-based) to aid iterator comparison.
+  const int end_index_;
+};  // class RangeGenerator
+
+
+// Generates values from a pair of STL-style iterators. Used in the
+// ValuesIn() function. The elements are copied from the source range
+// since the source can be located on the stack, and the generator
+// is likely to persist beyond that stack frame.
+template <typename T>
+class ValuesInIteratorRangeGenerator : public ParamGeneratorInterface<T> {
+ public:
+  template <typename ForwardIterator>
+  ValuesInIteratorRangeGenerator(ForwardIterator begin, ForwardIterator end)
+      : container_(begin, end) {}
+  ~ValuesInIteratorRangeGenerator() override {}
+
+  ParamIteratorInterface<T>* Begin() const override {
+    return new Iterator(this, container_.begin());
+  }
+  ParamIteratorInterface<T>* End() const override {
+    return new Iterator(this, container_.end());
+  }
+
+ private:
+  typedef typename ::std::vector<T> ContainerType;
+
+  class Iterator : public ParamIteratorInterface<T> {
+   public:
+    Iterator(const ParamGeneratorInterface<T>* base,
+             typename ContainerType::const_iterator iterator)
+        : base_(base), iterator_(iterator) {}
+    ~Iterator() override {}
+
+    const ParamGeneratorInterface<T>* BaseGenerator() const override {
+      return base_;
+    }
+    void Advance() override {
+      ++iterator_;
+      value_.reset();
+    }
+    ParamIteratorInterface<T>* Clone() const override {
+      return new Iterator(*this);
+    }
+    // We need to use cached value referenced by iterator_ because *iterator_
+    // can return a temporary object (and of type other then T), so just
+    // having "return &*iterator_;" doesn't work.
+    // value_ is updated here and not in Advance() because Advance()
+    // can advance iterator_ beyond the end of the range, and we cannot
+    // detect that fact. The client code, on the other hand, is
+    // responsible for not calling Current() on an out-of-range iterator.
+    const T* Current() const override {
+      if (value_.get() == nullptr) value_.reset(new T(*iterator_));
+      return value_.get();
+    }
+    bool Equals(const ParamIteratorInterface<T>& other) const override {
+      // Having the same base generator guarantees that the other
+      // iterator is of the same type and we can downcast.
+      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
+          << "The program attempted to compare iterators "
+          << "from different generators." << std::endl;
+      return iterator_ ==
+          CheckedDowncastToActualType<const Iterator>(&other)->iterator_;
+    }
+
+   private:
+    Iterator(const Iterator& other)
+          // The explicit constructor call suppresses a false warning
+          // emitted by gcc when supplied with the -Wextra option.
+        : ParamIteratorInterface<T>(),
+          base_(other.base_),
+          iterator_(other.iterator_) {}
+
+    const ParamGeneratorInterface<T>* const base_;
+    typename ContainerType::const_iterator iterator_;
+    // A cached value of *iterator_. We keep it here to allow access by
+    // pointer in the wrapping iterator's operator->().
+    // value_ needs to be mutable to be accessed in Current().
+    // Use of std::unique_ptr helps manage cached value's lifetime,
+    // which is bound by the lifespan of the iterator itself.
+    mutable std::unique_ptr<const T> value_;
+  };  // class ValuesInIteratorRangeGenerator::Iterator
+
+  // No implementation - assignment is unsupported.
+  void operator=(const ValuesInIteratorRangeGenerator& other);
+
+  const ContainerType container_;
+};  // class ValuesInIteratorRangeGenerator
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Default parameterized test name generator, returns a string containing the
+// integer test parameter index.
+template <class ParamType>
+std::string DefaultParamName(const TestParamInfo<ParamType>& info) {
+  Message name_stream;
+  name_stream << info.index;
+  return name_stream.GetString();
+}
+
+template <typename T = int>
+void TestNotEmpty() {
+  static_assert(sizeof(T) == 0, "Empty arguments are not allowed.");
+}
+template <typename T = int>
+void TestNotEmpty(const T&) {}
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Stores a parameter value and later creates tests parameterized with that
+// value.
+template <class TestClass>
+class ParameterizedTestFactory : public TestFactoryBase {
+ public:
+  typedef typename TestClass::ParamType ParamType;
+  explicit ParameterizedTestFactory(ParamType parameter) :
+      parameter_(parameter) {}
+  Test* CreateTest() override {
+    TestClass::SetParam(&parameter_);
+    return new TestClass();
+  }
+
+ private:
+  const ParamType parameter_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestFactory);
+};
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// TestMetaFactoryBase is a base class for meta-factories that create
+// test factories for passing into MakeAndRegisterTestInfo function.
+template <class ParamType>
+class TestMetaFactoryBase {
+ public:
+  virtual ~TestMetaFactoryBase() {}
+
+  virtual TestFactoryBase* CreateTestFactory(ParamType parameter) = 0;
+};
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// TestMetaFactory creates test factories for passing into
+// MakeAndRegisterTestInfo function. Since MakeAndRegisterTestInfo receives
+// ownership of test factory pointer, same factory object cannot be passed
+// into that method twice. But ParameterizedTestSuiteInfo is going to call
+// it for each Test/Parameter value combination. Thus it needs meta factory
+// creator class.
+template <class TestSuite>
+class TestMetaFactory
+    : public TestMetaFactoryBase<typename TestSuite::ParamType> {
+ public:
+  using ParamType = typename TestSuite::ParamType;
+
+  TestMetaFactory() {}
+
+  TestFactoryBase* CreateTestFactory(ParamType parameter) override {
+    return new ParameterizedTestFactory<TestSuite>(parameter);
+  }
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestMetaFactory);
+};
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// ParameterizedTestSuiteInfoBase is a generic interface
+// to ParameterizedTestSuiteInfo classes. ParameterizedTestSuiteInfoBase
+// accumulates test information provided by TEST_P macro invocations
+// and generators provided by INSTANTIATE_TEST_SUITE_P macro invocations
+// and uses that information to register all resulting test instances
+// in RegisterTests method. The ParameterizeTestSuiteRegistry class holds
+// a collection of pointers to the ParameterizedTestSuiteInfo objects
+// and calls RegisterTests() on each of them when asked.
+class ParameterizedTestSuiteInfoBase {
+ public:
+  virtual ~ParameterizedTestSuiteInfoBase() {}
+
+  // Base part of test suite name for display purposes.
+  virtual const std::string& GetTestSuiteName() const = 0;
+  // Test case id to verify identity.
+  virtual TypeId GetTestSuiteTypeId() const = 0;
+  // UnitTest class invokes this method to register tests in this
+  // test suite right before running them in RUN_ALL_TESTS macro.
+  // This method should not be called more than once on any single
+  // instance of a ParameterizedTestSuiteInfoBase derived class.
+  virtual void RegisterTests() = 0;
+
+ protected:
+  ParameterizedTestSuiteInfoBase() {}
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestSuiteInfoBase);
+};
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// ParameterizedTestSuiteInfo accumulates tests obtained from TEST_P
+// macro invocations for a particular test suite and generators
+// obtained from INSTANTIATE_TEST_SUITE_P macro invocations for that
+// test suite. It registers tests with all values generated by all
+// generators when asked.
+template <class TestSuite>
+class ParameterizedTestSuiteInfo : public ParameterizedTestSuiteInfoBase {
+ public:
+  // ParamType and GeneratorCreationFunc are private types but are required
+  // for declarations of public methods AddTestPattern() and
+  // AddTestSuiteInstantiation().
+  using ParamType = typename TestSuite::ParamType;
+  // A function that returns an instance of appropriate generator type.
+  typedef ParamGenerator<ParamType>(GeneratorCreationFunc)();
+  using ParamNameGeneratorFunc = std::string(const TestParamInfo<ParamType>&);
+
+  explicit ParameterizedTestSuiteInfo(const char* name,
+                                      CodeLocation code_location)
+      : test_suite_name_(name), code_location_(code_location) {}
+
+  // Test case base name for display purposes.
+  const std::string& GetTestSuiteName() const override {
+    return test_suite_name_;
+  }
+  // Test case id to verify identity.
+  TypeId GetTestSuiteTypeId() const override { return GetTypeId<TestSuite>(); }
+  // TEST_P macro uses AddTestPattern() to record information
+  // about a single test in a LocalTestInfo structure.
+  // test_suite_name is the base name of the test suite (without invocation
+  // prefix). test_base_name is the name of an individual test without
+  // parameter index. For the test SequenceA/FooTest.DoBar/1 FooTest is
+  // test suite base name and DoBar is test base name.
+  void AddTestPattern(const char* test_suite_name, const char* test_base_name,
+                      TestMetaFactoryBase<ParamType>* meta_factory) {
+    tests_.push_back(std::shared_ptr<TestInfo>(
+        new TestInfo(test_suite_name, test_base_name, meta_factory)));
+  }
+  // INSTANTIATE_TEST_SUITE_P macro uses AddGenerator() to record information
+  // about a generator.
+  int AddTestSuiteInstantiation(const std::string& instantiation_name,
+                                GeneratorCreationFunc* func,
+                                ParamNameGeneratorFunc* name_func,
+                                const char* file, int line) {
+    instantiations_.push_back(
+        InstantiationInfo(instantiation_name, func, name_func, file, line));
+    return 0;  // Return value used only to run this method in namespace scope.
+  }
+  // UnitTest class invokes this method to register tests in this test suite
+  // test suites right before running tests in RUN_ALL_TESTS macro.
+  // This method should not be called more than once on any single
+  // instance of a ParameterizedTestSuiteInfoBase derived class.
+  // UnitTest has a guard to prevent from calling this method more than once.
+  void RegisterTests() override {
+    for (typename TestInfoContainer::iterator test_it = tests_.begin();
+         test_it != tests_.end(); ++test_it) {
+      std::shared_ptr<TestInfo> test_info = *test_it;
+      for (typename InstantiationContainer::iterator gen_it =
+               instantiations_.begin(); gen_it != instantiations_.end();
+               ++gen_it) {
+        const std::string& instantiation_name = gen_it->name;
+        ParamGenerator<ParamType> generator((*gen_it->generator)());
+        ParamNameGeneratorFunc* name_func = gen_it->name_func;
+        const char* file = gen_it->file;
+        int line = gen_it->line;
+
+        std::string test_suite_name;
+        if ( !instantiation_name.empty() )
+          test_suite_name = instantiation_name + "/";
+        test_suite_name += test_info->test_suite_base_name;
+
+        size_t i = 0;
+        std::set<std::string> test_param_names;
+        for (typename ParamGenerator<ParamType>::iterator param_it =
+                 generator.begin();
+             param_it != generator.end(); ++param_it, ++i) {
+          Message test_name_stream;
+
+          std::string param_name = name_func(
+              TestParamInfo<ParamType>(*param_it, i));
+
+          GTEST_CHECK_(IsValidParamName(param_name))
+              << "Parameterized test name '" << param_name
+              << "' is invalid, in " << file
+              << " line " << line << std::endl;
+
+          GTEST_CHECK_(test_param_names.count(param_name) == 0)
+              << "Duplicate parameterized test name '" << param_name
+              << "', in " << file << " line " << line << std::endl;
+
+          test_param_names.insert(param_name);
+
+          if (!test_info->test_base_name.empty()) {
+            test_name_stream << test_info->test_base_name << "/";
+          }
+          test_name_stream << param_name;
+          MakeAndRegisterTestInfo(
+              test_suite_name.c_str(), test_name_stream.GetString().c_str(),
+              nullptr,  // No type parameter.
+              PrintToString(*param_it).c_str(), code_location_,
+              GetTestSuiteTypeId(),
+              SuiteApiResolver<TestSuite>::GetSetUpCaseOrSuite(file, line),
+              SuiteApiResolver<TestSuite>::GetTearDownCaseOrSuite(file, line),
+              test_info->test_meta_factory->CreateTestFactory(*param_it));
+        }  // for param_it
+      }  // for gen_it
+    }  // for test_it
+  }    // RegisterTests
+
+ private:
+  // LocalTestInfo structure keeps information about a single test registered
+  // with TEST_P macro.
+  struct TestInfo {
+    TestInfo(const char* a_test_suite_base_name, const char* a_test_base_name,
+             TestMetaFactoryBase<ParamType>* a_test_meta_factory)
+        : test_suite_base_name(a_test_suite_base_name),
+          test_base_name(a_test_base_name),
+          test_meta_factory(a_test_meta_factory) {}
+
+    const std::string test_suite_base_name;
+    const std::string test_base_name;
+    const std::unique_ptr<TestMetaFactoryBase<ParamType> > test_meta_factory;
+  };
+  using TestInfoContainer = ::std::vector<std::shared_ptr<TestInfo> >;
+  // Records data received from INSTANTIATE_TEST_SUITE_P macros:
+  //  <Instantiation name, Sequence generator creation function,
+  //     Name generator function, Source file, Source line>
+  struct InstantiationInfo {
+      InstantiationInfo(const std::string &name_in,
+                        GeneratorCreationFunc* generator_in,
+                        ParamNameGeneratorFunc* name_func_in,
+                        const char* file_in,
+                        int line_in)
+          : name(name_in),
+            generator(generator_in),
+            name_func(name_func_in),
+            file(file_in),
+            line(line_in) {}
+
+      std::string name;
+      GeneratorCreationFunc* generator;
+      ParamNameGeneratorFunc* name_func;
+      const char* file;
+      int line;
+  };
+  typedef ::std::vector<InstantiationInfo> InstantiationContainer;
+
+  static bool IsValidParamName(const std::string& name) {
+    // Check for empty string
+    if (name.empty())
+      return false;
+
+    // Check for invalid characters
+    for (std::string::size_type index = 0; index < name.size(); ++index) {
+      if (!isalnum(name[index]) && name[index] != '_')
+        return false;
+    }
+
+    return true;
+  }
+
+  const std::string test_suite_name_;
+  CodeLocation code_location_;
+  TestInfoContainer tests_;
+  InstantiationContainer instantiations_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestSuiteInfo);
+};  // class ParameterizedTestSuiteInfo
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+template <class TestCase>
+using ParameterizedTestCaseInfo = ParameterizedTestSuiteInfo<TestCase>;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// ParameterizedTestSuiteRegistry contains a map of
+// ParameterizedTestSuiteInfoBase classes accessed by test suite names. TEST_P
+// and INSTANTIATE_TEST_SUITE_P macros use it to locate their corresponding
+// ParameterizedTestSuiteInfo descriptors.
+class ParameterizedTestSuiteRegistry {
+ public:
+  ParameterizedTestSuiteRegistry() {}
+  ~ParameterizedTestSuiteRegistry() {
+    for (auto& test_suite_info : test_suite_infos_) {
+      delete test_suite_info;
+    }
+  }
+
+  // Looks up or creates and returns a structure containing information about
+  // tests and instantiations of a particular test suite.
+  template <class TestSuite>
+  ParameterizedTestSuiteInfo<TestSuite>* GetTestSuitePatternHolder(
+      const char* test_suite_name, CodeLocation code_location) {
+    ParameterizedTestSuiteInfo<TestSuite>* typed_test_info = nullptr;
+    for (auto& test_suite_info : test_suite_infos_) {
+      if (test_suite_info->GetTestSuiteName() == test_suite_name) {
+        if (test_suite_info->GetTestSuiteTypeId() != GetTypeId<TestSuite>()) {
+          // Complain about incorrect usage of Google Test facilities
+          // and terminate the program since we cannot guaranty correct
+          // test suite setup and tear-down in this case.
+          ReportInvalidTestSuiteType(test_suite_name, code_location);
+          posix::Abort();
+        } else {
+          // At this point we are sure that the object we found is of the same
+          // type we are looking for, so we downcast it to that type
+          // without further checks.
+          typed_test_info = CheckedDowncastToActualType<
+              ParameterizedTestSuiteInfo<TestSuite> >(test_suite_info);
+        }
+        break;
+      }
+    }
+    if (typed_test_info == nullptr) {
+      typed_test_info = new ParameterizedTestSuiteInfo<TestSuite>(
+          test_suite_name, code_location);
+      test_suite_infos_.push_back(typed_test_info);
+    }
+    return typed_test_info;
+  }
+  void RegisterTests() {
+    for (auto& test_suite_info : test_suite_infos_) {
+      test_suite_info->RegisterTests();
+    }
+  }
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  template <class TestCase>
+  ParameterizedTestCaseInfo<TestCase>* GetTestCasePatternHolder(
+      const char* test_case_name, CodeLocation code_location) {
+    return GetTestSuitePatternHolder<TestCase>(test_case_name, code_location);
+  }
+
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+ private:
+  using TestSuiteInfoContainer = ::std::vector<ParameterizedTestSuiteInfoBase*>;
+
+  TestSuiteInfoContainer test_suite_infos_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestSuiteRegistry);
+};
+
+}  // namespace internal
+
+// Forward declarations of ValuesIn(), which is implemented in
+// include/gtest/gtest-param-test.h.
+template <class Container>
+internal::ParamGenerator<typename Container::value_type> ValuesIn(
+    const Container& container);
+
+namespace internal {
+// Used in the Values() function to provide polymorphic capabilities.
+
+template <typename... Ts>
+class ValueArray {
+ public:
+  ValueArray(Ts... v) : v_{std::move(v)...} {}
+
+  template <typename T>
+  operator ParamGenerator<T>() const {  // NOLINT
+    return ValuesIn(MakeVector<T>(MakeIndexSequence<sizeof...(Ts)>()));
+  }
+
+ private:
+  template <typename T, size_t... I>
+  std::vector<T> MakeVector(IndexSequence<I...>) const {
+    return std::vector<T>{static_cast<T>(v_.template Get<I>())...};
+  }
+
+  FlatTuple<Ts...> v_;
+};
+
+template <typename... T>
+class CartesianProductGenerator
+    : public ParamGeneratorInterface<::std::tuple<T...>> {
+ public:
+  typedef ::std::tuple<T...> ParamType;
+
+  CartesianProductGenerator(const std::tuple<ParamGenerator<T>...>& g)
+      : generators_(g) {}
+  ~CartesianProductGenerator() override {}
+
+  ParamIteratorInterface<ParamType>* Begin() const override {
+    return new Iterator(this, generators_, false);
+  }
+  ParamIteratorInterface<ParamType>* End() const override {
+    return new Iterator(this, generators_, true);
+  }
+
+ private:
+  template <class I>
+  class IteratorImpl;
+  template <size_t... I>
+  class IteratorImpl<IndexSequence<I...>>
+      : public ParamIteratorInterface<ParamType> {
+   public:
+    IteratorImpl(const ParamGeneratorInterface<ParamType>* base,
+             const std::tuple<ParamGenerator<T>...>& generators, bool is_end)
+        : base_(base),
+          begin_(std::get<I>(generators).begin()...),
+          end_(std::get<I>(generators).end()...),
+          current_(is_end ? end_ : begin_) {
+      ComputeCurrentValue();
+    }
+    ~IteratorImpl() override {}
+
+    const ParamGeneratorInterface<ParamType>* BaseGenerator() const override {
+      return base_;
+    }
+    // Advance should not be called on beyond-of-range iterators
+    // so no component iterators must be beyond end of range, either.
+    void Advance() override {
+      assert(!AtEnd());
+      // Advance the last iterator.
+      ++std::get<sizeof...(T) - 1>(current_);
+      // if that reaches end, propagate that up.
+      AdvanceIfEnd<sizeof...(T) - 1>();
+      ComputeCurrentValue();
+    }
+    ParamIteratorInterface<ParamType>* Clone() const override {
+      return new IteratorImpl(*this);
+    }
+
+    const ParamType* Current() const override { return current_value_.get(); }
+
+    bool Equals(const ParamIteratorInterface<ParamType>& other) const override {
+      // Having the same base generator guarantees that the other
+      // iterator is of the same type and we can downcast.
+      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
+          << "The program attempted to compare iterators "
+          << "from different generators." << std::endl;
+      const IteratorImpl* typed_other =
+          CheckedDowncastToActualType<const IteratorImpl>(&other);
+
+      // We must report iterators equal if they both point beyond their
+      // respective ranges. That can happen in a variety of fashions,
+      // so we have to consult AtEnd().
+      if (AtEnd() && typed_other->AtEnd()) return true;
+
+      bool same = true;
+      bool dummy[] = {
+          (same = same && std::get<I>(current_) ==
+                              std::get<I>(typed_other->current_))...};
+      (void)dummy;
+      return same;
+    }
+
+   private:
+    template <size_t ThisI>
+    void AdvanceIfEnd() {
+      if (std::get<ThisI>(current_) != std::get<ThisI>(end_)) return;
+
+      bool last = ThisI == 0;
+      if (last) {
+        // We are done. Nothing else to propagate.
+        return;
+      }
+
+      constexpr size_t NextI = ThisI - (ThisI != 0);
+      std::get<ThisI>(current_) = std::get<ThisI>(begin_);
+      ++std::get<NextI>(current_);
+      AdvanceIfEnd<NextI>();
+    }
+
+    void ComputeCurrentValue() {
+      if (!AtEnd())
+        current_value_ = std::make_shared<ParamType>(*std::get<I>(current_)...);
+    }
+    bool AtEnd() const {
+      bool at_end = false;
+      bool dummy[] = {
+          (at_end = at_end || std::get<I>(current_) == std::get<I>(end_))...};
+      (void)dummy;
+      return at_end;
+    }
+
+    const ParamGeneratorInterface<ParamType>* const base_;
+    std::tuple<typename ParamGenerator<T>::iterator...> begin_;
+    std::tuple<typename ParamGenerator<T>::iterator...> end_;
+    std::tuple<typename ParamGenerator<T>::iterator...> current_;
+    std::shared_ptr<ParamType> current_value_;
+  };
+
+  using Iterator = IteratorImpl<typename MakeIndexSequence<sizeof...(T)>::type>;
+
+  std::tuple<ParamGenerator<T>...> generators_;
+};
+
+template <class... Gen>
+class CartesianProductHolder {
+ public:
+  CartesianProductHolder(const Gen&... g) : generators_(g...) {}
+  template <typename... T>
+  operator ParamGenerator<::std::tuple<T...>>() const {
+    return ParamGenerator<::std::tuple<T...>>(
+        new CartesianProductGenerator<T...>(generators_));
+  }
+
+ private:
+  std::tuple<Gen...> generators_;
+};
+
+}  // namespace internal
+}  // namespace testing
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
diff --git a/3rdparty/gtest/include/gtest/internal/gtest-port-arch.h b/3rdparty/gtest/include/gtest/internal/gtest-port-arch.h
new file mode 100644
index 0000000..cece93d
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/gtest-port-arch.h
@@ -0,0 +1,107 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file defines the GTEST_OS_* macro.
+// It is separate from gtest-port.h so that custom/gtest-port.h can include it.
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_ARCH_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_ARCH_H_
+
+// Determines the platform on which Google Test is compiled.
+#ifdef __CYGWIN__
+# define GTEST_OS_CYGWIN 1
+# elif defined(__MINGW__) || defined(__MINGW32__) || defined(__MINGW64__)
+#  define GTEST_OS_WINDOWS_MINGW 1
+#  define GTEST_OS_WINDOWS 1
+#elif defined _WIN32
+# define GTEST_OS_WINDOWS 1
+# ifdef _WIN32_WCE
+#  define GTEST_OS_WINDOWS_MOBILE 1
+# elif defined(WINAPI_FAMILY)
+#  include <winapifamily.h>
+#  if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
+#   define GTEST_OS_WINDOWS_DESKTOP 1
+#  elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_PHONE_APP)
+#   define GTEST_OS_WINDOWS_PHONE 1
+#  elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)
+#   define GTEST_OS_WINDOWS_RT 1
+#  elif WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_TV_TITLE)
+#   define GTEST_OS_WINDOWS_PHONE 1
+#   define GTEST_OS_WINDOWS_TV_TITLE 1
+#  else
+    // WINAPI_FAMILY defined but no known partition matched.
+    // Default to desktop.
+#   define GTEST_OS_WINDOWS_DESKTOP 1
+#  endif
+# else
+#  define GTEST_OS_WINDOWS_DESKTOP 1
+# endif  // _WIN32_WCE
+#elif defined __OS2__
+# define GTEST_OS_OS2 1
+#elif defined __APPLE__
+# define GTEST_OS_MAC 1
+# if TARGET_OS_IPHONE
+#  define GTEST_OS_IOS 1
+# endif
+#elif defined __DragonFly__
+# define GTEST_OS_DRAGONFLY 1
+#elif defined __FreeBSD__
+# define GTEST_OS_FREEBSD 1
+#elif defined __Fuchsia__
+# define GTEST_OS_FUCHSIA 1
+#elif defined(__GLIBC__) && defined(__FreeBSD_kernel__)
+# define GTEST_OS_GNU_KFREEBSD 1
+#elif defined __linux__
+# define GTEST_OS_LINUX 1
+# if defined __ANDROID__
+#  define GTEST_OS_LINUX_ANDROID 1
+# endif
+#elif defined __MVS__
+# define GTEST_OS_ZOS 1
+#elif defined(__sun) && defined(__SVR4)
+# define GTEST_OS_SOLARIS 1
+#elif defined(_AIX)
+# define GTEST_OS_AIX 1
+#elif defined(__hpux)
+# define GTEST_OS_HPUX 1
+#elif defined __native_client__
+# define GTEST_OS_NACL 1
+#elif defined __NetBSD__
+# define GTEST_OS_NETBSD 1
+#elif defined __OpenBSD__
+# define GTEST_OS_OPENBSD 1
+#elif defined __QNX__
+# define GTEST_OS_QNX 1
+#elif defined(__HAIKU__)
+#define GTEST_OS_HAIKU 1
+#endif  // __CYGWIN__
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_ARCH_H_
diff --git a/3rdparty/gtest/include/gtest/internal/gtest-port.h b/3rdparty/gtest/include/gtest/internal/gtest-port.h
new file mode 100644
index 0000000..063fcb1
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/gtest-port.h
@@ -0,0 +1,2231 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Low-level types and utilities for porting Google Test to various
+// platforms.  All macros ending with _ and symbols defined in an
+// internal namespace are subject to change without notice.  Code
+// outside Google Test MUST NOT USE THEM DIRECTLY.  Macros that don't
+// end with _ are part of Google Test's public API and can be used by
+// code outside Google Test.
+//
+// This file is fundamental to Google Test.  All other Google Test source
+// files are expected to #include this.  Therefore, it cannot #include
+// any other Google Test header.
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
+
+// Environment-describing macros
+// -----------------------------
+//
+// Google Test can be used in many different environments.  Macros in
+// this section tell Google Test what kind of environment it is being
+// used in, such that Google Test can provide environment-specific
+// features and implementations.
+//
+// Google Test tries to automatically detect the properties of its
+// environment, so users usually don't need to worry about these
+// macros.  However, the automatic detection is not perfect.
+// Sometimes it's necessary for a user to define some of the following
+// macros in the build script to override Google Test's decisions.
+//
+// If the user doesn't define a macro in the list, Google Test will
+// provide a default definition.  After this header is #included, all
+// macros in this list will be defined to either 1 or 0.
+//
+// Notes to maintainers:
+//   - Each macro here is a user-tweakable knob; do not grow the list
+//     lightly.
+//   - Use #if to key off these macros.  Don't use #ifdef or "#if
+//     defined(...)", which will not work as these macros are ALWAYS
+//     defined.
+//
+//   GTEST_HAS_CLONE          - Define it to 1/0 to indicate that clone(2)
+//                              is/isn't available.
+//   GTEST_HAS_EXCEPTIONS     - Define it to 1/0 to indicate that exceptions
+//                              are enabled.
+//   GTEST_HAS_POSIX_RE       - Define it to 1/0 to indicate that POSIX regular
+//                              expressions are/aren't available.
+//   GTEST_HAS_PTHREAD        - Define it to 1/0 to indicate that <pthread.h>
+//                              is/isn't available.
+//   GTEST_HAS_RTTI           - Define it to 1/0 to indicate that RTTI is/isn't
+//                              enabled.
+//   GTEST_HAS_STD_WSTRING    - Define it to 1/0 to indicate that
+//                              std::wstring does/doesn't work (Google Test can
+//                              be used where std::wstring is unavailable).
+//   GTEST_HAS_SEH            - Define it to 1/0 to indicate whether the
+//                              compiler supports Microsoft's "Structured
+//                              Exception Handling".
+//   GTEST_HAS_STREAM_REDIRECTION
+//                            - Define it to 1/0 to indicate whether the
+//                              platform supports I/O stream redirection using
+//                              dup() and dup2().
+//   GTEST_LINKED_AS_SHARED_LIBRARY
+//                            - Define to 1 when compiling tests that use
+//                              Google Test as a shared library (known as
+//                              DLL on Windows).
+//   GTEST_CREATE_SHARED_LIBRARY
+//                            - Define to 1 when compiling Google Test itself
+//                              as a shared library.
+//   GTEST_DEFAULT_DEATH_TEST_STYLE
+//                            - The default value of --gtest_death_test_style.
+//                              The legacy default has been "fast" in the open
+//                              source version since 2008. The recommended value
+//                              is "threadsafe", and can be set in
+//                              custom/gtest-port.h.
+
+// Platform-indicating macros
+// --------------------------
+//
+// Macros indicating the platform on which Google Test is being used
+// (a macro is defined to 1 if compiled on the given platform;
+// otherwise UNDEFINED -- it's never defined to 0.).  Google Test
+// defines these macros automatically.  Code outside Google Test MUST
+// NOT define them.
+//
+//   GTEST_OS_AIX      - IBM AIX
+//   GTEST_OS_CYGWIN   - Cygwin
+//   GTEST_OS_DRAGONFLY - DragonFlyBSD
+//   GTEST_OS_FREEBSD  - FreeBSD
+//   GTEST_OS_FUCHSIA  - Fuchsia
+//   GTEST_OS_GNU_KFREEBSD - GNU/kFreeBSD
+//   GTEST_OS_HAIKU    - Haiku
+//   GTEST_OS_HPUX     - HP-UX
+//   GTEST_OS_LINUX    - Linux
+//     GTEST_OS_LINUX_ANDROID - Google Android
+//   GTEST_OS_MAC      - Mac OS X
+//     GTEST_OS_IOS    - iOS
+//   GTEST_OS_NACL     - Google Native Client (NaCl)
+//   GTEST_OS_NETBSD   - NetBSD
+//   GTEST_OS_OPENBSD  - OpenBSD
+//   GTEST_OS_OS2      - OS/2
+//   GTEST_OS_QNX      - QNX
+//   GTEST_OS_SOLARIS  - Sun Solaris
+//   GTEST_OS_WINDOWS  - Windows (Desktop, MinGW, or Mobile)
+//     GTEST_OS_WINDOWS_DESKTOP  - Windows Desktop
+//     GTEST_OS_WINDOWS_MINGW    - MinGW
+//     GTEST_OS_WINDOWS_MOBILE   - Windows Mobile
+//     GTEST_OS_WINDOWS_PHONE    - Windows Phone
+//     GTEST_OS_WINDOWS_RT       - Windows Store App/WinRT
+//   GTEST_OS_ZOS      - z/OS
+//
+// Among the platforms, Cygwin, Linux, Mac OS X, and Windows have the
+// most stable support.  Since core members of the Google Test project
+// don't have access to other platforms, support for them may be less
+// stable.  If you notice any problems on your platform, please notify
+// googletestframework@googlegroups.com (patches for fixing them are
+// even more welcome!).
+//
+// It is possible that none of the GTEST_OS_* macros are defined.
+
+// Feature-indicating macros
+// -------------------------
+//
+// Macros indicating which Google Test features are available (a macro
+// is defined to 1 if the corresponding feature is supported;
+// otherwise UNDEFINED -- it's never defined to 0.).  Google Test
+// defines these macros automatically.  Code outside Google Test MUST
+// NOT define them.
+//
+// These macros are public so that portable tests can be written.
+// Such tests typically surround code using a feature with an #if
+// which controls that code.  For example:
+//
+// #if GTEST_HAS_DEATH_TEST
+//   EXPECT_DEATH(DoSomethingDeadly());
+// #endif
+//
+//   GTEST_HAS_DEATH_TEST   - death tests
+//   GTEST_HAS_TYPED_TEST   - typed tests
+//   GTEST_HAS_TYPED_TEST_P - type-parameterized tests
+//   GTEST_IS_THREADSAFE    - Google Test is thread-safe.
+//   GOOGLETEST_CM0007 DO NOT DELETE
+//   GTEST_USES_POSIX_RE    - enhanced POSIX regex is used. Do not confuse with
+//                            GTEST_HAS_POSIX_RE (see above) which users can
+//                            define themselves.
+//   GTEST_USES_SIMPLE_RE   - our own simple regex is used;
+//                            the above RE\b(s) are mutually exclusive.
+
+// Misc public macros
+// ------------------
+//
+//   GTEST_FLAG(flag_name)  - references the variable corresponding to
+//                            the given Google Test flag.
+
+// Internal utilities
+// ------------------
+//
+// The following macros and utilities are for Google Test's INTERNAL
+// use only.  Code outside Google Test MUST NOT USE THEM DIRECTLY.
+//
+// Macros for basic C++ coding:
+//   GTEST_AMBIGUOUS_ELSE_BLOCKER_ - for disabling a gcc warning.
+//   GTEST_ATTRIBUTE_UNUSED_  - declares that a class' instances or a
+//                              variable don't have to be used.
+//   GTEST_DISALLOW_ASSIGN_   - disables operator=.
+//   GTEST_DISALLOW_COPY_AND_ASSIGN_ - disables copy ctor and operator=.
+//   GTEST_MUST_USE_RESULT_   - declares that a function's result must be used.
+//   GTEST_INTENTIONAL_CONST_COND_PUSH_ - start code section where MSVC C4127 is
+//                                        suppressed (constant conditional).
+//   GTEST_INTENTIONAL_CONST_COND_POP_  - finish code section where MSVC C4127
+//                                        is suppressed.
+//
+// Synchronization:
+//   Mutex, MutexLock, ThreadLocal, GetThreadCount()
+//                            - synchronization primitives.
+//
+// Regular expressions:
+//   RE             - a simple regular expression class using the POSIX
+//                    Extended Regular Expression syntax on UNIX-like platforms
+//                    GOOGLETEST_CM0008 DO NOT DELETE
+//                    or a reduced regular exception syntax on other
+//                    platforms, including Windows.
+// Logging:
+//   GTEST_LOG_()   - logs messages at the specified severity level.
+//   LogToStderr()  - directs all log messages to stderr.
+//   FlushInfoLog() - flushes informational log messages.
+//
+// Stdout and stderr capturing:
+//   CaptureStdout()     - starts capturing stdout.
+//   GetCapturedStdout() - stops capturing stdout and returns the captured
+//                         string.
+//   CaptureStderr()     - starts capturing stderr.
+//   GetCapturedStderr() - stops capturing stderr and returns the captured
+//                         string.
+//
+// Integer types:
+//   TypeWithSize   - maps an integer to a int type.
+//   Int32, UInt32, Int64, UInt64, TimeInMillis
+//                  - integers of known sizes.
+//   BiggestInt     - the biggest signed integer type.
+//
+// Command-line utilities:
+//   GTEST_DECLARE_*()  - declares a flag.
+//   GTEST_DEFINE_*()   - defines a flag.
+//   GetInjectableArgvs() - returns the command line as a vector of strings.
+//
+// Environment variable utilities:
+//   GetEnv()             - gets the value of an environment variable.
+//   BoolFromGTestEnv()   - parses a bool environment variable.
+//   Int32FromGTestEnv()  - parses an Int32 environment variable.
+//   StringFromGTestEnv() - parses a string environment variable.
+//
+// Deprecation warnings:
+//   GTEST_INTERNAL_DEPRECATED(message) - attribute marking a function as
+//                                        deprecated; calling a marked function
+//                                        should generate a compiler warning
+
+#include <ctype.h>   // for isspace, etc
+#include <stddef.h>  // for ptrdiff_t
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <memory>
+#include <type_traits>
+
+#ifndef _WIN32_WCE
+# include <sys/types.h>
+# include <sys/stat.h>
+#endif  // !_WIN32_WCE
+
+#if defined __APPLE__
+# include <AvailabilityMacros.h>
+# include <TargetConditionals.h>
+#endif
+
+#include <algorithm>  // NOLINT
+#include <iostream>   // NOLINT
+#include <sstream>    // NOLINT
+#include <string>     // NOLINT
+#include <tuple>
+#include <utility>
+#include <vector>  // NOLINT
+
+#include "gtest/internal/gtest-port-arch.h"
+#include "gtest/internal/custom/gtest-port.h"
+
+#if !defined(GTEST_DEV_EMAIL_)
+# define GTEST_DEV_EMAIL_ "googletestframework@@googlegroups.com"
+# define GTEST_FLAG_PREFIX_ "gtest_"
+# define GTEST_FLAG_PREFIX_DASH_ "gtest-"
+# define GTEST_FLAG_PREFIX_UPPER_ "GTEST_"
+# define GTEST_NAME_ "Google Test"
+# define GTEST_PROJECT_URL_ "https://github.com/google/googletest/"
+#endif  // !defined(GTEST_DEV_EMAIL_)
+
+#if !defined(GTEST_INIT_GOOGLE_TEST_NAME_)
+# define GTEST_INIT_GOOGLE_TEST_NAME_ "testing::InitGoogleTest"
+#endif  // !defined(GTEST_INIT_GOOGLE_TEST_NAME_)
+
+// Determines the version of gcc that is used to compile this.
+#ifdef __GNUC__
+// 40302 means version 4.3.2.
+# define GTEST_GCC_VER_ \
+    (__GNUC__*10000 + __GNUC_MINOR__*100 + __GNUC_PATCHLEVEL__)
+#endif  // __GNUC__
+
+// Macros for disabling Microsoft Visual C++ warnings.
+//
+//   GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800 4385)
+//   /* code that triggers warnings C4800 and C4385 */
+//   GTEST_DISABLE_MSC_WARNINGS_POP_()
+#if defined(_MSC_VER)
+# define GTEST_DISABLE_MSC_WARNINGS_PUSH_(warnings) \
+    __pragma(warning(push))                        \
+    __pragma(warning(disable: warnings))
+# define GTEST_DISABLE_MSC_WARNINGS_POP_()          \
+    __pragma(warning(pop))
+#else
+// Not all compilers are MSVC
+# define GTEST_DISABLE_MSC_WARNINGS_PUSH_(warnings)
+# define GTEST_DISABLE_MSC_WARNINGS_POP_()
+#endif
+
+// Clang on Windows does not understand MSVC's pragma warning.
+// We need clang-specific way to disable function deprecation warning.
+#ifdef __clang__
+# define GTEST_DISABLE_MSC_DEPRECATED_PUSH_()                         \
+    _Pragma("clang diagnostic push")                                  \
+    _Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"") \
+    _Pragma("clang diagnostic ignored \"-Wdeprecated-implementations\"")
+#define GTEST_DISABLE_MSC_DEPRECATED_POP_() \
+    _Pragma("clang diagnostic pop")
+#else
+# define GTEST_DISABLE_MSC_DEPRECATED_PUSH_() \
+    GTEST_DISABLE_MSC_WARNINGS_PUSH_(4996)
+# define GTEST_DISABLE_MSC_DEPRECATED_POP_() \
+    GTEST_DISABLE_MSC_WARNINGS_POP_()
+#endif
+
+// Brings in definitions for functions used in the testing::internal::posix
+// namespace (read, write, close, chdir, isatty, stat). We do not currently
+// use them on Windows Mobile.
+#if GTEST_OS_WINDOWS
+# if !GTEST_OS_WINDOWS_MOBILE
+#  include <direct.h>
+#  include <io.h>
+# endif
+// In order to avoid having to include <windows.h>, use forward declaration
+#if GTEST_OS_WINDOWS_MINGW && !defined(__MINGW64_VERSION_MAJOR)
+// MinGW defined _CRITICAL_SECTION and _RTL_CRITICAL_SECTION as two
+// separate (equivalent) structs, instead of using typedef
+typedef struct _CRITICAL_SECTION GTEST_CRITICAL_SECTION;
+#else
+// Assume CRITICAL_SECTION is a typedef of _RTL_CRITICAL_SECTION.
+// This assumption is verified by
+// WindowsTypesTest.CRITICAL_SECTIONIs_RTL_CRITICAL_SECTION.
+typedef struct _RTL_CRITICAL_SECTION GTEST_CRITICAL_SECTION;
+#endif
+#else
+// This assumes that non-Windows OSes provide unistd.h. For OSes where this
+// is not the case, we need to include headers that provide the functions
+// mentioned above.
+# include <unistd.h>
+# include <strings.h>
+#endif  // GTEST_OS_WINDOWS
+
+#if GTEST_OS_LINUX_ANDROID
+// Used to define __ANDROID_API__ matching the target NDK API level.
+#  include <android/api-level.h>  // NOLINT
+#endif
+
+// Defines this to true if and only if Google Test can use POSIX regular
+// expressions.
+#ifndef GTEST_HAS_POSIX_RE
+# if GTEST_OS_LINUX_ANDROID
+// On Android, <regex.h> is only available starting with Gingerbread.
+#  define GTEST_HAS_POSIX_RE (__ANDROID_API__ >= 9)
+# else
+#  define GTEST_HAS_POSIX_RE (!GTEST_OS_WINDOWS)
+# endif
+#endif
+
+#if GTEST_USES_PCRE
+// The appropriate headers have already been included.
+
+#elif GTEST_HAS_POSIX_RE
+
+// On some platforms, <regex.h> needs someone to define size_t, and
+// won't compile otherwise.  We can #include it here as we already
+// included <stdlib.h>, which is guaranteed to define size_t through
+// <stddef.h>.
+# include <regex.h>  // NOLINT
+
+# define GTEST_USES_POSIX_RE 1
+
+#elif GTEST_OS_WINDOWS
+
+// <regex.h> is not available on Windows.  Use our own simple regex
+// implementation instead.
+# define GTEST_USES_SIMPLE_RE 1
+
+#else
+
+// <regex.h> may not be available on this platform.  Use our own
+// simple regex implementation instead.
+# define GTEST_USES_SIMPLE_RE 1
+
+#endif  // GTEST_USES_PCRE
+
+#ifndef GTEST_HAS_EXCEPTIONS
+// The user didn't tell us whether exceptions are enabled, so we need
+// to figure it out.
+# if defined(_MSC_VER) && defined(_CPPUNWIND)
+// MSVC defines _CPPUNWIND to 1 if and only if exceptions are enabled.
+#  define GTEST_HAS_EXCEPTIONS 1
+# elif defined(__BORLANDC__)
+// C++Builder's implementation of the STL uses the _HAS_EXCEPTIONS
+// macro to enable exceptions, so we'll do the same.
+// Assumes that exceptions are enabled by default.
+#  ifndef _HAS_EXCEPTIONS
+#   define _HAS_EXCEPTIONS 1
+#  endif  // _HAS_EXCEPTIONS
+#  define GTEST_HAS_EXCEPTIONS _HAS_EXCEPTIONS
+# elif defined(__clang__)
+// clang defines __EXCEPTIONS if and only if exceptions are enabled before clang
+// 220714, but if and only if cleanups are enabled after that. In Obj-C++ files,
+// there can be cleanups for ObjC exceptions which also need cleanups, even if
+// C++ exceptions are disabled. clang has __has_feature(cxx_exceptions) which
+// checks for C++ exceptions starting at clang r206352, but which checked for
+// cleanups prior to that. To reliably check for C++ exception availability with
+// clang, check for
+// __EXCEPTIONS && __has_feature(cxx_exceptions).
+#  define GTEST_HAS_EXCEPTIONS (__EXCEPTIONS && __has_feature(cxx_exceptions))
+# elif defined(__GNUC__) && __EXCEPTIONS
+// gcc defines __EXCEPTIONS to 1 if and only if exceptions are enabled.
+#  define GTEST_HAS_EXCEPTIONS 1
+# elif defined(__SUNPRO_CC)
+// Sun Pro CC supports exceptions.  However, there is no compile-time way of
+// detecting whether they are enabled or not.  Therefore, we assume that
+// they are enabled unless the user tells us otherwise.
+#  define GTEST_HAS_EXCEPTIONS 1
+# elif defined(__IBMCPP__) && __EXCEPTIONS
+// xlC defines __EXCEPTIONS to 1 if and only if exceptions are enabled.
+#  define GTEST_HAS_EXCEPTIONS 1
+# elif defined(__HP_aCC)
+// Exception handling is in effect by default in HP aCC compiler. It has to
+// be turned of by +noeh compiler option if desired.
+#  define GTEST_HAS_EXCEPTIONS 1
+# else
+// For other compilers, we assume exceptions are disabled to be
+// conservative.
+#  define GTEST_HAS_EXCEPTIONS 0
+# endif  // defined(_MSC_VER) || defined(__BORLANDC__)
+#endif  // GTEST_HAS_EXCEPTIONS
+
+#if !defined(GTEST_HAS_STD_STRING)
+// Even though we don't use this macro any longer, we keep it in case
+// some clients still depend on it.
+# define GTEST_HAS_STD_STRING 1
+#elif !GTEST_HAS_STD_STRING
+// The user told us that ::std::string isn't available.
+# error "::std::string isn't available."
+#endif  // !defined(GTEST_HAS_STD_STRING)
+
+#ifndef GTEST_HAS_STD_WSTRING
+// The user didn't tell us whether ::std::wstring is available, so we need
+// to figure it out.
+// Cygwin 1.7 and below doesn't support ::std::wstring.
+// Solaris' libc++ doesn't support it either.  Android has
+// no support for it at least as recent as Froyo (2.2).
+#define GTEST_HAS_STD_WSTRING                                         \
+  (!(GTEST_OS_LINUX_ANDROID || GTEST_OS_CYGWIN || GTEST_OS_SOLARIS || \
+     GTEST_OS_HAIKU))
+
+#endif  // GTEST_HAS_STD_WSTRING
+
+// Determines whether RTTI is available.
+#ifndef GTEST_HAS_RTTI
+// The user didn't tell us whether RTTI is enabled, so we need to
+// figure it out.
+
+# ifdef _MSC_VER
+
+#ifdef _CPPRTTI  // MSVC defines this macro if and only if RTTI is enabled.
+#   define GTEST_HAS_RTTI 1
+#  else
+#   define GTEST_HAS_RTTI 0
+#  endif
+
+// Starting with version 4.3.2, gcc defines __GXX_RTTI if and only if RTTI is
+// enabled.
+# elif defined(__GNUC__)
+
+#  ifdef __GXX_RTTI
+// When building against STLport with the Android NDK and with
+// -frtti -fno-exceptions, the build fails at link time with undefined
+// references to __cxa_bad_typeid. Note sure if STL or toolchain bug,
+// so disable RTTI when detected.
+#   if GTEST_OS_LINUX_ANDROID && defined(_STLPORT_MAJOR) && \
+       !defined(__EXCEPTIONS)
+#    define GTEST_HAS_RTTI 0
+#   else
+#    define GTEST_HAS_RTTI 1
+#   endif  // GTEST_OS_LINUX_ANDROID && __STLPORT_MAJOR && !__EXCEPTIONS
+#  else
+#   define GTEST_HAS_RTTI 0
+#  endif  // __GXX_RTTI
+
+// Clang defines __GXX_RTTI starting with version 3.0, but its manual recommends
+// using has_feature instead. has_feature(cxx_rtti) is supported since 2.7, the
+// first version with C++ support.
+# elif defined(__clang__)
+
+#  define GTEST_HAS_RTTI __has_feature(cxx_rtti)
+
+// Starting with version 9.0 IBM Visual Age defines __RTTI_ALL__ to 1 if
+// both the typeid and dynamic_cast features are present.
+# elif defined(__IBMCPP__) && (__IBMCPP__ >= 900)
+
+#  ifdef __RTTI_ALL__
+#   define GTEST_HAS_RTTI 1
+#  else
+#   define GTEST_HAS_RTTI 0
+#  endif
+
+# else
+
+// For all other compilers, we assume RTTI is enabled.
+#  define GTEST_HAS_RTTI 1
+
+# endif  // _MSC_VER
+
+#endif  // GTEST_HAS_RTTI
+
+// It's this header's responsibility to #include <typeinfo> when RTTI
+// is enabled.
+#if GTEST_HAS_RTTI
+# include <typeinfo>
+#endif
+
+// Determines whether Google Test can use the pthreads library.
+#ifndef GTEST_HAS_PTHREAD
+// The user didn't tell us explicitly, so we make reasonable assumptions about
+// which platforms have pthreads support.
+//
+// To disable threading support in Google Test, add -DGTEST_HAS_PTHREAD=0
+// to your compiler flags.
+#define GTEST_HAS_PTHREAD                                                      \
+  (GTEST_OS_LINUX || GTEST_OS_MAC || GTEST_OS_HPUX || GTEST_OS_QNX ||          \
+   GTEST_OS_FREEBSD || GTEST_OS_NACL || GTEST_OS_NETBSD || GTEST_OS_FUCHSIA || \
+   GTEST_OS_DRAGONFLY || GTEST_OS_GNU_KFREEBSD || GTEST_OS_OPENBSD ||          \
+   GTEST_OS_HAIKU)
+#endif  // GTEST_HAS_PTHREAD
+
+#if GTEST_HAS_PTHREAD
+// gtest-port.h guarantees to #include <pthread.h> when GTEST_HAS_PTHREAD is
+// true.
+# include <pthread.h>  // NOLINT
+
+// For timespec and nanosleep, used below.
+# include <time.h>  // NOLINT
+#endif
+
+// Determines whether clone(2) is supported.
+// Usually it will only be available on Linux, excluding
+// Linux on the Itanium architecture.
+// Also see http://linux.die.net/man/2/clone.
+#ifndef GTEST_HAS_CLONE
+// The user didn't tell us, so we need to figure it out.
+
+# if GTEST_OS_LINUX && !defined(__ia64__)
+#  if GTEST_OS_LINUX_ANDROID
+// On Android, clone() became available at different API levels for each 32-bit
+// architecture.
+#    if defined(__LP64__) || \
+        (defined(__arm__) && __ANDROID_API__ >= 9) || \
+        (defined(__mips__) && __ANDROID_API__ >= 12) || \
+        (defined(__i386__) && __ANDROID_API__ >= 17)
+#     define GTEST_HAS_CLONE 1
+#    else
+#     define GTEST_HAS_CLONE 0
+#    endif
+#  else
+#   define GTEST_HAS_CLONE 1
+#  endif
+# else
+#  define GTEST_HAS_CLONE 0
+# endif  // GTEST_OS_LINUX && !defined(__ia64__)
+
+#endif  // GTEST_HAS_CLONE
+
+// Determines whether to support stream redirection. This is used to test
+// output correctness and to implement death tests.
+#ifndef GTEST_HAS_STREAM_REDIRECTION
+// By default, we assume that stream redirection is supported on all
+// platforms except known mobile ones.
+# if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_PHONE || GTEST_OS_WINDOWS_RT
+#  define GTEST_HAS_STREAM_REDIRECTION 0
+# else
+#  define GTEST_HAS_STREAM_REDIRECTION 1
+# endif  // !GTEST_OS_WINDOWS_MOBILE
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+// Determines whether to support death tests.
+// pops up a dialog window that cannot be suppressed programmatically.
+#if (GTEST_OS_LINUX || GTEST_OS_CYGWIN || GTEST_OS_SOLARIS ||             \
+     (GTEST_OS_MAC && !GTEST_OS_IOS) ||                                   \
+     (GTEST_OS_WINDOWS_DESKTOP && _MSC_VER) || GTEST_OS_WINDOWS_MINGW ||  \
+     GTEST_OS_AIX || GTEST_OS_HPUX || GTEST_OS_OPENBSD || GTEST_OS_QNX || \
+     GTEST_OS_FREEBSD || GTEST_OS_NETBSD || GTEST_OS_FUCHSIA ||           \
+     GTEST_OS_DRAGONFLY || GTEST_OS_GNU_KFREEBSD || GTEST_OS_HAIKU)
+# define GTEST_HAS_DEATH_TEST 1
+#endif
+
+// Determines whether to support type-driven tests.
+
+// Typed tests need <typeinfo> and variadic macros, which GCC, VC++ 8.0,
+// Sun Pro CC, IBM Visual Age, and HP aCC support.
+#if defined(__GNUC__) || defined(_MSC_VER) || defined(__SUNPRO_CC) || \
+    defined(__IBMCPP__) || defined(__HP_aCC)
+# define GTEST_HAS_TYPED_TEST 1
+# define GTEST_HAS_TYPED_TEST_P 1
+#endif
+
+// Determines whether the system compiler uses UTF-16 for encoding wide strings.
+#define GTEST_WIDE_STRING_USES_UTF16_ \
+  (GTEST_OS_WINDOWS || GTEST_OS_CYGWIN || GTEST_OS_AIX || GTEST_OS_OS2)
+
+// Determines whether test results can be streamed to a socket.
+#if GTEST_OS_LINUX || GTEST_OS_GNU_KFREEBSD || GTEST_OS_DRAGONFLY || \
+    GTEST_OS_FREEBSD || GTEST_OS_NETBSD || GTEST_OS_OPENBSD
+# define GTEST_CAN_STREAM_RESULTS_ 1
+#endif
+
+// Defines some utility macros.
+
+// The GNU compiler emits a warning if nested "if" statements are followed by
+// an "else" statement and braces are not used to explicitly disambiguate the
+// "else" binding.  This leads to problems with code like:
+//
+//   if (gate)
+//     ASSERT_*(condition) << "Some message";
+//
+// The "switch (0) case 0:" idiom is used to suppress this.
+#ifdef __INTEL_COMPILER
+# define GTEST_AMBIGUOUS_ELSE_BLOCKER_
+#else
+# define GTEST_AMBIGUOUS_ELSE_BLOCKER_ switch (0) case 0: default:  // NOLINT
+#endif
+
+// Use this annotation at the end of a struct/class definition to
+// prevent the compiler from optimizing away instances that are never
+// used.  This is useful when all interesting logic happens inside the
+// c'tor and / or d'tor.  Example:
+//
+//   struct Foo {
+//     Foo() { ... }
+//   } GTEST_ATTRIBUTE_UNUSED_;
+//
+// Also use it after a variable or parameter declaration to tell the
+// compiler the variable/parameter does not have to be used.
+#if defined(__GNUC__) && !defined(COMPILER_ICC)
+# define GTEST_ATTRIBUTE_UNUSED_ __attribute__ ((unused))
+#elif defined(__clang__)
+# if __has_attribute(unused)
+#  define GTEST_ATTRIBUTE_UNUSED_ __attribute__ ((unused))
+# endif
+#endif
+#ifndef GTEST_ATTRIBUTE_UNUSED_
+# define GTEST_ATTRIBUTE_UNUSED_
+#endif
+
+// Use this annotation before a function that takes a printf format string.
+#if (defined(__GNUC__) || defined(__clang__)) && !defined(COMPILER_ICC)
+# if defined(__MINGW_PRINTF_FORMAT)
+// MinGW has two different printf implementations. Ensure the format macro
+// matches the selected implementation. See
+// https://sourceforge.net/p/mingw-w64/wiki2/gnu%20printf/.
+#  define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check) \
+       __attribute__((__format__(__MINGW_PRINTF_FORMAT, string_index, \
+                                 first_to_check)))
+# else
+#  define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check) \
+       __attribute__((__format__(__printf__, string_index, first_to_check)))
+# endif
+#else
+# define GTEST_ATTRIBUTE_PRINTF_(string_index, first_to_check)
+#endif
+
+
+// A macro to disallow operator=
+// This should be used in the private: declarations for a class.
+#define GTEST_DISALLOW_ASSIGN_(type) \
+  void operator=(type const &) = delete
+
+// A macro to disallow copy constructor and operator=
+// This should be used in the private: declarations for a class.
+#define GTEST_DISALLOW_COPY_AND_ASSIGN_(type) \
+  type(type const &) = delete; \
+  GTEST_DISALLOW_ASSIGN_(type)
+
+// Tell the compiler to warn about unused return values for functions declared
+// with this macro.  The macro should be used on function declarations
+// following the argument list:
+//
+//   Sprocket* AllocateSprocket() GTEST_MUST_USE_RESULT_;
+#if defined(__GNUC__) && !defined(COMPILER_ICC)
+# define GTEST_MUST_USE_RESULT_ __attribute__ ((warn_unused_result))
+#else
+# define GTEST_MUST_USE_RESULT_
+#endif  // __GNUC__ && !COMPILER_ICC
+
+// MS C++ compiler emits warning when a conditional expression is compile time
+// constant. In some contexts this warning is false positive and needs to be
+// suppressed. Use the following two macros in such cases:
+//
+// GTEST_INTENTIONAL_CONST_COND_PUSH_()
+// while (true) {
+// GTEST_INTENTIONAL_CONST_COND_POP_()
+// }
+# define GTEST_INTENTIONAL_CONST_COND_PUSH_() \
+    GTEST_DISABLE_MSC_WARNINGS_PUSH_(4127)
+# define GTEST_INTENTIONAL_CONST_COND_POP_() \
+    GTEST_DISABLE_MSC_WARNINGS_POP_()
+
+// Determine whether the compiler supports Microsoft's Structured Exception
+// Handling.  This is supported by several Windows compilers but generally
+// does not exist on any other system.
+#ifndef GTEST_HAS_SEH
+// The user didn't tell us, so we need to figure it out.
+
+# if defined(_MSC_VER) || defined(__BORLANDC__)
+// These two compilers are known to support SEH.
+#  define GTEST_HAS_SEH 1
+# else
+// Assume no SEH.
+#  define GTEST_HAS_SEH 0
+# endif
+
+#endif  // GTEST_HAS_SEH
+
+#ifndef GTEST_IS_THREADSAFE
+
+#define GTEST_IS_THREADSAFE                                                 \
+  (GTEST_HAS_MUTEX_AND_THREAD_LOCAL_ ||                                     \
+   (GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT) || \
+   GTEST_HAS_PTHREAD)
+
+#endif  // GTEST_IS_THREADSAFE
+
+// GTEST_API_ qualifies all symbols that must be exported. The definitions below
+// are guarded by #ifndef to give embedders a chance to define GTEST_API_ in
+// gtest/internal/custom/gtest-port.h
+#ifndef GTEST_API_
+
+#ifdef _MSC_VER
+# if GTEST_LINKED_AS_SHARED_LIBRARY
+#  define GTEST_API_ __declspec(dllimport)
+# elif GTEST_CREATE_SHARED_LIBRARY
+#  define GTEST_API_ __declspec(dllexport)
+# endif
+#elif __GNUC__ >= 4 || defined(__clang__)
+# define GTEST_API_ __attribute__((visibility ("default")))
+#endif  // _MSC_VER
+
+#endif  // GTEST_API_
+
+#ifndef GTEST_API_
+# define GTEST_API_
+#endif  // GTEST_API_
+
+#ifndef GTEST_DEFAULT_DEATH_TEST_STYLE
+# define GTEST_DEFAULT_DEATH_TEST_STYLE  "fast"
+#endif  // GTEST_DEFAULT_DEATH_TEST_STYLE
+
+#ifdef __GNUC__
+// Ask the compiler to never inline a given function.
+# define GTEST_NO_INLINE_ __attribute__((noinline))
+#else
+# define GTEST_NO_INLINE_
+#endif
+
+// _LIBCPP_VERSION is defined by the libc++ library from the LLVM project.
+#if !defined(GTEST_HAS_CXXABI_H_)
+# if defined(__GLIBCXX__) || (defined(_LIBCPP_VERSION) && !defined(_MSC_VER))
+#  define GTEST_HAS_CXXABI_H_ 1
+# else
+#  define GTEST_HAS_CXXABI_H_ 0
+# endif
+#endif
+
+// A function level attribute to disable checking for use of uninitialized
+// memory when built with MemorySanitizer.
+#if defined(__clang__)
+# if __has_feature(memory_sanitizer)
+#  define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_ \
+       __attribute__((no_sanitize_memory))
+# else
+#  define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
+# endif  // __has_feature(memory_sanitizer)
+#else
+# define GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
+#endif  // __clang__
+
+// A function level attribute to disable AddressSanitizer instrumentation.
+#if defined(__clang__)
+# if __has_feature(address_sanitizer)
+#  define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_ \
+       __attribute__((no_sanitize_address))
+# else
+#  define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+# endif  // __has_feature(address_sanitizer)
+#else
+# define GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+#endif  // __clang__
+
+// A function level attribute to disable HWAddressSanitizer instrumentation.
+#if defined(__clang__)
+# if __has_feature(hwaddress_sanitizer)
+#  define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_ \
+       __attribute__((no_sanitize("hwaddress")))
+# else
+#  define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+# endif  // __has_feature(hwaddress_sanitizer)
+#else
+# define GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+#endif  // __clang__
+
+// A function level attribute to disable ThreadSanitizer instrumentation.
+#if defined(__clang__)
+# if __has_feature(thread_sanitizer)
+#  define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_ \
+       __attribute__((no_sanitize_thread))
+# else
+#  define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
+# endif  // __has_feature(thread_sanitizer)
+#else
+# define GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
+#endif  // __clang__
+
+namespace testing {
+
+class Message;
+
+// Legacy imports for backwards compatibility.
+// New code should use std:: names directly.
+using std::get;
+using std::make_tuple;
+using std::tuple;
+using std::tuple_element;
+using std::tuple_size;
+
+namespace internal {
+
+// A secret type that Google Test users don't know about.  It has no
+// definition on purpose.  Therefore it's impossible to create a
+// Secret object, which is what we want.
+class Secret;
+
+// The GTEST_COMPILE_ASSERT_ is a legacy macro used to verify that a compile
+// time expression is true (in new code, use static_assert instead). For
+// example, you could use it to verify the size of a static array:
+//
+//   GTEST_COMPILE_ASSERT_(GTEST_ARRAY_SIZE_(names) == NUM_NAMES,
+//                         names_incorrect_size);
+//
+// The second argument to the macro must be a valid C++ identifier. If the
+// expression is false, compiler will issue an error containing this identifier.
+#define GTEST_COMPILE_ASSERT_(expr, msg) static_assert(expr, #msg)
+
+// Evaluates to the number of elements in 'array'.
+#define GTEST_ARRAY_SIZE_(array) (sizeof(array) / sizeof(array[0]))
+
+// A helper for suppressing warnings on constant condition.  It just
+// returns 'condition'.
+GTEST_API_ bool IsTrue(bool condition);
+
+// Defines RE.
+
+#if GTEST_USES_PCRE
+// if used, PCRE is injected by custom/gtest-port.h
+#elif GTEST_USES_POSIX_RE || GTEST_USES_SIMPLE_RE
+
+// A simple C++ wrapper for <regex.h>.  It uses the POSIX Extended
+// Regular Expression syntax.
+class GTEST_API_ RE {
+ public:
+  // A copy constructor is required by the Standard to initialize object
+  // references from r-values.
+  RE(const RE& other) { Init(other.pattern()); }
+
+  // Constructs an RE from a string.
+  RE(const ::std::string& regex) { Init(regex.c_str()); }  // NOLINT
+
+  RE(const char* regex) { Init(regex); }  // NOLINT
+  ~RE();
+
+  // Returns the string representation of the regex.
+  const char* pattern() const { return pattern_; }
+
+  // FullMatch(str, re) returns true if and only if regular expression re
+  // matches the entire str.
+  // PartialMatch(str, re) returns true if and only if regular expression re
+  // matches a substring of str (including str itself).
+  static bool FullMatch(const ::std::string& str, const RE& re) {
+    return FullMatch(str.c_str(), re);
+  }
+  static bool PartialMatch(const ::std::string& str, const RE& re) {
+    return PartialMatch(str.c_str(), re);
+  }
+
+  static bool FullMatch(const char* str, const RE& re);
+  static bool PartialMatch(const char* str, const RE& re);
+
+ private:
+  void Init(const char* regex);
+  const char* pattern_;
+  bool is_valid_;
+
+# if GTEST_USES_POSIX_RE
+
+  regex_t full_regex_;     // For FullMatch().
+  regex_t partial_regex_;  // For PartialMatch().
+
+# else  // GTEST_USES_SIMPLE_RE
+
+  const char* full_pattern_;  // For FullMatch();
+
+# endif
+
+  GTEST_DISALLOW_ASSIGN_(RE);
+};
+
+#endif  // GTEST_USES_PCRE
+
+// Formats a source file path and a line number as they would appear
+// in an error message from the compiler used to compile this code.
+GTEST_API_ ::std::string FormatFileLocation(const char* file, int line);
+
+// Formats a file location for compiler-independent XML output.
+// Although this function is not platform dependent, we put it next to
+// FormatFileLocation in order to contrast the two functions.
+GTEST_API_ ::std::string FormatCompilerIndependentFileLocation(const char* file,
+                                                               int line);
+
+// Defines logging utilities:
+//   GTEST_LOG_(severity) - logs messages at the specified severity level. The
+//                          message itself is streamed into the macro.
+//   LogToStderr()  - directs all log messages to stderr.
+//   FlushInfoLog() - flushes informational log messages.
+
+enum GTestLogSeverity {
+  GTEST_INFO,
+  GTEST_WARNING,
+  GTEST_ERROR,
+  GTEST_FATAL
+};
+
+// Formats log entry severity, provides a stream object for streaming the
+// log message, and terminates the message with a newline when going out of
+// scope.
+class GTEST_API_ GTestLog {
+ public:
+  GTestLog(GTestLogSeverity severity, const char* file, int line);
+
+  // Flushes the buffers and, if severity is GTEST_FATAL, aborts the program.
+  ~GTestLog();
+
+  ::std::ostream& GetStream() { return ::std::cerr; }
+
+ private:
+  const GTestLogSeverity severity_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(GTestLog);
+};
+
+#if !defined(GTEST_LOG_)
+
+# define GTEST_LOG_(severity) \
+    ::testing::internal::GTestLog(::testing::internal::GTEST_##severity, \
+                                  __FILE__, __LINE__).GetStream()
+
+inline void LogToStderr() {}
+inline void FlushInfoLog() { fflush(nullptr); }
+
+#endif  // !defined(GTEST_LOG_)
+
+#if !defined(GTEST_CHECK_)
+// INTERNAL IMPLEMENTATION - DO NOT USE.
+//
+// GTEST_CHECK_ is an all-mode assert. It aborts the program if the condition
+// is not satisfied.
+//  Synopsys:
+//    GTEST_CHECK_(boolean_condition);
+//     or
+//    GTEST_CHECK_(boolean_condition) << "Additional message";
+//
+//    This checks the condition and if the condition is not satisfied
+//    it prints message about the condition violation, including the
+//    condition itself, plus additional message streamed into it, if any,
+//    and then it aborts the program. It aborts the program irrespective of
+//    whether it is built in the debug mode or not.
+# define GTEST_CHECK_(condition) \
+    GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
+    if (::testing::internal::IsTrue(condition)) \
+      ; \
+    else \
+      GTEST_LOG_(FATAL) << "Condition " #condition " failed. "
+#endif  // !defined(GTEST_CHECK_)
+
+// An all-mode assert to verify that the given POSIX-style function
+// call returns 0 (indicating success).  Known limitation: this
+// doesn't expand to a balanced 'if' statement, so enclose the macro
+// in {} if you need to use it as the only statement in an 'if'
+// branch.
+#define GTEST_CHECK_POSIX_SUCCESS_(posix_call) \
+  if (const int gtest_error = (posix_call)) \
+    GTEST_LOG_(FATAL) << #posix_call << "failed with error " \
+                      << gtest_error
+
+// Transforms "T" into "const T&" according to standard reference collapsing
+// rules (this is only needed as a backport for C++98 compilers that do not
+// support reference collapsing). Specifically, it transforms:
+//
+//   char         ==> const char&
+//   const char   ==> const char&
+//   char&        ==> char&
+//   const char&  ==> const char&
+//
+// Note that the non-const reference will not have "const" added. This is
+// standard, and necessary so that "T" can always bind to "const T&".
+template <typename T>
+struct ConstRef { typedef const T& type; };
+template <typename T>
+struct ConstRef<T&> { typedef T& type; };
+
+// The argument T must depend on some template parameters.
+#define GTEST_REFERENCE_TO_CONST_(T) \
+  typename ::testing::internal::ConstRef<T>::type
+
+// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
+//
+// Use ImplicitCast_ as a safe version of static_cast for upcasting in
+// the type hierarchy (e.g. casting a Foo* to a SuperclassOfFoo* or a
+// const Foo*).  When you use ImplicitCast_, the compiler checks that
+// the cast is safe.  Such explicit ImplicitCast_s are necessary in
+// surprisingly many situations where C++ demands an exact type match
+// instead of an argument type convertable to a target type.
+//
+// The syntax for using ImplicitCast_ is the same as for static_cast:
+//
+//   ImplicitCast_<ToType>(expr)
+//
+// ImplicitCast_ would have been part of the C++ standard library,
+// but the proposal was submitted too late.  It will probably make
+// its way into the language in the future.
+//
+// This relatively ugly name is intentional. It prevents clashes with
+// similar functions users may have (e.g., implicit_cast). The internal
+// namespace alone is not enough because the function can be found by ADL.
+template<typename To>
+inline To ImplicitCast_(To x) { return x; }
+
+// When you upcast (that is, cast a pointer from type Foo to type
+// SuperclassOfFoo), it's fine to use ImplicitCast_<>, since upcasts
+// always succeed.  When you downcast (that is, cast a pointer from
+// type Foo to type SubclassOfFoo), static_cast<> isn't safe, because
+// how do you know the pointer is really of type SubclassOfFoo?  It
+// could be a bare Foo, or of type DifferentSubclassOfFoo.  Thus,
+// when you downcast, you should use this macro.  In debug mode, we
+// use dynamic_cast<> to double-check the downcast is legal (we die
+// if it's not).  In normal mode, we do the efficient static_cast<>
+// instead.  Thus, it's important to test in debug mode to make sure
+// the cast is legal!
+//    This is the only place in the code we should use dynamic_cast<>.
+// In particular, you SHOULDN'T be using dynamic_cast<> in order to
+// do RTTI (eg code like this:
+//    if (dynamic_cast<Subclass1>(foo)) HandleASubclass1Object(foo);
+//    if (dynamic_cast<Subclass2>(foo)) HandleASubclass2Object(foo);
+// You should design the code some other way not to need this.
+//
+// This relatively ugly name is intentional. It prevents clashes with
+// similar functions users may have (e.g., down_cast). The internal
+// namespace alone is not enough because the function can be found by ADL.
+template<typename To, typename From>  // use like this: DownCast_<T*>(foo);
+inline To DownCast_(From* f) {  // so we only accept pointers
+  // Ensures that To is a sub-type of From *.  This test is here only
+  // for compile-time type checking, and has no overhead in an
+  // optimized build at run-time, as it will be optimized away
+  // completely.
+  GTEST_INTENTIONAL_CONST_COND_PUSH_()
+  if (false) {
+  GTEST_INTENTIONAL_CONST_COND_POP_()
+  const To to = nullptr;
+  ::testing::internal::ImplicitCast_<From*>(to);
+  }
+
+#if GTEST_HAS_RTTI
+  // RTTI: debug mode only!
+  GTEST_CHECK_(f == nullptr || dynamic_cast<To>(f) != nullptr);
+#endif
+  return static_cast<To>(f);
+}
+
+// Downcasts the pointer of type Base to Derived.
+// Derived must be a subclass of Base. The parameter MUST
+// point to a class of type Derived, not any subclass of it.
+// When RTTI is available, the function performs a runtime
+// check to enforce this.
+template <class Derived, class Base>
+Derived* CheckedDowncastToActualType(Base* base) {
+#if GTEST_HAS_RTTI
+  GTEST_CHECK_(typeid(*base) == typeid(Derived));
+#endif
+
+#if GTEST_HAS_DOWNCAST_
+  return ::down_cast<Derived*>(base);
+#elif GTEST_HAS_RTTI
+  return dynamic_cast<Derived*>(base);  // NOLINT
+#else
+  return static_cast<Derived*>(base);  // Poor man's downcast.
+#endif
+}
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Defines the stderr capturer:
+//   CaptureStdout     - starts capturing stdout.
+//   GetCapturedStdout - stops capturing stdout and returns the captured string.
+//   CaptureStderr     - starts capturing stderr.
+//   GetCapturedStderr - stops capturing stderr and returns the captured string.
+//
+GTEST_API_ void CaptureStdout();
+GTEST_API_ std::string GetCapturedStdout();
+GTEST_API_ void CaptureStderr();
+GTEST_API_ std::string GetCapturedStderr();
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+// Returns the size (in bytes) of a file.
+GTEST_API_ size_t GetFileSize(FILE* file);
+
+// Reads the entire content of a file as a string.
+GTEST_API_ std::string ReadEntireFile(FILE* file);
+
+// All command line arguments.
+GTEST_API_ std::vector<std::string> GetArgvs();
+
+#if GTEST_HAS_DEATH_TEST
+
+std::vector<std::string> GetInjectableArgvs();
+// Deprecated: pass the args vector by value instead.
+void SetInjectableArgvs(const std::vector<std::string>* new_argvs);
+void SetInjectableArgvs(const std::vector<std::string>& new_argvs);
+void ClearInjectableArgvs();
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+// Defines synchronization primitives.
+#if GTEST_IS_THREADSAFE
+# if GTEST_HAS_PTHREAD
+// Sleeps for (roughly) n milliseconds.  This function is only for testing
+// Google Test's own constructs.  Don't use it in user tests, either
+// directly or indirectly.
+inline void SleepMilliseconds(int n) {
+  const timespec time = {
+    0,                  // 0 seconds.
+    n * 1000L * 1000L,  // And n ms.
+  };
+  nanosleep(&time, nullptr);
+}
+# endif  // GTEST_HAS_PTHREAD
+
+# if GTEST_HAS_NOTIFICATION_
+// Notification has already been imported into the namespace.
+// Nothing to do here.
+
+# elif GTEST_HAS_PTHREAD
+// Allows a controller thread to pause execution of newly created
+// threads until notified.  Instances of this class must be created
+// and destroyed in the controller thread.
+//
+// This class is only for testing Google Test's own constructs. Do not
+// use it in user tests, either directly or indirectly.
+class Notification {
+ public:
+  Notification() : notified_(false) {
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_init(&mutex_, nullptr));
+  }
+  ~Notification() {
+    pthread_mutex_destroy(&mutex_);
+  }
+
+  // Notifies all threads created with this notification to start. Must
+  // be called from the controller thread.
+  void Notify() {
+    pthread_mutex_lock(&mutex_);
+    notified_ = true;
+    pthread_mutex_unlock(&mutex_);
+  }
+
+  // Blocks until the controller thread notifies. Must be called from a test
+  // thread.
+  void WaitForNotification() {
+    for (;;) {
+      pthread_mutex_lock(&mutex_);
+      const bool notified = notified_;
+      pthread_mutex_unlock(&mutex_);
+      if (notified)
+        break;
+      SleepMilliseconds(10);
+    }
+  }
+
+ private:
+  pthread_mutex_t mutex_;
+  bool notified_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(Notification);
+};
+
+# elif GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
+
+GTEST_API_ void SleepMilliseconds(int n);
+
+// Provides leak-safe Windows kernel handle ownership.
+// Used in death tests and in threading support.
+class GTEST_API_ AutoHandle {
+ public:
+  // Assume that Win32 HANDLE type is equivalent to void*. Doing so allows us to
+  // avoid including <windows.h> in this header file. Including <windows.h> is
+  // undesirable because it defines a lot of symbols and macros that tend to
+  // conflict with client code. This assumption is verified by
+  // WindowsTypesTest.HANDLEIsVoidStar.
+  typedef void* Handle;
+  AutoHandle();
+  explicit AutoHandle(Handle handle);
+
+  ~AutoHandle();
+
+  Handle Get() const;
+  void Reset();
+  void Reset(Handle handle);
+
+ private:
+  // Returns true if and only if the handle is a valid handle object that can be
+  // closed.
+  bool IsCloseable() const;
+
+  Handle handle_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(AutoHandle);
+};
+
+// Allows a controller thread to pause execution of newly created
+// threads until notified.  Instances of this class must be created
+// and destroyed in the controller thread.
+//
+// This class is only for testing Google Test's own constructs. Do not
+// use it in user tests, either directly or indirectly.
+class GTEST_API_ Notification {
+ public:
+  Notification();
+  void Notify();
+  void WaitForNotification();
+
+ private:
+  AutoHandle event_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(Notification);
+};
+# endif  // GTEST_HAS_NOTIFICATION_
+
+// On MinGW, we can have both GTEST_OS_WINDOWS and GTEST_HAS_PTHREAD
+// defined, but we don't want to use MinGW's pthreads implementation, which
+// has conformance problems with some versions of the POSIX standard.
+# if GTEST_HAS_PTHREAD && !GTEST_OS_WINDOWS_MINGW
+
+// As a C-function, ThreadFuncWithCLinkage cannot be templated itself.
+// Consequently, it cannot select a correct instantiation of ThreadWithParam
+// in order to call its Run(). Introducing ThreadWithParamBase as a
+// non-templated base class for ThreadWithParam allows us to bypass this
+// problem.
+class ThreadWithParamBase {
+ public:
+  virtual ~ThreadWithParamBase() {}
+  virtual void Run() = 0;
+};
+
+// pthread_create() accepts a pointer to a function type with the C linkage.
+// According to the Standard (7.5/1), function types with different linkages
+// are different even if they are otherwise identical.  Some compilers (for
+// example, SunStudio) treat them as different types.  Since class methods
+// cannot be defined with C-linkage we need to define a free C-function to
+// pass into pthread_create().
+extern "C" inline void* ThreadFuncWithCLinkage(void* thread) {
+  static_cast<ThreadWithParamBase*>(thread)->Run();
+  return nullptr;
+}
+
+// Helper class for testing Google Test's multi-threading constructs.
+// To use it, write:
+//
+//   void ThreadFunc(int param) { /* Do things with param */ }
+//   Notification thread_can_start;
+//   ...
+//   // The thread_can_start parameter is optional; you can supply NULL.
+//   ThreadWithParam<int> thread(&ThreadFunc, 5, &thread_can_start);
+//   thread_can_start.Notify();
+//
+// These classes are only for testing Google Test's own constructs. Do
+// not use them in user tests, either directly or indirectly.
+template <typename T>
+class ThreadWithParam : public ThreadWithParamBase {
+ public:
+  typedef void UserThreadFunc(T);
+
+  ThreadWithParam(UserThreadFunc* func, T param, Notification* thread_can_start)
+      : func_(func),
+        param_(param),
+        thread_can_start_(thread_can_start),
+        finished_(false) {
+    ThreadWithParamBase* const base = this;
+    // The thread can be created only after all fields except thread_
+    // have been initialized.
+    GTEST_CHECK_POSIX_SUCCESS_(
+        pthread_create(&thread_, nullptr, &ThreadFuncWithCLinkage, base));
+  }
+  ~ThreadWithParam() override { Join(); }
+
+  void Join() {
+    if (!finished_) {
+      GTEST_CHECK_POSIX_SUCCESS_(pthread_join(thread_, nullptr));
+      finished_ = true;
+    }
+  }
+
+  void Run() override {
+    if (thread_can_start_ != nullptr) thread_can_start_->WaitForNotification();
+    func_(param_);
+  }
+
+ private:
+  UserThreadFunc* const func_;  // User-supplied thread function.
+  const T param_;  // User-supplied parameter to the thread function.
+  // When non-NULL, used to block execution until the controller thread
+  // notifies.
+  Notification* const thread_can_start_;
+  bool finished_;  // true if and only if we know that the thread function has
+                   // finished.
+  pthread_t thread_;  // The native thread object.
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParam);
+};
+# endif  // !GTEST_OS_WINDOWS && GTEST_HAS_PTHREAD ||
+         // GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
+
+# if GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
+// Mutex and ThreadLocal have already been imported into the namespace.
+// Nothing to do here.
+
+# elif GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
+
+// Mutex implements mutex on Windows platforms.  It is used in conjunction
+// with class MutexLock:
+//
+//   Mutex mutex;
+//   ...
+//   MutexLock lock(&mutex);  // Acquires the mutex and releases it at the
+//                            // end of the current scope.
+//
+// A static Mutex *must* be defined or declared using one of the following
+// macros:
+//   GTEST_DEFINE_STATIC_MUTEX_(g_some_mutex);
+//   GTEST_DECLARE_STATIC_MUTEX_(g_some_mutex);
+//
+// (A non-static Mutex is defined/declared in the usual way).
+class GTEST_API_ Mutex {
+ public:
+  enum MutexType { kStatic = 0, kDynamic = 1 };
+  // We rely on kStaticMutex being 0 as it is to what the linker initializes
+  // type_ in static mutexes.  critical_section_ will be initialized lazily
+  // in ThreadSafeLazyInit().
+  enum StaticConstructorSelector { kStaticMutex = 0 };
+
+  // This constructor intentionally does nothing.  It relies on type_ being
+  // statically initialized to 0 (effectively setting it to kStatic) and on
+  // ThreadSafeLazyInit() to lazily initialize the rest of the members.
+  explicit Mutex(StaticConstructorSelector /*dummy*/) {}
+
+  Mutex();
+  ~Mutex();
+
+  void Lock();
+
+  void Unlock();
+
+  // Does nothing if the current thread holds the mutex. Otherwise, crashes
+  // with high probability.
+  void AssertHeld();
+
+ private:
+  // Initializes owner_thread_id_ and critical_section_ in static mutexes.
+  void ThreadSafeLazyInit();
+
+  // Per https://blogs.msdn.microsoft.com/oldnewthing/20040223-00/?p=40503,
+  // we assume that 0 is an invalid value for thread IDs.
+  unsigned int owner_thread_id_;
+
+  // For static mutexes, we rely on these members being initialized to zeros
+  // by the linker.
+  MutexType type_;
+  long critical_section_init_phase_;  // NOLINT
+  GTEST_CRITICAL_SECTION* critical_section_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(Mutex);
+};
+
+# define GTEST_DECLARE_STATIC_MUTEX_(mutex) \
+    extern ::testing::internal::Mutex mutex
+
+# define GTEST_DEFINE_STATIC_MUTEX_(mutex) \
+    ::testing::internal::Mutex mutex(::testing::internal::Mutex::kStaticMutex)
+
+// We cannot name this class MutexLock because the ctor declaration would
+// conflict with a macro named MutexLock, which is defined on some
+// platforms. That macro is used as a defensive measure to prevent against
+// inadvertent misuses of MutexLock like "MutexLock(&mu)" rather than
+// "MutexLock l(&mu)".  Hence the typedef trick below.
+class GTestMutexLock {
+ public:
+  explicit GTestMutexLock(Mutex* mutex)
+      : mutex_(mutex) { mutex_->Lock(); }
+
+  ~GTestMutexLock() { mutex_->Unlock(); }
+
+ private:
+  Mutex* const mutex_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(GTestMutexLock);
+};
+
+typedef GTestMutexLock MutexLock;
+
+// Base class for ValueHolder<T>.  Allows a caller to hold and delete a value
+// without knowing its type.
+class ThreadLocalValueHolderBase {
+ public:
+  virtual ~ThreadLocalValueHolderBase() {}
+};
+
+// Provides a way for a thread to send notifications to a ThreadLocal
+// regardless of its parameter type.
+class ThreadLocalBase {
+ public:
+  // Creates a new ValueHolder<T> object holding a default value passed to
+  // this ThreadLocal<T>'s constructor and returns it.  It is the caller's
+  // responsibility not to call this when the ThreadLocal<T> instance already
+  // has a value on the current thread.
+  virtual ThreadLocalValueHolderBase* NewValueForCurrentThread() const = 0;
+
+ protected:
+  ThreadLocalBase() {}
+  virtual ~ThreadLocalBase() {}
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadLocalBase);
+};
+
+// Maps a thread to a set of ThreadLocals that have values instantiated on that
+// thread and notifies them when the thread exits.  A ThreadLocal instance is
+// expected to persist until all threads it has values on have terminated.
+class GTEST_API_ ThreadLocalRegistry {
+ public:
+  // Registers thread_local_instance as having value on the current thread.
+  // Returns a value that can be used to identify the thread from other threads.
+  static ThreadLocalValueHolderBase* GetValueOnCurrentThread(
+      const ThreadLocalBase* thread_local_instance);
+
+  // Invoked when a ThreadLocal instance is destroyed.
+  static void OnThreadLocalDestroyed(
+      const ThreadLocalBase* thread_local_instance);
+};
+
+class GTEST_API_ ThreadWithParamBase {
+ public:
+  void Join();
+
+ protected:
+  class Runnable {
+   public:
+    virtual ~Runnable() {}
+    virtual void Run() = 0;
+  };
+
+  ThreadWithParamBase(Runnable *runnable, Notification* thread_can_start);
+  virtual ~ThreadWithParamBase();
+
+ private:
+  AutoHandle thread_;
+};
+
+// Helper class for testing Google Test's multi-threading constructs.
+template <typename T>
+class ThreadWithParam : public ThreadWithParamBase {
+ public:
+  typedef void UserThreadFunc(T);
+
+  ThreadWithParam(UserThreadFunc* func, T param, Notification* thread_can_start)
+      : ThreadWithParamBase(new RunnableImpl(func, param), thread_can_start) {
+  }
+  virtual ~ThreadWithParam() {}
+
+ private:
+  class RunnableImpl : public Runnable {
+   public:
+    RunnableImpl(UserThreadFunc* func, T param)
+        : func_(func),
+          param_(param) {
+    }
+    virtual ~RunnableImpl() {}
+    virtual void Run() {
+      func_(param_);
+    }
+
+   private:
+    UserThreadFunc* const func_;
+    const T param_;
+
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(RunnableImpl);
+  };
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParam);
+};
+
+// Implements thread-local storage on Windows systems.
+//
+//   // Thread 1
+//   ThreadLocal<int> tl(100);  // 100 is the default value for each thread.
+//
+//   // Thread 2
+//   tl.set(150);  // Changes the value for thread 2 only.
+//   EXPECT_EQ(150, tl.get());
+//
+//   // Thread 1
+//   EXPECT_EQ(100, tl.get());  // In thread 1, tl has the original value.
+//   tl.set(200);
+//   EXPECT_EQ(200, tl.get());
+//
+// The template type argument T must have a public copy constructor.
+// In addition, the default ThreadLocal constructor requires T to have
+// a public default constructor.
+//
+// The users of a TheadLocal instance have to make sure that all but one
+// threads (including the main one) using that instance have exited before
+// destroying it. Otherwise, the per-thread objects managed for them by the
+// ThreadLocal instance are not guaranteed to be destroyed on all platforms.
+//
+// Google Test only uses global ThreadLocal objects.  That means they
+// will die after main() has returned.  Therefore, no per-thread
+// object managed by Google Test will be leaked as long as all threads
+// using Google Test have exited when main() returns.
+template <typename T>
+class ThreadLocal : public ThreadLocalBase {
+ public:
+  ThreadLocal() : default_factory_(new DefaultValueHolderFactory()) {}
+  explicit ThreadLocal(const T& value)
+      : default_factory_(new InstanceValueHolderFactory(value)) {}
+
+  ~ThreadLocal() { ThreadLocalRegistry::OnThreadLocalDestroyed(this); }
+
+  T* pointer() { return GetOrCreateValue(); }
+  const T* pointer() const { return GetOrCreateValue(); }
+  const T& get() const { return *pointer(); }
+  void set(const T& value) { *pointer() = value; }
+
+ private:
+  // Holds a value of T.  Can be deleted via its base class without the caller
+  // knowing the type of T.
+  class ValueHolder : public ThreadLocalValueHolderBase {
+   public:
+    ValueHolder() : value_() {}
+    explicit ValueHolder(const T& value) : value_(value) {}
+
+    T* pointer() { return &value_; }
+
+   private:
+    T value_;
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(ValueHolder);
+  };
+
+
+  T* GetOrCreateValue() const {
+    return static_cast<ValueHolder*>(
+        ThreadLocalRegistry::GetValueOnCurrentThread(this))->pointer();
+  }
+
+  virtual ThreadLocalValueHolderBase* NewValueForCurrentThread() const {
+    return default_factory_->MakeNewHolder();
+  }
+
+  class ValueHolderFactory {
+   public:
+    ValueHolderFactory() {}
+    virtual ~ValueHolderFactory() {}
+    virtual ValueHolder* MakeNewHolder() const = 0;
+
+   private:
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(ValueHolderFactory);
+  };
+
+  class DefaultValueHolderFactory : public ValueHolderFactory {
+   public:
+    DefaultValueHolderFactory() {}
+    virtual ValueHolder* MakeNewHolder() const { return new ValueHolder(); }
+
+   private:
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultValueHolderFactory);
+  };
+
+  class InstanceValueHolderFactory : public ValueHolderFactory {
+   public:
+    explicit InstanceValueHolderFactory(const T& value) : value_(value) {}
+    virtual ValueHolder* MakeNewHolder() const {
+      return new ValueHolder(value_);
+    }
+
+   private:
+    const T value_;  // The value for each thread.
+
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(InstanceValueHolderFactory);
+  };
+
+  std::unique_ptr<ValueHolderFactory> default_factory_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadLocal);
+};
+
+# elif GTEST_HAS_PTHREAD
+
+// MutexBase and Mutex implement mutex on pthreads-based platforms.
+class MutexBase {
+ public:
+  // Acquires this mutex.
+  void Lock() {
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_lock(&mutex_));
+    owner_ = pthread_self();
+    has_owner_ = true;
+  }
+
+  // Releases this mutex.
+  void Unlock() {
+    // Since the lock is being released the owner_ field should no longer be
+    // considered valid. We don't protect writing to has_owner_ here, as it's
+    // the caller's responsibility to ensure that the current thread holds the
+    // mutex when this is called.
+    has_owner_ = false;
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_unlock(&mutex_));
+  }
+
+  // Does nothing if the current thread holds the mutex. Otherwise, crashes
+  // with high probability.
+  void AssertHeld() const {
+    GTEST_CHECK_(has_owner_ && pthread_equal(owner_, pthread_self()))
+        << "The current thread is not holding the mutex @" << this;
+  }
+
+  // A static mutex may be used before main() is entered.  It may even
+  // be used before the dynamic initialization stage.  Therefore we
+  // must be able to initialize a static mutex object at link time.
+  // This means MutexBase has to be a POD and its member variables
+  // have to be public.
+ public:
+  pthread_mutex_t mutex_;  // The underlying pthread mutex.
+  // has_owner_ indicates whether the owner_ field below contains a valid thread
+  // ID and is therefore safe to inspect (e.g., to use in pthread_equal()). All
+  // accesses to the owner_ field should be protected by a check of this field.
+  // An alternative might be to memset() owner_ to all zeros, but there's no
+  // guarantee that a zero'd pthread_t is necessarily invalid or even different
+  // from pthread_self().
+  bool has_owner_;
+  pthread_t owner_;  // The thread holding the mutex.
+};
+
+// Forward-declares a static mutex.
+#  define GTEST_DECLARE_STATIC_MUTEX_(mutex) \
+     extern ::testing::internal::MutexBase mutex
+
+// Defines and statically (i.e. at link time) initializes a static mutex.
+// The initialization list here does not explicitly initialize each field,
+// instead relying on default initialization for the unspecified fields. In
+// particular, the owner_ field (a pthread_t) is not explicitly initialized.
+// This allows initialization to work whether pthread_t is a scalar or struct.
+// The flag -Wmissing-field-initializers must not be specified for this to work.
+#define GTEST_DEFINE_STATIC_MUTEX_(mutex) \
+  ::testing::internal::MutexBase mutex = {PTHREAD_MUTEX_INITIALIZER, false, 0}
+
+// The Mutex class can only be used for mutexes created at runtime. It
+// shares its API with MutexBase otherwise.
+class Mutex : public MutexBase {
+ public:
+  Mutex() {
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_init(&mutex_, nullptr));
+    has_owner_ = false;
+  }
+  ~Mutex() {
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_destroy(&mutex_));
+  }
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(Mutex);
+};
+
+// We cannot name this class MutexLock because the ctor declaration would
+// conflict with a macro named MutexLock, which is defined on some
+// platforms. That macro is used as a defensive measure to prevent against
+// inadvertent misuses of MutexLock like "MutexLock(&mu)" rather than
+// "MutexLock l(&mu)".  Hence the typedef trick below.
+class GTestMutexLock {
+ public:
+  explicit GTestMutexLock(MutexBase* mutex)
+      : mutex_(mutex) { mutex_->Lock(); }
+
+  ~GTestMutexLock() { mutex_->Unlock(); }
+
+ private:
+  MutexBase* const mutex_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(GTestMutexLock);
+};
+
+typedef GTestMutexLock MutexLock;
+
+// Helpers for ThreadLocal.
+
+// pthread_key_create() requires DeleteThreadLocalValue() to have
+// C-linkage.  Therefore it cannot be templatized to access
+// ThreadLocal<T>.  Hence the need for class
+// ThreadLocalValueHolderBase.
+class ThreadLocalValueHolderBase {
+ public:
+  virtual ~ThreadLocalValueHolderBase() {}
+};
+
+// Called by pthread to delete thread-local data stored by
+// pthread_setspecific().
+extern "C" inline void DeleteThreadLocalValue(void* value_holder) {
+  delete static_cast<ThreadLocalValueHolderBase*>(value_holder);
+}
+
+// Implements thread-local storage on pthreads-based systems.
+template <typename T>
+class GTEST_API_ ThreadLocal {
+ public:
+  ThreadLocal()
+      : key_(CreateKey()), default_factory_(new DefaultValueHolderFactory()) {}
+  explicit ThreadLocal(const T& value)
+      : key_(CreateKey()),
+        default_factory_(new InstanceValueHolderFactory(value)) {}
+
+  ~ThreadLocal() {
+    // Destroys the managed object for the current thread, if any.
+    DeleteThreadLocalValue(pthread_getspecific(key_));
+
+    // Releases resources associated with the key.  This will *not*
+    // delete managed objects for other threads.
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_key_delete(key_));
+  }
+
+  T* pointer() { return GetOrCreateValue(); }
+  const T* pointer() const { return GetOrCreateValue(); }
+  const T& get() const { return *pointer(); }
+  void set(const T& value) { *pointer() = value; }
+
+ private:
+  // Holds a value of type T.
+  class ValueHolder : public ThreadLocalValueHolderBase {
+   public:
+    ValueHolder() : value_() {}
+    explicit ValueHolder(const T& value) : value_(value) {}
+
+    T* pointer() { return &value_; }
+
+   private:
+    T value_;
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(ValueHolder);
+  };
+
+  static pthread_key_t CreateKey() {
+    pthread_key_t key;
+    // When a thread exits, DeleteThreadLocalValue() will be called on
+    // the object managed for that thread.
+    GTEST_CHECK_POSIX_SUCCESS_(
+        pthread_key_create(&key, &DeleteThreadLocalValue));
+    return key;
+  }
+
+  T* GetOrCreateValue() const {
+    ThreadLocalValueHolderBase* const holder =
+        static_cast<ThreadLocalValueHolderBase*>(pthread_getspecific(key_));
+    if (holder != nullptr) {
+      return CheckedDowncastToActualType<ValueHolder>(holder)->pointer();
+    }
+
+    ValueHolder* const new_holder = default_factory_->MakeNewHolder();
+    ThreadLocalValueHolderBase* const holder_base = new_holder;
+    GTEST_CHECK_POSIX_SUCCESS_(pthread_setspecific(key_, holder_base));
+    return new_holder->pointer();
+  }
+
+  class ValueHolderFactory {
+   public:
+    ValueHolderFactory() {}
+    virtual ~ValueHolderFactory() {}
+    virtual ValueHolder* MakeNewHolder() const = 0;
+
+   private:
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(ValueHolderFactory);
+  };
+
+  class DefaultValueHolderFactory : public ValueHolderFactory {
+   public:
+    DefaultValueHolderFactory() {}
+    virtual ValueHolder* MakeNewHolder() const { return new ValueHolder(); }
+
+   private:
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultValueHolderFactory);
+  };
+
+  class InstanceValueHolderFactory : public ValueHolderFactory {
+   public:
+    explicit InstanceValueHolderFactory(const T& value) : value_(value) {}
+    virtual ValueHolder* MakeNewHolder() const {
+      return new ValueHolder(value_);
+    }
+
+   private:
+    const T value_;  // The value for each thread.
+
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(InstanceValueHolderFactory);
+  };
+
+  // A key pthreads uses for looking up per-thread values.
+  const pthread_key_t key_;
+  std::unique_ptr<ValueHolderFactory> default_factory_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadLocal);
+};
+
+# endif  // GTEST_HAS_MUTEX_AND_THREAD_LOCAL_
+
+#else  // GTEST_IS_THREADSAFE
+
+// A dummy implementation of synchronization primitives (mutex, lock,
+// and thread-local variable).  Necessary for compiling Google Test where
+// mutex is not supported - using Google Test in multiple threads is not
+// supported on such platforms.
+
+class Mutex {
+ public:
+  Mutex() {}
+  void Lock() {}
+  void Unlock() {}
+  void AssertHeld() const {}
+};
+
+# define GTEST_DECLARE_STATIC_MUTEX_(mutex) \
+  extern ::testing::internal::Mutex mutex
+
+# define GTEST_DEFINE_STATIC_MUTEX_(mutex) ::testing::internal::Mutex mutex
+
+// We cannot name this class MutexLock because the ctor declaration would
+// conflict with a macro named MutexLock, which is defined on some
+// platforms. That macro is used as a defensive measure to prevent against
+// inadvertent misuses of MutexLock like "MutexLock(&mu)" rather than
+// "MutexLock l(&mu)".  Hence the typedef trick below.
+class GTestMutexLock {
+ public:
+  explicit GTestMutexLock(Mutex*) {}  // NOLINT
+};
+
+typedef GTestMutexLock MutexLock;
+
+template <typename T>
+class GTEST_API_ ThreadLocal {
+ public:
+  ThreadLocal() : value_() {}
+  explicit ThreadLocal(const T& value) : value_(value) {}
+  T* pointer() { return &value_; }
+  const T* pointer() const { return &value_; }
+  const T& get() const { return value_; }
+  void set(const T& value) { value_ = value; }
+ private:
+  T value_;
+};
+
+#endif  // GTEST_IS_THREADSAFE
+
+// Returns the number of threads running in the process, or 0 to indicate that
+// we cannot detect it.
+GTEST_API_ size_t GetThreadCount();
+
+template <bool B>
+using bool_constant = std::integral_constant<bool, B>;
+
+#if GTEST_OS_WINDOWS
+# define GTEST_PATH_SEP_ "\\"
+# define GTEST_HAS_ALT_PATH_SEP_ 1
+// The biggest signed integer type the compiler supports.
+typedef __int64 BiggestInt;
+#else
+# define GTEST_PATH_SEP_ "/"
+# define GTEST_HAS_ALT_PATH_SEP_ 0
+typedef long long BiggestInt;  // NOLINT
+#endif  // GTEST_OS_WINDOWS
+
+// Utilities for char.
+
+// isspace(int ch) and friends accept an unsigned char or EOF.  char
+// may be signed, depending on the compiler (or compiler flags).
+// Therefore we need to cast a char to unsigned char before calling
+// isspace(), etc.
+
+inline bool IsAlpha(char ch) {
+  return isalpha(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsAlNum(char ch) {
+  return isalnum(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsDigit(char ch) {
+  return isdigit(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsLower(char ch) {
+  return islower(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsSpace(char ch) {
+  return isspace(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsUpper(char ch) {
+  return isupper(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsXDigit(char ch) {
+  return isxdigit(static_cast<unsigned char>(ch)) != 0;
+}
+inline bool IsXDigit(wchar_t ch) {
+  const unsigned char low_byte = static_cast<unsigned char>(ch);
+  return ch == low_byte && isxdigit(low_byte) != 0;
+}
+
+inline char ToLower(char ch) {
+  return static_cast<char>(tolower(static_cast<unsigned char>(ch)));
+}
+inline char ToUpper(char ch) {
+  return static_cast<char>(toupper(static_cast<unsigned char>(ch)));
+}
+
+inline std::string StripTrailingSpaces(std::string str) {
+  std::string::iterator it = str.end();
+  while (it != str.begin() && IsSpace(*--it))
+    it = str.erase(it);
+  return str;
+}
+
+// The testing::internal::posix namespace holds wrappers for common
+// POSIX functions.  These wrappers hide the differences between
+// Windows/MSVC and POSIX systems.  Since some compilers define these
+// standard functions as macros, the wrapper cannot have the same name
+// as the wrapped function.
+
+namespace posix {
+
+// Functions with a different name on Windows.
+
+#if GTEST_OS_WINDOWS
+
+typedef struct _stat StatStruct;
+
+# ifdef __BORLANDC__
+inline int IsATTY(int fd) { return isatty(fd); }
+inline int StrCaseCmp(const char* s1, const char* s2) {
+  return stricmp(s1, s2);
+}
+inline char* StrDup(const char* src) { return strdup(src); }
+# else  // !__BORLANDC__
+#  if GTEST_OS_WINDOWS_MOBILE
+inline int IsATTY(int /* fd */) { return 0; }
+#  else
+inline int IsATTY(int fd) { return _isatty(fd); }
+#  endif  // GTEST_OS_WINDOWS_MOBILE
+inline int StrCaseCmp(const char* s1, const char* s2) {
+  return _stricmp(s1, s2);
+}
+inline char* StrDup(const char* src) { return _strdup(src); }
+# endif  // __BORLANDC__
+
+# if GTEST_OS_WINDOWS_MOBILE
+inline int FileNo(FILE* file) { return reinterpret_cast<int>(_fileno(file)); }
+// Stat(), RmDir(), and IsDir() are not needed on Windows CE at this
+// time and thus not defined there.
+# else
+inline int FileNo(FILE* file) { return _fileno(file); }
+inline int Stat(const char* path, StatStruct* buf) { return _stat(path, buf); }
+inline int RmDir(const char* dir) { return _rmdir(dir); }
+inline bool IsDir(const StatStruct& st) {
+  return (_S_IFDIR & st.st_mode) != 0;
+}
+# endif  // GTEST_OS_WINDOWS_MOBILE
+
+#else
+
+typedef struct stat StatStruct;
+
+inline int FileNo(FILE* file) { return fileno(file); }
+inline int IsATTY(int fd) { return isatty(fd); }
+inline int Stat(const char* path, StatStruct* buf) { return stat(path, buf); }
+inline int StrCaseCmp(const char* s1, const char* s2) {
+  return strcasecmp(s1, s2);
+}
+inline char* StrDup(const char* src) { return strdup(src); }
+inline int RmDir(const char* dir) { return rmdir(dir); }
+inline bool IsDir(const StatStruct& st) { return S_ISDIR(st.st_mode); }
+
+#endif  // GTEST_OS_WINDOWS
+
+// Functions deprecated by MSVC 8.0.
+
+GTEST_DISABLE_MSC_DEPRECATED_PUSH_()
+
+inline const char* StrNCpy(char* dest, const char* src, size_t n) {
+  return strncpy(dest, src, n);
+}
+
+// ChDir(), FReopen(), FDOpen(), Read(), Write(), Close(), and
+// StrError() aren't needed on Windows CE at this time and thus not
+// defined there.
+
+#if !GTEST_OS_WINDOWS_MOBILE && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
+inline int ChDir(const char* dir) { return chdir(dir); }
+#endif
+inline FILE* FOpen(const char* path, const char* mode) {
+  return fopen(path, mode);
+}
+#if !GTEST_OS_WINDOWS_MOBILE
+inline FILE *FReopen(const char* path, const char* mode, FILE* stream) {
+  return freopen(path, mode, stream);
+}
+inline FILE* FDOpen(int fd, const char* mode) { return fdopen(fd, mode); }
+#endif
+inline int FClose(FILE* fp) { return fclose(fp); }
+#if !GTEST_OS_WINDOWS_MOBILE
+inline int Read(int fd, void* buf, unsigned int count) {
+  return static_cast<int>(read(fd, buf, count));
+}
+inline int Write(int fd, const void* buf, unsigned int count) {
+  return static_cast<int>(write(fd, buf, count));
+}
+inline int Close(int fd) { return close(fd); }
+inline const char* StrError(int errnum) { return strerror(errnum); }
+#endif
+inline const char* GetEnv(const char* name) {
+#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_PHONE || GTEST_OS_WINDOWS_RT
+  // We are on Windows CE, which has no environment variables.
+  static_cast<void>(name);  // To prevent 'unused argument' warning.
+  return nullptr;
+#elif defined(__BORLANDC__) || defined(__SunOS_5_8) || defined(__SunOS_5_9)
+  // Environment variables which we programmatically clear will be set to the
+  // empty string rather than unset (NULL).  Handle that case.
+  const char* const env = getenv(name);
+  return (env != nullptr && env[0] != '\0') ? env : nullptr;
+#else
+  return getenv(name);
+#endif
+}
+
+GTEST_DISABLE_MSC_DEPRECATED_POP_()
+
+#if GTEST_OS_WINDOWS_MOBILE
+// Windows CE has no C library. The abort() function is used in
+// several places in Google Test. This implementation provides a reasonable
+// imitation of standard behaviour.
+[[noreturn]] void Abort();
+#else
+[[noreturn]] inline void Abort() { abort(); }
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+}  // namespace posix
+
+// MSVC "deprecates" snprintf and issues warnings wherever it is used.  In
+// order to avoid these warnings, we need to use _snprintf or _snprintf_s on
+// MSVC-based platforms.  We map the GTEST_SNPRINTF_ macro to the appropriate
+// function in order to achieve that.  We use macro definition here because
+// snprintf is a variadic function.
+#if _MSC_VER && !GTEST_OS_WINDOWS_MOBILE
+// MSVC 2005 and above support variadic macros.
+# define GTEST_SNPRINTF_(buffer, size, format, ...) \
+     _snprintf_s(buffer, size, size, format, __VA_ARGS__)
+#elif defined(_MSC_VER)
+// Windows CE does not define _snprintf_s
+# define GTEST_SNPRINTF_ _snprintf
+#else
+# define GTEST_SNPRINTF_ snprintf
+#endif
+
+// The maximum number a BiggestInt can represent.  This definition
+// works no matter BiggestInt is represented in one's complement or
+// two's complement.
+//
+// We cannot rely on numeric_limits in STL, as __int64 and long long
+// are not part of standard C++ and numeric_limits doesn't need to be
+// defined for them.
+const BiggestInt kMaxBiggestInt =
+    ~(static_cast<BiggestInt>(1) << (8*sizeof(BiggestInt) - 1));
+
+// This template class serves as a compile-time function from size to
+// type.  It maps a size in bytes to a primitive type with that
+// size. e.g.
+//
+//   TypeWithSize<4>::UInt
+//
+// is typedef-ed to be unsigned int (unsigned integer made up of 4
+// bytes).
+//
+// Such functionality should belong to STL, but I cannot find it
+// there.
+//
+// Google Test uses this class in the implementation of floating-point
+// comparison.
+//
+// For now it only handles UInt (unsigned int) as that's all Google Test
+// needs.  Other types can be easily added in the future if need
+// arises.
+template <size_t size>
+class TypeWithSize {
+ public:
+  // This prevents the user from using TypeWithSize<N> with incorrect
+  // values of N.
+  typedef void UInt;
+};
+
+// The specialization for size 4.
+template <>
+class TypeWithSize<4> {
+ public:
+  // unsigned int has size 4 in both gcc and MSVC.
+  //
+  // As base/basictypes.h doesn't compile on Windows, we cannot use
+  // uint32, uint64, and etc here.
+  typedef int Int;
+  typedef unsigned int UInt;
+};
+
+// The specialization for size 8.
+template <>
+class TypeWithSize<8> {
+ public:
+#if GTEST_OS_WINDOWS
+  typedef __int64 Int;
+  typedef unsigned __int64 UInt;
+#else
+  typedef long long Int;  // NOLINT
+  typedef unsigned long long UInt;  // NOLINT
+#endif  // GTEST_OS_WINDOWS
+};
+
+// Integer types of known sizes.
+typedef TypeWithSize<4>::Int Int32;
+typedef TypeWithSize<4>::UInt UInt32;
+typedef TypeWithSize<8>::Int Int64;
+typedef TypeWithSize<8>::UInt UInt64;
+typedef TypeWithSize<8>::Int TimeInMillis;  // Represents time in milliseconds.
+
+// Utilities for command line flags and environment variables.
+
+// Macro for referencing flags.
+#if !defined(GTEST_FLAG)
+# define GTEST_FLAG(name) FLAGS_gtest_##name
+#endif  // !defined(GTEST_FLAG)
+
+#if !defined(GTEST_USE_OWN_FLAGFILE_FLAG_)
+# define GTEST_USE_OWN_FLAGFILE_FLAG_ 1
+#endif  // !defined(GTEST_USE_OWN_FLAGFILE_FLAG_)
+
+#if !defined(GTEST_DECLARE_bool_)
+# define GTEST_FLAG_SAVER_ ::testing::internal::GTestFlagSaver
+
+// Macros for declaring flags.
+# define GTEST_DECLARE_bool_(name) GTEST_API_ extern bool GTEST_FLAG(name)
+# define GTEST_DECLARE_int32_(name) \
+    GTEST_API_ extern ::testing::internal::Int32 GTEST_FLAG(name)
+# define GTEST_DECLARE_string_(name) \
+    GTEST_API_ extern ::std::string GTEST_FLAG(name)
+
+// Macros for defining flags.
+# define GTEST_DEFINE_bool_(name, default_val, doc) \
+    GTEST_API_ bool GTEST_FLAG(name) = (default_val)
+# define GTEST_DEFINE_int32_(name, default_val, doc) \
+    GTEST_API_ ::testing::internal::Int32 GTEST_FLAG(name) = (default_val)
+# define GTEST_DEFINE_string_(name, default_val, doc) \
+    GTEST_API_ ::std::string GTEST_FLAG(name) = (default_val)
+
+#endif  // !defined(GTEST_DECLARE_bool_)
+
+// Thread annotations
+#if !defined(GTEST_EXCLUSIVE_LOCK_REQUIRED_)
+# define GTEST_EXCLUSIVE_LOCK_REQUIRED_(locks)
+# define GTEST_LOCK_EXCLUDED_(locks)
+#endif  // !defined(GTEST_EXCLUSIVE_LOCK_REQUIRED_)
+
+// Parses 'str' for a 32-bit signed integer.  If successful, writes the result
+// to *value and returns true; otherwise leaves *value unchanged and returns
+// false.
+bool ParseInt32(const Message& src_text, const char* str, Int32* value);
+
+// Parses a bool/Int32/string from the environment variable
+// corresponding to the given Google Test flag.
+bool BoolFromGTestEnv(const char* flag, bool default_val);
+GTEST_API_ Int32 Int32FromGTestEnv(const char* flag, Int32 default_val);
+std::string OutputFlagAlsoCheckEnvVar();
+const char* StringFromGTestEnv(const char* flag, const char* default_val);
+
+}  // namespace internal
+}  // namespace testing
+
+#if !defined(GTEST_INTERNAL_DEPRECATED)
+
+// Internal Macro to mark an API deprecated, for googletest usage only
+// Usage: class GTEST_INTERNAL_DEPRECATED(message) MyClass or
+// GTEST_INTERNAL_DEPRECATED(message) <return_type> myFunction(); Every usage of
+// a deprecated entity will trigger a warning when compiled with
+// `-Wdeprecated-declarations` option (clang, gcc, any __GNUC__ compiler).
+// For msvc /W3 option will need to be used
+// Note that for 'other' compilers this macro evaluates to nothing to prevent
+// compilations errors.
+#if defined(_MSC_VER)
+#define GTEST_INTERNAL_DEPRECATED(message) __declspec(deprecated(message))
+#elif defined(__GNUC__)
+#define GTEST_INTERNAL_DEPRECATED(message) __attribute__((deprecated(message)))
+#else
+#define GTEST_INTERNAL_DEPRECATED(message)
+#endif
+
+#endif  // !defined(GTEST_INTERNAL_DEPRECATED)
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
diff --git a/3rdparty/gtest/include/gtest/internal/gtest-string.h b/3rdparty/gtest/include/gtest/internal/gtest-string.h
new file mode 100644
index 0000000..82aaa63
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/gtest-string.h
@@ -0,0 +1,171 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file declares the String class and functions used internally by
+// Google Test.  They are subject to change without notice. They should not used
+// by code external to Google Test.
+//
+// This header file is #included by gtest-internal.h.
+// It should not be #included by other files.
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
+
+#ifdef __BORLANDC__
+// string.h is not guaranteed to provide strcpy on C++ Builder.
+# include <mem.h>
+#endif
+
+#include <string.h>
+#include <string>
+
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+namespace internal {
+
+// String - an abstract class holding static string utilities.
+class GTEST_API_ String {
+ public:
+  // Static utility methods
+
+  // Clones a 0-terminated C string, allocating memory using new.  The
+  // caller is responsible for deleting the return value using
+  // delete[].  Returns the cloned string, or NULL if the input is
+  // NULL.
+  //
+  // This is different from strdup() in string.h, which allocates
+  // memory using malloc().
+  static const char* CloneCString(const char* c_str);
+
+#if GTEST_OS_WINDOWS_MOBILE
+  // Windows CE does not have the 'ANSI' versions of Win32 APIs. To be
+  // able to pass strings to Win32 APIs on CE we need to convert them
+  // to 'Unicode', UTF-16.
+
+  // Creates a UTF-16 wide string from the given ANSI string, allocating
+  // memory using new. The caller is responsible for deleting the return
+  // value using delete[]. Returns the wide string, or NULL if the
+  // input is NULL.
+  //
+  // The wide string is created using the ANSI codepage (CP_ACP) to
+  // match the behaviour of the ANSI versions of Win32 calls and the
+  // C runtime.
+  static LPCWSTR AnsiToUtf16(const char* c_str);
+
+  // Creates an ANSI string from the given wide string, allocating
+  // memory using new. The caller is responsible for deleting the return
+  // value using delete[]. Returns the ANSI string, or NULL if the
+  // input is NULL.
+  //
+  // The returned string is created using the ANSI codepage (CP_ACP) to
+  // match the behaviour of the ANSI versions of Win32 calls and the
+  // C runtime.
+  static const char* Utf16ToAnsi(LPCWSTR utf16_str);
+#endif
+
+  // Compares two C strings.  Returns true if and only if they have the same
+  // content.
+  //
+  // Unlike strcmp(), this function can handle NULL argument(s).  A
+  // NULL C string is considered different to any non-NULL C string,
+  // including the empty string.
+  static bool CStringEquals(const char* lhs, const char* rhs);
+
+  // Converts a wide C string to a String using the UTF-8 encoding.
+  // NULL will be converted to "(null)".  If an error occurred during
+  // the conversion, "(failed to convert from wide string)" is
+  // returned.
+  static std::string ShowWideCString(const wchar_t* wide_c_str);
+
+  // Compares two wide C strings.  Returns true if and only if they have the
+  // same content.
+  //
+  // Unlike wcscmp(), this function can handle NULL argument(s).  A
+  // NULL C string is considered different to any non-NULL C string,
+  // including the empty string.
+  static bool WideCStringEquals(const wchar_t* lhs, const wchar_t* rhs);
+
+  // Compares two C strings, ignoring case.  Returns true if and only if
+  // they have the same content.
+  //
+  // Unlike strcasecmp(), this function can handle NULL argument(s).
+  // A NULL C string is considered different to any non-NULL C string,
+  // including the empty string.
+  static bool CaseInsensitiveCStringEquals(const char* lhs,
+                                           const char* rhs);
+
+  // Compares two wide C strings, ignoring case.  Returns true if and only if
+  // they have the same content.
+  //
+  // Unlike wcscasecmp(), this function can handle NULL argument(s).
+  // A NULL C string is considered different to any non-NULL wide C string,
+  // including the empty string.
+  // NB: The implementations on different platforms slightly differ.
+  // On windows, this method uses _wcsicmp which compares according to LC_CTYPE
+  // environment variable. On GNU platform this method uses wcscasecmp
+  // which compares according to LC_CTYPE category of the current locale.
+  // On MacOS X, it uses towlower, which also uses LC_CTYPE category of the
+  // current locale.
+  static bool CaseInsensitiveWideCStringEquals(const wchar_t* lhs,
+                                               const wchar_t* rhs);
+
+  // Returns true if and only if the given string ends with the given suffix,
+  // ignoring case. Any string is considered to end with an empty suffix.
+  static bool EndsWithCaseInsensitive(
+      const std::string& str, const std::string& suffix);
+
+  // Formats an int value as "%02d".
+  static std::string FormatIntWidth2(int value);  // "%02d" for width == 2
+
+  // Formats an int value as "%X".
+  static std::string FormatHexInt(int value);
+
+  // Formats an int value as "%X".
+  static std::string FormatHexUInt32(UInt32 value);
+
+  // Formats a byte as "%02X".
+  static std::string FormatByte(unsigned char value);
+
+ private:
+  String();  // Not meant to be instantiated.
+};  // class String
+
+// Gets the content of the stringstream's buffer as an std::string.  Each '\0'
+// character in the buffer is replaced with "\\0".
+GTEST_API_ std::string StringStreamToString(::std::stringstream* stream);
+
+}  // namespace internal
+}  // namespace testing
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
diff --git a/3rdparty/gtest/include/gtest/internal/gtest-type-util.h b/3rdparty/gtest/include/gtest/internal/gtest-type-util.h
new file mode 100644
index 0000000..3d7542d
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/gtest-type-util.h
@@ -0,0 +1,3335 @@
+// This file was GENERATED by command:
+//     pump.py gtest-type-util.h.pump
+// DO NOT EDIT BY HAND!!!
+
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Type utilities needed for implementing typed and type-parameterized
+// tests.  This file is generated by a SCRIPT.  DO NOT EDIT BY HAND!
+//
+// Currently we support at most 50 types in a list, and at most 50
+// type-parameterized tests in one type-parameterized test suite.
+// Please contact googletestframework@googlegroups.com if you need
+// more.
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
+
+#include "gtest/internal/gtest-port.h"
+
+// #ifdef __GNUC__ is too general here.  It is possible to use gcc without using
+// libstdc++ (which is where cxxabi.h comes from).
+# if GTEST_HAS_CXXABI_H_
+#  include <cxxabi.h>
+# elif defined(__HP_aCC)
+#  include <acxx_demangle.h>
+# endif  // GTEST_HASH_CXXABI_H_
+
+namespace testing {
+namespace internal {
+
+// Canonicalizes a given name with respect to the Standard C++ Library.
+// This handles removing the inline namespace within `std` that is
+// used by various standard libraries (e.g., `std::__1`).  Names outside
+// of namespace std are returned unmodified.
+inline std::string CanonicalizeForStdLibVersioning(std::string s) {
+  static const char prefix[] = "std::__";
+  if (s.compare(0, strlen(prefix), prefix) == 0) {
+    std::string::size_type end = s.find("::", strlen(prefix));
+    if (end != s.npos) {
+      // Erase everything between the initial `std` and the second `::`.
+      s.erase(strlen("std"), end - strlen("std"));
+    }
+  }
+  return s;
+}
+
+// GetTypeName<T>() returns a human-readable name of type T.
+// NB: This function is also used in Google Mock, so don't move it inside of
+// the typed-test-only section below.
+template <typename T>
+std::string GetTypeName() {
+# if GTEST_HAS_RTTI
+
+  const char* const name = typeid(T).name();
+#  if GTEST_HAS_CXXABI_H_ || defined(__HP_aCC)
+  int status = 0;
+  // gcc's implementation of typeid(T).name() mangles the type name,
+  // so we have to demangle it.
+#   if GTEST_HAS_CXXABI_H_
+  using abi::__cxa_demangle;
+#   endif  // GTEST_HAS_CXXABI_H_
+  char* const readable_name = __cxa_demangle(name, nullptr, nullptr, &status);
+  const std::string name_str(status == 0 ? readable_name : name);
+  free(readable_name);
+  return CanonicalizeForStdLibVersioning(name_str);
+#  else
+  return name;
+#  endif  // GTEST_HAS_CXXABI_H_ || __HP_aCC
+
+# else
+
+  return "<type>";
+
+# endif  // GTEST_HAS_RTTI
+}
+
+#if GTEST_HAS_TYPED_TEST || GTEST_HAS_TYPED_TEST_P
+
+// A unique type used as the default value for the arguments of class
+// template Types.  This allows us to simulate variadic templates
+// (e.g. Types<int>, Type<int, double>, and etc), which C++ doesn't
+// support directly.
+struct None {};
+
+// The following family of struct and struct templates are used to
+// represent type lists.  In particular, TypesN<T1, T2, ..., TN>
+// represents a type list with N types (T1, T2, ..., and TN) in it.
+// Except for Types0, every struct in the family has two member types:
+// Head for the first type in the list, and Tail for the rest of the
+// list.
+
+// The empty type list.
+struct Types0 {};
+
+// Type lists of length 1, 2, 3, and so on.
+
+template <typename T1>
+struct Types1 {
+  typedef T1 Head;
+  typedef Types0 Tail;
+};
+template <typename T1, typename T2>
+struct Types2 {
+  typedef T1 Head;
+  typedef Types1<T2> Tail;
+};
+
+template <typename T1, typename T2, typename T3>
+struct Types3 {
+  typedef T1 Head;
+  typedef Types2<T2, T3> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4>
+struct Types4 {
+  typedef T1 Head;
+  typedef Types3<T2, T3, T4> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5>
+struct Types5 {
+  typedef T1 Head;
+  typedef Types4<T2, T3, T4, T5> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6>
+struct Types6 {
+  typedef T1 Head;
+  typedef Types5<T2, T3, T4, T5, T6> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7>
+struct Types7 {
+  typedef T1 Head;
+  typedef Types6<T2, T3, T4, T5, T6, T7> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8>
+struct Types8 {
+  typedef T1 Head;
+  typedef Types7<T2, T3, T4, T5, T6, T7, T8> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9>
+struct Types9 {
+  typedef T1 Head;
+  typedef Types8<T2, T3, T4, T5, T6, T7, T8, T9> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10>
+struct Types10 {
+  typedef T1 Head;
+  typedef Types9<T2, T3, T4, T5, T6, T7, T8, T9, T10> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11>
+struct Types11 {
+  typedef T1 Head;
+  typedef Types10<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12>
+struct Types12 {
+  typedef T1 Head;
+  typedef Types11<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13>
+struct Types13 {
+  typedef T1 Head;
+  typedef Types12<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14>
+struct Types14 {
+  typedef T1 Head;
+  typedef Types13<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15>
+struct Types15 {
+  typedef T1 Head;
+  typedef Types14<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16>
+struct Types16 {
+  typedef T1 Head;
+  typedef Types15<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17>
+struct Types17 {
+  typedef T1 Head;
+  typedef Types16<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18>
+struct Types18 {
+  typedef T1 Head;
+  typedef Types17<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19>
+struct Types19 {
+  typedef T1 Head;
+  typedef Types18<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20>
+struct Types20 {
+  typedef T1 Head;
+  typedef Types19<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21>
+struct Types21 {
+  typedef T1 Head;
+  typedef Types20<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22>
+struct Types22 {
+  typedef T1 Head;
+  typedef Types21<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23>
+struct Types23 {
+  typedef T1 Head;
+  typedef Types22<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24>
+struct Types24 {
+  typedef T1 Head;
+  typedef Types23<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25>
+struct Types25 {
+  typedef T1 Head;
+  typedef Types24<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26>
+struct Types26 {
+  typedef T1 Head;
+  typedef Types25<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27>
+struct Types27 {
+  typedef T1 Head;
+  typedef Types26<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28>
+struct Types28 {
+  typedef T1 Head;
+  typedef Types27<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29>
+struct Types29 {
+  typedef T1 Head;
+  typedef Types28<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30>
+struct Types30 {
+  typedef T1 Head;
+  typedef Types29<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31>
+struct Types31 {
+  typedef T1 Head;
+  typedef Types30<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32>
+struct Types32 {
+  typedef T1 Head;
+  typedef Types31<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33>
+struct Types33 {
+  typedef T1 Head;
+  typedef Types32<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34>
+struct Types34 {
+  typedef T1 Head;
+  typedef Types33<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35>
+struct Types35 {
+  typedef T1 Head;
+  typedef Types34<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36>
+struct Types36 {
+  typedef T1 Head;
+  typedef Types35<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37>
+struct Types37 {
+  typedef T1 Head;
+  typedef Types36<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38>
+struct Types38 {
+  typedef T1 Head;
+  typedef Types37<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39>
+struct Types39 {
+  typedef T1 Head;
+  typedef Types38<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40>
+struct Types40 {
+  typedef T1 Head;
+  typedef Types39<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41>
+struct Types41 {
+  typedef T1 Head;
+  typedef Types40<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42>
+struct Types42 {
+  typedef T1 Head;
+  typedef Types41<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43>
+struct Types43 {
+  typedef T1 Head;
+  typedef Types42<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42,
+      T43> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44>
+struct Types44 {
+  typedef T1 Head;
+  typedef Types43<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+      T44> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45>
+struct Types45 {
+  typedef T1 Head;
+  typedef Types44<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+      T44, T45> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46>
+struct Types46 {
+  typedef T1 Head;
+  typedef Types45<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+      T44, T45, T46> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46, typename T47>
+struct Types47 {
+  typedef T1 Head;
+  typedef Types46<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+      T44, T45, T46, T47> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46, typename T47, typename T48>
+struct Types48 {
+  typedef T1 Head;
+  typedef Types47<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+      T44, T45, T46, T47, T48> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46, typename T47, typename T48, typename T49>
+struct Types49 {
+  typedef T1 Head;
+  typedef Types48<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+      T44, T45, T46, T47, T48, T49> Tail;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46, typename T47, typename T48, typename T49, typename T50>
+struct Types50 {
+  typedef T1 Head;
+  typedef Types49<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+      T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+      T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+      T44, T45, T46, T47, T48, T49, T50> Tail;
+};
+
+
+}  // namespace internal
+
+// We don't want to require the users to write TypesN<...> directly,
+// as that would require them to count the length.  Types<...> is much
+// easier to write, but generates horrible messages when there is a
+// compiler error, as gcc insists on printing out each template
+// argument, even if it has the default value (this means Types<int>
+// will appear as Types<int, None, None, ..., None> in the compiler
+// errors).
+//
+// Our solution is to combine the best part of the two approaches: a
+// user would write Types<T1, ..., TN>, and Google Test will translate
+// that to TypesN<T1, ..., TN> internally to make error messages
+// readable.  The translation is done by the 'type' member of the
+// Types template.
+template <typename T1 = internal::None, typename T2 = internal::None,
+    typename T3 = internal::None, typename T4 = internal::None,
+    typename T5 = internal::None, typename T6 = internal::None,
+    typename T7 = internal::None, typename T8 = internal::None,
+    typename T9 = internal::None, typename T10 = internal::None,
+    typename T11 = internal::None, typename T12 = internal::None,
+    typename T13 = internal::None, typename T14 = internal::None,
+    typename T15 = internal::None, typename T16 = internal::None,
+    typename T17 = internal::None, typename T18 = internal::None,
+    typename T19 = internal::None, typename T20 = internal::None,
+    typename T21 = internal::None, typename T22 = internal::None,
+    typename T23 = internal::None, typename T24 = internal::None,
+    typename T25 = internal::None, typename T26 = internal::None,
+    typename T27 = internal::None, typename T28 = internal::None,
+    typename T29 = internal::None, typename T30 = internal::None,
+    typename T31 = internal::None, typename T32 = internal::None,
+    typename T33 = internal::None, typename T34 = internal::None,
+    typename T35 = internal::None, typename T36 = internal::None,
+    typename T37 = internal::None, typename T38 = internal::None,
+    typename T39 = internal::None, typename T40 = internal::None,
+    typename T41 = internal::None, typename T42 = internal::None,
+    typename T43 = internal::None, typename T44 = internal::None,
+    typename T45 = internal::None, typename T46 = internal::None,
+    typename T47 = internal::None, typename T48 = internal::None,
+    typename T49 = internal::None, typename T50 = internal::None>
+struct Types {
+  typedef internal::Types50<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42, T43, T44, T45, T46, T47, T48, T49, T50> type;
+};
+
+template <>
+struct Types<internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types0 type;
+};
+template <typename T1>
+struct Types<T1, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types1<T1> type;
+};
+template <typename T1, typename T2>
+struct Types<T1, T2, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types2<T1, T2> type;
+};
+template <typename T1, typename T2, typename T3>
+struct Types<T1, T2, T3, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types3<T1, T2, T3> type;
+};
+template <typename T1, typename T2, typename T3, typename T4>
+struct Types<T1, T2, T3, T4, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types4<T1, T2, T3, T4> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5>
+struct Types<T1, T2, T3, T4, T5, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types5<T1, T2, T3, T4, T5> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6>
+struct Types<T1, T2, T3, T4, T5, T6, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types6<T1, T2, T3, T4, T5, T6> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7>
+struct Types<T1, T2, T3, T4, T5, T6, T7, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types7<T1, T2, T3, T4, T5, T6, T7> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types8<T1, T2, T3, T4, T5, T6, T7, T8> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types9<T1, T2, T3, T4, T5, T6, T7, T8, T9> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types10<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types11<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types12<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11,
+      T12> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types13<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types14<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types15<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types16<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types17<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types18<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types19<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types20<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types21<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types22<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types23<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types24<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types25<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types26<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25,
+      T26> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types27<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types28<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types29<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types30<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types31<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types32<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types33<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types34<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types35<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types36<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types37<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types38<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types39<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types40<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39,
+      T40> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types41<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, internal::None,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types42<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None, internal::None> {
+  typedef internal::Types43<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42, T43> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None, internal::None> {
+  typedef internal::Types44<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42, T43, T44> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44, T45,
+    internal::None, internal::None, internal::None, internal::None,
+    internal::None> {
+  typedef internal::Types45<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42, T43, T44, T45> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44, T45,
+    T46, internal::None, internal::None, internal::None, internal::None> {
+  typedef internal::Types46<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42, T43, T44, T45, T46> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46, typename T47>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44, T45,
+    T46, T47, internal::None, internal::None, internal::None> {
+  typedef internal::Types47<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42, T43, T44, T45, T46, T47> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46, typename T47, typename T48>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44, T45,
+    T46, T47, T48, internal::None, internal::None> {
+  typedef internal::Types48<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42, T43, T44, T45, T46, T47, T48> type;
+};
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46, typename T47, typename T48, typename T49>
+struct Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15,
+    T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29, T30,
+    T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44, T45,
+    T46, T47, T48, T49, internal::None> {
+  typedef internal::Types49<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42, T43, T44, T45, T46, T47, T48, T49> type;
+};
+
+namespace internal {
+
+# define GTEST_TEMPLATE_ template <typename T> class
+
+// The template "selector" struct TemplateSel<Tmpl> is used to
+// represent Tmpl, which must be a class template with one type
+// parameter, as a type.  TemplateSel<Tmpl>::Bind<T>::type is defined
+// as the type Tmpl<T>.  This allows us to actually instantiate the
+// template "selected" by TemplateSel<Tmpl>.
+//
+// This trick is necessary for simulating typedef for class templates,
+// which C++ doesn't support directly.
+template <GTEST_TEMPLATE_ Tmpl>
+struct TemplateSel {
+  template <typename T>
+  struct Bind {
+    typedef Tmpl<T> type;
+  };
+};
+
+# define GTEST_BIND_(TmplSel, T) \
+  TmplSel::template Bind<T>::type
+
+// A unique struct template used as the default value for the
+// arguments of class template Templates.  This allows us to simulate
+// variadic templates (e.g. Templates<int>, Templates<int, double>,
+// and etc), which C++ doesn't support directly.
+template <typename T>
+struct NoneT {};
+
+// The following family of struct and struct templates are used to
+// represent template lists.  In particular, TemplatesN<T1, T2, ...,
+// TN> represents a list of N templates (T1, T2, ..., and TN).  Except
+// for Templates0, every struct in the family has two member types:
+// Head for the selector of the first template in the list, and Tail
+// for the rest of the list.
+
+// The empty template list.
+struct Templates0 {};
+
+// Template lists of length 1, 2, 3, and so on.
+
+template <GTEST_TEMPLATE_ T1>
+struct Templates1 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates0 Tail;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2>
+struct Templates2 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates1<T2> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3>
+struct Templates3 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates2<T2, T3> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4>
+struct Templates4 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates3<T2, T3, T4> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5>
+struct Templates5 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates4<T2, T3, T4, T5> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6>
+struct Templates6 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates5<T2, T3, T4, T5, T6> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7>
+struct Templates7 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates6<T2, T3, T4, T5, T6, T7> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8>
+struct Templates8 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates7<T2, T3, T4, T5, T6, T7, T8> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9>
+struct Templates9 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates8<T2, T3, T4, T5, T6, T7, T8, T9> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10>
+struct Templates10 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates9<T2, T3, T4, T5, T6, T7, T8, T9, T10> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11>
+struct Templates11 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates10<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12>
+struct Templates12 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates11<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13>
+struct Templates13 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates12<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14>
+struct Templates14 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates13<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15>
+struct Templates15 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates14<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16>
+struct Templates16 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates15<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17>
+struct Templates17 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates16<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18>
+struct Templates18 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates17<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19>
+struct Templates19 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates18<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20>
+struct Templates20 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates19<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21>
+struct Templates21 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates20<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22>
+struct Templates22 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates21<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23>
+struct Templates23 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates22<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24>
+struct Templates24 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates23<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25>
+struct Templates25 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates24<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26>
+struct Templates26 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates25<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27>
+struct Templates27 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates26<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28>
+struct Templates28 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates27<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29>
+struct Templates29 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates28<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30>
+struct Templates30 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates29<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31>
+struct Templates31 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates30<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32>
+struct Templates32 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates31<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33>
+struct Templates33 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates32<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34>
+struct Templates34 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates33<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35>
+struct Templates35 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates34<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36>
+struct Templates36 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates35<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37>
+struct Templates37 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates36<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38>
+struct Templates38 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates37<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39>
+struct Templates39 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates38<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40>
+struct Templates40 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates39<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41>
+struct Templates41 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates40<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42>
+struct Templates42 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates41<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43>
+struct Templates43 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates42<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42,
+      T43> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44>
+struct Templates44 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates43<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42,
+      T43, T44> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45>
+struct Templates45 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates44<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42,
+      T43, T44, T45> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45,
+    GTEST_TEMPLATE_ T46>
+struct Templates46 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates45<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42,
+      T43, T44, T45, T46> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45,
+    GTEST_TEMPLATE_ T46, GTEST_TEMPLATE_ T47>
+struct Templates47 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates46<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42,
+      T43, T44, T45, T46, T47> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45,
+    GTEST_TEMPLATE_ T46, GTEST_TEMPLATE_ T47, GTEST_TEMPLATE_ T48>
+struct Templates48 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates47<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42,
+      T43, T44, T45, T46, T47, T48> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45,
+    GTEST_TEMPLATE_ T46, GTEST_TEMPLATE_ T47, GTEST_TEMPLATE_ T48,
+    GTEST_TEMPLATE_ T49>
+struct Templates49 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates48<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42,
+      T43, T44, T45, T46, T47, T48, T49> Tail;
+};
+
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45,
+    GTEST_TEMPLATE_ T46, GTEST_TEMPLATE_ T47, GTEST_TEMPLATE_ T48,
+    GTEST_TEMPLATE_ T49, GTEST_TEMPLATE_ T50>
+struct Templates50 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates49<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+      T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+      T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42,
+      T43, T44, T45, T46, T47, T48, T49, T50> Tail;
+};
+
+
+// We don't want to require the users to write TemplatesN<...> directly,
+// as that would require them to count the length.  Templates<...> is much
+// easier to write, but generates horrible messages when there is a
+// compiler error, as gcc insists on printing out each template
+// argument, even if it has the default value (this means Templates<list>
+// will appear as Templates<list, NoneT, NoneT, ..., NoneT> in the compiler
+// errors).
+//
+// Our solution is to combine the best part of the two approaches: a
+// user would write Templates<T1, ..., TN>, and Google Test will translate
+// that to TemplatesN<T1, ..., TN> internally to make error messages
+// readable.  The translation is done by the 'type' member of the
+// Templates template.
+template <GTEST_TEMPLATE_ T1 = NoneT, GTEST_TEMPLATE_ T2 = NoneT,
+    GTEST_TEMPLATE_ T3 = NoneT, GTEST_TEMPLATE_ T4 = NoneT,
+    GTEST_TEMPLATE_ T5 = NoneT, GTEST_TEMPLATE_ T6 = NoneT,
+    GTEST_TEMPLATE_ T7 = NoneT, GTEST_TEMPLATE_ T8 = NoneT,
+    GTEST_TEMPLATE_ T9 = NoneT, GTEST_TEMPLATE_ T10 = NoneT,
+    GTEST_TEMPLATE_ T11 = NoneT, GTEST_TEMPLATE_ T12 = NoneT,
+    GTEST_TEMPLATE_ T13 = NoneT, GTEST_TEMPLATE_ T14 = NoneT,
+    GTEST_TEMPLATE_ T15 = NoneT, GTEST_TEMPLATE_ T16 = NoneT,
+    GTEST_TEMPLATE_ T17 = NoneT, GTEST_TEMPLATE_ T18 = NoneT,
+    GTEST_TEMPLATE_ T19 = NoneT, GTEST_TEMPLATE_ T20 = NoneT,
+    GTEST_TEMPLATE_ T21 = NoneT, GTEST_TEMPLATE_ T22 = NoneT,
+    GTEST_TEMPLATE_ T23 = NoneT, GTEST_TEMPLATE_ T24 = NoneT,
+    GTEST_TEMPLATE_ T25 = NoneT, GTEST_TEMPLATE_ T26 = NoneT,
+    GTEST_TEMPLATE_ T27 = NoneT, GTEST_TEMPLATE_ T28 = NoneT,
+    GTEST_TEMPLATE_ T29 = NoneT, GTEST_TEMPLATE_ T30 = NoneT,
+    GTEST_TEMPLATE_ T31 = NoneT, GTEST_TEMPLATE_ T32 = NoneT,
+    GTEST_TEMPLATE_ T33 = NoneT, GTEST_TEMPLATE_ T34 = NoneT,
+    GTEST_TEMPLATE_ T35 = NoneT, GTEST_TEMPLATE_ T36 = NoneT,
+    GTEST_TEMPLATE_ T37 = NoneT, GTEST_TEMPLATE_ T38 = NoneT,
+    GTEST_TEMPLATE_ T39 = NoneT, GTEST_TEMPLATE_ T40 = NoneT,
+    GTEST_TEMPLATE_ T41 = NoneT, GTEST_TEMPLATE_ T42 = NoneT,
+    GTEST_TEMPLATE_ T43 = NoneT, GTEST_TEMPLATE_ T44 = NoneT,
+    GTEST_TEMPLATE_ T45 = NoneT, GTEST_TEMPLATE_ T46 = NoneT,
+    GTEST_TEMPLATE_ T47 = NoneT, GTEST_TEMPLATE_ T48 = NoneT,
+    GTEST_TEMPLATE_ T49 = NoneT, GTEST_TEMPLATE_ T50 = NoneT>
+struct Templates {
+  typedef Templates50<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42, T43, T44, T45, T46, T47, T48, T49, T50> type;
+};
+
+template <>
+struct Templates<NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT> {
+  typedef Templates0 type;
+};
+template <GTEST_TEMPLATE_ T1>
+struct Templates<T1, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT> {
+  typedef Templates1<T1> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2>
+struct Templates<T1, T2, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT> {
+  typedef Templates2<T1, T2> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3>
+struct Templates<T1, T2, T3, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates3<T1, T2, T3> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4>
+struct Templates<T1, T2, T3, T4, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates4<T1, T2, T3, T4> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5>
+struct Templates<T1, T2, T3, T4, T5, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates5<T1, T2, T3, T4, T5> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6>
+struct Templates<T1, T2, T3, T4, T5, T6, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates6<T1, T2, T3, T4, T5, T6> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates7<T1, T2, T3, T4, T5, T6, T7> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates8<T1, T2, T3, T4, T5, T6, T7, T8> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates9<T1, T2, T3, T4, T5, T6, T7, T8, T9> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates10<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates11<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates12<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates13<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates14<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates15<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates16<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates17<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates18<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates19<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates20<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates21<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT> {
+  typedef Templates22<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT> {
+  typedef Templates23<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT> {
+  typedef Templates24<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT> {
+  typedef Templates25<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT> {
+  typedef Templates26<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT> {
+  typedef Templates27<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT> {
+  typedef Templates28<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT> {
+  typedef Templates29<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates30<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates31<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates32<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates33<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates34<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates35<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates36<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, NoneT, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates37<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, NoneT, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates38<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates39<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, NoneT, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates40<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, NoneT, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates41<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, NoneT,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates42<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates43<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42, T43> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44,
+    NoneT, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates44<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42, T43, T44> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44,
+    T45, NoneT, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates45<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42, T43, T44, T45> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45,
+    GTEST_TEMPLATE_ T46>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44,
+    T45, T46, NoneT, NoneT, NoneT, NoneT> {
+  typedef Templates46<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42, T43, T44, T45, T46> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45,
+    GTEST_TEMPLATE_ T46, GTEST_TEMPLATE_ T47>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44,
+    T45, T46, T47, NoneT, NoneT, NoneT> {
+  typedef Templates47<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42, T43, T44, T45, T46, T47> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45,
+    GTEST_TEMPLATE_ T46, GTEST_TEMPLATE_ T47, GTEST_TEMPLATE_ T48>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44,
+    T45, T46, T47, T48, NoneT, NoneT> {
+  typedef Templates48<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42, T43, T44, T45, T46, T47, T48> type;
+};
+template <GTEST_TEMPLATE_ T1, GTEST_TEMPLATE_ T2, GTEST_TEMPLATE_ T3,
+    GTEST_TEMPLATE_ T4, GTEST_TEMPLATE_ T5, GTEST_TEMPLATE_ T6,
+    GTEST_TEMPLATE_ T7, GTEST_TEMPLATE_ T8, GTEST_TEMPLATE_ T9,
+    GTEST_TEMPLATE_ T10, GTEST_TEMPLATE_ T11, GTEST_TEMPLATE_ T12,
+    GTEST_TEMPLATE_ T13, GTEST_TEMPLATE_ T14, GTEST_TEMPLATE_ T15,
+    GTEST_TEMPLATE_ T16, GTEST_TEMPLATE_ T17, GTEST_TEMPLATE_ T18,
+    GTEST_TEMPLATE_ T19, GTEST_TEMPLATE_ T20, GTEST_TEMPLATE_ T21,
+    GTEST_TEMPLATE_ T22, GTEST_TEMPLATE_ T23, GTEST_TEMPLATE_ T24,
+    GTEST_TEMPLATE_ T25, GTEST_TEMPLATE_ T26, GTEST_TEMPLATE_ T27,
+    GTEST_TEMPLATE_ T28, GTEST_TEMPLATE_ T29, GTEST_TEMPLATE_ T30,
+    GTEST_TEMPLATE_ T31, GTEST_TEMPLATE_ T32, GTEST_TEMPLATE_ T33,
+    GTEST_TEMPLATE_ T34, GTEST_TEMPLATE_ T35, GTEST_TEMPLATE_ T36,
+    GTEST_TEMPLATE_ T37, GTEST_TEMPLATE_ T38, GTEST_TEMPLATE_ T39,
+    GTEST_TEMPLATE_ T40, GTEST_TEMPLATE_ T41, GTEST_TEMPLATE_ T42,
+    GTEST_TEMPLATE_ T43, GTEST_TEMPLATE_ T44, GTEST_TEMPLATE_ T45,
+    GTEST_TEMPLATE_ T46, GTEST_TEMPLATE_ T47, GTEST_TEMPLATE_ T48,
+    GTEST_TEMPLATE_ T49>
+struct Templates<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14,
+    T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28, T29,
+    T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43, T44,
+    T45, T46, T47, T48, T49, NoneT> {
+  typedef Templates49<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+      T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27,
+      T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41,
+      T42, T43, T44, T45, T46, T47, T48, T49> type;
+};
+
+// The TypeList template makes it possible to use either a single type
+// or a Types<...> list in TYPED_TEST_SUITE() and
+// INSTANTIATE_TYPED_TEST_SUITE_P().
+
+template <typename T>
+struct TypeList {
+  typedef Types1<T> type;
+};
+
+template <typename T1, typename T2, typename T3, typename T4, typename T5,
+    typename T6, typename T7, typename T8, typename T9, typename T10,
+    typename T11, typename T12, typename T13, typename T14, typename T15,
+    typename T16, typename T17, typename T18, typename T19, typename T20,
+    typename T21, typename T22, typename T23, typename T24, typename T25,
+    typename T26, typename T27, typename T28, typename T29, typename T30,
+    typename T31, typename T32, typename T33, typename T34, typename T35,
+    typename T36, typename T37, typename T38, typename T39, typename T40,
+    typename T41, typename T42, typename T43, typename T44, typename T45,
+    typename T46, typename T47, typename T48, typename T49, typename T50>
+struct TypeList<Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,
+    T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26, T27, T28,
+    T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40, T41, T42, T43,
+    T44, T45, T46, T47, T48, T49, T50> > {
+  typedef typename Types<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
+      T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25, T26,
+      T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38, T39, T40,
+      T41, T42, T43, T44, T45, T46, T47, T48, T49, T50>::type type;
+};
+
+#endif  // GTEST_HAS_TYPED_TEST || GTEST_HAS_TYPED_TEST_P
+
+}  // namespace internal
+}  // namespace testing
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
diff --git a/3rdparty/gtest/include/gtest/internal/gtest-type-util.h.pump b/3rdparty/gtest/include/gtest/internal/gtest-type-util.h.pump
new file mode 100644
index 0000000..5e31b7b
--- /dev/null
+++ b/3rdparty/gtest/include/gtest/internal/gtest-type-util.h.pump
@@ -0,0 +1,302 @@
+$$ -*- mode: c++; -*-
+$var n = 50  $$ Maximum length of type lists we want to support.
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Type utilities needed for implementing typed and type-parameterized
+// tests.  This file is generated by a SCRIPT.  DO NOT EDIT BY HAND!
+//
+// Currently we support at most $n types in a list, and at most $n
+// type-parameterized tests in one type-parameterized test suite.
+// Please contact googletestframework@googlegroups.com if you need
+// more.
+
+// GOOGLETEST_CM0001 DO NOT DELETE
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
+
+#include "gtest/internal/gtest-port.h"
+
+// #ifdef __GNUC__ is too general here.  It is possible to use gcc without using
+// libstdc++ (which is where cxxabi.h comes from).
+# if GTEST_HAS_CXXABI_H_
+#  include <cxxabi.h>
+# elif defined(__HP_aCC)
+#  include <acxx_demangle.h>
+# endif  // GTEST_HASH_CXXABI_H_
+
+namespace testing {
+namespace internal {
+
+// Canonicalizes a given name with respect to the Standard C++ Library.
+// This handles removing the inline namespace within `std` that is
+// used by various standard libraries (e.g., `std::__1`).  Names outside
+// of namespace std are returned unmodified.
+inline std::string CanonicalizeForStdLibVersioning(std::string s) {
+  static const char prefix[] = "std::__";
+  if (s.compare(0, strlen(prefix), prefix) == 0) {
+    std::string::size_type end = s.find("::", strlen(prefix));
+    if (end != s.npos) {
+      // Erase everything between the initial `std` and the second `::`.
+      s.erase(strlen("std"), end - strlen("std"));
+    }
+  }
+  return s;
+}
+
+// GetTypeName<T>() returns a human-readable name of type T.
+// NB: This function is also used in Google Mock, so don't move it inside of
+// the typed-test-only section below.
+template <typename T>
+std::string GetTypeName() {
+# if GTEST_HAS_RTTI
+
+  const char* const name = typeid(T).name();
+#  if GTEST_HAS_CXXABI_H_ || defined(__HP_aCC)
+  int status = 0;
+  // gcc's implementation of typeid(T).name() mangles the type name,
+  // so we have to demangle it.
+#   if GTEST_HAS_CXXABI_H_
+  using abi::__cxa_demangle;
+#   endif  // GTEST_HAS_CXXABI_H_
+  char* const readable_name = __cxa_demangle(name, nullptr, nullptr, &status);
+  const std::string name_str(status == 0 ? readable_name : name);
+  free(readable_name);
+  return CanonicalizeForStdLibVersioning(name_str);
+#  else
+  return name;
+#  endif  // GTEST_HAS_CXXABI_H_ || __HP_aCC
+
+# else
+
+  return "<type>";
+
+# endif  // GTEST_HAS_RTTI
+}
+
+#if GTEST_HAS_TYPED_TEST || GTEST_HAS_TYPED_TEST_P
+
+// A unique type used as the default value for the arguments of class
+// template Types.  This allows us to simulate variadic templates
+// (e.g. Types<int>, Type<int, double>, and etc), which C++ doesn't
+// support directly.
+struct None {};
+
+// The following family of struct and struct templates are used to
+// represent type lists.  In particular, TypesN<T1, T2, ..., TN>
+// represents a type list with N types (T1, T2, ..., and TN) in it.
+// Except for Types0, every struct in the family has two member types:
+// Head for the first type in the list, and Tail for the rest of the
+// list.
+
+// The empty type list.
+struct Types0 {};
+
+// Type lists of length 1, 2, 3, and so on.
+
+template <typename T1>
+struct Types1 {
+  typedef T1 Head;
+  typedef Types0 Tail;
+};
+
+$range i 2..n
+
+$for i [[
+$range j 1..i
+$range k 2..i
+template <$for j, [[typename T$j]]>
+struct Types$i {
+  typedef T1 Head;
+  typedef Types$(i-1)<$for k, [[T$k]]> Tail;
+};
+
+
+]]
+
+}  // namespace internal
+
+// We don't want to require the users to write TypesN<...> directly,
+// as that would require them to count the length.  Types<...> is much
+// easier to write, but generates horrible messages when there is a
+// compiler error, as gcc insists on printing out each template
+// argument, even if it has the default value (this means Types<int>
+// will appear as Types<int, None, None, ..., None> in the compiler
+// errors).
+//
+// Our solution is to combine the best part of the two approaches: a
+// user would write Types<T1, ..., TN>, and Google Test will translate
+// that to TypesN<T1, ..., TN> internally to make error messages
+// readable.  The translation is done by the 'type' member of the
+// Types template.
+
+$range i 1..n
+template <$for i, [[typename T$i = internal::None]]>
+struct Types {
+  typedef internal::Types$n<$for i, [[T$i]]> type;
+};
+
+template <>
+struct Types<$for i, [[internal::None]]> {
+  typedef internal::Types0 type;
+};
+
+$range i 1..n-1
+$for i [[
+$range j 1..i
+$range k i+1..n
+template <$for j, [[typename T$j]]>
+struct Types<$for j, [[T$j]]$for k[[, internal::None]]> {
+  typedef internal::Types$i<$for j, [[T$j]]> type;
+};
+
+]]
+
+namespace internal {
+
+# define GTEST_TEMPLATE_ template <typename T> class
+
+// The template "selector" struct TemplateSel<Tmpl> is used to
+// represent Tmpl, which must be a class template with one type
+// parameter, as a type.  TemplateSel<Tmpl>::Bind<T>::type is defined
+// as the type Tmpl<T>.  This allows us to actually instantiate the
+// template "selected" by TemplateSel<Tmpl>.
+//
+// This trick is necessary for simulating typedef for class templates,
+// which C++ doesn't support directly.
+template <GTEST_TEMPLATE_ Tmpl>
+struct TemplateSel {
+  template <typename T>
+  struct Bind {
+    typedef Tmpl<T> type;
+  };
+};
+
+# define GTEST_BIND_(TmplSel, T) \
+  TmplSel::template Bind<T>::type
+
+// A unique struct template used as the default value for the
+// arguments of class template Templates.  This allows us to simulate
+// variadic templates (e.g. Templates<int>, Templates<int, double>,
+// and etc), which C++ doesn't support directly.
+template <typename T>
+struct NoneT {};
+
+// The following family of struct and struct templates are used to
+// represent template lists.  In particular, TemplatesN<T1, T2, ...,
+// TN> represents a list of N templates (T1, T2, ..., and TN).  Except
+// for Templates0, every struct in the family has two member types:
+// Head for the selector of the first template in the list, and Tail
+// for the rest of the list.
+
+// The empty template list.
+struct Templates0 {};
+
+// Template lists of length 1, 2, 3, and so on.
+
+template <GTEST_TEMPLATE_ T1>
+struct Templates1 {
+  typedef TemplateSel<T1> Head;
+  typedef Templates0 Tail;
+};
+
+$range i 2..n
+
+$for i [[
+$range j 1..i
+$range k 2..i
+template <$for j, [[GTEST_TEMPLATE_ T$j]]>
+struct Templates$i {
+  typedef TemplateSel<T1> Head;
+  typedef Templates$(i-1)<$for k, [[T$k]]> Tail;
+};
+
+
+]]
+
+// We don't want to require the users to write TemplatesN<...> directly,
+// as that would require them to count the length.  Templates<...> is much
+// easier to write, but generates horrible messages when there is a
+// compiler error, as gcc insists on printing out each template
+// argument, even if it has the default value (this means Templates<list>
+// will appear as Templates<list, NoneT, NoneT, ..., NoneT> in the compiler
+// errors).
+//
+// Our solution is to combine the best part of the two approaches: a
+// user would write Templates<T1, ..., TN>, and Google Test will translate
+// that to TemplatesN<T1, ..., TN> internally to make error messages
+// readable.  The translation is done by the 'type' member of the
+// Templates template.
+
+$range i 1..n
+template <$for i, [[GTEST_TEMPLATE_ T$i = NoneT]]>
+struct Templates {
+  typedef Templates$n<$for i, [[T$i]]> type;
+};
+
+template <>
+struct Templates<$for i, [[NoneT]]> {
+  typedef Templates0 type;
+};
+
+$range i 1..n-1
+$for i [[
+$range j 1..i
+$range k i+1..n
+template <$for j, [[GTEST_TEMPLATE_ T$j]]>
+struct Templates<$for j, [[T$j]]$for k[[, NoneT]]> {
+  typedef Templates$i<$for j, [[T$j]]> type;
+};
+
+]]
+
+// The TypeList template makes it possible to use either a single type
+// or a Types<...> list in TYPED_TEST_SUITE() and
+// INSTANTIATE_TYPED_TEST_SUITE_P().
+
+template <typename T>
+struct TypeList {
+  typedef Types1<T> type;
+};
+
+
+$range i 1..n
+template <$for i, [[typename T$i]]>
+struct TypeList<Types<$for i, [[T$i]]> > {
+  typedef typename Types<$for i, [[T$i]]>::type type;
+};
+
+#endif  // GTEST_HAS_TYPED_TEST || GTEST_HAS_TYPED_TEST_P
+
+}  // namespace internal
+}  // namespace testing
+
+#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
diff --git a/3rdparty/gtest/samples/prime_tables.h b/3rdparty/gtest/samples/prime_tables.h
new file mode 100644
index 0000000..72539bf
--- /dev/null
+++ b/3rdparty/gtest/samples/prime_tables.h
@@ -0,0 +1,126 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+
+// This provides interface PrimeTable that determines whether a number is a
+// prime and determines a next prime number. This interface is used
+// in Google Test samples demonstrating use of parameterized tests.
+
+#ifndef GTEST_SAMPLES_PRIME_TABLES_H_
+#define GTEST_SAMPLES_PRIME_TABLES_H_
+
+#include <algorithm>
+
+// The prime table interface.
+class PrimeTable {
+ public:
+  virtual ~PrimeTable() {}
+
+  // Returns true if and only if n is a prime number.
+  virtual bool IsPrime(int n) const = 0;
+
+  // Returns the smallest prime number greater than p; or returns -1
+  // if the next prime is beyond the capacity of the table.
+  virtual int GetNextPrime(int p) const = 0;
+};
+
+// Implementation #1 calculates the primes on-the-fly.
+class OnTheFlyPrimeTable : public PrimeTable {
+ public:
+  bool IsPrime(int n) const override {
+    if (n <= 1) return false;
+
+    for (int i = 2; i*i <= n; i++) {
+      // n is divisible by an integer other than 1 and itself.
+      if ((n % i) == 0) return false;
+    }
+
+    return true;
+  }
+
+  int GetNextPrime(int p) const override {
+    for (int n = p + 1; n > 0; n++) {
+      if (IsPrime(n)) return n;
+    }
+
+    return -1;
+  }
+};
+
+// Implementation #2 pre-calculates the primes and stores the result
+// in an array.
+class PreCalculatedPrimeTable : public PrimeTable {
+ public:
+  // 'max' specifies the maximum number the prime table holds.
+  explicit PreCalculatedPrimeTable(int max)
+      : is_prime_size_(max + 1), is_prime_(new bool[max + 1]) {
+    CalculatePrimesUpTo(max);
+  }
+  ~PreCalculatedPrimeTable() override { delete[] is_prime_; }
+
+  bool IsPrime(int n) const override {
+    return 0 <= n && n < is_prime_size_ && is_prime_[n];
+  }
+
+  int GetNextPrime(int p) const override {
+    for (int n = p + 1; n < is_prime_size_; n++) {
+      if (is_prime_[n]) return n;
+    }
+
+    return -1;
+  }
+
+ private:
+  void CalculatePrimesUpTo(int max) {
+    ::std::fill(is_prime_, is_prime_ + is_prime_size_, true);
+    is_prime_[0] = is_prime_[1] = false;
+
+    // Checks every candidate for prime number (we know that 2 is the only even
+    // prime).
+    for (int i = 2; i*i <= max; i += i%2+1) {
+      if (!is_prime_[i]) continue;
+
+      // Marks all multiples of i (except i itself) as non-prime.
+      // We are starting here from i-th multiplier, because all smaller
+      // complex numbers were already marked.
+      for (int j = i*i; j <= max; j += i) {
+        is_prime_[j] = false;
+      }
+    }
+  }
+
+  const int is_prime_size_;
+  bool* const is_prime_;
+
+  // Disables compiler warning "assignment operator could not be generated."
+  void operator=(const PreCalculatedPrimeTable& rhs);
+};
+
+#endif  // GTEST_SAMPLES_PRIME_TABLES_H_
diff --git a/3rdparty/gtest/samples/sample1.cc b/3rdparty/gtest/samples/sample1.cc
new file mode 100644
index 0000000..1d42759
--- /dev/null
+++ b/3rdparty/gtest/samples/sample1.cc
@@ -0,0 +1,66 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+
+#include "sample1.h"
+
+// Returns n! (the factorial of n).  For negative n, n! is defined to be 1.
+int Factorial(int n) {
+  int result = 1;
+  for (int i = 1; i <= n; i++) {
+    result *= i;
+  }
+
+  return result;
+}
+
+// Returns true if and only if n is a prime number.
+bool IsPrime(int n) {
+  // Trivial case 1: small numbers
+  if (n <= 1) return false;
+
+  // Trivial case 2: even numbers
+  if (n % 2 == 0) return n == 2;
+
+  // Now, we have that n is odd and n >= 3.
+
+  // Try to divide n by every odd number i, starting from 3
+  for (int i = 3; ; i += 2) {
+    // We only have to try i up to the square root of n
+    if (i > n/i) break;
+
+    // Now, we have i <= n/i < n.
+    // If n is divisible by i, n is not prime.
+    if (n % i == 0) return false;
+  }
+
+  // n has no integer factor in the range (1, n), and thus is prime.
+  return true;
+}
diff --git a/3rdparty/gtest/samples/sample1.h b/3rdparty/gtest/samples/sample1.h
new file mode 100644
index 0000000..12e49de
--- /dev/null
+++ b/3rdparty/gtest/samples/sample1.h
@@ -0,0 +1,41 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+
+#ifndef GTEST_SAMPLES_SAMPLE1_H_
+#define GTEST_SAMPLES_SAMPLE1_H_
+
+// Returns n! (the factorial of n).  For negative n, n! is defined to be 1.
+int Factorial(int n);
+
+// Returns true if and only if n is a prime number.
+bool IsPrime(int n);
+
+#endif  // GTEST_SAMPLES_SAMPLE1_H_
diff --git a/3rdparty/gtest/samples/sample10_unittest.cc b/3rdparty/gtest/samples/sample10_unittest.cc
new file mode 100644
index 0000000..36cdac2
--- /dev/null
+++ b/3rdparty/gtest/samples/sample10_unittest.cc
@@ -0,0 +1,139 @@
+// Copyright 2009 Google Inc. All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// This sample shows how to use Google Test listener API to implement
+// a primitive leak checker.
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "gtest/gtest.h"
+using ::testing::EmptyTestEventListener;
+using ::testing::InitGoogleTest;
+using ::testing::Test;
+using ::testing::TestEventListeners;
+using ::testing::TestInfo;
+using ::testing::TestPartResult;
+using ::testing::UnitTest;
+
+namespace {
+// We will track memory used by this class.
+class Water {
+ public:
+  // Normal Water declarations go here.
+
+  // operator new and operator delete help us control water allocation.
+  void* operator new(size_t allocation_size) {
+    allocated_++;
+    return malloc(allocation_size);
+  }
+
+  void operator delete(void* block, size_t /* allocation_size */) {
+    allocated_--;
+    free(block);
+  }
+
+  static int allocated() { return allocated_; }
+
+ private:
+  static int allocated_;
+};
+
+int Water::allocated_ = 0;
+
+// This event listener monitors how many Water objects are created and
+// destroyed by each test, and reports a failure if a test leaks some Water
+// objects. It does this by comparing the number of live Water objects at
+// the beginning of a test and at the end of a test.
+class LeakChecker : public EmptyTestEventListener {
+ private:
+  // Called before a test starts.
+  void OnTestStart(const TestInfo& /* test_info */) override {
+    initially_allocated_ = Water::allocated();
+  }
+
+  // Called after a test ends.
+  void OnTestEnd(const TestInfo& /* test_info */) override {
+    int difference = Water::allocated() - initially_allocated_;
+
+    // You can generate a failure in any event handler except
+    // OnTestPartResult. Just use an appropriate Google Test assertion to do
+    // it.
+    EXPECT_LE(difference, 0) << "Leaked " << difference << " unit(s) of Water!";
+  }
+
+  int initially_allocated_;
+};
+
+TEST(ListenersTest, DoesNotLeak) {
+  Water* water = new Water;
+  delete water;
+}
+
+// This should fail when the --check_for_leaks command line flag is
+// specified.
+TEST(ListenersTest, LeaksWater) {
+  Water* water = new Water;
+  EXPECT_TRUE(water != nullptr);
+}
+}  // namespace
+
+int main(int argc, char **argv) {
+  InitGoogleTest(&argc, argv);
+
+  bool check_for_leaks = false;
+  if (argc > 1 && strcmp(argv[1], "--check_for_leaks") == 0 )
+    check_for_leaks = true;
+  else
+    printf("%s\n", "Run this program with --check_for_leaks to enable "
+           "custom leak checking in the tests.");
+
+  // If we are given the --check_for_leaks command line flag, installs the
+  // leak checker.
+  if (check_for_leaks) {
+    TestEventListeners& listeners = UnitTest::GetInstance()->listeners();
+
+    // Adds the leak checker to the end of the test event listener list,
+    // after the default text output printer and the default XML report
+    // generator.
+    //
+    // The order is important - it ensures that failures generated in the
+    // leak checker's OnTestEnd() method are processed by the text and XML
+    // printers *before* their OnTestEnd() methods are called, such that
+    // they are attributed to the right test. Remember that a listener
+    // receives an OnXyzStart event *after* listeners preceding it in the
+    // list received that event, and receives an OnXyzEnd event *before*
+    // listeners preceding it.
+    //
+    // We don't need to worry about deleting the new listener later, as
+    // Google Test will do it.
+    listeners.Append(new LeakChecker);
+  }
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/samples/sample1_unittest.cc b/3rdparty/gtest/samples/sample1_unittest.cc
new file mode 100644
index 0000000..cb08b61
--- /dev/null
+++ b/3rdparty/gtest/samples/sample1_unittest.cc
@@ -0,0 +1,151 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+
+// This sample shows how to write a simple unit test for a function,
+// using Google C++ testing framework.
+//
+// Writing a unit test using Google C++ testing framework is easy as 1-2-3:
+
+
+// Step 1. Include necessary header files such that the stuff your
+// test logic needs is declared.
+//
+// Don't forget gtest.h, which declares the testing framework.
+
+#include <limits.h>
+#include "sample1.h"
+#include "gtest/gtest.h"
+namespace {
+
+// Step 2. Use the TEST macro to define your tests.
+//
+// TEST has two parameters: the test case name and the test name.
+// After using the macro, you should define your test logic between a
+// pair of braces.  You can use a bunch of macros to indicate the
+// success or failure of a test.  EXPECT_TRUE and EXPECT_EQ are
+// examples of such macros.  For a complete list, see gtest.h.
+//
+// <TechnicalDetails>
+//
+// In Google Test, tests are grouped into test cases.  This is how we
+// keep test code organized.  You should put logically related tests
+// into the same test case.
+//
+// The test case name and the test name should both be valid C++
+// identifiers.  And you should not use underscore (_) in the names.
+//
+// Google Test guarantees that each test you define is run exactly
+// once, but it makes no guarantee on the order the tests are
+// executed.  Therefore, you should write your tests in such a way
+// that their results don't depend on their order.
+//
+// </TechnicalDetails>
+
+
+// Tests Factorial().
+
+// Tests factorial of negative numbers.
+TEST(FactorialTest, Negative) {
+  // This test is named "Negative", and belongs to the "FactorialTest"
+  // test case.
+  EXPECT_EQ(1, Factorial(-5));
+  EXPECT_EQ(1, Factorial(-1));
+  EXPECT_GT(Factorial(-10), 0);
+
+  // <TechnicalDetails>
+  //
+  // EXPECT_EQ(expected, actual) is the same as
+  //
+  //   EXPECT_TRUE((expected) == (actual))
+  //
+  // except that it will print both the expected value and the actual
+  // value when the assertion fails.  This is very helpful for
+  // debugging.  Therefore in this case EXPECT_EQ is preferred.
+  //
+  // On the other hand, EXPECT_TRUE accepts any Boolean expression,
+  // and is thus more general.
+  //
+  // </TechnicalDetails>
+}
+
+// Tests factorial of 0.
+TEST(FactorialTest, Zero) {
+  EXPECT_EQ(1, Factorial(0));
+}
+
+// Tests factorial of positive numbers.
+TEST(FactorialTest, Positive) {
+  EXPECT_EQ(1, Factorial(1));
+  EXPECT_EQ(2, Factorial(2));
+  EXPECT_EQ(6, Factorial(3));
+  EXPECT_EQ(40320, Factorial(8));
+}
+
+
+// Tests IsPrime()
+
+// Tests negative input.
+TEST(IsPrimeTest, Negative) {
+  // This test belongs to the IsPrimeTest test case.
+
+  EXPECT_FALSE(IsPrime(-1));
+  EXPECT_FALSE(IsPrime(-2));
+  EXPECT_FALSE(IsPrime(INT_MIN));
+}
+
+// Tests some trivial cases.
+TEST(IsPrimeTest, Trivial) {
+  EXPECT_FALSE(IsPrime(0));
+  EXPECT_FALSE(IsPrime(1));
+  EXPECT_TRUE(IsPrime(2));
+  EXPECT_TRUE(IsPrime(3));
+}
+
+// Tests positive input.
+TEST(IsPrimeTest, Positive) {
+  EXPECT_FALSE(IsPrime(4));
+  EXPECT_TRUE(IsPrime(5));
+  EXPECT_FALSE(IsPrime(6));
+  EXPECT_TRUE(IsPrime(23));
+}
+}  // namespace
+
+// Step 3. Call RUN_ALL_TESTS() in main().
+//
+// We do this by linking in src/gtest_main.cc file, which consists of
+// a main() function which calls RUN_ALL_TESTS() for us.
+//
+// This runs all the tests you've defined, prints the result, and
+// returns 0 if successful, or 1 otherwise.
+//
+// Did you notice that we didn't register the tests?  The
+// RUN_ALL_TESTS() macro magically knows about all the tests we
+// defined.  Isn't this convenient?
diff --git a/3rdparty/gtest/samples/sample2.cc b/3rdparty/gtest/samples/sample2.cc
new file mode 100644
index 0000000..d8e8723
--- /dev/null
+++ b/3rdparty/gtest/samples/sample2.cc
@@ -0,0 +1,54 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+
+#include "sample2.h"
+
+#include <string.h>
+
+// Clones a 0-terminated C string, allocating memory using new.
+const char* MyString::CloneCString(const char* a_c_string) {
+  if (a_c_string == nullptr) return nullptr;
+
+  const size_t len = strlen(a_c_string);
+  char* const clone = new char[ len + 1 ];
+  memcpy(clone, a_c_string, len + 1);
+
+  return clone;
+}
+
+// Sets the 0-terminated C string this MyString object
+// represents.
+void MyString::Set(const char* a_c_string) {
+  // Makes sure this works when c_string == c_string_
+  const char* const temp = MyString::CloneCString(a_c_string);
+  delete[] c_string_;
+  c_string_ = temp;
+}
diff --git a/3rdparty/gtest/samples/sample2.h b/3rdparty/gtest/samples/sample2.h
new file mode 100644
index 0000000..e9a5a70
--- /dev/null
+++ b/3rdparty/gtest/samples/sample2.h
@@ -0,0 +1,81 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+
+#ifndef GTEST_SAMPLES_SAMPLE2_H_
+#define GTEST_SAMPLES_SAMPLE2_H_
+
+#include <string.h>
+
+
+// A simple string class.
+class MyString {
+ private:
+  const char* c_string_;
+  const MyString& operator=(const MyString& rhs);
+
+ public:
+  // Clones a 0-terminated C string, allocating memory using new.
+  static const char* CloneCString(const char* a_c_string);
+
+  ////////////////////////////////////////////////////////////
+  //
+  // C'tors
+
+  // The default c'tor constructs a NULL string.
+  MyString() : c_string_(nullptr) {}
+
+  // Constructs a MyString by cloning a 0-terminated C string.
+  explicit MyString(const char* a_c_string) : c_string_(nullptr) {
+    Set(a_c_string);
+  }
+
+  // Copy c'tor
+  MyString(const MyString& string) : c_string_(nullptr) {
+    Set(string.c_string_);
+  }
+
+  ////////////////////////////////////////////////////////////
+  //
+  // D'tor.  MyString is intended to be a final class, so the d'tor
+  // doesn't need to be virtual.
+  ~MyString() { delete[] c_string_; }
+
+  // Gets the 0-terminated C string this MyString object represents.
+  const char* c_string() const { return c_string_; }
+
+  size_t Length() const { return c_string_ == nullptr ? 0 : strlen(c_string_); }
+
+  // Sets the 0-terminated C string this MyString object represents.
+  void Set(const char* c_string);
+};
+
+
+#endif  // GTEST_SAMPLES_SAMPLE2_H_
diff --git a/3rdparty/gtest/samples/sample2_unittest.cc b/3rdparty/gtest/samples/sample2_unittest.cc
new file mode 100644
index 0000000..41e31c1
--- /dev/null
+++ b/3rdparty/gtest/samples/sample2_unittest.cc
@@ -0,0 +1,107 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+
+// This sample shows how to write a more complex unit test for a class
+// that has multiple member functions.
+//
+// Usually, it's a good idea to have one test for each method in your
+// class.  You don't have to do that exactly, but it helps to keep
+// your tests organized.  You may also throw in additional tests as
+// needed.
+
+#include "sample2.h"
+#include "gtest/gtest.h"
+namespace {
+// In this example, we test the MyString class (a simple string).
+
+// Tests the default c'tor.
+TEST(MyString, DefaultConstructor) {
+  const MyString s;
+
+  // Asserts that s.c_string() returns NULL.
+  //
+  // <TechnicalDetails>
+  //
+  // If we write NULL instead of
+  //
+  //   static_cast<const char *>(NULL)
+  //
+  // in this assertion, it will generate a warning on gcc 3.4.  The
+  // reason is that EXPECT_EQ needs to know the types of its
+  // arguments in order to print them when it fails.  Since NULL is
+  // #defined as 0, the compiler will use the formatter function for
+  // int to print it.  However, gcc thinks that NULL should be used as
+  // a pointer, not an int, and therefore complains.
+  //
+  // The root of the problem is C++'s lack of distinction between the
+  // integer number 0 and the null pointer constant.  Unfortunately,
+  // we have to live with this fact.
+  //
+  // </TechnicalDetails>
+  EXPECT_STREQ(nullptr, s.c_string());
+
+  EXPECT_EQ(0u, s.Length());
+}
+
+const char kHelloString[] = "Hello, world!";
+
+// Tests the c'tor that accepts a C string.
+TEST(MyString, ConstructorFromCString) {
+  const MyString s(kHelloString);
+  EXPECT_EQ(0, strcmp(s.c_string(), kHelloString));
+  EXPECT_EQ(sizeof(kHelloString)/sizeof(kHelloString[0]) - 1,
+            s.Length());
+}
+
+// Tests the copy c'tor.
+TEST(MyString, CopyConstructor) {
+  const MyString s1(kHelloString);
+  const MyString s2 = s1;
+  EXPECT_EQ(0, strcmp(s2.c_string(), kHelloString));
+}
+
+// Tests the Set method.
+TEST(MyString, Set) {
+  MyString s;
+
+  s.Set(kHelloString);
+  EXPECT_EQ(0, strcmp(s.c_string(), kHelloString));
+
+  // Set should work when the input pointer is the same as the one
+  // already in the MyString object.
+  s.Set(s.c_string());
+  EXPECT_EQ(0, strcmp(s.c_string(), kHelloString));
+
+  // Can we set the MyString to NULL?
+  s.Set(nullptr);
+  EXPECT_STREQ(nullptr, s.c_string());
+}
+}  // namespace
diff --git a/3rdparty/gtest/samples/sample3-inl.h b/3rdparty/gtest/samples/sample3-inl.h
new file mode 100644
index 0000000..80ba6b9
--- /dev/null
+++ b/3rdparty/gtest/samples/sample3-inl.h
@@ -0,0 +1,172 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+
+#ifndef GTEST_SAMPLES_SAMPLE3_INL_H_
+#define GTEST_SAMPLES_SAMPLE3_INL_H_
+
+#include <stddef.h>
+
+
+// Queue is a simple queue implemented as a singled-linked list.
+//
+// The element type must support copy constructor.
+template <typename E>  // E is the element type
+class Queue;
+
+// QueueNode is a node in a Queue, which consists of an element of
+// type E and a pointer to the next node.
+template <typename E>  // E is the element type
+class QueueNode {
+  friend class Queue<E>;
+
+ public:
+  // Gets the element in this node.
+  const E& element() const { return element_; }
+
+  // Gets the next node in the queue.
+  QueueNode* next() { return next_; }
+  const QueueNode* next() const { return next_; }
+
+ private:
+  // Creates a node with a given element value.  The next pointer is
+  // set to NULL.
+  explicit QueueNode(const E& an_element)
+      : element_(an_element), next_(nullptr) {}
+
+  // We disable the default assignment operator and copy c'tor.
+  const QueueNode& operator = (const QueueNode&);
+  QueueNode(const QueueNode&);
+
+  E element_;
+  QueueNode* next_;
+};
+
+template <typename E>  // E is the element type.
+class Queue {
+ public:
+  // Creates an empty queue.
+  Queue() : head_(nullptr), last_(nullptr), size_(0) {}
+
+  // D'tor.  Clears the queue.
+  ~Queue() { Clear(); }
+
+  // Clears the queue.
+  void Clear() {
+    if (size_ > 0) {
+      // 1. Deletes every node.
+      QueueNode<E>* node = head_;
+      QueueNode<E>* next = node->next();
+      for (; ;) {
+        delete node;
+        node = next;
+        if (node == nullptr) break;
+        next = node->next();
+      }
+
+      // 2. Resets the member variables.
+      head_ = last_ = nullptr;
+      size_ = 0;
+    }
+  }
+
+  // Gets the number of elements.
+  size_t Size() const { return size_; }
+
+  // Gets the first element of the queue, or NULL if the queue is empty.
+  QueueNode<E>* Head() { return head_; }
+  const QueueNode<E>* Head() const { return head_; }
+
+  // Gets the last element of the queue, or NULL if the queue is empty.
+  QueueNode<E>* Last() { return last_; }
+  const QueueNode<E>* Last() const { return last_; }
+
+  // Adds an element to the end of the queue.  A copy of the element is
+  // created using the copy constructor, and then stored in the queue.
+  // Changes made to the element in the queue doesn't affect the source
+  // object, and vice versa.
+  void Enqueue(const E& element) {
+    QueueNode<E>* new_node = new QueueNode<E>(element);
+
+    if (size_ == 0) {
+      head_ = last_ = new_node;
+      size_ = 1;
+    } else {
+      last_->next_ = new_node;
+      last_ = new_node;
+      size_++;
+    }
+  }
+
+  // Removes the head of the queue and returns it.  Returns NULL if
+  // the queue is empty.
+  E* Dequeue() {
+    if (size_ == 0) {
+      return nullptr;
+    }
+
+    const QueueNode<E>* const old_head = head_;
+    head_ = head_->next_;
+    size_--;
+    if (size_ == 0) {
+      last_ = nullptr;
+    }
+
+    E* element = new E(old_head->element());
+    delete old_head;
+
+    return element;
+  }
+
+  // Applies a function/functor on each element of the queue, and
+  // returns the result in a new queue.  The original queue is not
+  // affected.
+  template <typename F>
+  Queue* Map(F function) const {
+    Queue* new_queue = new Queue();
+    for (const QueueNode<E>* node = head_; node != nullptr;
+         node = node->next_) {
+      new_queue->Enqueue(function(node->element()));
+    }
+
+    return new_queue;
+  }
+
+ private:
+  QueueNode<E>* head_;  // The first node of the queue.
+  QueueNode<E>* last_;  // The last node of the queue.
+  size_t size_;  // The number of elements in the queue.
+
+  // We disallow copying a queue.
+  Queue(const Queue&);
+  const Queue& operator = (const Queue&);
+};
+
+#endif  // GTEST_SAMPLES_SAMPLE3_INL_H_
diff --git a/3rdparty/gtest/samples/sample3_unittest.cc b/3rdparty/gtest/samples/sample3_unittest.cc
new file mode 100644
index 0000000..b19416d
--- /dev/null
+++ b/3rdparty/gtest/samples/sample3_unittest.cc
@@ -0,0 +1,149 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+
+// In this example, we use a more advanced feature of Google Test called
+// test fixture.
+//
+// A test fixture is a place to hold objects and functions shared by
+// all tests in a test case.  Using a test fixture avoids duplicating
+// the test code necessary to initialize and cleanup those common
+// objects for each test.  It is also useful for defining sub-routines
+// that your tests need to invoke a lot.
+//
+// <TechnicalDetails>
+//
+// The tests share the test fixture in the sense of code sharing, not
+// data sharing.  Each test is given its own fresh copy of the
+// fixture.  You cannot expect the data modified by one test to be
+// passed on to another test, which is a bad idea.
+//
+// The reason for this design is that tests should be independent and
+// repeatable.  In particular, a test should not fail as the result of
+// another test's failure.  If one test depends on info produced by
+// another test, then the two tests should really be one big test.
+//
+// The macros for indicating the success/failure of a test
+// (EXPECT_TRUE, FAIL, etc) need to know what the current test is
+// (when Google Test prints the test result, it tells you which test
+// each failure belongs to).  Technically, these macros invoke a
+// member function of the Test class.  Therefore, you cannot use them
+// in a global function.  That's why you should put test sub-routines
+// in a test fixture.
+//
+// </TechnicalDetails>
+
+#include "sample3-inl.h"
+#include "gtest/gtest.h"
+namespace {
+// To use a test fixture, derive a class from testing::Test.
+class QueueTestSmpl3 : public testing::Test {
+ protected:  // You should make the members protected s.t. they can be
+             // accessed from sub-classes.
+
+  // virtual void SetUp() will be called before each test is run.  You
+  // should define it if you need to initialize the variables.
+  // Otherwise, this can be skipped.
+  void SetUp() override {
+    q1_.Enqueue(1);
+    q2_.Enqueue(2);
+    q2_.Enqueue(3);
+  }
+
+  // virtual void TearDown() will be called after each test is run.
+  // You should define it if there is cleanup work to do.  Otherwise,
+  // you don't have to provide it.
+  //
+  // virtual void TearDown() {
+  // }
+
+  // A helper function that some test uses.
+  static int Double(int n) {
+    return 2*n;
+  }
+
+  // A helper function for testing Queue::Map().
+  void MapTester(const Queue<int> * q) {
+    // Creates a new queue, where each element is twice as big as the
+    // corresponding one in q.
+    const Queue<int> * const new_q = q->Map(Double);
+
+    // Verifies that the new queue has the same size as q.
+    ASSERT_EQ(q->Size(), new_q->Size());
+
+    // Verifies the relationship between the elements of the two queues.
+    for (const QueueNode<int>*n1 = q->Head(), *n2 = new_q->Head();
+         n1 != nullptr; n1 = n1->next(), n2 = n2->next()) {
+      EXPECT_EQ(2 * n1->element(), n2->element());
+    }
+
+    delete new_q;
+  }
+
+  // Declares the variables your tests want to use.
+  Queue<int> q0_;
+  Queue<int> q1_;
+  Queue<int> q2_;
+};
+
+// When you have a test fixture, you define a test using TEST_F
+// instead of TEST.
+
+// Tests the default c'tor.
+TEST_F(QueueTestSmpl3, DefaultConstructor) {
+  // You can access data in the test fixture here.
+  EXPECT_EQ(0u, q0_.Size());
+}
+
+// Tests Dequeue().
+TEST_F(QueueTestSmpl3, Dequeue) {
+  int * n = q0_.Dequeue();
+  EXPECT_TRUE(n == nullptr);
+
+  n = q1_.Dequeue();
+  ASSERT_TRUE(n != nullptr);
+  EXPECT_EQ(1, *n);
+  EXPECT_EQ(0u, q1_.Size());
+  delete n;
+
+  n = q2_.Dequeue();
+  ASSERT_TRUE(n != nullptr);
+  EXPECT_EQ(2, *n);
+  EXPECT_EQ(1u, q2_.Size());
+  delete n;
+}
+
+// Tests the Queue::Map() function.
+TEST_F(QueueTestSmpl3, Map) {
+  MapTester(&q0_);
+  MapTester(&q1_);
+  MapTester(&q2_);
+}
+}  // namespace
diff --git a/3rdparty/gtest/samples/sample4.cc b/3rdparty/gtest/samples/sample4.cc
new file mode 100644
index 0000000..b0ee609
--- /dev/null
+++ b/3rdparty/gtest/samples/sample4.cc
@@ -0,0 +1,54 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+
+#include <stdio.h>
+
+#include "sample4.h"
+
+// Returns the current counter value, and increments it.
+int Counter::Increment() {
+  return counter_++;
+}
+
+// Returns the current counter value, and decrements it.
+// counter can not be less than 0, return 0 in this case
+int Counter::Decrement() {
+  if (counter_ == 0) {
+    return counter_;
+  } else  {
+    return counter_--;
+  }
+}
+
+// Prints the current counter value to STDOUT.
+void Counter::Print() const {
+  printf("%d", counter_);
+}
diff --git a/3rdparty/gtest/samples/sample4.h b/3rdparty/gtest/samples/sample4.h
new file mode 100644
index 0000000..e256f40
--- /dev/null
+++ b/3rdparty/gtest/samples/sample4.h
@@ -0,0 +1,53 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// A sample program demonstrating using Google C++ testing framework.
+#ifndef GTEST_SAMPLES_SAMPLE4_H_
+#define GTEST_SAMPLES_SAMPLE4_H_
+
+// A simple monotonic counter.
+class Counter {
+ private:
+  int counter_;
+
+ public:
+  // Creates a counter that starts at 0.
+  Counter() : counter_(0) {}
+
+  // Returns the current counter value, and increments it.
+  int Increment();
+
+  // Returns the current counter value, and decrements it.
+  int Decrement();
+
+  // Prints the current counter value to STDOUT.
+  void Print() const;
+};
+
+#endif  // GTEST_SAMPLES_SAMPLE4_H_
diff --git a/3rdparty/gtest/samples/sample4_unittest.cc b/3rdparty/gtest/samples/sample4_unittest.cc
new file mode 100644
index 0000000..d5144c0
--- /dev/null
+++ b/3rdparty/gtest/samples/sample4_unittest.cc
@@ -0,0 +1,53 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include "sample4.h"
+#include "gtest/gtest.h"
+
+namespace {
+// Tests the Increment() method.
+
+TEST(Counter, Increment) {
+  Counter c;
+
+  // Test that counter 0 returns 0
+  EXPECT_EQ(0, c.Decrement());
+
+  // EXPECT_EQ() evaluates its arguments exactly once, so they
+  // can have side effects.
+
+  EXPECT_EQ(0, c.Increment());
+  EXPECT_EQ(1, c.Increment());
+  EXPECT_EQ(2, c.Increment());
+
+  EXPECT_EQ(3, c.Decrement());
+}
+
+}  // namespace
diff --git a/3rdparty/gtest/samples/sample5_unittest.cc b/3rdparty/gtest/samples/sample5_unittest.cc
new file mode 100644
index 0000000..0a21dd2
--- /dev/null
+++ b/3rdparty/gtest/samples/sample5_unittest.cc
@@ -0,0 +1,196 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// This sample teaches how to reuse a test fixture in multiple test
+// cases by deriving sub-fixtures from it.
+//
+// When you define a test fixture, you specify the name of the test
+// case that will use this fixture.  Therefore, a test fixture can
+// be used by only one test case.
+//
+// Sometimes, more than one test cases may want to use the same or
+// slightly different test fixtures.  For example, you may want to
+// make sure that all tests for a GUI library don't leak important
+// system resources like fonts and brushes.  In Google Test, you do
+// this by putting the shared logic in a super (as in "super class")
+// test fixture, and then have each test case use a fixture derived
+// from this super fixture.
+
+#include <limits.h>
+#include <time.h>
+#include "gtest/gtest.h"
+#include "sample1.h"
+#include "sample3-inl.h"
+namespace {
+// In this sample, we want to ensure that every test finishes within
+// ~5 seconds.  If a test takes longer to run, we consider it a
+// failure.
+//
+// We put the code for timing a test in a test fixture called
+// "QuickTest".  QuickTest is intended to be the super fixture that
+// other fixtures derive from, therefore there is no test case with
+// the name "QuickTest".  This is OK.
+//
+// Later, we will derive multiple test fixtures from QuickTest.
+class QuickTest : public testing::Test {
+ protected:
+  // Remember that SetUp() is run immediately before a test starts.
+  // This is a good place to record the start time.
+  void SetUp() override { start_time_ = time(nullptr); }
+
+  // TearDown() is invoked immediately after a test finishes.  Here we
+  // check if the test was too slow.
+  void TearDown() override {
+    // Gets the time when the test finishes
+    const time_t end_time = time(nullptr);
+
+    // Asserts that the test took no more than ~5 seconds.  Did you
+    // know that you can use assertions in SetUp() and TearDown() as
+    // well?
+    EXPECT_TRUE(end_time - start_time_ <= 5) << "The test took too long.";
+  }
+
+  // The UTC time (in seconds) when the test starts
+  time_t start_time_;
+};
+
+
+// We derive a fixture named IntegerFunctionTest from the QuickTest
+// fixture.  All tests using this fixture will be automatically
+// required to be quick.
+class IntegerFunctionTest : public QuickTest {
+  // We don't need any more logic than already in the QuickTest fixture.
+  // Therefore the body is empty.
+};
+
+
+// Now we can write tests in the IntegerFunctionTest test case.
+
+// Tests Factorial()
+TEST_F(IntegerFunctionTest, Factorial) {
+  // Tests factorial of negative numbers.
+  EXPECT_EQ(1, Factorial(-5));
+  EXPECT_EQ(1, Factorial(-1));
+  EXPECT_GT(Factorial(-10), 0);
+
+  // Tests factorial of 0.
+  EXPECT_EQ(1, Factorial(0));
+
+  // Tests factorial of positive numbers.
+  EXPECT_EQ(1, Factorial(1));
+  EXPECT_EQ(2, Factorial(2));
+  EXPECT_EQ(6, Factorial(3));
+  EXPECT_EQ(40320, Factorial(8));
+}
+
+
+// Tests IsPrime()
+TEST_F(IntegerFunctionTest, IsPrime) {
+  // Tests negative input.
+  EXPECT_FALSE(IsPrime(-1));
+  EXPECT_FALSE(IsPrime(-2));
+  EXPECT_FALSE(IsPrime(INT_MIN));
+
+  // Tests some trivial cases.
+  EXPECT_FALSE(IsPrime(0));
+  EXPECT_FALSE(IsPrime(1));
+  EXPECT_TRUE(IsPrime(2));
+  EXPECT_TRUE(IsPrime(3));
+
+  // Tests positive input.
+  EXPECT_FALSE(IsPrime(4));
+  EXPECT_TRUE(IsPrime(5));
+  EXPECT_FALSE(IsPrime(6));
+  EXPECT_TRUE(IsPrime(23));
+}
+
+
+// The next test case (named "QueueTest") also needs to be quick, so
+// we derive another fixture from QuickTest.
+//
+// The QueueTest test fixture has some logic and shared objects in
+// addition to what's in QuickTest already.  We define the additional
+// stuff inside the body of the test fixture, as usual.
+class QueueTest : public QuickTest {
+ protected:
+  void SetUp() override {
+    // First, we need to set up the super fixture (QuickTest).
+    QuickTest::SetUp();
+
+    // Second, some additional setup for this fixture.
+    q1_.Enqueue(1);
+    q2_.Enqueue(2);
+    q2_.Enqueue(3);
+  }
+
+  // By default, TearDown() inherits the behavior of
+  // QuickTest::TearDown().  As we have no additional cleaning work
+  // for QueueTest, we omit it here.
+  //
+  // virtual void TearDown() {
+  //   QuickTest::TearDown();
+  // }
+
+  Queue<int> q0_;
+  Queue<int> q1_;
+  Queue<int> q2_;
+};
+
+
+// Now, let's write tests using the QueueTest fixture.
+
+// Tests the default constructor.
+TEST_F(QueueTest, DefaultConstructor) {
+  EXPECT_EQ(0u, q0_.Size());
+}
+
+// Tests Dequeue().
+TEST_F(QueueTest, Dequeue) {
+  int* n = q0_.Dequeue();
+  EXPECT_TRUE(n == nullptr);
+
+  n = q1_.Dequeue();
+  EXPECT_TRUE(n != nullptr);
+  EXPECT_EQ(1, *n);
+  EXPECT_EQ(0u, q1_.Size());
+  delete n;
+
+  n = q2_.Dequeue();
+  EXPECT_TRUE(n != nullptr);
+  EXPECT_EQ(2, *n);
+  EXPECT_EQ(1u, q2_.Size());
+  delete n;
+}
+}  // namespace
+// If necessary, you can derive further test fixtures from a derived
+// fixture itself.  For example, you can derive another fixture from
+// QueueTest.  Google Test imposes no limit on how deep the hierarchy
+// can be.  In practice, however, you probably don't want it to be too
+// deep as to be confusing.
diff --git a/3rdparty/gtest/samples/sample6_unittest.cc b/3rdparty/gtest/samples/sample6_unittest.cc
new file mode 100644
index 0000000..0266e27
--- /dev/null
+++ b/3rdparty/gtest/samples/sample6_unittest.cc
@@ -0,0 +1,224 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// This sample shows how to test common properties of multiple
+// implementations of the same interface (aka interface tests).
+
+// The interface and its implementations are in this header.
+#include "prime_tables.h"
+
+#include "gtest/gtest.h"
+namespace {
+// First, we define some factory functions for creating instances of
+// the implementations.  You may be able to skip this step if all your
+// implementations can be constructed the same way.
+
+template <class T>
+PrimeTable* CreatePrimeTable();
+
+template <>
+PrimeTable* CreatePrimeTable<OnTheFlyPrimeTable>() {
+  return new OnTheFlyPrimeTable;
+}
+
+template <>
+PrimeTable* CreatePrimeTable<PreCalculatedPrimeTable>() {
+  return new PreCalculatedPrimeTable(10000);
+}
+
+// Then we define a test fixture class template.
+template <class T>
+class PrimeTableTest : public testing::Test {
+ protected:
+  // The ctor calls the factory function to create a prime table
+  // implemented by T.
+  PrimeTableTest() : table_(CreatePrimeTable<T>()) {}
+
+  ~PrimeTableTest() override { delete table_; }
+
+  // Note that we test an implementation via the base interface
+  // instead of the actual implementation class.  This is important
+  // for keeping the tests close to the real world scenario, where the
+  // implementation is invoked via the base interface.  It avoids
+  // got-yas where the implementation class has a method that shadows
+  // a method with the same name (but slightly different argument
+  // types) in the base interface, for example.
+  PrimeTable* const table_;
+};
+
+#if GTEST_HAS_TYPED_TEST
+
+using testing::Types;
+
+// Google Test offers two ways for reusing tests for different types.
+// The first is called "typed tests".  You should use it if you
+// already know *all* the types you are gonna exercise when you write
+// the tests.
+
+// To write a typed test case, first use
+//
+//   TYPED_TEST_SUITE(TestCaseName, TypeList);
+//
+// to declare it and specify the type parameters.  As with TEST_F,
+// TestCaseName must match the test fixture name.
+
+// The list of types we want to test.
+typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable> Implementations;
+
+TYPED_TEST_SUITE(PrimeTableTest, Implementations);
+
+// Then use TYPED_TEST(TestCaseName, TestName) to define a typed test,
+// similar to TEST_F.
+TYPED_TEST(PrimeTableTest, ReturnsFalseForNonPrimes) {
+  // Inside the test body, you can refer to the type parameter by
+  // TypeParam, and refer to the fixture class by TestFixture.  We
+  // don't need them in this example.
+
+  // Since we are in the template world, C++ requires explicitly
+  // writing 'this->' when referring to members of the fixture class.
+  // This is something you have to learn to live with.
+  EXPECT_FALSE(this->table_->IsPrime(-5));
+  EXPECT_FALSE(this->table_->IsPrime(0));
+  EXPECT_FALSE(this->table_->IsPrime(1));
+  EXPECT_FALSE(this->table_->IsPrime(4));
+  EXPECT_FALSE(this->table_->IsPrime(6));
+  EXPECT_FALSE(this->table_->IsPrime(100));
+}
+
+TYPED_TEST(PrimeTableTest, ReturnsTrueForPrimes) {
+  EXPECT_TRUE(this->table_->IsPrime(2));
+  EXPECT_TRUE(this->table_->IsPrime(3));
+  EXPECT_TRUE(this->table_->IsPrime(5));
+  EXPECT_TRUE(this->table_->IsPrime(7));
+  EXPECT_TRUE(this->table_->IsPrime(11));
+  EXPECT_TRUE(this->table_->IsPrime(131));
+}
+
+TYPED_TEST(PrimeTableTest, CanGetNextPrime) {
+  EXPECT_EQ(2, this->table_->GetNextPrime(0));
+  EXPECT_EQ(3, this->table_->GetNextPrime(2));
+  EXPECT_EQ(5, this->table_->GetNextPrime(3));
+  EXPECT_EQ(7, this->table_->GetNextPrime(5));
+  EXPECT_EQ(11, this->table_->GetNextPrime(7));
+  EXPECT_EQ(131, this->table_->GetNextPrime(128));
+}
+
+// That's it!  Google Test will repeat each TYPED_TEST for each type
+// in the type list specified in TYPED_TEST_SUITE.  Sit back and be
+// happy that you don't have to define them multiple times.
+
+#endif  // GTEST_HAS_TYPED_TEST
+
+#if GTEST_HAS_TYPED_TEST_P
+
+using testing::Types;
+
+// Sometimes, however, you don't yet know all the types that you want
+// to test when you write the tests.  For example, if you are the
+// author of an interface and expect other people to implement it, you
+// might want to write a set of tests to make sure each implementation
+// conforms to some basic requirements, but you don't know what
+// implementations will be written in the future.
+//
+// How can you write the tests without committing to the type
+// parameters?  That's what "type-parameterized tests" can do for you.
+// It is a bit more involved than typed tests, but in return you get a
+// test pattern that can be reused in many contexts, which is a big
+// win.  Here's how you do it:
+
+// First, define a test fixture class template.  Here we just reuse
+// the PrimeTableTest fixture defined earlier:
+
+template <class T>
+class PrimeTableTest2 : public PrimeTableTest<T> {
+};
+
+// Then, declare the test case.  The argument is the name of the test
+// fixture, and also the name of the test case (as usual).  The _P
+// suffix is for "parameterized" or "pattern".
+TYPED_TEST_SUITE_P(PrimeTableTest2);
+
+// Next, use TYPED_TEST_P(TestCaseName, TestName) to define a test,
+// similar to what you do with TEST_F.
+TYPED_TEST_P(PrimeTableTest2, ReturnsFalseForNonPrimes) {
+  EXPECT_FALSE(this->table_->IsPrime(-5));
+  EXPECT_FALSE(this->table_->IsPrime(0));
+  EXPECT_FALSE(this->table_->IsPrime(1));
+  EXPECT_FALSE(this->table_->IsPrime(4));
+  EXPECT_FALSE(this->table_->IsPrime(6));
+  EXPECT_FALSE(this->table_->IsPrime(100));
+}
+
+TYPED_TEST_P(PrimeTableTest2, ReturnsTrueForPrimes) {
+  EXPECT_TRUE(this->table_->IsPrime(2));
+  EXPECT_TRUE(this->table_->IsPrime(3));
+  EXPECT_TRUE(this->table_->IsPrime(5));
+  EXPECT_TRUE(this->table_->IsPrime(7));
+  EXPECT_TRUE(this->table_->IsPrime(11));
+  EXPECT_TRUE(this->table_->IsPrime(131));
+}
+
+TYPED_TEST_P(PrimeTableTest2, CanGetNextPrime) {
+  EXPECT_EQ(2, this->table_->GetNextPrime(0));
+  EXPECT_EQ(3, this->table_->GetNextPrime(2));
+  EXPECT_EQ(5, this->table_->GetNextPrime(3));
+  EXPECT_EQ(7, this->table_->GetNextPrime(5));
+  EXPECT_EQ(11, this->table_->GetNextPrime(7));
+  EXPECT_EQ(131, this->table_->GetNextPrime(128));
+}
+
+// Type-parameterized tests involve one extra step: you have to
+// enumerate the tests you defined:
+REGISTER_TYPED_TEST_SUITE_P(
+    PrimeTableTest2,  // The first argument is the test case name.
+    // The rest of the arguments are the test names.
+    ReturnsFalseForNonPrimes, ReturnsTrueForPrimes, CanGetNextPrime);
+
+// At this point the test pattern is done.  However, you don't have
+// any real test yet as you haven't said which types you want to run
+// the tests with.
+
+// To turn the abstract test pattern into real tests, you instantiate
+// it with a list of types.  Usually the test pattern will be defined
+// in a .h file, and anyone can #include and instantiate it.  You can
+// even instantiate it more than once in the same program.  To tell
+// different instances apart, you give each of them a name, which will
+// become part of the test case name and can be used in test filters.
+
+// The list of types we want to test.  Note that it doesn't have to be
+// defined at the time we write the TYPED_TEST_P()s.
+typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable>
+    PrimeTableImplementations;
+INSTANTIATE_TYPED_TEST_SUITE_P(OnTheFlyAndPreCalculated,    // Instance name
+                               PrimeTableTest2,             // Test case name
+                               PrimeTableImplementations);  // Type list
+
+#endif  // GTEST_HAS_TYPED_TEST_P
+}  // namespace
diff --git a/3rdparty/gtest/samples/sample7_unittest.cc b/3rdparty/gtest/samples/sample7_unittest.cc
new file mode 100644
index 0000000..e0efc29
--- /dev/null
+++ b/3rdparty/gtest/samples/sample7_unittest.cc
@@ -0,0 +1,117 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// This sample shows how to test common properties of multiple
+// implementations of an interface (aka interface tests) using
+// value-parameterized tests. Each test in the test case has
+// a parameter that is an interface pointer to an implementation
+// tested.
+
+// The interface and its implementations are in this header.
+#include "prime_tables.h"
+
+#include "gtest/gtest.h"
+namespace {
+
+using ::testing::TestWithParam;
+using ::testing::Values;
+
+// As a general rule, to prevent a test from affecting the tests that come
+// after it, you should create and destroy the tested objects for each test
+// instead of reusing them.  In this sample we will define a simple factory
+// function for PrimeTable objects.  We will instantiate objects in test's
+// SetUp() method and delete them in TearDown() method.
+typedef PrimeTable* CreatePrimeTableFunc();
+
+PrimeTable* CreateOnTheFlyPrimeTable() {
+  return new OnTheFlyPrimeTable();
+}
+
+template <size_t max_precalculated>
+PrimeTable* CreatePreCalculatedPrimeTable() {
+  return new PreCalculatedPrimeTable(max_precalculated);
+}
+
+// Inside the test body, fixture constructor, SetUp(), and TearDown() you
+// can refer to the test parameter by GetParam().  In this case, the test
+// parameter is a factory function which we call in fixture's SetUp() to
+// create and store an instance of PrimeTable.
+class PrimeTableTestSmpl7 : public TestWithParam<CreatePrimeTableFunc*> {
+ public:
+  ~PrimeTableTestSmpl7() override { delete table_; }
+  void SetUp() override { table_ = (*GetParam())(); }
+  void TearDown() override {
+    delete table_;
+    table_ = nullptr;
+  }
+
+ protected:
+  PrimeTable* table_;
+};
+
+TEST_P(PrimeTableTestSmpl7, ReturnsFalseForNonPrimes) {
+  EXPECT_FALSE(table_->IsPrime(-5));
+  EXPECT_FALSE(table_->IsPrime(0));
+  EXPECT_FALSE(table_->IsPrime(1));
+  EXPECT_FALSE(table_->IsPrime(4));
+  EXPECT_FALSE(table_->IsPrime(6));
+  EXPECT_FALSE(table_->IsPrime(100));
+}
+
+TEST_P(PrimeTableTestSmpl7, ReturnsTrueForPrimes) {
+  EXPECT_TRUE(table_->IsPrime(2));
+  EXPECT_TRUE(table_->IsPrime(3));
+  EXPECT_TRUE(table_->IsPrime(5));
+  EXPECT_TRUE(table_->IsPrime(7));
+  EXPECT_TRUE(table_->IsPrime(11));
+  EXPECT_TRUE(table_->IsPrime(131));
+}
+
+TEST_P(PrimeTableTestSmpl7, CanGetNextPrime) {
+  EXPECT_EQ(2, table_->GetNextPrime(0));
+  EXPECT_EQ(3, table_->GetNextPrime(2));
+  EXPECT_EQ(5, table_->GetNextPrime(3));
+  EXPECT_EQ(7, table_->GetNextPrime(5));
+  EXPECT_EQ(11, table_->GetNextPrime(7));
+  EXPECT_EQ(131, table_->GetNextPrime(128));
+}
+
+// In order to run value-parameterized tests, you need to instantiate them,
+// or bind them to a list of values which will be used as test parameters.
+// You can instantiate them in a different translation module, or even
+// instantiate them several times.
+//
+// Here, we instantiate our tests with a list of two PrimeTable object
+// factory functions:
+INSTANTIATE_TEST_SUITE_P(OnTheFlyAndPreCalculated, PrimeTableTestSmpl7,
+                         Values(&CreateOnTheFlyPrimeTable,
+                                &CreatePreCalculatedPrimeTable<1000>));
+
+}  // namespace
diff --git a/3rdparty/gtest/samples/sample8_unittest.cc b/3rdparty/gtest/samples/sample8_unittest.cc
new file mode 100644
index 0000000..10488b0
--- /dev/null
+++ b/3rdparty/gtest/samples/sample8_unittest.cc
@@ -0,0 +1,154 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// This sample shows how to test code relying on some global flag variables.
+// Combine() helps with generating all possible combinations of such flags,
+// and each test is given one combination as a parameter.
+
+// Use class definitions to test from this header.
+#include "prime_tables.h"
+
+#include "gtest/gtest.h"
+namespace {
+
+// Suppose we want to introduce a new, improved implementation of PrimeTable
+// which combines speed of PrecalcPrimeTable and versatility of
+// OnTheFlyPrimeTable (see prime_tables.h). Inside it instantiates both
+// PrecalcPrimeTable and OnTheFlyPrimeTable and uses the one that is more
+// appropriate under the circumstances. But in low memory conditions, it can be
+// told to instantiate without PrecalcPrimeTable instance at all and use only
+// OnTheFlyPrimeTable.
+class HybridPrimeTable : public PrimeTable {
+ public:
+  HybridPrimeTable(bool force_on_the_fly, int max_precalculated)
+      : on_the_fly_impl_(new OnTheFlyPrimeTable),
+        precalc_impl_(force_on_the_fly
+                          ? nullptr
+                          : new PreCalculatedPrimeTable(max_precalculated)),
+        max_precalculated_(max_precalculated) {}
+  ~HybridPrimeTable() override {
+    delete on_the_fly_impl_;
+    delete precalc_impl_;
+  }
+
+  bool IsPrime(int n) const override {
+    if (precalc_impl_ != nullptr && n < max_precalculated_)
+      return precalc_impl_->IsPrime(n);
+    else
+      return on_the_fly_impl_->IsPrime(n);
+  }
+
+  int GetNextPrime(int p) const override {
+    int next_prime = -1;
+    if (precalc_impl_ != nullptr && p < max_precalculated_)
+      next_prime = precalc_impl_->GetNextPrime(p);
+
+    return next_prime != -1 ? next_prime : on_the_fly_impl_->GetNextPrime(p);
+  }
+
+ private:
+  OnTheFlyPrimeTable* on_the_fly_impl_;
+  PreCalculatedPrimeTable* precalc_impl_;
+  int max_precalculated_;
+};
+
+using ::testing::TestWithParam;
+using ::testing::Bool;
+using ::testing::Values;
+using ::testing::Combine;
+
+// To test all code paths for HybridPrimeTable we must test it with numbers
+// both within and outside PreCalculatedPrimeTable's capacity and also with
+// PreCalculatedPrimeTable disabled. We do this by defining fixture which will
+// accept different combinations of parameters for instantiating a
+// HybridPrimeTable instance.
+class PrimeTableTest : public TestWithParam< ::std::tuple<bool, int> > {
+ protected:
+  void SetUp() override {
+    bool force_on_the_fly;
+    int max_precalculated;
+    std::tie(force_on_the_fly, max_precalculated) = GetParam();
+    table_ = new HybridPrimeTable(force_on_the_fly, max_precalculated);
+  }
+  void TearDown() override {
+    delete table_;
+    table_ = nullptr;
+  }
+  HybridPrimeTable* table_;
+};
+
+TEST_P(PrimeTableTest, ReturnsFalseForNonPrimes) {
+  // Inside the test body, you can refer to the test parameter by GetParam().
+  // In this case, the test parameter is a PrimeTable interface pointer which
+  // we can use directly.
+  // Please note that you can also save it in the fixture's SetUp() method
+  // or constructor and use saved copy in the tests.
+
+  EXPECT_FALSE(table_->IsPrime(-5));
+  EXPECT_FALSE(table_->IsPrime(0));
+  EXPECT_FALSE(table_->IsPrime(1));
+  EXPECT_FALSE(table_->IsPrime(4));
+  EXPECT_FALSE(table_->IsPrime(6));
+  EXPECT_FALSE(table_->IsPrime(100));
+}
+
+TEST_P(PrimeTableTest, ReturnsTrueForPrimes) {
+  EXPECT_TRUE(table_->IsPrime(2));
+  EXPECT_TRUE(table_->IsPrime(3));
+  EXPECT_TRUE(table_->IsPrime(5));
+  EXPECT_TRUE(table_->IsPrime(7));
+  EXPECT_TRUE(table_->IsPrime(11));
+  EXPECT_TRUE(table_->IsPrime(131));
+}
+
+TEST_P(PrimeTableTest, CanGetNextPrime) {
+  EXPECT_EQ(2, table_->GetNextPrime(0));
+  EXPECT_EQ(3, table_->GetNextPrime(2));
+  EXPECT_EQ(5, table_->GetNextPrime(3));
+  EXPECT_EQ(7, table_->GetNextPrime(5));
+  EXPECT_EQ(11, table_->GetNextPrime(7));
+  EXPECT_EQ(131, table_->GetNextPrime(128));
+}
+
+// In order to run value-parameterized tests, you need to instantiate them,
+// or bind them to a list of values which will be used as test parameters.
+// You can instantiate them in a different translation module, or even
+// instantiate them several times.
+//
+// Here, we instantiate our tests with a list of parameters. We must combine
+// all variations of the boolean flag suppressing PrecalcPrimeTable and some
+// meaningful values for tests. We choose a small value (1), and a value that
+// will put some of the tested numbers beyond the capability of the
+// PrecalcPrimeTable instance and some inside it (10). Combine will produce all
+// possible combinations.
+INSTANTIATE_TEST_SUITE_P(MeaningfulTestParameters, PrimeTableTest,
+                         Combine(Bool(), Values(1, 10)));
+
+}  // namespace
diff --git a/3rdparty/gtest/samples/sample9_unittest.cc b/3rdparty/gtest/samples/sample9_unittest.cc
new file mode 100644
index 0000000..e502d08
--- /dev/null
+++ b/3rdparty/gtest/samples/sample9_unittest.cc
@@ -0,0 +1,156 @@
+// Copyright 2009 Google Inc. All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// This sample shows how to use Google Test listener API to implement
+// an alternative console output and how to use the UnitTest reflection API
+// to enumerate test cases and tests and to inspect their results.
+
+#include <stdio.h>
+
+#include "gtest/gtest.h"
+
+using ::testing::EmptyTestEventListener;
+using ::testing::InitGoogleTest;
+using ::testing::Test;
+using ::testing::TestCase;
+using ::testing::TestEventListeners;
+using ::testing::TestInfo;
+using ::testing::TestPartResult;
+using ::testing::UnitTest;
+namespace {
+// Provides alternative output mode which produces minimal amount of
+// information about tests.
+class TersePrinter : public EmptyTestEventListener {
+ private:
+  // Called before any test activity starts.
+  void OnTestProgramStart(const UnitTest& /* unit_test */) override {}
+
+  // Called after all test activities have ended.
+  void OnTestProgramEnd(const UnitTest& unit_test) override {
+    fprintf(stdout, "TEST %s\n", unit_test.Passed() ? "PASSED" : "FAILED");
+    fflush(stdout);
+  }
+
+  // Called before a test starts.
+  void OnTestStart(const TestInfo& test_info) override {
+    fprintf(stdout,
+            "*** Test %s.%s starting.\n",
+            test_info.test_case_name(),
+            test_info.name());
+    fflush(stdout);
+  }
+
+  // Called after a failed assertion or a SUCCEED() invocation.
+  void OnTestPartResult(const TestPartResult& test_part_result) override {
+    fprintf(stdout,
+            "%s in %s:%d\n%s\n",
+            test_part_result.failed() ? "*** Failure" : "Success",
+            test_part_result.file_name(),
+            test_part_result.line_number(),
+            test_part_result.summary());
+    fflush(stdout);
+  }
+
+  // Called after a test ends.
+  void OnTestEnd(const TestInfo& test_info) override {
+    fprintf(stdout,
+            "*** Test %s.%s ending.\n",
+            test_info.test_case_name(),
+            test_info.name());
+    fflush(stdout);
+  }
+};  // class TersePrinter
+
+TEST(CustomOutputTest, PrintsMessage) {
+  printf("Printing something from the test body...\n");
+}
+
+TEST(CustomOutputTest, Succeeds) {
+  SUCCEED() << "SUCCEED() has been invoked from here";
+}
+
+TEST(CustomOutputTest, Fails) {
+  EXPECT_EQ(1, 2)
+      << "This test fails in order to demonstrate alternative failure messages";
+}
+}  // namespace
+
+int main(int argc, char **argv) {
+  InitGoogleTest(&argc, argv);
+
+  bool terse_output = false;
+  if (argc > 1 && strcmp(argv[1], "--terse_output") == 0 )
+    terse_output = true;
+  else
+    printf("%s\n", "Run this program with --terse_output to change the way "
+           "it prints its output.");
+
+  UnitTest& unit_test = *UnitTest::GetInstance();
+
+  // If we are given the --terse_output command line flag, suppresses the
+  // standard output and attaches own result printer.
+  if (terse_output) {
+    TestEventListeners& listeners = unit_test.listeners();
+
+    // Removes the default console output listener from the list so it will
+    // not receive events from Google Test and won't print any output. Since
+    // this operation transfers ownership of the listener to the caller we
+    // have to delete it as well.
+    delete listeners.Release(listeners.default_result_printer());
+
+    // Adds the custom output listener to the list. It will now receive
+    // events from Google Test and print the alternative output. We don't
+    // have to worry about deleting it since Google Test assumes ownership
+    // over it after adding it to the list.
+    listeners.Append(new TersePrinter);
+  }
+  int ret_val = RUN_ALL_TESTS();
+
+  // This is an example of using the UnitTest reflection API to inspect test
+  // results. Here we discount failures from the tests we expected to fail.
+  int unexpectedly_failed_tests = 0;
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    const testing::TestSuite& test_suite = *unit_test.GetTestSuite(i);
+    for (int j = 0; j < test_suite.total_test_count(); ++j) {
+      const TestInfo& test_info = *test_suite.GetTestInfo(j);
+      // Counts failed tests that were not meant to fail (those without
+      // 'Fails' in the name).
+      if (test_info.result()->Failed() &&
+          strcmp(test_info.name(), "Fails") != 0) {
+        unexpectedly_failed_tests++;
+      }
+    }
+  }
+
+  // Test that were meant to fail should not affect the test program outcome.
+  if (unexpectedly_failed_tests == 0)
+    ret_val = 0;
+
+  return ret_val;
+}
diff --git a/3rdparty/gtest/scripts/common.py b/3rdparty/gtest/scripts/common.py
new file mode 100644
index 0000000..3c0347a
--- /dev/null
+++ b/3rdparty/gtest/scripts/common.py
@@ -0,0 +1,83 @@
+# Copyright 2013 Google Inc. All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Shared utilities for writing scripts for Google Test/Mock."""
+
+__author__ = 'wan@google.com (Zhanyong Wan)'
+
+
+import os
+import re
+
+
+# Matches the line from 'svn info .' output that describes what SVN
+# path the current local directory corresponds to.  For example, in
+# a googletest SVN workspace's trunk/test directory, the output will be:
+#
+# URL: https://googletest.googlecode.com/svn/trunk/test
+_SVN_INFO_URL_RE = re.compile(r'^URL: https://(\w+)\.googlecode\.com/svn(.*)')
+
+
+def GetCommandOutput(command):
+  """Runs the shell command and returns its stdout as a list of lines."""
+
+  f = os.popen(command, 'r')
+  lines = [line.strip() for line in f.readlines()]
+  f.close()
+  return lines
+
+
+def GetSvnInfo():
+  """Returns the project name and the current SVN workspace's root path."""
+
+  for line in GetCommandOutput('svn info .'):
+    m = _SVN_INFO_URL_RE.match(line)
+    if m:
+      project = m.group(1)  # googletest or googlemock
+      rel_path = m.group(2)
+      root = os.path.realpath(rel_path.count('/') * '../')
+      return project, root
+
+  return None, None
+
+
+def GetSvnTrunk():
+  """Returns the current SVN workspace's trunk root path."""
+
+  _, root = GetSvnInfo()
+  return root + '/trunk' if root else None
+
+
+def IsInGTestSvn():
+  project, _ = GetSvnInfo()
+  return project == 'googletest'
+
+
+def IsInGMockSvn():
+  project, _ = GetSvnInfo()
+  return project == 'googlemock'
diff --git a/3rdparty/gtest/scripts/fuse_gtest_files.py b/3rdparty/gtest/scripts/fuse_gtest_files.py
new file mode 100644
index 0000000..d0dd464
--- /dev/null
+++ b/3rdparty/gtest/scripts/fuse_gtest_files.py
@@ -0,0 +1,253 @@
+#!/usr/bin/env python
+#
+# Copyright 2009, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""fuse_gtest_files.py v0.2.0
+Fuses Google Test source code into a .h file and a .cc file.
+
+SYNOPSIS
+       fuse_gtest_files.py [GTEST_ROOT_DIR] OUTPUT_DIR
+
+       Scans GTEST_ROOT_DIR for Google Test source code, and generates
+       two files: OUTPUT_DIR/gtest/gtest.h and OUTPUT_DIR/gtest/gtest-all.cc.
+       Then you can build your tests by adding OUTPUT_DIR to the include
+       search path and linking with OUTPUT_DIR/gtest/gtest-all.cc.  These
+       two files contain everything you need to use Google Test.  Hence
+       you can "install" Google Test by copying them to wherever you want.
+
+       GTEST_ROOT_DIR can be omitted and defaults to the parent
+       directory of the directory holding this script.
+
+EXAMPLES
+       ./fuse_gtest_files.py fused_gtest
+       ./fuse_gtest_files.py path/to/unpacked/gtest fused_gtest
+
+This tool is experimental.  In particular, it assumes that there is no
+conditional inclusion of Google Test headers.  Please report any
+problems to googletestframework@googlegroups.com.  You can read
+https://github.com/google/googletest/blob/master/googletest/docs/advanced.md for
+more information.
+"""
+
+__author__ = 'wan@google.com (Zhanyong Wan)'
+
+import os
+import re
+try:
+  from sets import Set as set  # For Python 2.3 compatibility
+except ImportError:
+  pass
+import sys
+
+# We assume that this file is in the scripts/ directory in the Google
+# Test root directory.
+DEFAULT_GTEST_ROOT_DIR = os.path.join(os.path.dirname(__file__), '..')
+
+# Regex for matching '#include "gtest/..."'.
+INCLUDE_GTEST_FILE_REGEX = re.compile(r'^\s*#\s*include\s*"(gtest/.+)"')
+
+# Regex for matching '#include "src/..."'.
+INCLUDE_SRC_FILE_REGEX = re.compile(r'^\s*#\s*include\s*"(src/.+)"')
+
+# Where to find the source seed files.
+GTEST_H_SEED = 'include/gtest/gtest.h'
+GTEST_SPI_H_SEED = 'include/gtest/gtest-spi.h'
+GTEST_ALL_CC_SEED = 'src/gtest-all.cc'
+
+# Where to put the generated files.
+GTEST_H_OUTPUT = 'gtest/gtest.h'
+GTEST_ALL_CC_OUTPUT = 'gtest/gtest-all.cc'
+
+
+def VerifyFileExists(directory, relative_path):
+  """Verifies that the given file exists; aborts on failure.
+
+  relative_path is the file path relative to the given directory.
+  """
+
+  if not os.path.isfile(os.path.join(directory, relative_path)):
+    print('ERROR: Cannot find %s in directory %s.' % (relative_path,
+                                                      directory))
+    print('Please either specify a valid project root directory '
+          'or omit it on the command line.')
+    sys.exit(1)
+
+
+def ValidateGTestRootDir(gtest_root):
+  """Makes sure gtest_root points to a valid gtest root directory.
+
+  The function aborts the program on failure.
+  """
+
+  VerifyFileExists(gtest_root, GTEST_H_SEED)
+  VerifyFileExists(gtest_root, GTEST_ALL_CC_SEED)
+
+
+def VerifyOutputFile(output_dir, relative_path):
+  """Verifies that the given output file path is valid.
+
+  relative_path is relative to the output_dir directory.
+  """
+
+  # Makes sure the output file either doesn't exist or can be overwritten.
+  output_file = os.path.join(output_dir, relative_path)
+  if os.path.exists(output_file):
+    # TODO(wan@google.com): The following user-interaction doesn't
+    # work with automated processes.  We should provide a way for the
+    # Makefile to force overwriting the files.
+    print('%s already exists in directory %s - overwrite it? (y/N) ' %
+          (relative_path, output_dir))
+    answer = sys.stdin.readline().strip()
+    if answer not in ['y', 'Y']:
+      print('ABORTED.')
+      sys.exit(1)
+
+  # Makes sure the directory holding the output file exists; creates
+  # it and all its ancestors if necessary.
+  parent_directory = os.path.dirname(output_file)
+  if not os.path.isdir(parent_directory):
+    os.makedirs(parent_directory)
+
+
+def ValidateOutputDir(output_dir):
+  """Makes sure output_dir points to a valid output directory.
+
+  The function aborts the program on failure.
+  """
+
+  VerifyOutputFile(output_dir, GTEST_H_OUTPUT)
+  VerifyOutputFile(output_dir, GTEST_ALL_CC_OUTPUT)
+
+
+def FuseGTestH(gtest_root, output_dir):
+  """Scans folder gtest_root to generate gtest/gtest.h in output_dir."""
+
+  output_file = open(os.path.join(output_dir, GTEST_H_OUTPUT), 'w')
+  processed_files = set()  # Holds all gtest headers we've processed.
+
+  def ProcessFile(gtest_header_path):
+    """Processes the given gtest header file."""
+
+    # We don't process the same header twice.
+    if gtest_header_path in processed_files:
+      return
+
+    processed_files.add(gtest_header_path)
+
+    # Reads each line in the given gtest header.
+    for line in open(os.path.join(gtest_root, gtest_header_path), 'r'):
+      m = INCLUDE_GTEST_FILE_REGEX.match(line)
+      if m:
+        # It's '#include "gtest/..."' - let's process it recursively.
+        ProcessFile('include/' + m.group(1))
+      else:
+        # Otherwise we copy the line unchanged to the output file.
+        output_file.write(line)
+
+  ProcessFile(GTEST_H_SEED)
+  output_file.close()
+
+
+def FuseGTestAllCcToFile(gtest_root, output_file):
+  """Scans folder gtest_root to generate gtest/gtest-all.cc in output_file."""
+
+  processed_files = set()
+
+  def ProcessFile(gtest_source_file):
+    """Processes the given gtest source file."""
+
+    # We don't process the same #included file twice.
+    if gtest_source_file in processed_files:
+      return
+
+    processed_files.add(gtest_source_file)
+
+    # Reads each line in the given gtest source file.
+    for line in open(os.path.join(gtest_root, gtest_source_file), 'r'):
+      m = INCLUDE_GTEST_FILE_REGEX.match(line)
+      if m:
+        if 'include/' + m.group(1) == GTEST_SPI_H_SEED:
+          # It's '#include "gtest/gtest-spi.h"'.  This file is not
+          # #included by "gtest/gtest.h", so we need to process it.
+          ProcessFile(GTEST_SPI_H_SEED)
+        else:
+          # It's '#include "gtest/foo.h"' where foo is not gtest-spi.
+          # We treat it as '#include "gtest/gtest.h"', as all other
+          # gtest headers are being fused into gtest.h and cannot be
+          # #included directly.
+
+          # There is no need to #include "gtest/gtest.h" more than once.
+          if not GTEST_H_SEED in processed_files:
+            processed_files.add(GTEST_H_SEED)
+            output_file.write('#include "%s"\n' % (GTEST_H_OUTPUT,))
+      else:
+        m = INCLUDE_SRC_FILE_REGEX.match(line)
+        if m:
+          # It's '#include "src/foo"' - let's process it recursively.
+          ProcessFile(m.group(1))
+        else:
+          output_file.write(line)
+
+  ProcessFile(GTEST_ALL_CC_SEED)
+
+
+def FuseGTestAllCc(gtest_root, output_dir):
+  """Scans folder gtest_root to generate gtest/gtest-all.cc in output_dir."""
+
+  output_file = open(os.path.join(output_dir, GTEST_ALL_CC_OUTPUT), 'w')
+  FuseGTestAllCcToFile(gtest_root, output_file)
+  output_file.close()
+
+
+def FuseGTest(gtest_root, output_dir):
+  """Fuses gtest.h and gtest-all.cc."""
+
+  ValidateGTestRootDir(gtest_root)
+  ValidateOutputDir(output_dir)
+
+  FuseGTestH(gtest_root, output_dir)
+  FuseGTestAllCc(gtest_root, output_dir)
+
+
+def main():
+  argc = len(sys.argv)
+  if argc == 2:
+    # fuse_gtest_files.py OUTPUT_DIR
+    FuseGTest(DEFAULT_GTEST_ROOT_DIR, sys.argv[1])
+  elif argc == 3:
+    # fuse_gtest_files.py GTEST_ROOT_DIR OUTPUT_DIR
+    FuseGTest(sys.argv[1], sys.argv[2])
+  else:
+    print(__doc__)
+    sys.exit(1)
+
+
+if __name__ == '__main__':
+  main()
diff --git a/3rdparty/gtest/scripts/gen_gtest_pred_impl.py b/3rdparty/gtest/scripts/gen_gtest_pred_impl.py
new file mode 100644
index 0000000..b43efdf
--- /dev/null
+++ b/3rdparty/gtest/scripts/gen_gtest_pred_impl.py
@@ -0,0 +1,730 @@
+#!/usr/bin/env python
+#
+# Copyright 2006, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""gen_gtest_pred_impl.py v0.1
+
+Generates the implementation of Google Test predicate assertions and
+accompanying tests.
+
+Usage:
+
+  gen_gtest_pred_impl.py MAX_ARITY
+
+where MAX_ARITY is a positive integer.
+
+The command generates the implementation of up-to MAX_ARITY-ary
+predicate assertions, and writes it to file gtest_pred_impl.h in the
+directory where the script is.  It also generates the accompanying
+unit test in file gtest_pred_impl_unittest.cc.
+"""
+
+__author__ = 'wan@google.com (Zhanyong Wan)'
+
+import os
+import sys
+import time
+
+# Where this script is.
+SCRIPT_DIR = os.path.dirname(sys.argv[0])
+
+# Where to store the generated header.
+HEADER = os.path.join(SCRIPT_DIR, '../include/gtest/gtest_pred_impl.h')
+
+# Where to store the generated unit test.
+UNIT_TEST = os.path.join(SCRIPT_DIR, '../test/gtest_pred_impl_unittest.cc')
+
+
+def HeaderPreamble(n):
+  """Returns the preamble for the header file.
+
+  Args:
+    n:  the maximum arity of the predicate macros to be generated.
+  """
+
+  # A map that defines the values used in the preamble template.
+  DEFS = {
+    'today' : time.strftime('%m/%d/%Y'),
+    'year' : time.strftime('%Y'),
+    'command' : '%s %s' % (os.path.basename(sys.argv[0]), n),
+    'n' : n
+    }
+
+  return (
+"""// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// This file is AUTOMATICALLY GENERATED on %(today)s by command
+// '%(command)s'.  DO NOT EDIT BY HAND!
+//
+// Implements a family of generic predicate assertion macros.
+
+#ifndef GTEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
+#define GTEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
+
+#include "gtest/gtest.h"
+
+namespace testing {
+
+// This header implements a family of generic predicate assertion
+// macros:
+//
+//   ASSERT_PRED_FORMAT1(pred_format, v1)
+//   ASSERT_PRED_FORMAT2(pred_format, v1, v2)
+//   ...
+//
+// where pred_format is a function or functor that takes n (in the
+// case of ASSERT_PRED_FORMATn) values and their source expression
+// text, and returns a testing::AssertionResult.  See the definition
+// of ASSERT_EQ in gtest.h for an example.
+//
+// If you don't care about formatting, you can use the more
+// restrictive version:
+//
+//   ASSERT_PRED1(pred, v1)
+//   ASSERT_PRED2(pred, v1, v2)
+//   ...
+//
+// where pred is an n-ary function or functor that returns bool,
+// and the values v1, v2, ..., must support the << operator for
+// streaming to std::ostream.
+//
+// We also define the EXPECT_* variations.
+//
+// For now we only support predicates whose arity is at most %(n)s.
+// Please email googletestframework@googlegroups.com if you need
+// support for higher arities.
+
+// GTEST_ASSERT_ is the basic statement to which all of the assertions
+// in this file reduce.  Don't use this in your code.
+
+#define GTEST_ASSERT_(expression, on_failure) \\
+  GTEST_AMBIGUOUS_ELSE_BLOCKER_ \\
+  if (const ::testing::AssertionResult gtest_ar = (expression)) \\
+    ; \\
+  else \\
+    on_failure(gtest_ar.failure_message())
+""" % DEFS)
+
+
+def Arity(n):
+  """Returns the English name of the given arity."""
+
+  if n < 0:
+    return None
+  elif n <= 3:
+    return ['nullary', 'unary', 'binary', 'ternary'][n]
+  else:
+    return '%s-ary' % n
+
+
+def Title(word):
+  """Returns the given word in title case.  The difference between
+  this and string's title() method is that Title('4-ary') is '4-ary'
+  while '4-ary'.title() is '4-Ary'."""
+
+  return word[0].upper() + word[1:]
+
+
+def OneTo(n):
+  """Returns the list [1, 2, 3, ..., n]."""
+
+  return range(1, n + 1)
+
+
+def Iter(n, format, sep=''):
+  """Given a positive integer n, a format string that contains 0 or
+  more '%s' format specs, and optionally a separator string, returns
+  the join of n strings, each formatted with the format string on an
+  iterator ranged from 1 to n.
+
+  Example:
+
+  Iter(3, 'v%s', sep=', ') returns 'v1, v2, v3'.
+  """
+
+  # How many '%s' specs are in format?
+  spec_count = len(format.split('%s')) - 1
+  return sep.join([format % (spec_count * (i,)) for i in OneTo(n)])
+
+
+def ImplementationForArity(n):
+  """Returns the implementation of n-ary predicate assertions."""
+
+  # A map the defines the values used in the implementation template.
+  DEFS = {
+    'n' : str(n),
+    'vs' : Iter(n, 'v%s', sep=', '),
+    'vts' : Iter(n, '#v%s', sep=', '),
+    'arity' : Arity(n),
+    'Arity' : Title(Arity(n))
+    }
+
+  impl = """
+
+// Helper function for implementing {EXPECT|ASSERT}_PRED%(n)s.  Don't use
+// this in your code.
+template <typename Pred""" % DEFS
+
+  impl += Iter(n, """,
+          typename T%s""")
+
+  impl += """>
+AssertionResult AssertPred%(n)sHelper(const char* pred_text""" % DEFS
+
+  impl += Iter(n, """,
+                                  const char* e%s""")
+
+  impl += """,
+                                  Pred pred"""
+
+  impl += Iter(n, """,
+                                  const T%s& v%s""")
+
+  impl += """) {
+  if (pred(%(vs)s)) return AssertionSuccess();
+
+""" % DEFS
+
+  impl += '  return AssertionFailure() << pred_text << "("'
+
+  impl += Iter(n, """
+                            << e%s""", sep=' << ", "')
+
+  impl += ' << ") evaluates to false, where"'
+
+  impl += Iter(n, """
+                            << "\\n" << e%s << " evaluates to " << v%s""")
+
+  impl += """;
+}
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT%(n)s.
+// Don't use this in your code.
+#define GTEST_PRED_FORMAT%(n)s_(pred_format, %(vs)s, on_failure)\\
+  GTEST_ASSERT_(pred_format(%(vts)s, %(vs)s), \\
+                on_failure)
+
+// Internal macro for implementing {EXPECT|ASSERT}_PRED%(n)s.  Don't use
+// this in your code.
+#define GTEST_PRED%(n)s_(pred, %(vs)s, on_failure)\\
+  GTEST_ASSERT_(::testing::AssertPred%(n)sHelper(#pred""" % DEFS
+
+  impl += Iter(n, """, \\
+                                             #v%s""")
+
+  impl += """, \\
+                                             pred"""
+
+  impl += Iter(n, """, \\
+                                             v%s""")
+
+  impl += """), on_failure)
+
+// %(Arity)s predicate assertion macros.
+#define EXPECT_PRED_FORMAT%(n)s(pred_format, %(vs)s) \\
+  GTEST_PRED_FORMAT%(n)s_(pred_format, %(vs)s, GTEST_NONFATAL_FAILURE_)
+#define EXPECT_PRED%(n)s(pred, %(vs)s) \\
+  GTEST_PRED%(n)s_(pred, %(vs)s, GTEST_NONFATAL_FAILURE_)
+#define ASSERT_PRED_FORMAT%(n)s(pred_format, %(vs)s) \\
+  GTEST_PRED_FORMAT%(n)s_(pred_format, %(vs)s, GTEST_FATAL_FAILURE_)
+#define ASSERT_PRED%(n)s(pred, %(vs)s) \\
+  GTEST_PRED%(n)s_(pred, %(vs)s, GTEST_FATAL_FAILURE_)
+
+""" % DEFS
+
+  return impl
+
+
+def HeaderPostamble():
+  """Returns the postamble for the header file."""
+
+  return """
+
+}  // namespace testing
+
+#endif  // GTEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
+"""
+
+
+def GenerateFile(path, content):
+  """Given a file path and a content string
+     overwrites it with the given content.
+  """
+  print 'Updating file %s . . .' % path
+  f = file(path, 'w+')
+  print >>f, content,
+  f.close()
+
+  print 'File %s has been updated.' % path
+
+
+def GenerateHeader(n):
+  """Given the maximum arity n, updates the header file that implements
+  the predicate assertions.
+  """
+  GenerateFile(HEADER,
+               HeaderPreamble(n)
+               + ''.join([ImplementationForArity(i) for i in OneTo(n)])
+               + HeaderPostamble())
+
+
+def UnitTestPreamble():
+  """Returns the preamble for the unit test file."""
+
+  # A map that defines the values used in the preamble template.
+  DEFS = {
+    'today' : time.strftime('%m/%d/%Y'),
+    'year' : time.strftime('%Y'),
+    'command' : '%s %s' % (os.path.basename(sys.argv[0]), sys.argv[1]),
+    }
+
+  return (
+"""// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// This file is AUTOMATICALLY GENERATED on %(today)s by command
+// '%(command)s'.  DO NOT EDIT BY HAND!
+
+// Regression test for gtest_pred_impl.h
+//
+// This file is generated by a script and quite long.  If you intend to
+// learn how Google Test works by reading its unit tests, read
+// gtest_unittest.cc instead.
+//
+// This is intended as a regression test for the Google Test predicate
+// assertions.  We compile it as part of the gtest_unittest target
+// only to keep the implementation tidy and compact, as it is quite
+// involved to set up the stage for testing Google Test using Google
+// Test itself.
+//
+// Currently, gtest_unittest takes ~11 seconds to run in the testing
+// daemon.  In the future, if it grows too large and needs much more
+// time to finish, we should consider separating this file into a
+// stand-alone regression test.
+
+#include <iostream>
+
+#include "gtest/gtest.h"
+#include "gtest/gtest-spi.h"
+
+// A user-defined data type.
+struct Bool {
+  explicit Bool(int val) : value(val != 0) {}
+
+  bool operator>(int n) const { return value > Bool(n).value; }
+
+  Bool operator+(const Bool& rhs) const { return Bool(value + rhs.value); }
+
+  bool operator==(const Bool& rhs) const { return value == rhs.value; }
+
+  bool value;
+};
+
+// Enables Bool to be used in assertions.
+std::ostream& operator<<(std::ostream& os, const Bool& x) {
+  return os << (x.value ? "true" : "false");
+}
+
+""" % DEFS)
+
+
+def TestsForArity(n):
+  """Returns the tests for n-ary predicate assertions."""
+
+  # A map that defines the values used in the template for the tests.
+  DEFS = {
+    'n' : n,
+    'es' : Iter(n, 'e%s', sep=', '),
+    'vs' : Iter(n, 'v%s', sep=', '),
+    'vts' : Iter(n, '#v%s', sep=', '),
+    'tvs' : Iter(n, 'T%s v%s', sep=', '),
+    'int_vs' : Iter(n, 'int v%s', sep=', '),
+    'Bool_vs' : Iter(n, 'Bool v%s', sep=', '),
+    'types' : Iter(n, 'typename T%s', sep=', '),
+    'v_sum' : Iter(n, 'v%s', sep=' + '),
+    'arity' : Arity(n),
+    'Arity' : Title(Arity(n)),
+    }
+
+  tests = (
+"""// Sample functions/functors for testing %(arity)s predicate assertions.
+
+// A %(arity)s predicate function.
+template <%(types)s>
+bool PredFunction%(n)s(%(tvs)s) {
+  return %(v_sum)s > 0;
+}
+
+// The following two functions are needed to circumvent a bug in
+// gcc 2.95.3, which sometimes has problem with the above template
+// function.
+bool PredFunction%(n)sInt(%(int_vs)s) {
+  return %(v_sum)s > 0;
+}
+bool PredFunction%(n)sBool(%(Bool_vs)s) {
+  return %(v_sum)s > 0;
+}
+""" % DEFS)
+
+  tests += """
+// A %(arity)s predicate functor.
+struct PredFunctor%(n)s {
+  template <%(types)s>
+  bool operator()(""" % DEFS
+
+  tests += Iter(n, 'const T%s& v%s', sep=""",
+                  """)
+
+  tests += """) {
+    return %(v_sum)s > 0;
+  }
+};
+""" % DEFS
+
+  tests += """
+// A %(arity)s predicate-formatter function.
+template <%(types)s>
+testing::AssertionResult PredFormatFunction%(n)s(""" % DEFS
+
+  tests += Iter(n, 'const char* e%s', sep=""",
+                                             """)
+
+  tests += Iter(n, """,
+                                             const T%s& v%s""")
+
+  tests += """) {
+  if (PredFunction%(n)s(%(vs)s))
+    return testing::AssertionSuccess();
+
+  return testing::AssertionFailure()
+      << """ % DEFS
+
+  tests += Iter(n, 'e%s', sep=' << " + " << ')
+
+  tests += """
+      << " is expected to be positive, but evaluates to "
+      << %(v_sum)s << ".";
+}
+""" % DEFS
+
+  tests += """
+// A %(arity)s predicate-formatter functor.
+struct PredFormatFunctor%(n)s {
+  template <%(types)s>
+  testing::AssertionResult operator()(""" % DEFS
+
+  tests += Iter(n, 'const char* e%s', sep=""",
+                                      """)
+
+  tests += Iter(n, """,
+                                      const T%s& v%s""")
+
+  tests += """) const {
+    return PredFormatFunction%(n)s(%(es)s, %(vs)s);
+  }
+};
+""" % DEFS
+
+  tests += """
+// Tests for {EXPECT|ASSERT}_PRED_FORMAT%(n)s.
+
+class Predicate%(n)sTest : public testing::Test {
+ protected:
+  virtual void SetUp() {
+    expected_to_finish_ = true;
+    finished_ = false;""" % DEFS
+
+  tests += """
+    """ + Iter(n, 'n%s_ = ') + """0;
+  }
+"""
+
+  tests += """
+  virtual void TearDown() {
+    // Verifies that each of the predicate's arguments was evaluated
+    // exactly once."""
+
+  tests += ''.join(["""
+    EXPECT_EQ(1, n%s_) <<
+        "The predicate assertion didn't evaluate argument %s "
+        "exactly once.";""" % (i, i + 1) for i in OneTo(n)])
+
+  tests += """
+
+    // Verifies that the control flow in the test function is expected.
+    if (expected_to_finish_ && !finished_) {
+      FAIL() << "The predicate assertion unexpactedly aborted the test.";
+    } else if (!expected_to_finish_ && finished_) {
+      FAIL() << "The failed predicate assertion didn't abort the test "
+                "as expected.";
+    }
+  }
+
+  // true iff the test function is expected to run to finish.
+  static bool expected_to_finish_;
+
+  // true iff the test function did run to finish.
+  static bool finished_;
+""" % DEFS
+
+  tests += Iter(n, """
+  static int n%s_;""")
+
+  tests += """
+};
+
+bool Predicate%(n)sTest::expected_to_finish_;
+bool Predicate%(n)sTest::finished_;
+""" % DEFS
+
+  tests += Iter(n, """int Predicate%%(n)sTest::n%s_;
+""") % DEFS
+
+  tests += """
+typedef Predicate%(n)sTest EXPECT_PRED_FORMAT%(n)sTest;
+typedef Predicate%(n)sTest ASSERT_PRED_FORMAT%(n)sTest;
+typedef Predicate%(n)sTest EXPECT_PRED%(n)sTest;
+typedef Predicate%(n)sTest ASSERT_PRED%(n)sTest;
+""" % DEFS
+
+  def GenTest(use_format, use_assert, expect_failure,
+              use_functor, use_user_type):
+    """Returns the test for a predicate assertion macro.
+
+    Args:
+      use_format:     true iff the assertion is a *_PRED_FORMAT*.
+      use_assert:     true iff the assertion is a ASSERT_*.
+      expect_failure: true iff the assertion is expected to fail.
+      use_functor:    true iff the first argument of the assertion is
+                      a functor (as opposed to a function)
+      use_user_type:  true iff the predicate functor/function takes
+                      argument(s) of a user-defined type.
+
+    Example:
+
+      GenTest(1, 0, 0, 1, 0) returns a test that tests the behavior
+      of a successful EXPECT_PRED_FORMATn() that takes a functor
+      whose arguments have built-in types."""
+
+    if use_assert:
+      assrt = 'ASSERT'  # 'assert' is reserved, so we cannot use
+                        # that identifier here.
+    else:
+      assrt = 'EXPECT'
+
+    assertion = assrt + '_PRED'
+
+    if use_format:
+      pred_format = 'PredFormat'
+      assertion += '_FORMAT'
+    else:
+      pred_format = 'Pred'
+
+    assertion += '%(n)s' % DEFS
+
+    if use_functor:
+      pred_format_type = 'functor'
+      pred_format += 'Functor%(n)s()'
+    else:
+      pred_format_type = 'function'
+      pred_format += 'Function%(n)s'
+      if not use_format:
+        if use_user_type:
+          pred_format += 'Bool'
+        else:
+          pred_format += 'Int'
+
+    test_name = pred_format_type.title()
+
+    if use_user_type:
+      arg_type = 'user-defined type (Bool)'
+      test_name += 'OnUserType'
+      if expect_failure:
+        arg = 'Bool(n%s_++)'
+      else:
+        arg = 'Bool(++n%s_)'
+    else:
+      arg_type = 'built-in type (int)'
+      test_name += 'OnBuiltInType'
+      if expect_failure:
+        arg = 'n%s_++'
+      else:
+        arg = '++n%s_'
+
+    if expect_failure:
+      successful_or_failed = 'failed'
+      expected_or_not = 'expected.'
+      test_name +=  'Failure'
+    else:
+      successful_or_failed = 'successful'
+      expected_or_not = 'UNEXPECTED!'
+      test_name +=  'Success'
+
+    # A map that defines the values used in the test template.
+    defs = DEFS.copy()
+    defs.update({
+      'assert' : assrt,
+      'assertion' : assertion,
+      'test_name' : test_name,
+      'pf_type' : pred_format_type,
+      'pf' : pred_format,
+      'arg_type' : arg_type,
+      'arg' : arg,
+      'successful' : successful_or_failed,
+      'expected' : expected_or_not,
+      })
+
+    test = """
+// Tests a %(successful)s %(assertion)s where the
+// predicate-formatter is a %(pf_type)s on a %(arg_type)s.
+TEST_F(%(assertion)sTest, %(test_name)s) {""" % defs
+
+    indent = (len(assertion) + 3)*' '
+    extra_indent = ''
+
+    if expect_failure:
+      extra_indent = '  '
+      if use_assert:
+        test += """
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT"""
+      else:
+        test += """
+  EXPECT_NONFATAL_FAILURE({  // NOLINT"""
+
+    test += '\n' + extra_indent + """  %(assertion)s(%(pf)s""" % defs
+
+    test = test % defs
+    test += Iter(n, ',\n' + indent + extra_indent + '%(arg)s' % defs)
+    test += ');\n' + extra_indent + '  finished_ = true;\n'
+
+    if expect_failure:
+      test += '  }, "");\n'
+
+    test += '}\n'
+    return test
+
+  # Generates tests for all 2**6 = 64 combinations.
+  tests += ''.join([GenTest(use_format, use_assert, expect_failure,
+                            use_functor, use_user_type)
+                    for use_format in [0, 1]
+                    for use_assert in [0, 1]
+                    for expect_failure in [0, 1]
+                    for use_functor in [0, 1]
+                    for use_user_type in [0, 1]
+                    ])
+
+  return tests
+
+
+def UnitTestPostamble():
+  """Returns the postamble for the tests."""
+
+  return ''
+
+
+def GenerateUnitTest(n):
+  """Returns the tests for up-to n-ary predicate assertions."""
+
+  GenerateFile(UNIT_TEST,
+               UnitTestPreamble()
+               + ''.join([TestsForArity(i) for i in OneTo(n)])
+               + UnitTestPostamble())
+
+
+def _Main():
+  """The entry point of the script.  Generates the header file and its
+  unit test."""
+
+  if len(sys.argv) != 2:
+    print __doc__
+    print 'Author: ' + __author__
+    sys.exit(1)
+
+  n = int(sys.argv[1])
+  GenerateHeader(n)
+  GenerateUnitTest(n)
+
+
+if __name__ == '__main__':
+  _Main()
diff --git a/3rdparty/gtest/scripts/gtest-config.in b/3rdparty/gtest/scripts/gtest-config.in
new file mode 100644
index 0000000..780f843
--- /dev/null
+++ b/3rdparty/gtest/scripts/gtest-config.in
@@ -0,0 +1,274 @@
+#!/bin/sh
+
+# These variables are automatically filled in by the configure script.
+name="@PACKAGE_TARNAME@"
+version="@PACKAGE_VERSION@"
+
+show_usage()
+{
+  echo "Usage: gtest-config [OPTIONS...]"
+}
+
+show_help()
+{
+  show_usage
+  cat <<\EOF
+
+The `gtest-config' script provides access to the necessary compile and linking
+flags to connect with Google C++ Testing Framework, both in a build prior to
+installation, and on the system proper after installation. The installation
+overrides may be issued in combination with any other queries, but will only
+affect installation queries if called on a built but not installed gtest. The
+installation queries may not be issued with any other types of queries, and
+only one installation query may be made at a time. The version queries and
+compiler flag queries may be combined as desired but not mixed. Different
+version queries are always combined with logical "and" semantics, and only the
+last of any particular query is used while all previous ones ignored. All
+versions must be specified as a sequence of numbers separated by periods.
+Compiler flag queries output the union of the sets of flags when combined.
+
+ Examples:
+  gtest-config --min-version=1.0 || echo "Insufficient Google Test version."
+
+  g++ $(gtest-config --cppflags --cxxflags) -o foo.o -c foo.cpp
+  g++ $(gtest-config --ldflags --libs) -o foo foo.o
+
+  # When using a built but not installed Google Test:
+  g++ $(../../my_gtest_build/scripts/gtest-config ...) ...
+
+  # When using an installed Google Test, but with installation overrides:
+  export GTEST_PREFIX="/opt"
+  g++ $(gtest-config --libdir="/opt/lib64" ...) ...
+
+ Help:
+  --usage                    brief usage information
+  --help                     display this help message
+
+ Installation Overrides:
+  --prefix=<dir>             overrides the installation prefix
+  --exec-prefix=<dir>        overrides the executable installation prefix
+  --libdir=<dir>             overrides the library installation prefix
+  --includedir=<dir>         overrides the header file installation prefix
+
+ Installation Queries:
+  --prefix                   installation prefix
+  --exec-prefix              executable installation prefix
+  --libdir                   library installation directory
+  --includedir               header file installation directory
+  --version                  the version of the Google Test installation
+
+ Version Queries:
+  --min-version=VERSION      return 0 if the version is at least VERSION
+  --exact-version=VERSION    return 0 if the version is exactly VERSION
+  --max-version=VERSION      return 0 if the version is at most VERSION
+
+ Compilation Flag Queries:
+  --cppflags                 compile flags specific to the C-like preprocessors
+  --cxxflags                 compile flags appropriate for C++ programs
+  --ldflags                  linker flags
+  --libs                     libraries for linking
+
+EOF
+}
+
+# This function bounds our version with a min and a max. It uses some clever
+# POSIX-compliant variable expansion to portably do all the work in the shell
+# and avoid any dependency on a particular "sed" or "awk" implementation.
+# Notable is that it will only ever compare the first 3 components of versions.
+# Further components will be cleanly stripped off. All versions must be
+# unadorned, so "v1.0" will *not* work. The minimum version must be in $1, and
+# the max in $2. TODO(chandlerc@google.com): If this ever breaks, we should
+# investigate expanding this via autom4te from AS_VERSION_COMPARE rather than
+# continuing to maintain our own shell version.
+check_versions()
+{
+  major_version=${version%%.*}
+  minor_version="0"
+  point_version="0"
+  if test "${version#*.}" != "${version}"; then
+    minor_version=${version#*.}
+    minor_version=${minor_version%%.*}
+  fi
+  if test "${version#*.*.}" != "${version}"; then
+    point_version=${version#*.*.}
+    point_version=${point_version%%.*}
+  fi
+
+  min_version="$1"
+  min_major_version=${min_version%%.*}
+  min_minor_version="0"
+  min_point_version="0"
+  if test "${min_version#*.}" != "${min_version}"; then
+    min_minor_version=${min_version#*.}
+    min_minor_version=${min_minor_version%%.*}
+  fi
+  if test "${min_version#*.*.}" != "${min_version}"; then
+    min_point_version=${min_version#*.*.}
+    min_point_version=${min_point_version%%.*}
+  fi
+
+  max_version="$2"
+  max_major_version=${max_version%%.*}
+  max_minor_version="0"
+  max_point_version="0"
+  if test "${max_version#*.}" != "${max_version}"; then
+    max_minor_version=${max_version#*.}
+    max_minor_version=${max_minor_version%%.*}
+  fi
+  if test "${max_version#*.*.}" != "${max_version}"; then
+    max_point_version=${max_version#*.*.}
+    max_point_version=${max_point_version%%.*}
+  fi
+
+  test $(($major_version)) -lt $(($min_major_version)) && exit 1
+  if test $(($major_version)) -eq $(($min_major_version)); then
+    test $(($minor_version)) -lt $(($min_minor_version)) && exit 1
+    if test $(($minor_version)) -eq $(($min_minor_version)); then
+      test $(($point_version)) -lt $(($min_point_version)) && exit 1
+    fi
+  fi
+
+  test $(($major_version)) -gt $(($max_major_version)) && exit 1
+  if test $(($major_version)) -eq $(($max_major_version)); then
+    test $(($minor_version)) -gt $(($max_minor_version)) && exit 1
+    if test $(($minor_version)) -eq $(($max_minor_version)); then
+      test $(($point_version)) -gt $(($max_point_version)) && exit 1
+    fi
+  fi
+
+  exit 0
+}
+
+# Show the usage line when no arguments are specified.
+if test $# -eq 0; then
+  show_usage
+  exit 1
+fi
+
+while test $# -gt 0; do
+  case $1 in
+    --usage)          show_usage;         exit 0;;
+    --help)           show_help;          exit 0;;
+
+    # Installation overrides
+    --prefix=*)       GTEST_PREFIX=${1#--prefix=};;
+    --exec-prefix=*)  GTEST_EXEC_PREFIX=${1#--exec-prefix=};;
+    --libdir=*)       GTEST_LIBDIR=${1#--libdir=};;
+    --includedir=*)   GTEST_INCLUDEDIR=${1#--includedir=};;
+
+    # Installation queries
+    --prefix|--exec-prefix|--libdir|--includedir|--version)
+      if test -n "${do_query}"; then
+        show_usage
+        exit 1
+      fi
+      do_query=${1#--}
+      ;;
+
+    # Version checking
+    --min-version=*)
+      do_check_versions=yes
+      min_version=${1#--min-version=}
+      ;;
+    --max-version=*)
+      do_check_versions=yes
+      max_version=${1#--max-version=}
+      ;;
+    --exact-version=*)
+      do_check_versions=yes
+      exact_version=${1#--exact-version=}
+      ;;
+
+    # Compiler flag output
+    --cppflags)       echo_cppflags=yes;;
+    --cxxflags)       echo_cxxflags=yes;;
+    --ldflags)        echo_ldflags=yes;;
+    --libs)           echo_libs=yes;;
+
+    # Everything else is an error
+    *)                show_usage;         exit 1;;
+  esac
+  shift
+done
+
+# These have defaults filled in by the configure script but can also be
+# overridden by environment variables or command line parameters.
+prefix="${GTEST_PREFIX:-@prefix@}"
+exec_prefix="${GTEST_EXEC_PREFIX:-@exec_prefix@}"
+libdir="${GTEST_LIBDIR:-@libdir@}"
+includedir="${GTEST_INCLUDEDIR:-@includedir@}"
+
+# We try and detect if our binary is not located at its installed location. If
+# it's not, we provide variables pointing to the source and build tree rather
+# than to the install tree. This allows building against a just-built gtest
+# rather than an installed gtest.
+bindir="@bindir@"
+this_relative_bindir=`dirname $0`
+this_bindir=`cd ${this_relative_bindir}; pwd -P`
+if test "${this_bindir}" = "${this_bindir%${bindir}}"; then
+  # The path to the script doesn't end in the bindir sequence from Autoconf,
+  # assume that we are in a build tree.
+  build_dir=`dirname ${this_bindir}`
+  src_dir=`cd ${this_bindir}; cd @top_srcdir@; pwd -P`
+
+  # TODO(chandlerc@google.com): This is a dangerous dependency on libtool, we
+  # should work to remove it, and/or remove libtool altogether, replacing it
+  # with direct references to the library and a link path.
+  gtest_libs="${build_dir}/lib/libgtest.la @PTHREAD_CFLAGS@ @PTHREAD_LIBS@"
+  gtest_ldflags=""
+
+  # We provide hooks to include from either the source or build dir, where the
+  # build dir is always preferred. This will potentially allow us to write
+  # build rules for generated headers and have them automatically be preferred
+  # over provided versions.
+  gtest_cppflags="-I${build_dir}/include -I${src_dir}/include"
+  gtest_cxxflags="@PTHREAD_CFLAGS@"
+else
+  # We're using an installed gtest, although it may be staged under some
+  # prefix. Assume (as our own libraries do) that we can resolve the prefix,
+  # and are present in the dynamic link paths.
+  gtest_ldflags="-L${libdir}"
+  gtest_libs="-l${name} @PTHREAD_CFLAGS@ @PTHREAD_LIBS@"
+  gtest_cppflags="-I${includedir}"
+  gtest_cxxflags="@PTHREAD_CFLAGS@"
+fi
+
+# Do an installation query if requested.
+if test -n "$do_query"; then
+  case $do_query in
+    prefix)           echo $prefix;       exit 0;;
+    exec-prefix)      echo $exec_prefix;  exit 0;;
+    libdir)           echo $libdir;       exit 0;;
+    includedir)       echo $includedir;   exit 0;;
+    version)          echo $version;      exit 0;;
+    *)                show_usage;         exit 1;;
+  esac
+fi
+
+# Do a version check if requested.
+if test "$do_check_versions" = "yes"; then
+  # Make sure we didn't receive a bad combination of parameters.
+  test "$echo_cppflags" = "yes" && show_usage && exit 1
+  test "$echo_cxxflags" = "yes" && show_usage && exit 1
+  test "$echo_ldflags" = "yes"  && show_usage && exit 1
+  test "$echo_libs" = "yes"     && show_usage && exit 1
+
+  if test "$exact_version" != ""; then
+    check_versions $exact_version $exact_version
+    # unreachable
+  else
+    check_versions ${min_version:-0.0.0} ${max_version:-9999.9999.9999}
+    # unreachable
+  fi
+fi
+
+# Do the output in the correct order so that these can be used in-line of
+# a compiler invocation.
+output=""
+test "$echo_cppflags" = "yes" && output="$output $gtest_cppflags"
+test "$echo_cxxflags" = "yes" && output="$output $gtest_cxxflags"
+test "$echo_ldflags" = "yes"  && output="$output $gtest_ldflags"
+test "$echo_libs" = "yes"     && output="$output $gtest_libs"
+echo $output
+
+exit 0
diff --git a/3rdparty/gtest/scripts/pump.py b/3rdparty/gtest/scripts/pump.py
new file mode 100644
index 0000000..5efb653
--- /dev/null
+++ b/3rdparty/gtest/scripts/pump.py
@@ -0,0 +1,855 @@
+#!/usr/bin/env python
+#
+# Copyright 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""pump v0.2.0 - Pretty Useful for Meta Programming.
+
+A tool for preprocessor meta programming.  Useful for generating
+repetitive boilerplate code.  Especially useful for writing C++
+classes, functions, macros, and templates that need to work with
+various number of arguments.
+
+USAGE:
+       pump.py SOURCE_FILE
+
+EXAMPLES:
+       pump.py foo.cc.pump
+         Converts foo.cc.pump to foo.cc.
+
+GRAMMAR:
+       CODE ::= ATOMIC_CODE*
+       ATOMIC_CODE ::= $var ID = EXPRESSION
+           | $var ID = [[ CODE ]]
+           | $range ID EXPRESSION..EXPRESSION
+           | $for ID SEPARATOR [[ CODE ]]
+           | $($)
+           | $ID
+           | $(EXPRESSION)
+           | $if EXPRESSION [[ CODE ]] ELSE_BRANCH
+           | [[ CODE ]]
+           | RAW_CODE
+       SEPARATOR ::= RAW_CODE | EMPTY
+       ELSE_BRANCH ::= $else [[ CODE ]]
+           | $elif EXPRESSION [[ CODE ]] ELSE_BRANCH
+           | EMPTY
+       EXPRESSION has Python syntax.
+"""
+
+__author__ = 'wan@google.com (Zhanyong Wan)'
+
+import os
+import re
+import sys
+
+
+TOKEN_TABLE = [
+    (re.compile(r'\$var\s+'), '$var'),
+    (re.compile(r'\$elif\s+'), '$elif'),
+    (re.compile(r'\$else\s+'), '$else'),
+    (re.compile(r'\$for\s+'), '$for'),
+    (re.compile(r'\$if\s+'), '$if'),
+    (re.compile(r'\$range\s+'), '$range'),
+    (re.compile(r'\$[_A-Za-z]\w*'), '$id'),
+    (re.compile(r'\$\(\$\)'), '$($)'),
+    (re.compile(r'\$'), '$'),
+    (re.compile(r'\[\[\n?'), '[['),
+    (re.compile(r'\]\]\n?'), ']]'),
+    ]
+
+
+class Cursor:
+  """Represents a position (line and column) in a text file."""
+
+  def __init__(self, line=-1, column=-1):
+    self.line = line
+    self.column = column
+
+  def __eq__(self, rhs):
+    return self.line == rhs.line and self.column == rhs.column
+
+  def __ne__(self, rhs):
+    return not self == rhs
+
+  def __lt__(self, rhs):
+    return self.line < rhs.line or (
+        self.line == rhs.line and self.column < rhs.column)
+
+  def __le__(self, rhs):
+    return self < rhs or self == rhs
+
+  def __gt__(self, rhs):
+    return rhs < self
+
+  def __ge__(self, rhs):
+    return rhs <= self
+
+  def __str__(self):
+    if self == Eof():
+      return 'EOF'
+    else:
+      return '%s(%s)' % (self.line + 1, self.column)
+
+  def __add__(self, offset):
+    return Cursor(self.line, self.column + offset)
+
+  def __sub__(self, offset):
+    return Cursor(self.line, self.column - offset)
+
+  def Clone(self):
+    """Returns a copy of self."""
+
+    return Cursor(self.line, self.column)
+
+
+# Special cursor to indicate the end-of-file.
+def Eof():
+  """Returns the special cursor to denote the end-of-file."""
+  return Cursor(-1, -1)
+
+
+class Token:
+  """Represents a token in a Pump source file."""
+
+  def __init__(self, start=None, end=None, value=None, token_type=None):
+    if start is None:
+      self.start = Eof()
+    else:
+      self.start = start
+    if end is None:
+      self.end = Eof()
+    else:
+      self.end = end
+    self.value = value
+    self.token_type = token_type
+
+  def __str__(self):
+    return 'Token @%s: \'%s\' type=%s' % (
+        self.start, self.value, self.token_type)
+
+  def Clone(self):
+    """Returns a copy of self."""
+
+    return Token(self.start.Clone(), self.end.Clone(), self.value,
+                 self.token_type)
+
+
+def StartsWith(lines, pos, string):
+  """Returns True iff the given position in lines starts with 'string'."""
+
+  return lines[pos.line][pos.column:].startswith(string)
+
+
+def FindFirstInLine(line, token_table):
+  best_match_start = -1
+  for (regex, token_type) in token_table:
+    m = regex.search(line)
+    if m:
+      # We found regex in lines
+      if best_match_start < 0 or m.start() < best_match_start:
+        best_match_start = m.start()
+        best_match_length = m.end() - m.start()
+        best_match_token_type = token_type
+
+  if best_match_start < 0:
+    return None
+
+  return (best_match_start, best_match_length, best_match_token_type)
+
+
+def FindFirst(lines, token_table, cursor):
+  """Finds the first occurrence of any string in strings in lines."""
+
+  start = cursor.Clone()
+  cur_line_number = cursor.line
+  for line in lines[start.line:]:
+    if cur_line_number == start.line:
+      line = line[start.column:]
+    m = FindFirstInLine(line, token_table)
+    if m:
+      # We found a regex in line.
+      (start_column, length, token_type) = m
+      if cur_line_number == start.line:
+        start_column += start.column
+      found_start = Cursor(cur_line_number, start_column)
+      found_end = found_start + length
+      return MakeToken(lines, found_start, found_end, token_type)
+    cur_line_number += 1
+  # We failed to find str in lines
+  return None
+
+
+def SubString(lines, start, end):
+  """Returns a substring in lines."""
+
+  if end == Eof():
+    end = Cursor(len(lines) - 1, len(lines[-1]))
+
+  if start >= end:
+    return ''
+
+  if start.line == end.line:
+    return lines[start.line][start.column:end.column]
+
+  result_lines = ([lines[start.line][start.column:]] +
+                  lines[start.line + 1:end.line] +
+                  [lines[end.line][:end.column]])
+  return ''.join(result_lines)
+
+
+def StripMetaComments(str):
+  """Strip meta comments from each line in the given string."""
+
+  # First, completely remove lines containing nothing but a meta
+  # comment, including the trailing \n.
+  str = re.sub(r'^\s*\$\$.*\n', '', str)
+
+  # Then, remove meta comments from contentful lines.
+  return re.sub(r'\s*\$\$.*', '', str)
+
+
+def MakeToken(lines, start, end, token_type):
+  """Creates a new instance of Token."""
+
+  return Token(start, end, SubString(lines, start, end), token_type)
+
+
+def ParseToken(lines, pos, regex, token_type):
+  line = lines[pos.line][pos.column:]
+  m = regex.search(line)
+  if m and not m.start():
+    return MakeToken(lines, pos, pos + m.end(), token_type)
+  else:
+    print 'ERROR: %s expected at %s.' % (token_type, pos)
+    sys.exit(1)
+
+
+ID_REGEX = re.compile(r'[_A-Za-z]\w*')
+EQ_REGEX = re.compile(r'=')
+REST_OF_LINE_REGEX = re.compile(r'.*?(?=$|\$\$)')
+OPTIONAL_WHITE_SPACES_REGEX = re.compile(r'\s*')
+WHITE_SPACE_REGEX = re.compile(r'\s')
+DOT_DOT_REGEX = re.compile(r'\.\.')
+
+
+def Skip(lines, pos, regex):
+  line = lines[pos.line][pos.column:]
+  m = re.search(regex, line)
+  if m and not m.start():
+    return pos + m.end()
+  else:
+    return pos
+
+
+def SkipUntil(lines, pos, regex, token_type):
+  line = lines[pos.line][pos.column:]
+  m = re.search(regex, line)
+  if m:
+    return pos + m.start()
+  else:
+    print ('ERROR: %s expected on line %s after column %s.' %
+           (token_type, pos.line + 1, pos.column))
+    sys.exit(1)
+
+
+def ParseExpTokenInParens(lines, pos):
+  def ParseInParens(pos):
+    pos = Skip(lines, pos, OPTIONAL_WHITE_SPACES_REGEX)
+    pos = Skip(lines, pos, r'\(')
+    pos = Parse(pos)
+    pos = Skip(lines, pos, r'\)')
+    return pos
+
+  def Parse(pos):
+    pos = SkipUntil(lines, pos, r'\(|\)', ')')
+    if SubString(lines, pos, pos + 1) == '(':
+      pos = Parse(pos + 1)
+      pos = Skip(lines, pos, r'\)')
+      return Parse(pos)
+    else:
+      return pos
+
+  start = pos.Clone()
+  pos = ParseInParens(pos)
+  return MakeToken(lines, start, pos, 'exp')
+
+
+def RStripNewLineFromToken(token):
+  if token.value.endswith('\n'):
+    return Token(token.start, token.end, token.value[:-1], token.token_type)
+  else:
+    return token
+
+
+def TokenizeLines(lines, pos):
+  while True:
+    found = FindFirst(lines, TOKEN_TABLE, pos)
+    if not found:
+      yield MakeToken(lines, pos, Eof(), 'code')
+      return
+
+    if found.start == pos:
+      prev_token = None
+      prev_token_rstripped = None
+    else:
+      prev_token = MakeToken(lines, pos, found.start, 'code')
+      prev_token_rstripped = RStripNewLineFromToken(prev_token)
+
+    if found.token_type == '$var':
+      if prev_token_rstripped:
+        yield prev_token_rstripped
+      yield found
+      id_token = ParseToken(lines, found.end, ID_REGEX, 'id')
+      yield id_token
+      pos = Skip(lines, id_token.end, OPTIONAL_WHITE_SPACES_REGEX)
+
+      eq_token = ParseToken(lines, pos, EQ_REGEX, '=')
+      yield eq_token
+      pos = Skip(lines, eq_token.end, r'\s*')
+
+      if SubString(lines, pos, pos + 2) != '[[':
+        exp_token = ParseToken(lines, pos, REST_OF_LINE_REGEX, 'exp')
+        yield exp_token
+        pos = Cursor(exp_token.end.line + 1, 0)
+    elif found.token_type == '$for':
+      if prev_token_rstripped:
+        yield prev_token_rstripped
+      yield found
+      id_token = ParseToken(lines, found.end, ID_REGEX, 'id')
+      yield id_token
+      pos = Skip(lines, id_token.end, WHITE_SPACE_REGEX)
+    elif found.token_type == '$range':
+      if prev_token_rstripped:
+        yield prev_token_rstripped
+      yield found
+      id_token = ParseToken(lines, found.end, ID_REGEX, 'id')
+      yield id_token
+      pos = Skip(lines, id_token.end, OPTIONAL_WHITE_SPACES_REGEX)
+
+      dots_pos = SkipUntil(lines, pos, DOT_DOT_REGEX, '..')
+      yield MakeToken(lines, pos, dots_pos, 'exp')
+      yield MakeToken(lines, dots_pos, dots_pos + 2, '..')
+      pos = dots_pos + 2
+      new_pos = Cursor(pos.line + 1, 0)
+      yield MakeToken(lines, pos, new_pos, 'exp')
+      pos = new_pos
+    elif found.token_type == '$':
+      if prev_token:
+        yield prev_token
+      yield found
+      exp_token = ParseExpTokenInParens(lines, found.end)
+      yield exp_token
+      pos = exp_token.end
+    elif (found.token_type == ']]' or found.token_type == '$if' or
+          found.token_type == '$elif' or found.token_type == '$else'):
+      if prev_token_rstripped:
+        yield prev_token_rstripped
+      yield found
+      pos = found.end
+    else:
+      if prev_token:
+        yield prev_token
+      yield found
+      pos = found.end
+
+
+def Tokenize(s):
+  """A generator that yields the tokens in the given string."""
+  if s != '':
+    lines = s.splitlines(True)
+    for token in TokenizeLines(lines, Cursor(0, 0)):
+      yield token
+
+
+class CodeNode:
+  def __init__(self, atomic_code_list=None):
+    self.atomic_code = atomic_code_list
+
+
+class VarNode:
+  def __init__(self, identifier=None, atomic_code=None):
+    self.identifier = identifier
+    self.atomic_code = atomic_code
+
+
+class RangeNode:
+  def __init__(self, identifier=None, exp1=None, exp2=None):
+    self.identifier = identifier
+    self.exp1 = exp1
+    self.exp2 = exp2
+
+
+class ForNode:
+  def __init__(self, identifier=None, sep=None, code=None):
+    self.identifier = identifier
+    self.sep = sep
+    self.code = code
+
+
+class ElseNode:
+  def __init__(self, else_branch=None):
+    self.else_branch = else_branch
+
+
+class IfNode:
+  def __init__(self, exp=None, then_branch=None, else_branch=None):
+    self.exp = exp
+    self.then_branch = then_branch
+    self.else_branch = else_branch
+
+
+class RawCodeNode:
+  def __init__(self, token=None):
+    self.raw_code = token
+
+
+class LiteralDollarNode:
+  def __init__(self, token):
+    self.token = token
+
+
+class ExpNode:
+  def __init__(self, token, python_exp):
+    self.token = token
+    self.python_exp = python_exp
+
+
+def PopFront(a_list):
+  head = a_list[0]
+  a_list[:1] = []
+  return head
+
+
+def PushFront(a_list, elem):
+  a_list[:0] = [elem]
+
+
+def PopToken(a_list, token_type=None):
+  token = PopFront(a_list)
+  if token_type is not None and token.token_type != token_type:
+    print 'ERROR: %s expected at %s' % (token_type, token.start)
+    print 'ERROR: %s found instead' % (token,)
+    sys.exit(1)
+
+  return token
+
+
+def PeekToken(a_list):
+  if not a_list:
+    return None
+
+  return a_list[0]
+
+
+def ParseExpNode(token):
+  python_exp = re.sub(r'([_A-Za-z]\w*)', r'self.GetValue("\1")', token.value)
+  return ExpNode(token, python_exp)
+
+
+def ParseElseNode(tokens):
+  def Pop(token_type=None):
+    return PopToken(tokens, token_type)
+
+  next = PeekToken(tokens)
+  if not next:
+    return None
+  if next.token_type == '$else':
+    Pop('$else')
+    Pop('[[')
+    code_node = ParseCodeNode(tokens)
+    Pop(']]')
+    return code_node
+  elif next.token_type == '$elif':
+    Pop('$elif')
+    exp = Pop('code')
+    Pop('[[')
+    code_node = ParseCodeNode(tokens)
+    Pop(']]')
+    inner_else_node = ParseElseNode(tokens)
+    return CodeNode([IfNode(ParseExpNode(exp), code_node, inner_else_node)])
+  elif not next.value.strip():
+    Pop('code')
+    return ParseElseNode(tokens)
+  else:
+    return None
+
+
+def ParseAtomicCodeNode(tokens):
+  def Pop(token_type=None):
+    return PopToken(tokens, token_type)
+
+  head = PopFront(tokens)
+  t = head.token_type
+  if t == 'code':
+    return RawCodeNode(head)
+  elif t == '$var':
+    id_token = Pop('id')
+    Pop('=')
+    next = PeekToken(tokens)
+    if next.token_type == 'exp':
+      exp_token = Pop()
+      return VarNode(id_token, ParseExpNode(exp_token))
+    Pop('[[')
+    code_node = ParseCodeNode(tokens)
+    Pop(']]')
+    return VarNode(id_token, code_node)
+  elif t == '$for':
+    id_token = Pop('id')
+    next_token = PeekToken(tokens)
+    if next_token.token_type == 'code':
+      sep_token = next_token
+      Pop('code')
+    else:
+      sep_token = None
+    Pop('[[')
+    code_node = ParseCodeNode(tokens)
+    Pop(']]')
+    return ForNode(id_token, sep_token, code_node)
+  elif t == '$if':
+    exp_token = Pop('code')
+    Pop('[[')
+    code_node = ParseCodeNode(tokens)
+    Pop(']]')
+    else_node = ParseElseNode(tokens)
+    return IfNode(ParseExpNode(exp_token), code_node, else_node)
+  elif t == '$range':
+    id_token = Pop('id')
+    exp1_token = Pop('exp')
+    Pop('..')
+    exp2_token = Pop('exp')
+    return RangeNode(id_token, ParseExpNode(exp1_token),
+                     ParseExpNode(exp2_token))
+  elif t == '$id':
+    return ParseExpNode(Token(head.start + 1, head.end, head.value[1:], 'id'))
+  elif t == '$($)':
+    return LiteralDollarNode(head)
+  elif t == '$':
+    exp_token = Pop('exp')
+    return ParseExpNode(exp_token)
+  elif t == '[[':
+    code_node = ParseCodeNode(tokens)
+    Pop(']]')
+    return code_node
+  else:
+    PushFront(tokens, head)
+    return None
+
+
+def ParseCodeNode(tokens):
+  atomic_code_list = []
+  while True:
+    if not tokens:
+      break
+    atomic_code_node = ParseAtomicCodeNode(tokens)
+    if atomic_code_node:
+      atomic_code_list.append(atomic_code_node)
+    else:
+      break
+  return CodeNode(atomic_code_list)
+
+
+def ParseToAST(pump_src_text):
+  """Convert the given Pump source text into an AST."""
+  tokens = list(Tokenize(pump_src_text))
+  code_node = ParseCodeNode(tokens)
+  return code_node
+
+
+class Env:
+  def __init__(self):
+    self.variables = []
+    self.ranges = []
+
+  def Clone(self):
+    clone = Env()
+    clone.variables = self.variables[:]
+    clone.ranges = self.ranges[:]
+    return clone
+
+  def PushVariable(self, var, value):
+    # If value looks like an int, store it as an int.
+    try:
+      int_value = int(value)
+      if ('%s' % int_value) == value:
+        value = int_value
+    except Exception:
+      pass
+    self.variables[:0] = [(var, value)]
+
+  def PopVariable(self):
+    self.variables[:1] = []
+
+  def PushRange(self, var, lower, upper):
+    self.ranges[:0] = [(var, lower, upper)]
+
+  def PopRange(self):
+    self.ranges[:1] = []
+
+  def GetValue(self, identifier):
+    for (var, value) in self.variables:
+      if identifier == var:
+        return value
+
+    print 'ERROR: meta variable %s is undefined.' % (identifier,)
+    sys.exit(1)
+
+  def EvalExp(self, exp):
+    try:
+      result = eval(exp.python_exp)
+    except Exception, e:
+      print 'ERROR: caught exception %s: %s' % (e.__class__.__name__, e)
+      print ('ERROR: failed to evaluate meta expression %s at %s' %
+             (exp.python_exp, exp.token.start))
+      sys.exit(1)
+    return result
+
+  def GetRange(self, identifier):
+    for (var, lower, upper) in self.ranges:
+      if identifier == var:
+        return (lower, upper)
+
+    print 'ERROR: range %s is undefined.' % (identifier,)
+    sys.exit(1)
+
+
+class Output:
+  def __init__(self):
+    self.string = ''
+
+  def GetLastLine(self):
+    index = self.string.rfind('\n')
+    if index < 0:
+      return ''
+
+    return self.string[index + 1:]
+
+  def Append(self, s):
+    self.string += s
+
+
+def RunAtomicCode(env, node, output):
+  if isinstance(node, VarNode):
+    identifier = node.identifier.value.strip()
+    result = Output()
+    RunAtomicCode(env.Clone(), node.atomic_code, result)
+    value = result.string
+    env.PushVariable(identifier, value)
+  elif isinstance(node, RangeNode):
+    identifier = node.identifier.value.strip()
+    lower = int(env.EvalExp(node.exp1))
+    upper = int(env.EvalExp(node.exp2))
+    env.PushRange(identifier, lower, upper)
+  elif isinstance(node, ForNode):
+    identifier = node.identifier.value.strip()
+    if node.sep is None:
+      sep = ''
+    else:
+      sep = node.sep.value
+    (lower, upper) = env.GetRange(identifier)
+    for i in range(lower, upper + 1):
+      new_env = env.Clone()
+      new_env.PushVariable(identifier, i)
+      RunCode(new_env, node.code, output)
+      if i != upper:
+        output.Append(sep)
+  elif isinstance(node, RawCodeNode):
+    output.Append(node.raw_code.value)
+  elif isinstance(node, IfNode):
+    cond = env.EvalExp(node.exp)
+    if cond:
+      RunCode(env.Clone(), node.then_branch, output)
+    elif node.else_branch is not None:
+      RunCode(env.Clone(), node.else_branch, output)
+  elif isinstance(node, ExpNode):
+    value = env.EvalExp(node)
+    output.Append('%s' % (value,))
+  elif isinstance(node, LiteralDollarNode):
+    output.Append('$')
+  elif isinstance(node, CodeNode):
+    RunCode(env.Clone(), node, output)
+  else:
+    print 'BAD'
+    print node
+    sys.exit(1)
+
+
+def RunCode(env, code_node, output):
+  for atomic_code in code_node.atomic_code:
+    RunAtomicCode(env, atomic_code, output)
+
+
+def IsSingleLineComment(cur_line):
+  return '//' in cur_line
+
+
+def IsInPreprocessorDirective(prev_lines, cur_line):
+  if cur_line.lstrip().startswith('#'):
+    return True
+  return prev_lines and prev_lines[-1].endswith('\\')
+
+
+def WrapComment(line, output):
+  loc = line.find('//')
+  before_comment = line[:loc].rstrip()
+  if before_comment == '':
+    indent = loc
+  else:
+    output.append(before_comment)
+    indent = len(before_comment) - len(before_comment.lstrip())
+  prefix = indent*' ' + '// '
+  max_len = 80 - len(prefix)
+  comment = line[loc + 2:].strip()
+  segs = [seg for seg in re.split(r'(\w+\W*)', comment) if seg != '']
+  cur_line = ''
+  for seg in segs:
+    if len((cur_line + seg).rstrip()) < max_len:
+      cur_line += seg
+    else:
+      if cur_line.strip() != '':
+        output.append(prefix + cur_line.rstrip())
+      cur_line = seg.lstrip()
+  if cur_line.strip() != '':
+    output.append(prefix + cur_line.strip())
+
+
+def WrapCode(line, line_concat, output):
+  indent = len(line) - len(line.lstrip())
+  prefix = indent*' '  # Prefix of the current line
+  max_len = 80 - indent - len(line_concat)  # Maximum length of the current line
+  new_prefix = prefix + 4*' '  # Prefix of a continuation line
+  new_max_len = max_len - 4  # Maximum length of a continuation line
+  # Prefers to wrap a line after a ',' or ';'.
+  segs = [seg for seg in re.split(r'([^,;]+[,;]?)', line.strip()) if seg != '']
+  cur_line = ''  # The current line without leading spaces.
+  for seg in segs:
+    # If the line is still too long, wrap at a space.
+    while cur_line == '' and len(seg.strip()) > max_len:
+      seg = seg.lstrip()
+      split_at = seg.rfind(' ', 0, max_len)
+      output.append(prefix + seg[:split_at].strip() + line_concat)
+      seg = seg[split_at + 1:]
+      prefix = new_prefix
+      max_len = new_max_len
+
+    if len((cur_line + seg).rstrip()) < max_len:
+      cur_line = (cur_line + seg).lstrip()
+    else:
+      output.append(prefix + cur_line.rstrip() + line_concat)
+      prefix = new_prefix
+      max_len = new_max_len
+      cur_line = seg.lstrip()
+  if cur_line.strip() != '':
+    output.append(prefix + cur_line.strip())
+
+
+def WrapPreprocessorDirective(line, output):
+  WrapCode(line, ' \\', output)
+
+
+def WrapPlainCode(line, output):
+  WrapCode(line, '', output)
+
+
+def IsMultiLineIWYUPragma(line):
+  return re.search(r'/\* IWYU pragma: ', line)
+
+
+def IsHeaderGuardIncludeOrOneLineIWYUPragma(line):
+  return (re.match(r'^#(ifndef|define|endif\s*//)\s*[\w_]+\s*$', line) or
+          re.match(r'^#include\s', line) or
+          # Don't break IWYU pragmas, either; that causes iwyu.py problems.
+          re.search(r'// IWYU pragma: ', line))
+
+
+def WrapLongLine(line, output):
+  line = line.rstrip()
+  if len(line) <= 80:
+    output.append(line)
+  elif IsSingleLineComment(line):
+    if IsHeaderGuardIncludeOrOneLineIWYUPragma(line):
+      # The style guide made an exception to allow long header guard lines,
+      # includes and IWYU pragmas.
+      output.append(line)
+    else:
+      WrapComment(line, output)
+  elif IsInPreprocessorDirective(output, line):
+    if IsHeaderGuardIncludeOrOneLineIWYUPragma(line):
+      # The style guide made an exception to allow long header guard lines,
+      # includes and IWYU pragmas.
+      output.append(line)
+    else:
+      WrapPreprocessorDirective(line, output)
+  elif IsMultiLineIWYUPragma(line):
+    output.append(line)
+  else:
+    WrapPlainCode(line, output)
+
+
+def BeautifyCode(string):
+  lines = string.splitlines()
+  output = []
+  for line in lines:
+    WrapLongLine(line, output)
+  output2 = [line.rstrip() for line in output]
+  return '\n'.join(output2) + '\n'
+
+
+def ConvertFromPumpSource(src_text):
+  """Return the text generated from the given Pump source text."""
+  ast = ParseToAST(StripMetaComments(src_text))
+  output = Output()
+  RunCode(Env(), ast, output)
+  return BeautifyCode(output.string)
+
+
+def main(argv):
+  if len(argv) == 1:
+    print __doc__
+    sys.exit(1)
+
+  file_path = argv[-1]
+  output_str = ConvertFromPumpSource(file(file_path, 'r').read())
+  if file_path.endswith('.pump'):
+    output_file_path = file_path[:-5]
+  else:
+    output_file_path = '-'
+  if output_file_path == '-':
+    print output_str,
+  else:
+    output_file = file(output_file_path, 'w')
+    output_file.write('// This file was GENERATED by command:\n')
+    output_file.write('//     %s %s\n' %
+                      (os.path.basename(__file__), os.path.basename(file_path)))
+    output_file.write('// DO NOT EDIT BY HAND!!!\n\n')
+    output_file.write(output_str)
+    output_file.close()
+
+
+if __name__ == '__main__':
+  main(sys.argv)
diff --git a/3rdparty/gtest/scripts/release_docs.py b/3rdparty/gtest/scripts/release_docs.py
new file mode 100644
index 0000000..1291347
--- /dev/null
+++ b/3rdparty/gtest/scripts/release_docs.py
@@ -0,0 +1,158 @@
+#!/usr/bin/env python
+#
+# Copyright 2013 Google Inc. All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Script for branching Google Test/Mock wiki pages for a new version.
+
+SYNOPSIS
+       release_docs.py NEW_RELEASE_VERSION
+
+       Google Test and Google Mock's external user documentation is in
+       interlinked wiki files.  When we release a new version of
+       Google Test or Google Mock, we need to branch the wiki files
+       such that users of a specific version of Google Test/Mock can
+       look up documenation relevant for that version.  This script
+       automates that process by:
+
+         - branching the current wiki pages (which document the
+           behavior of the SVN trunk head) to pages for the specified
+           version (e.g. branching FAQ.wiki to V2_6_FAQ.wiki when
+           NEW_RELEASE_VERSION is 2.6);
+         - updating the links in the branched files to point to the branched
+           version (e.g. a link in V2_6_FAQ.wiki that pointed to
+           Primer.wiki#Anchor will now point to V2_6_Primer.wiki#Anchor).
+
+       NOTE: NEW_RELEASE_VERSION must be a NEW version number for
+       which the wiki pages don't yet exist; otherwise you'll get SVN
+       errors like "svn: Path 'V1_7_PumpManual.wiki' is not a
+       directory" when running the script.
+
+EXAMPLE
+       $ cd PATH/TO/GTEST_SVN_WORKSPACE/trunk
+       $ scripts/release_docs.py 2.6  # create wiki pages for v2.6
+       $ svn status                   # verify the file list
+       $ svn diff                     # verify the file contents
+       $ svn commit -m "release wiki pages for v2.6"
+"""
+
+__author__ = 'wan@google.com (Zhanyong Wan)'
+
+import os
+import re
+import sys
+
+import common
+
+
+# Wiki pages that shouldn't be branched for every gtest/gmock release.
+GTEST_UNVERSIONED_WIKIS = ['DevGuide.wiki']
+GMOCK_UNVERSIONED_WIKIS = [
+    'DesignDoc.wiki',
+    'DevGuide.wiki',
+    'KnownIssues.wiki'
+    ]
+
+
+def DropWikiSuffix(wiki_filename):
+  """Removes the .wiki suffix (if any) from the given filename."""
+
+  return (wiki_filename[:-len('.wiki')] if wiki_filename.endswith('.wiki')
+          else wiki_filename)
+
+
+class WikiBrancher(object):
+  """Branches ..."""
+
+  def __init__(self, dot_version):
+    self.project, svn_root_path = common.GetSvnInfo()
+    if self.project not in ('googletest', 'googlemock'):
+      sys.exit('This script must be run in a gtest or gmock SVN workspace.')
+    self.wiki_dir = svn_root_path + '/wiki'
+    # Turn '2.6' to 'V2_6_'.
+    self.version_prefix = 'V' + dot_version.replace('.', '_') + '_'
+    self.files_to_branch = self.GetFilesToBranch()
+    page_names = [DropWikiSuffix(f) for f in self.files_to_branch]
+    # A link to Foo.wiki is in one of the following forms:
+    #   [Foo words]
+    #   [Foo#Anchor words]
+    #   [http://code.google.com/.../wiki/Foo words]
+    #   [http://code.google.com/.../wiki/Foo#Anchor words]
+    # We want to replace 'Foo' with 'V2_6_Foo' in the above cases.
+    self.search_for_re = re.compile(
+        # This regex matches either
+        #   [Foo
+        # or
+        #   /wiki/Foo
+        # followed by a space or a #, where Foo is the name of an
+        # unversioned wiki page.
+        r'(\[|/wiki/)(%s)([ #])' % '|'.join(page_names))
+    self.replace_with = r'\1%s\2\3' % (self.version_prefix,)
+
+  def GetFilesToBranch(self):
+    """Returns a list of .wiki file names that need to be branched."""
+
+    unversioned_wikis = (GTEST_UNVERSIONED_WIKIS if self.project == 'googletest'
+                         else GMOCK_UNVERSIONED_WIKIS)
+    return [f for f in os.listdir(self.wiki_dir)
+            if (f.endswith('.wiki') and
+                not re.match(r'^V\d', f) and  # Excluded versioned .wiki files.
+                f not in unversioned_wikis)]
+
+  def BranchFiles(self):
+    """Branches the .wiki files needed to be branched."""
+
+    print 'Branching %d .wiki files:' % (len(self.files_to_branch),)
+    os.chdir(self.wiki_dir)
+    for f in self.files_to_branch:
+      command = 'svn cp %s %s%s' % (f, self.version_prefix, f)
+      print command
+      os.system(command)
+
+  def UpdateLinksInBranchedFiles(self):
+
+    for f in self.files_to_branch:
+      source_file = os.path.join(self.wiki_dir, f)
+      versioned_file = os.path.join(self.wiki_dir, self.version_prefix + f)
+      print 'Updating links in %s.' % (versioned_file,)
+      text = file(source_file, 'r').read()
+      new_text = self.search_for_re.sub(self.replace_with, text)
+      file(versioned_file, 'w').write(new_text)
+
+
+def main():
+  if len(sys.argv) != 2:
+    sys.exit(__doc__)
+
+  brancher = WikiBrancher(sys.argv[1])
+  brancher.BranchFiles()
+  brancher.UpdateLinksInBranchedFiles()
+
+
+if __name__ == '__main__':
+  main()
diff --git a/3rdparty/gtest/scripts/upload.py b/3rdparty/gtest/scripts/upload.py
new file mode 100644
index 0000000..c852e4c
--- /dev/null
+++ b/3rdparty/gtest/scripts/upload.py
@@ -0,0 +1,1387 @@
+#!/usr/bin/env python
+#
+# Copyright 2007 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tool for uploading diffs from a version control system to the codereview app.
+
+Usage summary: upload.py [options] [-- diff_options]
+
+Diff options are passed to the diff command of the underlying system.
+
+Supported version control systems:
+  Git
+  Mercurial
+  Subversion
+
+It is important for Git/Mercurial users to specify a tree/node/branch to diff
+against by using the '--rev' option.
+"""
+# This code is derived from appcfg.py in the App Engine SDK (open source),
+# and from ASPN recipe #146306.
+
+import cookielib
+import getpass
+import logging
+import md5
+import mimetypes
+import optparse
+import os
+import re
+import socket
+import subprocess
+import sys
+import urllib
+import urllib2
+import urlparse
+
+try:
+  import readline
+except ImportError:
+  pass
+
+# The logging verbosity:
+#  0: Errors only.
+#  1: Status messages.
+#  2: Info logs.
+#  3: Debug logs.
+verbosity = 1
+
+# Max size of patch or base file.
+MAX_UPLOAD_SIZE = 900 * 1024
+
+
+def GetEmail(prompt):
+  """Prompts the user for their email address and returns it.
+
+  The last used email address is saved to a file and offered up as a suggestion
+  to the user. If the user presses enter without typing in anything the last
+  used email address is used. If the user enters a new address, it is saved
+  for next time we prompt.
+
+  """
+  last_email_file_name = os.path.expanduser("~/.last_codereview_email_address")
+  last_email = ""
+  if os.path.exists(last_email_file_name):
+    try:
+      last_email_file = open(last_email_file_name, "r")
+      last_email = last_email_file.readline().strip("\n")
+      last_email_file.close()
+      prompt += " [%s]" % last_email
+    except IOError, e:
+      pass
+  email = raw_input(prompt + ": ").strip()
+  if email:
+    try:
+      last_email_file = open(last_email_file_name, "w")
+      last_email_file.write(email)
+      last_email_file.close()
+    except IOError, e:
+      pass
+  else:
+    email = last_email
+  return email
+
+
+def StatusUpdate(msg):
+  """Print a status message to stdout.
+
+  If 'verbosity' is greater than 0, print the message.
+
+  Args:
+    msg: The string to print.
+  """
+  if verbosity > 0:
+    print msg
+
+
+def ErrorExit(msg):
+  """Print an error message to stderr and exit."""
+  print >>sys.stderr, msg
+  sys.exit(1)
+
+
+class ClientLoginError(urllib2.HTTPError):
+  """Raised to indicate there was an error authenticating with ClientLogin."""
+
+  def __init__(self, url, code, msg, headers, args):
+    urllib2.HTTPError.__init__(self, url, code, msg, headers, None)
+    self.args = args
+    self.reason = args["Error"]
+
+
+class AbstractRpcServer(object):
+  """Provides a common interface for a simple RPC server."""
+
+  def __init__(self, host, auth_function, host_override=None, extra_headers={},
+               save_cookies=False):
+    """Creates a new HttpRpcServer.
+
+    Args:
+      host: The host to send requests to.
+      auth_function: A function that takes no arguments and returns an
+        (email, password) tuple when called. Will be called if authentication
+        is required.
+      host_override: The host header to send to the server (defaults to host).
+      extra_headers: A dict of extra headers to append to every request.
+      save_cookies: If True, save the authentication cookies to local disk.
+        If False, use an in-memory cookiejar instead.  Subclasses must
+        implement this functionality.  Defaults to False.
+    """
+    self.host = host
+    self.host_override = host_override
+    self.auth_function = auth_function
+    self.authenticated = False
+    self.extra_headers = extra_headers
+    self.save_cookies = save_cookies
+    self.opener = self._GetOpener()
+    if self.host_override:
+      logging.info("Server: %s; Host: %s", self.host, self.host_override)
+    else:
+      logging.info("Server: %s", self.host)
+
+  def _GetOpener(self):
+    """Returns an OpenerDirector for making HTTP requests.
+
+    Returns:
+      A urllib2.OpenerDirector object.
+    """
+    raise NotImplementedError()
+
+  def _CreateRequest(self, url, data=None):
+    """Creates a new urllib request."""
+    logging.debug("Creating request for: '%s' with payload:\n%s", url, data)
+    req = urllib2.Request(url, data=data)
+    if self.host_override:
+      req.add_header("Host", self.host_override)
+    for key, value in self.extra_headers.iteritems():
+      req.add_header(key, value)
+    return req
+
+  def _GetAuthToken(self, email, password):
+    """Uses ClientLogin to authenticate the user, returning an auth token.
+
+    Args:
+      email:    The user's email address
+      password: The user's password
+
+    Raises:
+      ClientLoginError: If there was an error authenticating with ClientLogin.
+      HTTPError: If there was some other form of HTTP error.
+
+    Returns:
+      The authentication token returned by ClientLogin.
+    """
+    account_type = "GOOGLE"
+    if self.host.endswith(".google.com"):
+      # Needed for use inside Google.
+      account_type = "HOSTED"
+    req = self._CreateRequest(
+        url="https://www.google.com/accounts/ClientLogin",
+        data=urllib.urlencode({
+            "Email": email,
+            "Passwd": password,
+            "service": "ah",
+            "source": "rietveld-codereview-upload",
+            "accountType": account_type,
+        }),
+    )
+    try:
+      response = self.opener.open(req)
+      response_body = response.read()
+      response_dict = dict(x.split("=")
+                           for x in response_body.split("\n") if x)
+      return response_dict["Auth"]
+    except urllib2.HTTPError, e:
+      if e.code == 403:
+        body = e.read()
+        response_dict = dict(x.split("=", 1) for x in body.split("\n") if x)
+        raise ClientLoginError(req.get_full_url(), e.code, e.msg,
+                               e.headers, response_dict)
+      else:
+        raise
+
+  def _GetAuthCookie(self, auth_token):
+    """Fetches authentication cookies for an authentication token.
+
+    Args:
+      auth_token: The authentication token returned by ClientLogin.
+
+    Raises:
+      HTTPError: If there was an error fetching the authentication cookies.
+    """
+    # This is a dummy value to allow us to identify when we're successful.
+    continue_location = "http://localhost/"
+    args = {"continue": continue_location, "auth": auth_token}
+    req = self._CreateRequest("http://%s/_ah/login?%s" %
+                              (self.host, urllib.urlencode(args)))
+    try:
+      response = self.opener.open(req)
+    except urllib2.HTTPError, e:
+      response = e
+    if (response.code != 302 or
+        response.info()["location"] != continue_location):
+      raise urllib2.HTTPError(req.get_full_url(), response.code, response.msg,
+                              response.headers, response.fp)
+    self.authenticated = True
+
+  def _Authenticate(self):
+    """Authenticates the user.
+
+    The authentication process works as follows:
+     1) We get a username and password from the user
+     2) We use ClientLogin to obtain an AUTH token for the user
+        (see https://developers.google.com/identity/protocols/AuthForInstalledApps).
+     3) We pass the auth token to /_ah/login on the server to obtain an
+        authentication cookie. If login was successful, it tries to redirect
+        us to the URL we provided.
+
+    If we attempt to access the upload API without first obtaining an
+    authentication cookie, it returns a 401 response and directs us to
+    authenticate ourselves with ClientLogin.
+    """
+    for i in range(3):
+      credentials = self.auth_function()
+      try:
+        auth_token = self._GetAuthToken(credentials[0], credentials[1])
+      except ClientLoginError, e:
+        if e.reason == "BadAuthentication":
+          print >>sys.stderr, "Invalid username or password."
+          continue
+        if e.reason == "CaptchaRequired":
+          print >>sys.stderr, (
+              "Please go to\n"
+              "https://www.google.com/accounts/DisplayUnlockCaptcha\n"
+              "and verify you are a human.  Then try again.")
+          break
+        if e.reason == "NotVerified":
+          print >>sys.stderr, "Account not verified."
+          break
+        if e.reason == "TermsNotAgreed":
+          print >>sys.stderr, "User has not agreed to TOS."
+          break
+        if e.reason == "AccountDeleted":
+          print >>sys.stderr, "The user account has been deleted."
+          break
+        if e.reason == "AccountDisabled":
+          print >>sys.stderr, "The user account has been disabled."
+          break
+        if e.reason == "ServiceDisabled":
+          print >>sys.stderr, ("The user's access to the service has been "
+                               "disabled.")
+          break
+        if e.reason == "ServiceUnavailable":
+          print >>sys.stderr, "The service is not available; try again later."
+          break
+        raise
+      self._GetAuthCookie(auth_token)
+      return
+
+  def Send(self, request_path, payload=None,
+           content_type="application/octet-stream",
+           timeout=None,
+           **kwargs):
+    """Sends an RPC and returns the response.
+
+    Args:
+      request_path: The path to send the request to, eg /api/appversion/create.
+      payload: The body of the request, or None to send an empty request.
+      content_type: The Content-Type header to use.
+      timeout: timeout in seconds; default None i.e. no timeout.
+        (Note: for large requests on OS X, the timeout doesn't work right.)
+      kwargs: Any keyword arguments are converted into query string parameters.
+
+    Returns:
+      The response body, as a string.
+    """
+    # TODO: Don't require authentication.  Let the server say
+    # whether it is necessary.
+    if not self.authenticated:
+      self._Authenticate()
+
+    old_timeout = socket.getdefaulttimeout()
+    socket.setdefaulttimeout(timeout)
+    try:
+      tries = 0
+      while True:
+        tries += 1
+        args = dict(kwargs)
+        url = "http://%s%s" % (self.host, request_path)
+        if args:
+          url += "?" + urllib.urlencode(args)
+        req = self._CreateRequest(url=url, data=payload)
+        req.add_header("Content-Type", content_type)
+        try:
+          f = self.opener.open(req)
+          response = f.read()
+          f.close()
+          return response
+        except urllib2.HTTPError, e:
+          if tries > 3:
+            raise
+          elif e.code == 401:
+            self._Authenticate()
+##           elif e.code >= 500 and e.code < 600:
+##             # Server Error - try again.
+##             continue
+          else:
+            raise
+    finally:
+      socket.setdefaulttimeout(old_timeout)
+
+
+class HttpRpcServer(AbstractRpcServer):
+  """Provides a simplified RPC-style interface for HTTP requests."""
+
+  def _Authenticate(self):
+    """Save the cookie jar after authentication."""
+    super(HttpRpcServer, self)._Authenticate()
+    if self.save_cookies:
+      StatusUpdate("Saving authentication cookies to %s" % self.cookie_file)
+      self.cookie_jar.save()
+
+  def _GetOpener(self):
+    """Returns an OpenerDirector that supports cookies and ignores redirects.
+
+    Returns:
+      A urllib2.OpenerDirector object.
+    """
+    opener = urllib2.OpenerDirector()
+    opener.add_handler(urllib2.ProxyHandler())
+    opener.add_handler(urllib2.UnknownHandler())
+    opener.add_handler(urllib2.HTTPHandler())
+    opener.add_handler(urllib2.HTTPDefaultErrorHandler())
+    opener.add_handler(urllib2.HTTPSHandler())
+    opener.add_handler(urllib2.HTTPErrorProcessor())
+    if self.save_cookies:
+      self.cookie_file = os.path.expanduser("~/.codereview_upload_cookies")
+      self.cookie_jar = cookielib.MozillaCookieJar(self.cookie_file)
+      if os.path.exists(self.cookie_file):
+        try:
+          self.cookie_jar.load()
+          self.authenticated = True
+          StatusUpdate("Loaded authentication cookies from %s" %
+                       self.cookie_file)
+        except (cookielib.LoadError, IOError):
+          # Failed to load cookies - just ignore them.
+          pass
+      else:
+        # Create an empty cookie file with mode 600
+        fd = os.open(self.cookie_file, os.O_CREAT, 0600)
+        os.close(fd)
+      # Always chmod the cookie file
+      os.chmod(self.cookie_file, 0600)
+    else:
+      # Don't save cookies across runs of update.py.
+      self.cookie_jar = cookielib.CookieJar()
+    opener.add_handler(urllib2.HTTPCookieProcessor(self.cookie_jar))
+    return opener
+
+
+parser = optparse.OptionParser(usage="%prog [options] [-- diff_options]")
+parser.add_option("-y", "--assume_yes", action="store_true",
+                  dest="assume_yes", default=False,
+                  help="Assume that the answer to yes/no questions is 'yes'.")
+# Logging
+group = parser.add_option_group("Logging options")
+group.add_option("-q", "--quiet", action="store_const", const=0,
+                 dest="verbose", help="Print errors only.")
+group.add_option("-v", "--verbose", action="store_const", const=2,
+                 dest="verbose", default=1,
+                 help="Print info level logs (default).")
+group.add_option("--noisy", action="store_const", const=3,
+                 dest="verbose", help="Print all logs.")
+# Review server
+group = parser.add_option_group("Review server options")
+group.add_option("-s", "--server", action="store", dest="server",
+                 default="codereview.appspot.com",
+                 metavar="SERVER",
+                 help=("The server to upload to. The format is host[:port]. "
+                       "Defaults to 'codereview.appspot.com'."))
+group.add_option("-e", "--email", action="store", dest="email",
+                 metavar="EMAIL", default=None,
+                 help="The username to use. Will prompt if omitted.")
+group.add_option("-H", "--host", action="store", dest="host",
+                 metavar="HOST", default=None,
+                 help="Overrides the Host header sent with all RPCs.")
+group.add_option("--no_cookies", action="store_false",
+                 dest="save_cookies", default=True,
+                 help="Do not save authentication cookies to local disk.")
+# Issue
+group = parser.add_option_group("Issue options")
+group.add_option("-d", "--description", action="store", dest="description",
+                 metavar="DESCRIPTION", default=None,
+                 help="Optional description when creating an issue.")
+group.add_option("-f", "--description_file", action="store",
+                 dest="description_file", metavar="DESCRIPTION_FILE",
+                 default=None,
+                 help="Optional path of a file that contains "
+                      "the description when creating an issue.")
+group.add_option("-r", "--reviewers", action="store", dest="reviewers",
+                 metavar="REVIEWERS", default=None,
+                 help="Add reviewers (comma separated email addresses).")
+group.add_option("--cc", action="store", dest="cc",
+                 metavar="CC", default=None,
+                 help="Add CC (comma separated email addresses).")
+# Upload options
+group = parser.add_option_group("Patch options")
+group.add_option("-m", "--message", action="store", dest="message",
+                 metavar="MESSAGE", default=None,
+                 help="A message to identify the patch. "
+                      "Will prompt if omitted.")
+group.add_option("-i", "--issue", type="int", action="store",
+                 metavar="ISSUE", default=None,
+                 help="Issue number to which to add. Defaults to new issue.")
+group.add_option("--download_base", action="store_true",
+                 dest="download_base", default=False,
+                 help="Base files will be downloaded by the server "
+                 "(side-by-side diffs may not work on files with CRs).")
+group.add_option("--rev", action="store", dest="revision",
+                 metavar="REV", default=None,
+                 help="Branch/tree/revision to diff against (used by DVCS).")
+group.add_option("--send_mail", action="store_true",
+                 dest="send_mail", default=False,
+                 help="Send notification email to reviewers.")
+
+
+def GetRpcServer(options):
+  """Returns an instance of an AbstractRpcServer.
+
+  Returns:
+    A new AbstractRpcServer, on which RPC calls can be made.
+  """
+
+  rpc_server_class = HttpRpcServer
+
+  def GetUserCredentials():
+    """Prompts the user for a username and password."""
+    email = options.email
+    if email is None:
+      email = GetEmail("Email (login for uploading to %s)" % options.server)
+    password = getpass.getpass("Password for %s: " % email)
+    return (email, password)
+
+  # If this is the dev_appserver, use fake authentication.
+  host = (options.host or options.server).lower()
+  if host == "localhost" or host.startswith("localhost:"):
+    email = options.email
+    if email is None:
+      email = "test@example.com"
+      logging.info("Using debug user %s.  Override with --email" % email)
+    server = rpc_server_class(
+        options.server,
+        lambda: (email, "password"),
+        host_override=options.host,
+        extra_headers={"Cookie":
+                       'dev_appserver_login="%s:False"' % email},
+        save_cookies=options.save_cookies)
+    # Don't try to talk to ClientLogin.
+    server.authenticated = True
+    return server
+
+  return rpc_server_class(options.server, GetUserCredentials,
+                          host_override=options.host,
+                          save_cookies=options.save_cookies)
+
+
+def EncodeMultipartFormData(fields, files):
+  """Encode form fields for multipart/form-data.
+
+  Args:
+    fields: A sequence of (name, value) elements for regular form fields.
+    files: A sequence of (name, filename, value) elements for data to be
+           uploaded as files.
+  Returns:
+    (content_type, body) ready for httplib.HTTP instance.
+
+  Source:
+    https://web.archive.org/web/20160116052001/code.activestate.com/recipes/146306
+  """
+  BOUNDARY = '-M-A-G-I-C---B-O-U-N-D-A-R-Y-'
+  CRLF = '\r\n'
+  lines = []
+  for (key, value) in fields:
+    lines.append('--' + BOUNDARY)
+    lines.append('Content-Disposition: form-data; name="%s"' % key)
+    lines.append('')
+    lines.append(value)
+  for (key, filename, value) in files:
+    lines.append('--' + BOUNDARY)
+    lines.append('Content-Disposition: form-data; name="%s"; filename="%s"' %
+             (key, filename))
+    lines.append('Content-Type: %s' % GetContentType(filename))
+    lines.append('')
+    lines.append(value)
+  lines.append('--' + BOUNDARY + '--')
+  lines.append('')
+  body = CRLF.join(lines)
+  content_type = 'multipart/form-data; boundary=%s' % BOUNDARY
+  return content_type, body
+
+
+def GetContentType(filename):
+  """Helper to guess the content-type from the filename."""
+  return mimetypes.guess_type(filename)[0] or 'application/octet-stream'
+
+
+# Use a shell for subcommands on Windows to get a PATH search.
+use_shell = sys.platform.startswith("win")
+
+def RunShellWithReturnCode(command, print_output=False,
+                           universal_newlines=True):
+  """Executes a command and returns the output from stdout and the return code.
+
+  Args:
+    command: Command to execute.
+    print_output: If True, the output is printed to stdout.
+                  If False, both stdout and stderr are ignored.
+    universal_newlines: Use universal_newlines flag (default: True).
+
+  Returns:
+    Tuple (output, return code)
+  """
+  logging.info("Running %s", command)
+  p = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                       shell=use_shell, universal_newlines=universal_newlines)
+  if print_output:
+    output_array = []
+    while True:
+      line = p.stdout.readline()
+      if not line:
+        break
+      print line.strip("\n")
+      output_array.append(line)
+    output = "".join(output_array)
+  else:
+    output = p.stdout.read()
+  p.wait()
+  errout = p.stderr.read()
+  if print_output and errout:
+    print >>sys.stderr, errout
+  p.stdout.close()
+  p.stderr.close()
+  return output, p.returncode
+
+
+def RunShell(command, silent_ok=False, universal_newlines=True,
+             print_output=False):
+  data, retcode = RunShellWithReturnCode(command, print_output,
+                                         universal_newlines)
+  if retcode:
+    ErrorExit("Got error status from %s:\n%s" % (command, data))
+  if not silent_ok and not data:
+    ErrorExit("No output from %s" % command)
+  return data
+
+
+class VersionControlSystem(object):
+  """Abstract base class providing an interface to the VCS."""
+
+  def __init__(self, options):
+    """Constructor.
+
+    Args:
+      options: Command line options.
+    """
+    self.options = options
+
+  def GenerateDiff(self, args):
+    """Return the current diff as a string.
+
+    Args:
+      args: Extra arguments to pass to the diff command.
+    """
+    raise NotImplementedError(
+        "abstract method -- subclass %s must override" % self.__class__)
+
+  def GetUnknownFiles(self):
+    """Return a list of files unknown to the VCS."""
+    raise NotImplementedError(
+        "abstract method -- subclass %s must override" % self.__class__)
+
+  def CheckForUnknownFiles(self):
+    """Show an "are you sure?" prompt if there are unknown files."""
+    unknown_files = self.GetUnknownFiles()
+    if unknown_files:
+      print "The following files are not added to version control:"
+      for line in unknown_files:
+        print line
+      prompt = "Are you sure to continue?(y/N) "
+      answer = raw_input(prompt).strip()
+      if answer != "y":
+        ErrorExit("User aborted")
+
+  def GetBaseFile(self, filename):
+    """Get the content of the upstream version of a file.
+
+    Returns:
+      A tuple (base_content, new_content, is_binary, status)
+        base_content: The contents of the base file.
+        new_content: For text files, this is empty.  For binary files, this is
+          the contents of the new file, since the diff output won't contain
+          information to reconstruct the current file.
+        is_binary: True iff the file is binary.
+        status: The status of the file.
+    """
+
+    raise NotImplementedError(
+        "abstract method -- subclass %s must override" % self.__class__)
+
+
+  def GetBaseFiles(self, diff):
+    """Helper that calls GetBase file for each file in the patch.
+
+    Returns:
+      A dictionary that maps from filename to GetBaseFile's tuple.  Filenames
+      are retrieved based on lines that start with "Index:" or
+      "Property changes on:".
+    """
+    files = {}
+    for line in diff.splitlines(True):
+      if line.startswith('Index:') or line.startswith('Property changes on:'):
+        unused, filename = line.split(':', 1)
+        # On Windows if a file has property changes its filename uses '\'
+        # instead of '/'.
+        filename = filename.strip().replace('\\', '/')
+        files[filename] = self.GetBaseFile(filename)
+    return files
+
+
+  def UploadBaseFiles(self, issue, rpc_server, patch_list, patchset, options,
+                      files):
+    """Uploads the base files (and if necessary, the current ones as well)."""
+
+    def UploadFile(filename, file_id, content, is_binary, status, is_base):
+      """Uploads a file to the server."""
+      file_too_large = False
+      if is_base:
+        type = "base"
+      else:
+        type = "current"
+      if len(content) > MAX_UPLOAD_SIZE:
+        print ("Not uploading the %s file for %s because it's too large." %
+               (type, filename))
+        file_too_large = True
+        content = ""
+      checksum = md5.new(content).hexdigest()
+      if options.verbose > 0 and not file_too_large:
+        print "Uploading %s file for %s" % (type, filename)
+      url = "/%d/upload_content/%d/%d" % (int(issue), int(patchset), file_id)
+      form_fields = [("filename", filename),
+                     ("status", status),
+                     ("checksum", checksum),
+                     ("is_binary", str(is_binary)),
+                     ("is_current", str(not is_base)),
+                    ]
+      if file_too_large:
+        form_fields.append(("file_too_large", "1"))
+      if options.email:
+        form_fields.append(("user", options.email))
+      ctype, body = EncodeMultipartFormData(form_fields,
+                                            [("data", filename, content)])
+      response_body = rpc_server.Send(url, body,
+                                      content_type=ctype)
+      if not response_body.startswith("OK"):
+        StatusUpdate("  --> %s" % response_body)
+        sys.exit(1)
+
+    patches = dict()
+    [patches.setdefault(v, k) for k, v in patch_list]
+    for filename in patches.keys():
+      base_content, new_content, is_binary, status = files[filename]
+      file_id_str = patches.get(filename)
+      if file_id_str.find("nobase") != -1:
+        base_content = None
+        file_id_str = file_id_str[file_id_str.rfind("_") + 1:]
+      file_id = int(file_id_str)
+      if base_content != None:
+        UploadFile(filename, file_id, base_content, is_binary, status, True)
+      if new_content != None:
+        UploadFile(filename, file_id, new_content, is_binary, status, False)
+
+  def IsImage(self, filename):
+    """Returns true if the filename has an image extension."""
+    mimetype =  mimetypes.guess_type(filename)[0]
+    if not mimetype:
+      return False
+    return mimetype.startswith("image/")
+
+
+class SubversionVCS(VersionControlSystem):
+  """Implementation of the VersionControlSystem interface for Subversion."""
+
+  def __init__(self, options):
+    super(SubversionVCS, self).__init__(options)
+    if self.options.revision:
+      match = re.match(r"(\d+)(:(\d+))?", self.options.revision)
+      if not match:
+        ErrorExit("Invalid Subversion revision %s." % self.options.revision)
+      self.rev_start = match.group(1)
+      self.rev_end = match.group(3)
+    else:
+      self.rev_start = self.rev_end = None
+    # Cache output from "svn list -r REVNO dirname".
+    # Keys: dirname, Values: 2-tuple (output for start rev and end rev).
+    self.svnls_cache = {}
+    # SVN base URL is required to fetch files deleted in an older revision.
+    # Result is cached to not guess it over and over again in GetBaseFile().
+    required = self.options.download_base or self.options.revision is not None
+    self.svn_base = self._GuessBase(required)
+
+  def GuessBase(self, required):
+    """Wrapper for _GuessBase."""
+    return self.svn_base
+
+  def _GuessBase(self, required):
+    """Returns the SVN base URL.
+
+    Args:
+      required: If true, exits if the url can't be guessed, otherwise None is
+        returned.
+    """
+    info = RunShell(["svn", "info"])
+    for line in info.splitlines():
+      words = line.split()
+      if len(words) == 2 and words[0] == "URL:":
+        url = words[1]
+        scheme, netloc, path, params, query, fragment = urlparse.urlparse(url)
+        username, netloc = urllib.splituser(netloc)
+        if username:
+          logging.info("Removed username from base URL")
+        if netloc.endswith("svn.python.org"):
+          if netloc == "svn.python.org":
+            if path.startswith("/projects/"):
+              path = path[9:]
+          elif netloc != "pythondev@svn.python.org":
+            ErrorExit("Unrecognized Python URL: %s" % url)
+          base = "http://svn.python.org/view/*checkout*%s/" % path
+          logging.info("Guessed Python base = %s", base)
+        elif netloc.endswith("svn.collab.net"):
+          if path.startswith("/repos/"):
+            path = path[6:]
+          base = "http://svn.collab.net/viewvc/*checkout*%s/" % path
+          logging.info("Guessed CollabNet base = %s", base)
+        elif netloc.endswith(".googlecode.com"):
+          path = path + "/"
+          base = urlparse.urlunparse(("http", netloc, path, params,
+                                      query, fragment))
+          logging.info("Guessed Google Code base = %s", base)
+        else:
+          path = path + "/"
+          base = urlparse.urlunparse((scheme, netloc, path, params,
+                                      query, fragment))
+          logging.info("Guessed base = %s", base)
+        return base
+    if required:
+      ErrorExit("Can't find URL in output from svn info")
+    return None
+
+  def GenerateDiff(self, args):
+    cmd = ["svn", "diff"]
+    if self.options.revision:
+      cmd += ["-r", self.options.revision]
+    cmd.extend(args)
+    data = RunShell(cmd)
+    count = 0
+    for line in data.splitlines():
+      if line.startswith("Index:") or line.startswith("Property changes on:"):
+        count += 1
+        logging.info(line)
+    if not count:
+      ErrorExit("No valid patches found in output from svn diff")
+    return data
+
+  def _CollapseKeywords(self, content, keyword_str):
+    """Collapses SVN keywords."""
+    # svn cat translates keywords but svn diff doesn't. As a result of this
+    # behavior patching.PatchChunks() fails with a chunk mismatch error.
+    # This part was originally written by the Review Board development team
+    # who had the same problem (https://reviews.reviewboard.org/r/276/).
+    # Mapping of keywords to known aliases
+    svn_keywords = {
+      # Standard keywords
+      'Date':                ['Date', 'LastChangedDate'],
+      'Revision':            ['Revision', 'LastChangedRevision', 'Rev'],
+      'Author':              ['Author', 'LastChangedBy'],
+      'HeadURL':             ['HeadURL', 'URL'],
+      'Id':                  ['Id'],
+
+      # Aliases
+      'LastChangedDate':     ['LastChangedDate', 'Date'],
+      'LastChangedRevision': ['LastChangedRevision', 'Rev', 'Revision'],
+      'LastChangedBy':       ['LastChangedBy', 'Author'],
+      'URL':                 ['URL', 'HeadURL'],
+    }
+
+    def repl(m):
+       if m.group(2):
+         return "$%s::%s$" % (m.group(1), " " * len(m.group(3)))
+       return "$%s$" % m.group(1)
+    keywords = [keyword
+                for name in keyword_str.split(" ")
+                for keyword in svn_keywords.get(name, [])]
+    return re.sub(r"\$(%s):(:?)([^\$]+)\$" % '|'.join(keywords), repl, content)
+
+  def GetUnknownFiles(self):
+    status = RunShell(["svn", "status", "--ignore-externals"], silent_ok=True)
+    unknown_files = []
+    for line in status.split("\n"):
+      if line and line[0] == "?":
+        unknown_files.append(line)
+    return unknown_files
+
+  def ReadFile(self, filename):
+    """Returns the contents of a file."""
+    file = open(filename, 'rb')
+    result = ""
+    try:
+      result = file.read()
+    finally:
+      file.close()
+    return result
+
+  def GetStatus(self, filename):
+    """Returns the status of a file."""
+    if not self.options.revision:
+      status = RunShell(["svn", "status", "--ignore-externals", filename])
+      if not status:
+        ErrorExit("svn status returned no output for %s" % filename)
+      status_lines = status.splitlines()
+      # If file is in a cl, the output will begin with
+      # "\n--- Changelist 'cl_name':\n".  See
+      # https://web.archive.org/web/20090918234815/svn.collab.net/repos/svn/trunk/notes/changelist-design.txt
+      if (len(status_lines) == 3 and
+          not status_lines[0] and
+          status_lines[1].startswith("--- Changelist")):
+        status = status_lines[2]
+      else:
+        status = status_lines[0]
+    # If we have a revision to diff against we need to run "svn list"
+    # for the old and the new revision and compare the results to get
+    # the correct status for a file.
+    else:
+      dirname, relfilename = os.path.split(filename)
+      if dirname not in self.svnls_cache:
+        cmd = ["svn", "list", "-r", self.rev_start, dirname or "."]
+        out, returncode = RunShellWithReturnCode(cmd)
+        if returncode:
+          ErrorExit("Failed to get status for %s." % filename)
+        old_files = out.splitlines()
+        args = ["svn", "list"]
+        if self.rev_end:
+          args += ["-r", self.rev_end]
+        cmd = args + [dirname or "."]
+        out, returncode = RunShellWithReturnCode(cmd)
+        if returncode:
+          ErrorExit("Failed to run command %s" % cmd)
+        self.svnls_cache[dirname] = (old_files, out.splitlines())
+      old_files, new_files = self.svnls_cache[dirname]
+      if relfilename in old_files and relfilename not in new_files:
+        status = "D   "
+      elif relfilename in old_files and relfilename in new_files:
+        status = "M   "
+      else:
+        status = "A   "
+    return status
+
+  def GetBaseFile(self, filename):
+    status = self.GetStatus(filename)
+    base_content = None
+    new_content = None
+
+    # If a file is copied its status will be "A  +", which signifies
+    # "addition-with-history".  See "svn st" for more information.  We need to
+    # upload the original file or else diff parsing will fail if the file was
+    # edited.
+    if status[0] == "A" and status[3] != "+":
+      # We'll need to upload the new content if we're adding a binary file
+      # since diff's output won't contain it.
+      mimetype = RunShell(["svn", "propget", "svn:mime-type", filename],
+                          silent_ok=True)
+      base_content = ""
+      is_binary = mimetype and not mimetype.startswith("text/")
+      if is_binary and self.IsImage(filename):
+        new_content = self.ReadFile(filename)
+    elif (status[0] in ("M", "D", "R") or
+          (status[0] == "A" and status[3] == "+") or  # Copied file.
+          (status[0] == " " and status[1] == "M")):  # Property change.
+      args = []
+      if self.options.revision:
+        url = "%s/%s@%s" % (self.svn_base, filename, self.rev_start)
+      else:
+        # Don't change filename, it's needed later.
+        url = filename
+        args += ["-r", "BASE"]
+      cmd = ["svn"] + args + ["propget", "svn:mime-type", url]
+      mimetype, returncode = RunShellWithReturnCode(cmd)
+      if returncode:
+        # File does not exist in the requested revision.
+        # Reset mimetype, it contains an error message.
+        mimetype = ""
+      get_base = False
+      is_binary = mimetype and not mimetype.startswith("text/")
+      if status[0] == " ":
+        # Empty base content just to force an upload.
+        base_content = ""
+      elif is_binary:
+        if self.IsImage(filename):
+          get_base = True
+          if status[0] == "M":
+            if not self.rev_end:
+              new_content = self.ReadFile(filename)
+            else:
+              url = "%s/%s@%s" % (self.svn_base, filename, self.rev_end)
+              new_content = RunShell(["svn", "cat", url],
+                                     universal_newlines=True, silent_ok=True)
+        else:
+          base_content = ""
+      else:
+        get_base = True
+
+      if get_base:
+        if is_binary:
+          universal_newlines = False
+        else:
+          universal_newlines = True
+        if self.rev_start:
+          # "svn cat -r REV delete_file.txt" doesn't work. cat requires
+          # the full URL with "@REV" appended instead of using "-r" option.
+          url = "%s/%s@%s" % (self.svn_base, filename, self.rev_start)
+          base_content = RunShell(["svn", "cat", url],
+                                  universal_newlines=universal_newlines,
+                                  silent_ok=True)
+        else:
+          base_content = RunShell(["svn", "cat", filename],
+                                  universal_newlines=universal_newlines,
+                                  silent_ok=True)
+        if not is_binary:
+          args = []
+          if self.rev_start:
+            url = "%s/%s@%s" % (self.svn_base, filename, self.rev_start)
+          else:
+            url = filename
+            args += ["-r", "BASE"]
+          cmd = ["svn"] + args + ["propget", "svn:keywords", url]
+          keywords, returncode = RunShellWithReturnCode(cmd)
+          if keywords and not returncode:
+            base_content = self._CollapseKeywords(base_content, keywords)
+    else:
+      StatusUpdate("svn status returned unexpected output: %s" % status)
+      sys.exit(1)
+    return base_content, new_content, is_binary, status[0:5]
+
+
+class GitVCS(VersionControlSystem):
+  """Implementation of the VersionControlSystem interface for Git."""
+
+  def __init__(self, options):
+    super(GitVCS, self).__init__(options)
+    # Map of filename -> hash of base file.
+    self.base_hashes = {}
+
+  def GenerateDiff(self, extra_args):
+    # This is more complicated than svn's GenerateDiff because we must convert
+    # the diff output to include an svn-style "Index:" line as well as record
+    # the hashes of the base files, so we can upload them along with our diff.
+    if self.options.revision:
+      extra_args = [self.options.revision] + extra_args
+    gitdiff = RunShell(["git", "diff", "--full-index"] + extra_args)
+    svndiff = []
+    filecount = 0
+    filename = None
+    for line in gitdiff.splitlines():
+      match = re.match(r"diff --git a/(.*) b/.*$", line)
+      if match:
+        filecount += 1
+        filename = match.group(1)
+        svndiff.append("Index: %s\n" % filename)
+      else:
+        # The "index" line in a git diff looks like this (long hashes elided):
+        #   index 82c0d44..b2cee3f 100755
+        # We want to save the left hash, as that identifies the base file.
+        match = re.match(r"index (\w+)\.\.", line)
+        if match:
+          self.base_hashes[filename] = match.group(1)
+      svndiff.append(line + "\n")
+    if not filecount:
+      ErrorExit("No valid patches found in output from git diff")
+    return "".join(svndiff)
+
+  def GetUnknownFiles(self):
+    status = RunShell(["git", "ls-files", "--exclude-standard", "--others"],
+                      silent_ok=True)
+    return status.splitlines()
+
+  def GetBaseFile(self, filename):
+    hash = self.base_hashes[filename]
+    base_content = None
+    new_content = None
+    is_binary = False
+    if hash == "0" * 40:  # All-zero hash indicates no base file.
+      status = "A"
+      base_content = ""
+    else:
+      status = "M"
+      base_content, returncode = RunShellWithReturnCode(["git", "show", hash])
+      if returncode:
+        ErrorExit("Got error status from 'git show %s'" % hash)
+    return (base_content, new_content, is_binary, status)
+
+
+class MercurialVCS(VersionControlSystem):
+  """Implementation of the VersionControlSystem interface for Mercurial."""
+
+  def __init__(self, options, repo_dir):
+    super(MercurialVCS, self).__init__(options)
+    # Absolute path to repository (we can be in a subdir)
+    self.repo_dir = os.path.normpath(repo_dir)
+    # Compute the subdir
+    cwd = os.path.normpath(os.getcwd())
+    assert cwd.startswith(self.repo_dir)
+    self.subdir = cwd[len(self.repo_dir):].lstrip(r"\/")
+    if self.options.revision:
+      self.base_rev = self.options.revision
+    else:
+      self.base_rev = RunShell(["hg", "parent", "-q"]).split(':')[1].strip()
+
+  def _GetRelPath(self, filename):
+    """Get relative path of a file according to the current directory,
+    given its logical path in the repo."""
+    assert filename.startswith(self.subdir), filename
+    return filename[len(self.subdir):].lstrip(r"\/")
+
+  def GenerateDiff(self, extra_args):
+    # If no file specified, restrict to the current subdir
+    extra_args = extra_args or ["."]
+    cmd = ["hg", "diff", "--git", "-r", self.base_rev] + extra_args
+    data = RunShell(cmd, silent_ok=True)
+    svndiff = []
+    filecount = 0
+    for line in data.splitlines():
+      m = re.match("diff --git a/(\S+) b/(\S+)", line)
+      if m:
+        # Modify line to make it look like as it comes from svn diff.
+        # With this modification no changes on the server side are required
+        # to make upload.py work with Mercurial repos.
+        # NOTE: for proper handling of moved/copied files, we have to use
+        # the second filename.
+        filename = m.group(2)
+        svndiff.append("Index: %s" % filename)
+        svndiff.append("=" * 67)
+        filecount += 1
+        logging.info(line)
+      else:
+        svndiff.append(line)
+    if not filecount:
+      ErrorExit("No valid patches found in output from hg diff")
+    return "\n".join(svndiff) + "\n"
+
+  def GetUnknownFiles(self):
+    """Return a list of files unknown to the VCS."""
+    args = []
+    status = RunShell(["hg", "status", "--rev", self.base_rev, "-u", "."],
+        silent_ok=True)
+    unknown_files = []
+    for line in status.splitlines():
+      st, fn = line.split(" ", 1)
+      if st == "?":
+        unknown_files.append(fn)
+    return unknown_files
+
+  def GetBaseFile(self, filename):
+    # "hg status" and "hg cat" both take a path relative to the current subdir
+    # rather than to the repo root, but "hg diff" has given us the full path
+    # to the repo root.
+    base_content = ""
+    new_content = None
+    is_binary = False
+    oldrelpath = relpath = self._GetRelPath(filename)
+    # "hg status -C" returns two lines for moved/copied files, one otherwise
+    out = RunShell(["hg", "status", "-C", "--rev", self.base_rev, relpath])
+    out = out.splitlines()
+    # HACK: strip error message about missing file/directory if it isn't in
+    # the working copy
+    if out[0].startswith('%s: ' % relpath):
+      out = out[1:]
+    if len(out) > 1:
+      # Moved/copied => considered as modified, use old filename to
+      # retrieve base contents
+      oldrelpath = out[1].strip()
+      status = "M"
+    else:
+      status, _ = out[0].split(' ', 1)
+    if status != "A":
+      base_content = RunShell(["hg", "cat", "-r", self.base_rev, oldrelpath],
+        silent_ok=True)
+      is_binary = "\0" in base_content  # Mercurial's heuristic
+    if status != "R":
+      new_content = open(relpath, "rb").read()
+      is_binary = is_binary or "\0" in new_content
+    if is_binary and base_content:
+      # Fetch again without converting newlines
+      base_content = RunShell(["hg", "cat", "-r", self.base_rev, oldrelpath],
+        silent_ok=True, universal_newlines=False)
+    if not is_binary or not self.IsImage(relpath):
+      new_content = None
+    return base_content, new_content, is_binary, status
+
+
+# NOTE: The SplitPatch function is duplicated in engine.py, keep them in sync.
+def SplitPatch(data):
+  """Splits a patch into separate pieces for each file.
+
+  Args:
+    data: A string containing the output of svn diff.
+
+  Returns:
+    A list of 2-tuple (filename, text) where text is the svn diff output
+      pertaining to filename.
+  """
+  patches = []
+  filename = None
+  diff = []
+  for line in data.splitlines(True):
+    new_filename = None
+    if line.startswith('Index:'):
+      unused, new_filename = line.split(':', 1)
+      new_filename = new_filename.strip()
+    elif line.startswith('Property changes on:'):
+      unused, temp_filename = line.split(':', 1)
+      # When a file is modified, paths use '/' between directories, however
+      # when a property is modified '\' is used on Windows.  Make them the same
+      # otherwise the file shows up twice.
+      temp_filename = temp_filename.strip().replace('\\', '/')
+      if temp_filename != filename:
+        # File has property changes but no modifications, create a new diff.
+        new_filename = temp_filename
+    if new_filename:
+      if filename and diff:
+        patches.append((filename, ''.join(diff)))
+      filename = new_filename
+      diff = [line]
+      continue
+    if diff is not None:
+      diff.append(line)
+  if filename and diff:
+    patches.append((filename, ''.join(diff)))
+  return patches
+
+
+def UploadSeparatePatches(issue, rpc_server, patchset, data, options):
+  """Uploads a separate patch for each file in the diff output.
+
+  Returns a list of [patch_key, filename] for each file.
+  """
+  patches = SplitPatch(data)
+  rv = []
+  for patch in patches:
+    if len(patch[1]) > MAX_UPLOAD_SIZE:
+      print ("Not uploading the patch for " + patch[0] +
+             " because the file is too large.")
+      continue
+    form_fields = [("filename", patch[0])]
+    if not options.download_base:
+      form_fields.append(("content_upload", "1"))
+    files = [("data", "data.diff", patch[1])]
+    ctype, body = EncodeMultipartFormData(form_fields, files)
+    url = "/%d/upload_patch/%d" % (int(issue), int(patchset))
+    print "Uploading patch for " + patch[0]
+    response_body = rpc_server.Send(url, body, content_type=ctype)
+    lines = response_body.splitlines()
+    if not lines or lines[0] != "OK":
+      StatusUpdate("  --> %s" % response_body)
+      sys.exit(1)
+    rv.append([lines[1], patch[0]])
+  return rv
+
+
+def GuessVCS(options):
+  """Helper to guess the version control system.
+
+  This examines the current directory, guesses which VersionControlSystem
+  we're using, and returns an instance of the appropriate class.  Exit with an
+  error if we can't figure it out.
+
+  Returns:
+    A VersionControlSystem instance. Exits if the VCS can't be guessed.
+  """
+  # Mercurial has a command to get the base directory of a repository
+  # Try running it, but don't die if we don't have hg installed.
+  # NOTE: we try Mercurial first as it can sit on top of an SVN working copy.
+  try:
+    out, returncode = RunShellWithReturnCode(["hg", "root"])
+    if returncode == 0:
+      return MercurialVCS(options, out.strip())
+  except OSError, (errno, message):
+    if errno != 2:  # ENOENT -- they don't have hg installed.
+      raise
+
+  # Subversion has a .svn in all working directories.
+  if os.path.isdir('.svn'):
+    logging.info("Guessed VCS = Subversion")
+    return SubversionVCS(options)
+
+  # Git has a command to test if you're in a git tree.
+  # Try running it, but don't die if we don't have git installed.
+  try:
+    out, returncode = RunShellWithReturnCode(["git", "rev-parse",
+                                              "--is-inside-work-tree"])
+    if returncode == 0:
+      return GitVCS(options)
+  except OSError, (errno, message):
+    if errno != 2:  # ENOENT -- they don't have git installed.
+      raise
+
+  ErrorExit(("Could not guess version control system. "
+             "Are you in a working copy directory?"))
+
+
+def RealMain(argv, data=None):
+  """The real main function.
+
+  Args:
+    argv: Command line arguments.
+    data: Diff contents. If None (default) the diff is generated by
+      the VersionControlSystem implementation returned by GuessVCS().
+
+  Returns:
+    A 2-tuple (issue id, patchset id).
+    The patchset id is None if the base files are not uploaded by this
+    script (applies only to SVN checkouts).
+  """
+  logging.basicConfig(format=("%(asctime).19s %(levelname)s %(filename)s:"
+                              "%(lineno)s %(message)s "))
+  os.environ['LC_ALL'] = 'C'
+  options, args = parser.parse_args(argv[1:])
+  global verbosity
+  verbosity = options.verbose
+  if verbosity >= 3:
+    logging.getLogger().setLevel(logging.DEBUG)
+  elif verbosity >= 2:
+    logging.getLogger().setLevel(logging.INFO)
+  vcs = GuessVCS(options)
+  if isinstance(vcs, SubversionVCS):
+    # base field is only allowed for Subversion.
+    # Note: Fetching base files may become deprecated in future releases.
+    base = vcs.GuessBase(options.download_base)
+  else:
+    base = None
+  if not base and options.download_base:
+    options.download_base = True
+    logging.info("Enabled upload of base file")
+  if not options.assume_yes:
+    vcs.CheckForUnknownFiles()
+  if data is None:
+    data = vcs.GenerateDiff(args)
+  files = vcs.GetBaseFiles(data)
+  if verbosity >= 1:
+    print "Upload server:", options.server, "(change with -s/--server)"
+  if options.issue:
+    prompt = "Message describing this patch set: "
+  else:
+    prompt = "New issue subject: "
+  message = options.message or raw_input(prompt).strip()
+  if not message:
+    ErrorExit("A non-empty message is required")
+  rpc_server = GetRpcServer(options)
+  form_fields = [("subject", message)]
+  if base:
+    form_fields.append(("base", base))
+  if options.issue:
+    form_fields.append(("issue", str(options.issue)))
+  if options.email:
+    form_fields.append(("user", options.email))
+  if options.reviewers:
+    for reviewer in options.reviewers.split(','):
+      if "@" in reviewer and not reviewer.split("@")[1].count(".") == 1:
+        ErrorExit("Invalid email address: %s" % reviewer)
+    form_fields.append(("reviewers", options.reviewers))
+  if options.cc:
+    for cc in options.cc.split(','):
+      if "@" in cc and not cc.split("@")[1].count(".") == 1:
+        ErrorExit("Invalid email address: %s" % cc)
+    form_fields.append(("cc", options.cc))
+  description = options.description
+  if options.description_file:
+    if options.description:
+      ErrorExit("Can't specify description and description_file")
+    file = open(options.description_file, 'r')
+    description = file.read()
+    file.close()
+  if description:
+    form_fields.append(("description", description))
+  # Send a hash of all the base file so the server can determine if a copy
+  # already exists in an earlier patchset.
+  base_hashes = ""
+  for file, info in files.iteritems():
+    if not info[0] is None:
+      checksum = md5.new(info[0]).hexdigest()
+      if base_hashes:
+        base_hashes += "|"
+      base_hashes += checksum + ":" + file
+  form_fields.append(("base_hashes", base_hashes))
+  # If we're uploading base files, don't send the email before the uploads, so
+  # that it contains the file status.
+  if options.send_mail and options.download_base:
+    form_fields.append(("send_mail", "1"))
+  if not options.download_base:
+    form_fields.append(("content_upload", "1"))
+  if len(data) > MAX_UPLOAD_SIZE:
+    print "Patch is large, so uploading file patches separately."
+    uploaded_diff_file = []
+    form_fields.append(("separate_patches", "1"))
+  else:
+    uploaded_diff_file = [("data", "data.diff", data)]
+  ctype, body = EncodeMultipartFormData(form_fields, uploaded_diff_file)
+  response_body = rpc_server.Send("/upload", body, content_type=ctype)
+  patchset = None
+  if not options.download_base or not uploaded_diff_file:
+    lines = response_body.splitlines()
+    if len(lines) >= 2:
+      msg = lines[0]
+      patchset = lines[1].strip()
+      patches = [x.split(" ", 1) for x in lines[2:]]
+    else:
+      msg = response_body
+  else:
+    msg = response_body
+  StatusUpdate(msg)
+  if not response_body.startswith("Issue created.") and \
+  not response_body.startswith("Issue updated."):
+    sys.exit(0)
+  issue = msg[msg.rfind("/")+1:]
+
+  if not uploaded_diff_file:
+    result = UploadSeparatePatches(issue, rpc_server, patchset, data, options)
+    if not options.download_base:
+      patches = result
+
+  if not options.download_base:
+    vcs.UploadBaseFiles(issue, rpc_server, patches, patchset, options, files)
+    if options.send_mail:
+      rpc_server.Send("/" + issue + "/mail", payload="")
+  return issue, patchset
+
+
+def main():
+  try:
+    RealMain(sys.argv)
+  except KeyboardInterrupt:
+    print
+    StatusUpdate("Interrupted.")
+    sys.exit(1)
+
+
+if __name__ == "__main__":
+  main()
diff --git a/3rdparty/gtest/scripts/upload_gtest.py b/3rdparty/gtest/scripts/upload_gtest.py
new file mode 100644
index 0000000..be19ae8
--- /dev/null
+++ b/3rdparty/gtest/scripts/upload_gtest.py
@@ -0,0 +1,78 @@
+#!/usr/bin/env python
+#
+# Copyright 2009, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""upload_gtest.py v0.1.0 -- uploads a Google Test patch for review.
+
+This simple wrapper passes all command line flags and
+--cc=googletestframework@googlegroups.com to upload.py.
+
+USAGE: upload_gtest.py [options for upload.py]
+"""
+
+__author__ = 'wan@google.com (Zhanyong Wan)'
+
+import os
+import sys
+
+CC_FLAG = '--cc='
+GTEST_GROUP = 'googletestframework@googlegroups.com'
+
+
+def main():
+  # Finds the path to upload.py, assuming it is in the same directory
+  # as this file.
+  my_dir = os.path.dirname(os.path.abspath(__file__))
+  upload_py_path = os.path.join(my_dir, 'upload.py')
+
+  # Adds Google Test discussion group to the cc line if it's not there
+  # already.
+  upload_py_argv = [upload_py_path]
+  found_cc_flag = False
+  for arg in sys.argv[1:]:
+    if arg.startswith(CC_FLAG):
+      found_cc_flag = True
+      cc_line = arg[len(CC_FLAG):]
+      cc_list = [addr for addr in cc_line.split(',') if addr]
+      if GTEST_GROUP not in cc_list:
+        cc_list.append(GTEST_GROUP)
+      upload_py_argv.append(CC_FLAG + ','.join(cc_list))
+    else:
+      upload_py_argv.append(arg)
+
+  if not found_cc_flag:
+    upload_py_argv.append(CC_FLAG + GTEST_GROUP)
+
+  # Invokes upload.py with the modified command line flags.
+  os.execv(upload_py_path, upload_py_argv)
+
+
+if __name__ == '__main__':
+  main()
diff --git a/3rdparty/gtest/src/gtest-all.cc b/3rdparty/gtest/src/gtest-all.cc
new file mode 100644
index 0000000..ad29290
--- /dev/null
+++ b/3rdparty/gtest/src/gtest-all.cc
@@ -0,0 +1,48 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Google C++ Testing and Mocking Framework (Google Test)
+//
+// Sometimes it's desirable to build Google Test by compiling a single file.
+// This file serves this purpose.
+
+// This line ensures that gtest.h can be compiled on its own, even
+// when it's fused.
+#include "gtest/gtest.h"
+
+// The following lines pull in the real gtest *.cc files.
+#include "src/gtest.cc"
+#include "src/gtest-death-test.cc"
+#include "src/gtest-filepath.cc"
+#include "src/gtest-matchers.cc"
+#include "src/gtest-port.cc"
+#include "src/gtest-printers.cc"
+#include "src/gtest-test-part.cc"
+#include "src/gtest-typed-test.cc"
diff --git a/3rdparty/gtest/src/gtest-death-test.cc b/3rdparty/gtest/src/gtest-death-test.cc
new file mode 100644
index 0000000..7419ba2
--- /dev/null
+++ b/3rdparty/gtest/src/gtest-death-test.cc
@@ -0,0 +1,1653 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// This file implements death tests.
+
+#include "gtest/gtest-death-test.h"
+
+#include <utility>
+
+#include "gtest/internal/gtest-port.h"
+#include "gtest/internal/custom/gtest.h"
+
+#if GTEST_HAS_DEATH_TEST
+
+# if GTEST_OS_MAC
+#  include <crt_externs.h>
+# endif  // GTEST_OS_MAC
+
+# include <errno.h>
+# include <fcntl.h>
+# include <limits.h>
+
+# if GTEST_OS_LINUX
+#  include <signal.h>
+# endif  // GTEST_OS_LINUX
+
+# include <stdarg.h>
+
+# if GTEST_OS_WINDOWS
+#  include <windows.h>
+# else
+#  include <sys/mman.h>
+#  include <sys/wait.h>
+# endif  // GTEST_OS_WINDOWS
+
+# if GTEST_OS_QNX
+#  include <spawn.h>
+# endif  // GTEST_OS_QNX
+
+# if GTEST_OS_FUCHSIA
+#  include <lib/fdio/fd.h>
+#  include <lib/fdio/io.h>
+#  include <lib/fdio/spawn.h>
+#  include <lib/zx/channel.h>
+#  include <lib/zx/port.h>
+#  include <lib/zx/process.h>
+#  include <lib/zx/socket.h>
+#  include <zircon/processargs.h>
+#  include <zircon/syscalls.h>
+#  include <zircon/syscalls/policy.h>
+#  include <zircon/syscalls/port.h>
+# endif  // GTEST_OS_FUCHSIA
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+#include "gtest/gtest-message.h"
+#include "gtest/internal/gtest-string.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+
+// Constants.
+
+// The default death test style.
+//
+// This is defined in internal/gtest-port.h as "fast", but can be overridden by
+// a definition in internal/custom/gtest-port.h. The recommended value, which is
+// used internally at Google, is "threadsafe".
+static const char kDefaultDeathTestStyle[] = GTEST_DEFAULT_DEATH_TEST_STYLE;
+
+GTEST_DEFINE_string_(
+    death_test_style,
+    internal::StringFromGTestEnv("death_test_style", kDefaultDeathTestStyle),
+    "Indicates how to run a death test in a forked child process: "
+    "\"threadsafe\" (child process re-executes the test binary "
+    "from the beginning, running only the specific death test) or "
+    "\"fast\" (child process runs the death test immediately "
+    "after forking).");
+
+GTEST_DEFINE_bool_(
+    death_test_use_fork,
+    internal::BoolFromGTestEnv("death_test_use_fork", false),
+    "Instructs to use fork()/_exit() instead of clone() in death tests. "
+    "Ignored and always uses fork() on POSIX systems where clone() is not "
+    "implemented. Useful when running under valgrind or similar tools if "
+    "those do not support clone(). Valgrind 3.3.1 will just fail if "
+    "it sees an unsupported combination of clone() flags. "
+    "It is not recommended to use this flag w/o valgrind though it will "
+    "work in 99% of the cases. Once valgrind is fixed, this flag will "
+    "most likely be removed.");
+
+namespace internal {
+GTEST_DEFINE_string_(
+    internal_run_death_test, "",
+    "Indicates the file, line number, temporal index of "
+    "the single death test to run, and a file descriptor to "
+    "which a success code may be sent, all separated by "
+    "the '|' characters.  This flag is specified if and only if the "
+    "current process is a sub-process launched for running a thread-safe "
+    "death test.  FOR INTERNAL USE ONLY.");
+}  // namespace internal
+
+#if GTEST_HAS_DEATH_TEST
+
+namespace internal {
+
+// Valid only for fast death tests. Indicates the code is running in the
+// child process of a fast style death test.
+# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+static bool g_in_fast_death_test_child = false;
+# endif
+
+// Returns a Boolean value indicating whether the caller is currently
+// executing in the context of the death test child process.  Tools such as
+// Valgrind heap checkers may need this to modify their behavior in death
+// tests.  IMPORTANT: This is an internal utility.  Using it may break the
+// implementation of death tests.  User code MUST NOT use it.
+bool InDeathTestChild() {
+# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+  // On Windows and Fuchsia, death tests are thread-safe regardless of the value
+  // of the death_test_style flag.
+  return !GTEST_FLAG(internal_run_death_test).empty();
+
+# else
+
+  if (GTEST_FLAG(death_test_style) == "threadsafe")
+    return !GTEST_FLAG(internal_run_death_test).empty();
+  else
+    return g_in_fast_death_test_child;
+#endif
+}
+
+}  // namespace internal
+
+// ExitedWithCode constructor.
+ExitedWithCode::ExitedWithCode(int exit_code) : exit_code_(exit_code) {
+}
+
+// ExitedWithCode function-call operator.
+bool ExitedWithCode::operator()(int exit_status) const {
+# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+  return exit_status == exit_code_;
+
+# else
+
+  return WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == exit_code_;
+
+# endif  // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+}
+
+# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+// KilledBySignal constructor.
+KilledBySignal::KilledBySignal(int signum) : signum_(signum) {
+}
+
+// KilledBySignal function-call operator.
+bool KilledBySignal::operator()(int exit_status) const {
+#  if defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
+  {
+    bool result;
+    if (GTEST_KILLED_BY_SIGNAL_OVERRIDE_(signum_, exit_status, &result)) {
+      return result;
+    }
+  }
+#  endif  // defined(GTEST_KILLED_BY_SIGNAL_OVERRIDE_)
+  return WIFSIGNALED(exit_status) && WTERMSIG(exit_status) == signum_;
+}
+# endif  // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+
+namespace internal {
+
+// Utilities needed for death tests.
+
+// Generates a textual description of a given exit code, in the format
+// specified by wait(2).
+static std::string ExitSummary(int exit_code) {
+  Message m;
+
+# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+  m << "Exited with exit status " << exit_code;
+
+# else
+
+  if (WIFEXITED(exit_code)) {
+    m << "Exited with exit status " << WEXITSTATUS(exit_code);
+  } else if (WIFSIGNALED(exit_code)) {
+    m << "Terminated by signal " << WTERMSIG(exit_code);
+  }
+#  ifdef WCOREDUMP
+  if (WCOREDUMP(exit_code)) {
+    m << " (core dumped)";
+  }
+#  endif
+# endif  // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+  return m.GetString();
+}
+
+// Returns true if exit_status describes a process that was terminated
+// by a signal, or exited normally with a nonzero exit code.
+bool ExitedUnsuccessfully(int exit_status) {
+  return !ExitedWithCode(0)(exit_status);
+}
+
+# if !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+// Generates a textual failure message when a death test finds more than
+// one thread running, or cannot determine the number of threads, prior
+// to executing the given statement.  It is the responsibility of the
+// caller not to pass a thread_count of 1.
+static std::string DeathTestThreadWarning(size_t thread_count) {
+  Message msg;
+  msg << "Death tests use fork(), which is unsafe particularly"
+      << " in a threaded context. For this test, " << GTEST_NAME_ << " ";
+  if (thread_count == 0) {
+    msg << "couldn't detect the number of threads.";
+  } else {
+    msg << "detected " << thread_count << " threads.";
+  }
+  msg << " See "
+         "https://github.com/google/googletest/blob/master/googletest/docs/"
+         "advanced.md#death-tests-and-threads"
+      << " for more explanation and suggested solutions, especially if"
+      << " this is the last message you see before your test times out.";
+  return msg.GetString();
+}
+# endif  // !GTEST_OS_WINDOWS && !GTEST_OS_FUCHSIA
+
+// Flag characters for reporting a death test that did not die.
+static const char kDeathTestLived = 'L';
+static const char kDeathTestReturned = 'R';
+static const char kDeathTestThrew = 'T';
+static const char kDeathTestInternalError = 'I';
+
+#if GTEST_OS_FUCHSIA
+
+// File descriptor used for the pipe in the child process.
+static const int kFuchsiaReadPipeFd = 3;
+
+#endif
+
+// An enumeration describing all of the possible ways that a death test can
+// conclude.  DIED means that the process died while executing the test
+// code; LIVED means that process lived beyond the end of the test code;
+// RETURNED means that the test statement attempted to execute a return
+// statement, which is not allowed; THREW means that the test statement
+// returned control by throwing an exception.  IN_PROGRESS means the test
+// has not yet concluded.
+enum DeathTestOutcome { IN_PROGRESS, DIED, LIVED, RETURNED, THREW };
+
+// Routine for aborting the program which is safe to call from an
+// exec-style death test child process, in which case the error
+// message is propagated back to the parent process.  Otherwise, the
+// message is simply printed to stderr.  In either case, the program
+// then exits with status 1.
+static void DeathTestAbort(const std::string& message) {
+  // On a POSIX system, this function may be called from a threadsafe-style
+  // death test child process, which operates on a very small stack.  Use
+  // the heap for any additional non-minuscule memory requirements.
+  const InternalRunDeathTestFlag* const flag =
+      GetUnitTestImpl()->internal_run_death_test_flag();
+  if (flag != nullptr) {
+    FILE* parent = posix::FDOpen(flag->write_fd(), "w");
+    fputc(kDeathTestInternalError, parent);
+    fprintf(parent, "%s", message.c_str());
+    fflush(parent);
+    _exit(1);
+  } else {
+    fprintf(stderr, "%s", message.c_str());
+    fflush(stderr);
+    posix::Abort();
+  }
+}
+
+// A replacement for CHECK that calls DeathTestAbort if the assertion
+// fails.
+# define GTEST_DEATH_TEST_CHECK_(expression) \
+  do { \
+    if (!::testing::internal::IsTrue(expression)) { \
+      DeathTestAbort( \
+          ::std::string("CHECK failed: File ") + __FILE__ +  ", line " \
+          + ::testing::internal::StreamableToString(__LINE__) + ": " \
+          + #expression); \
+    } \
+  } while (::testing::internal::AlwaysFalse())
+
+// This macro is similar to GTEST_DEATH_TEST_CHECK_, but it is meant for
+// evaluating any system call that fulfills two conditions: it must return
+// -1 on failure, and set errno to EINTR when it is interrupted and
+// should be tried again.  The macro expands to a loop that repeatedly
+// evaluates the expression as long as it evaluates to -1 and sets
+// errno to EINTR.  If the expression evaluates to -1 but errno is
+// something other than EINTR, DeathTestAbort is called.
+# define GTEST_DEATH_TEST_CHECK_SYSCALL_(expression) \
+  do { \
+    int gtest_retval; \
+    do { \
+      gtest_retval = (expression); \
+    } while (gtest_retval == -1 && errno == EINTR); \
+    if (gtest_retval == -1) { \
+      DeathTestAbort( \
+          ::std::string("CHECK failed: File ") + __FILE__ + ", line " \
+          + ::testing::internal::StreamableToString(__LINE__) + ": " \
+          + #expression + " != -1"); \
+    } \
+  } while (::testing::internal::AlwaysFalse())
+
+// Returns the message describing the last system error in errno.
+std::string GetLastErrnoDescription() {
+    return errno == 0 ? "" : posix::StrError(errno);
+}
+
+// This is called from a death test parent process to read a failure
+// message from the death test child process and log it with the FATAL
+// severity. On Windows, the message is read from a pipe handle. On other
+// platforms, it is read from a file descriptor.
+static void FailFromInternalError(int fd) {
+  Message error;
+  char buffer[256];
+  int num_read;
+
+  do {
+    while ((num_read = posix::Read(fd, buffer, 255)) > 0) {
+      buffer[num_read] = '\0';
+      error << buffer;
+    }
+  } while (num_read == -1 && errno == EINTR);
+
+  if (num_read == 0) {
+    GTEST_LOG_(FATAL) << error.GetString();
+  } else {
+    const int last_error = errno;
+    GTEST_LOG_(FATAL) << "Error while reading death test internal: "
+                      << GetLastErrnoDescription() << " [" << last_error << "]";
+  }
+}
+
+// Death test constructor.  Increments the running death test count
+// for the current test.
+DeathTest::DeathTest() {
+  TestInfo* const info = GetUnitTestImpl()->current_test_info();
+  if (info == nullptr) {
+    DeathTestAbort("Cannot run a death test outside of a TEST or "
+                   "TEST_F construct");
+  }
+}
+
+// Creates and returns a death test by dispatching to the current
+// death test factory.
+bool DeathTest::Create(const char* statement,
+                       Matcher<const std::string&> matcher, const char* file,
+                       int line, DeathTest** test) {
+  return GetUnitTestImpl()->death_test_factory()->Create(
+      statement, std::move(matcher), file, line, test);
+}
+
+const char* DeathTest::LastMessage() {
+  return last_death_test_message_.c_str();
+}
+
+void DeathTest::set_last_death_test_message(const std::string& message) {
+  last_death_test_message_ = message;
+}
+
+std::string DeathTest::last_death_test_message_;
+
+// Provides cross platform implementation for some death functionality.
+class DeathTestImpl : public DeathTest {
+ protected:
+  DeathTestImpl(const char* a_statement, Matcher<const std::string&> matcher)
+      : statement_(a_statement),
+        matcher_(std::move(matcher)),
+        spawned_(false),
+        status_(-1),
+        outcome_(IN_PROGRESS),
+        read_fd_(-1),
+        write_fd_(-1) {}
+
+  // read_fd_ is expected to be closed and cleared by a derived class.
+  ~DeathTestImpl() override { GTEST_DEATH_TEST_CHECK_(read_fd_ == -1); }
+
+  void Abort(AbortReason reason) override;
+  bool Passed(bool status_ok) override;
+
+  const char* statement() const { return statement_; }
+  bool spawned() const { return spawned_; }
+  void set_spawned(bool is_spawned) { spawned_ = is_spawned; }
+  int status() const { return status_; }
+  void set_status(int a_status) { status_ = a_status; }
+  DeathTestOutcome outcome() const { return outcome_; }
+  void set_outcome(DeathTestOutcome an_outcome) { outcome_ = an_outcome; }
+  int read_fd() const { return read_fd_; }
+  void set_read_fd(int fd) { read_fd_ = fd; }
+  int write_fd() const { return write_fd_; }
+  void set_write_fd(int fd) { write_fd_ = fd; }
+
+  // Called in the parent process only. Reads the result code of the death
+  // test child process via a pipe, interprets it to set the outcome_
+  // member, and closes read_fd_.  Outputs diagnostics and terminates in
+  // case of unexpected codes.
+  void ReadAndInterpretStatusByte();
+
+  // Returns stderr output from the child process.
+  virtual std::string GetErrorLogs();
+
+ private:
+  // The textual content of the code this object is testing.  This class
+  // doesn't own this string and should not attempt to delete it.
+  const char* const statement_;
+  // A matcher that's expected to match the stderr output by the child process.
+  Matcher<const std::string&> matcher_;
+  // True if the death test child process has been successfully spawned.
+  bool spawned_;
+  // The exit status of the child process.
+  int status_;
+  // How the death test concluded.
+  DeathTestOutcome outcome_;
+  // Descriptor to the read end of the pipe to the child process.  It is
+  // always -1 in the child process.  The child keeps its write end of the
+  // pipe in write_fd_.
+  int read_fd_;
+  // Descriptor to the child's write end of the pipe to the parent process.
+  // It is always -1 in the parent process.  The parent keeps its end of the
+  // pipe in read_fd_.
+  int write_fd_;
+};
+
+// Called in the parent process only. Reads the result code of the death
+// test child process via a pipe, interprets it to set the outcome_
+// member, and closes read_fd_.  Outputs diagnostics and terminates in
+// case of unexpected codes.
+void DeathTestImpl::ReadAndInterpretStatusByte() {
+  char flag;
+  int bytes_read;
+
+  // The read() here blocks until data is available (signifying the
+  // failure of the death test) or until the pipe is closed (signifying
+  // its success), so it's okay to call this in the parent before
+  // the child process has exited.
+  do {
+    bytes_read = posix::Read(read_fd(), &flag, 1);
+  } while (bytes_read == -1 && errno == EINTR);
+
+  if (bytes_read == 0) {
+    set_outcome(DIED);
+  } else if (bytes_read == 1) {
+    switch (flag) {
+      case kDeathTestReturned:
+        set_outcome(RETURNED);
+        break;
+      case kDeathTestThrew:
+        set_outcome(THREW);
+        break;
+      case kDeathTestLived:
+        set_outcome(LIVED);
+        break;
+      case kDeathTestInternalError:
+        FailFromInternalError(read_fd());  // Does not return.
+        break;
+      default:
+        GTEST_LOG_(FATAL) << "Death test child process reported "
+                          << "unexpected status byte ("
+                          << static_cast<unsigned int>(flag) << ")";
+    }
+  } else {
+    GTEST_LOG_(FATAL) << "Read from death test child process failed: "
+                      << GetLastErrnoDescription();
+  }
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Close(read_fd()));
+  set_read_fd(-1);
+}
+
+std::string DeathTestImpl::GetErrorLogs() {
+  return GetCapturedStderr();
+}
+
+// Signals that the death test code which should have exited, didn't.
+// Should be called only in a death test child process.
+// Writes a status byte to the child's status file descriptor, then
+// calls _exit(1).
+void DeathTestImpl::Abort(AbortReason reason) {
+  // The parent process considers the death test to be a failure if
+  // it finds any data in our pipe.  So, here we write a single flag byte
+  // to the pipe, then exit.
+  const char status_ch =
+      reason == TEST_DID_NOT_DIE ? kDeathTestLived :
+      reason == TEST_THREW_EXCEPTION ? kDeathTestThrew : kDeathTestReturned;
+
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(posix::Write(write_fd(), &status_ch, 1));
+  // We are leaking the descriptor here because on some platforms (i.e.,
+  // when built as Windows DLL), destructors of global objects will still
+  // run after calling _exit(). On such systems, write_fd_ will be
+  // indirectly closed from the destructor of UnitTestImpl, causing double
+  // close if it is also closed here. On debug configurations, double close
+  // may assert. As there are no in-process buffers to flush here, we are
+  // relying on the OS to close the descriptor after the process terminates
+  // when the destructors are not run.
+  _exit(1);  // Exits w/o any normal exit hooks (we were supposed to crash)
+}
+
+// Returns an indented copy of stderr output for a death test.
+// This makes distinguishing death test output lines from regular log lines
+// much easier.
+static ::std::string FormatDeathTestOutput(const ::std::string& output) {
+  ::std::string ret;
+  for (size_t at = 0; ; ) {
+    const size_t line_end = output.find('\n', at);
+    ret += "[  DEATH   ] ";
+    if (line_end == ::std::string::npos) {
+      ret += output.substr(at);
+      break;
+    }
+    ret += output.substr(at, line_end + 1 - at);
+    at = line_end + 1;
+  }
+  return ret;
+}
+
+// Assesses the success or failure of a death test, using both private
+// members which have previously been set, and one argument:
+//
+// Private data members:
+//   outcome:  An enumeration describing how the death test
+//             concluded: DIED, LIVED, THREW, or RETURNED.  The death test
+//             fails in the latter three cases.
+//   status:   The exit status of the child process. On *nix, it is in the
+//             in the format specified by wait(2). On Windows, this is the
+//             value supplied to the ExitProcess() API or a numeric code
+//             of the exception that terminated the program.
+//   matcher_: A matcher that's expected to match the stderr output by the child
+//             process.
+//
+// Argument:
+//   status_ok: true if exit_status is acceptable in the context of
+//              this particular death test, which fails if it is false
+//
+// Returns true if and only if all of the above conditions are met.  Otherwise,
+// the first failing condition, in the order given above, is the one that is
+// reported. Also sets the last death test message string.
+bool DeathTestImpl::Passed(bool status_ok) {
+  if (!spawned())
+    return false;
+
+  const std::string error_message = GetErrorLogs();
+
+  bool success = false;
+  Message buffer;
+
+  buffer << "Death test: " << statement() << "\n";
+  switch (outcome()) {
+    case LIVED:
+      buffer << "    Result: failed to die.\n"
+             << " Error msg:\n" << FormatDeathTestOutput(error_message);
+      break;
+    case THREW:
+      buffer << "    Result: threw an exception.\n"
+             << " Error msg:\n" << FormatDeathTestOutput(error_message);
+      break;
+    case RETURNED:
+      buffer << "    Result: illegal return in test statement.\n"
+             << " Error msg:\n" << FormatDeathTestOutput(error_message);
+      break;
+    case DIED:
+      if (status_ok) {
+        if (matcher_.Matches(error_message)) {
+          success = true;
+        } else {
+          std::ostringstream stream;
+          matcher_.DescribeTo(&stream);
+          buffer << "    Result: died but not with expected error.\n"
+                 << "  Expected: " << stream.str() << "\n"
+                 << "Actual msg:\n"
+                 << FormatDeathTestOutput(error_message);
+        }
+      } else {
+        buffer << "    Result: died but not with expected exit code:\n"
+               << "            " << ExitSummary(status()) << "\n"
+               << "Actual msg:\n" << FormatDeathTestOutput(error_message);
+      }
+      break;
+    case IN_PROGRESS:
+    default:
+      GTEST_LOG_(FATAL)
+          << "DeathTest::Passed somehow called before conclusion of test";
+  }
+
+  DeathTest::set_last_death_test_message(buffer.GetString());
+  return success;
+}
+
+# if GTEST_OS_WINDOWS
+// WindowsDeathTest implements death tests on Windows. Due to the
+// specifics of starting new processes on Windows, death tests there are
+// always threadsafe, and Google Test considers the
+// --gtest_death_test_style=fast setting to be equivalent to
+// --gtest_death_test_style=threadsafe there.
+//
+// A few implementation notes:  Like the Linux version, the Windows
+// implementation uses pipes for child-to-parent communication. But due to
+// the specifics of pipes on Windows, some extra steps are required:
+//
+// 1. The parent creates a communication pipe and stores handles to both
+//    ends of it.
+// 2. The parent starts the child and provides it with the information
+//    necessary to acquire the handle to the write end of the pipe.
+// 3. The child acquires the write end of the pipe and signals the parent
+//    using a Windows event.
+// 4. Now the parent can release the write end of the pipe on its side. If
+//    this is done before step 3, the object's reference count goes down to
+//    0 and it is destroyed, preventing the child from acquiring it. The
+//    parent now has to release it, or read operations on the read end of
+//    the pipe will not return when the child terminates.
+// 5. The parent reads child's output through the pipe (outcome code and
+//    any possible error messages) from the pipe, and its stderr and then
+//    determines whether to fail the test.
+//
+// Note: to distinguish Win32 API calls from the local method and function
+// calls, the former are explicitly resolved in the global namespace.
+//
+class WindowsDeathTest : public DeathTestImpl {
+ public:
+  WindowsDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
+                   const char* file, int line)
+      : DeathTestImpl(a_statement, std::move(matcher)),
+        file_(file),
+        line_(line) {}
+
+  // All of these virtual functions are inherited from DeathTest.
+  virtual int Wait();
+  virtual TestRole AssumeRole();
+
+ private:
+  // The name of the file in which the death test is located.
+  const char* const file_;
+  // The line number on which the death test is located.
+  const int line_;
+  // Handle to the write end of the pipe to the child process.
+  AutoHandle write_handle_;
+  // Child process handle.
+  AutoHandle child_handle_;
+  // Event the child process uses to signal the parent that it has
+  // acquired the handle to the write end of the pipe. After seeing this
+  // event the parent can release its own handles to make sure its
+  // ReadFile() calls return when the child terminates.
+  AutoHandle event_handle_;
+};
+
+// Waits for the child in a death test to exit, returning its exit
+// status, or 0 if no child process exists.  As a side effect, sets the
+// outcome data member.
+int WindowsDeathTest::Wait() {
+  if (!spawned())
+    return 0;
+
+  // Wait until the child either signals that it has acquired the write end
+  // of the pipe or it dies.
+  const HANDLE wait_handles[2] = { child_handle_.Get(), event_handle_.Get() };
+  switch (::WaitForMultipleObjects(2,
+                                   wait_handles,
+                                   FALSE,  // Waits for any of the handles.
+                                   INFINITE)) {
+    case WAIT_OBJECT_0:
+    case WAIT_OBJECT_0 + 1:
+      break;
+    default:
+      GTEST_DEATH_TEST_CHECK_(false);  // Should not get here.
+  }
+
+  // The child has acquired the write end of the pipe or exited.
+  // We release the handle on our side and continue.
+  write_handle_.Reset();
+  event_handle_.Reset();
+
+  ReadAndInterpretStatusByte();
+
+  // Waits for the child process to exit if it haven't already. This
+  // returns immediately if the child has already exited, regardless of
+  // whether previous calls to WaitForMultipleObjects synchronized on this
+  // handle or not.
+  GTEST_DEATH_TEST_CHECK_(
+      WAIT_OBJECT_0 == ::WaitForSingleObject(child_handle_.Get(),
+                                             INFINITE));
+  DWORD status_code;
+  GTEST_DEATH_TEST_CHECK_(
+      ::GetExitCodeProcess(child_handle_.Get(), &status_code) != FALSE);
+  child_handle_.Reset();
+  set_status(static_cast<int>(status_code));
+  return status();
+}
+
+// The AssumeRole process for a Windows death test.  It creates a child
+// process with the same executable as the current process to run the
+// death test.  The child process is given the --gtest_filter and
+// --gtest_internal_run_death_test flags such that it knows to run the
+// current death test only.
+DeathTest::TestRole WindowsDeathTest::AssumeRole() {
+  const UnitTestImpl* const impl = GetUnitTestImpl();
+  const InternalRunDeathTestFlag* const flag =
+      impl->internal_run_death_test_flag();
+  const TestInfo* const info = impl->current_test_info();
+  const int death_test_index = info->result()->death_test_count();
+
+  if (flag != nullptr) {
+    // ParseInternalRunDeathTestFlag() has performed all the necessary
+    // processing.
+    set_write_fd(flag->write_fd());
+    return EXECUTE_TEST;
+  }
+
+  // WindowsDeathTest uses an anonymous pipe to communicate results of
+  // a death test.
+  SECURITY_ATTRIBUTES handles_are_inheritable = {sizeof(SECURITY_ATTRIBUTES),
+                                                 nullptr, TRUE};
+  HANDLE read_handle, write_handle;
+  GTEST_DEATH_TEST_CHECK_(
+      ::CreatePipe(&read_handle, &write_handle, &handles_are_inheritable,
+                   0)  // Default buffer size.
+      != FALSE);
+  set_read_fd(::_open_osfhandle(reinterpret_cast<intptr_t>(read_handle),
+                                O_RDONLY));
+  write_handle_.Reset(write_handle);
+  event_handle_.Reset(::CreateEvent(
+      &handles_are_inheritable,
+      TRUE,       // The event will automatically reset to non-signaled state.
+      FALSE,      // The initial state is non-signalled.
+      nullptr));  // The even is unnamed.
+  GTEST_DEATH_TEST_CHECK_(event_handle_.Get() != nullptr);
+  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
+                                  kFilterFlag + "=" + info->test_suite_name() +
+                                  "." + info->name();
+  const std::string internal_flag =
+      std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag +
+      "=" + file_ + "|" + StreamableToString(line_) + "|" +
+      StreamableToString(death_test_index) + "|" +
+      StreamableToString(static_cast<unsigned int>(::GetCurrentProcessId())) +
+      // size_t has the same width as pointers on both 32-bit and 64-bit
+      // Windows platforms.
+      // See http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx.
+      "|" + StreamableToString(reinterpret_cast<size_t>(write_handle)) +
+      "|" + StreamableToString(reinterpret_cast<size_t>(event_handle_.Get()));
+
+  char executable_path[_MAX_PATH + 1];  // NOLINT
+  GTEST_DEATH_TEST_CHECK_(_MAX_PATH + 1 != ::GetModuleFileNameA(nullptr,
+                                                                executable_path,
+                                                                _MAX_PATH));
+
+  std::string command_line =
+      std::string(::GetCommandLineA()) + " " + filter_flag + " \"" +
+      internal_flag + "\"";
+
+  DeathTest::set_last_death_test_message("");
+
+  CaptureStderr();
+  // Flush the log buffers since the log streams are shared with the child.
+  FlushInfoLog();
+
+  // The child process will share the standard handles with the parent.
+  STARTUPINFOA startup_info;
+  memset(&startup_info, 0, sizeof(STARTUPINFO));
+  startup_info.dwFlags = STARTF_USESTDHANDLES;
+  startup_info.hStdInput = ::GetStdHandle(STD_INPUT_HANDLE);
+  startup_info.hStdOutput = ::GetStdHandle(STD_OUTPUT_HANDLE);
+  startup_info.hStdError = ::GetStdHandle(STD_ERROR_HANDLE);
+
+  PROCESS_INFORMATION process_info;
+  GTEST_DEATH_TEST_CHECK_(
+      ::CreateProcessA(
+          executable_path, const_cast<char*>(command_line.c_str()),
+          nullptr,  // Retuned process handle is not inheritable.
+          nullptr,  // Retuned thread handle is not inheritable.
+          TRUE,  // Child inherits all inheritable handles (for write_handle_).
+          0x0,   // Default creation flags.
+          nullptr,  // Inherit the parent's environment.
+          UnitTest::GetInstance()->original_working_dir(), &startup_info,
+          &process_info) != FALSE);
+  child_handle_.Reset(process_info.hProcess);
+  ::CloseHandle(process_info.hThread);
+  set_spawned(true);
+  return OVERSEE_TEST;
+}
+
+# elif GTEST_OS_FUCHSIA
+
+class FuchsiaDeathTest : public DeathTestImpl {
+ public:
+  FuchsiaDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
+                   const char* file, int line)
+      : DeathTestImpl(a_statement, std::move(matcher)),
+        file_(file),
+        line_(line) {}
+
+  // All of these virtual functions are inherited from DeathTest.
+  int Wait() override;
+  TestRole AssumeRole() override;
+  std::string GetErrorLogs() override;
+
+ private:
+  // The name of the file in which the death test is located.
+  const char* const file_;
+  // The line number on which the death test is located.
+  const int line_;
+  // The stderr data captured by the child process.
+  std::string captured_stderr_;
+
+  zx::process child_process_;
+  zx::channel exception_channel_;
+  zx::socket stderr_socket_;
+};
+
+// Utility class for accumulating command-line arguments.
+class Arguments {
+ public:
+  Arguments() { args_.push_back(nullptr); }
+
+  ~Arguments() {
+    for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
+         ++i) {
+      free(*i);
+    }
+  }
+  void AddArgument(const char* argument) {
+    args_.insert(args_.end() - 1, posix::StrDup(argument));
+  }
+
+  template <typename Str>
+  void AddArguments(const ::std::vector<Str>& arguments) {
+    for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
+         i != arguments.end();
+         ++i) {
+      args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
+    }
+  }
+  char* const* Argv() {
+    return &args_[0];
+  }
+
+  int size() {
+    return args_.size() - 1;
+  }
+
+ private:
+  std::vector<char*> args_;
+};
+
+// Waits for the child in a death test to exit, returning its exit
+// status, or 0 if no child process exists.  As a side effect, sets the
+// outcome data member.
+int FuchsiaDeathTest::Wait() {
+  const int kProcessKey = 0;
+  const int kSocketKey = 1;
+  const int kExceptionKey = 2;
+
+  if (!spawned())
+    return 0;
+
+  // Create a port to wait for socket/task/exception events.
+  zx_status_t status_zx;
+  zx::port port;
+  status_zx = zx::port::create(0, &port);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  // Register to wait for the child process to terminate.
+  status_zx = child_process_.wait_async(
+      port, kProcessKey, ZX_PROCESS_TERMINATED, ZX_WAIT_ASYNC_ONCE);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  // Register to wait for the socket to be readable or closed.
+  status_zx = stderr_socket_.wait_async(
+      port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED,
+      ZX_WAIT_ASYNC_ONCE);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  // Register to wait for an exception.
+  status_zx = exception_channel_.wait_async(
+      port, kExceptionKey, ZX_CHANNEL_READABLE, ZX_WAIT_ASYNC_ONCE);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  bool process_terminated = false;
+  bool socket_closed = false;
+  do {
+    zx_port_packet_t packet = {};
+    status_zx = port.wait(zx::time::infinite(), &packet);
+    GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+    if (packet.key == kExceptionKey) {
+      // Process encountered an exception. Kill it directly rather than
+      // letting other handlers process the event. We will get a kProcessKey
+      // event when the process actually terminates.
+      status_zx = child_process_.kill();
+      GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+    } else if (packet.key == kProcessKey) {
+      // Process terminated.
+      GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
+      GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_PROCESS_TERMINATED);
+      process_terminated = true;
+    } else if (packet.key == kSocketKey) {
+      GTEST_DEATH_TEST_CHECK_(ZX_PKT_IS_SIGNAL_ONE(packet.type));
+      if (packet.signal.observed & ZX_SOCKET_READABLE) {
+        // Read data from the socket.
+        constexpr size_t kBufferSize = 1024;
+        do {
+          size_t old_length = captured_stderr_.length();
+          size_t bytes_read = 0;
+          captured_stderr_.resize(old_length + kBufferSize);
+          status_zx = stderr_socket_.read(
+              0, &captured_stderr_.front() + old_length, kBufferSize,
+              &bytes_read);
+          captured_stderr_.resize(old_length + bytes_read);
+        } while (status_zx == ZX_OK);
+        if (status_zx == ZX_ERR_PEER_CLOSED) {
+          socket_closed = true;
+        } else {
+          GTEST_DEATH_TEST_CHECK_(status_zx == ZX_ERR_SHOULD_WAIT);
+          status_zx = stderr_socket_.wait_async(
+              port, kSocketKey, ZX_SOCKET_READABLE | ZX_SOCKET_PEER_CLOSED,
+              ZX_WAIT_ASYNC_ONCE);
+          GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+        }
+      } else {
+        GTEST_DEATH_TEST_CHECK_(packet.signal.observed & ZX_SOCKET_PEER_CLOSED);
+        socket_closed = true;
+      }
+    }
+  } while (!process_terminated && !socket_closed);
+
+  ReadAndInterpretStatusByte();
+
+  zx_info_process_t buffer;
+  status_zx = child_process_.get_info(
+      ZX_INFO_PROCESS, &buffer, sizeof(buffer), nullptr, nullptr);
+  GTEST_DEATH_TEST_CHECK_(status_zx == ZX_OK);
+
+  GTEST_DEATH_TEST_CHECK_(buffer.exited);
+  set_status(buffer.return_code);
+  return status();
+}
+
+// The AssumeRole process for a Fuchsia death test.  It creates a child
+// process with the same executable as the current process to run the
+// death test.  The child process is given the --gtest_filter and
+// --gtest_internal_run_death_test flags such that it knows to run the
+// current death test only.
+DeathTest::TestRole FuchsiaDeathTest::AssumeRole() {
+  const UnitTestImpl* const impl = GetUnitTestImpl();
+  const InternalRunDeathTestFlag* const flag =
+      impl->internal_run_death_test_flag();
+  const TestInfo* const info = impl->current_test_info();
+  const int death_test_index = info->result()->death_test_count();
+
+  if (flag != nullptr) {
+    // ParseInternalRunDeathTestFlag() has performed all the necessary
+    // processing.
+    set_write_fd(kFuchsiaReadPipeFd);
+    return EXECUTE_TEST;
+  }
+
+  // Flush the log buffers since the log streams are shared with the child.
+  FlushInfoLog();
+
+  // Build the child process command line.
+  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
+                                  kFilterFlag + "=" + info->test_suite_name() +
+                                  "." + info->name();
+  const std::string internal_flag =
+      std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag + "="
+      + file_ + "|"
+      + StreamableToString(line_) + "|"
+      + StreamableToString(death_test_index);
+  Arguments args;
+  args.AddArguments(GetInjectableArgvs());
+  args.AddArgument(filter_flag.c_str());
+  args.AddArgument(internal_flag.c_str());
+
+  // Build the pipe for communication with the child.
+  zx_status_t status;
+  zx_handle_t child_pipe_handle;
+  int child_pipe_fd;
+  status = fdio_pipe_half(&child_pipe_fd, &child_pipe_handle);
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+  set_read_fd(child_pipe_fd);
+
+  // Set the pipe handle for the child.
+  fdio_spawn_action_t spawn_actions[2] = {};
+  fdio_spawn_action_t* add_handle_action = &spawn_actions[0];
+  add_handle_action->action = FDIO_SPAWN_ACTION_ADD_HANDLE;
+  add_handle_action->h.id = PA_HND(PA_FD, kFuchsiaReadPipeFd);
+  add_handle_action->h.handle = child_pipe_handle;
+
+  // Create a socket pair will be used to receive the child process' stderr.
+  zx::socket stderr_producer_socket;
+  status =
+      zx::socket::create(0, &stderr_producer_socket, &stderr_socket_);
+  GTEST_DEATH_TEST_CHECK_(status >= 0);
+  int stderr_producer_fd = -1;
+  status =
+      fdio_fd_create(stderr_producer_socket.release(), &stderr_producer_fd);
+  GTEST_DEATH_TEST_CHECK_(status >= 0);
+
+  // Make the stderr socket nonblocking.
+  GTEST_DEATH_TEST_CHECK_(fcntl(stderr_producer_fd, F_SETFL, 0) == 0);
+
+  fdio_spawn_action_t* add_stderr_action = &spawn_actions[1];
+  add_stderr_action->action = FDIO_SPAWN_ACTION_CLONE_FD;
+  add_stderr_action->fd.local_fd = stderr_producer_fd;
+  add_stderr_action->fd.target_fd = STDERR_FILENO;
+
+  // Create a child job.
+  zx_handle_t child_job = ZX_HANDLE_INVALID;
+  status = zx_job_create(zx_job_default(), 0, & child_job);
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+  zx_policy_basic_t policy;
+  policy.condition = ZX_POL_NEW_ANY;
+  policy.policy = ZX_POL_ACTION_ALLOW;
+  status = zx_job_set_policy(
+      child_job, ZX_JOB_POL_RELATIVE, ZX_JOB_POL_BASIC, &policy, 1);
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+
+  // Create an exception channel attached to the |child_job|, to allow
+  // us to suppress the system default exception handler from firing.
+  status =
+      zx_task_create_exception_channel(
+          child_job, 0, exception_channel_.reset_and_get_address());
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+
+  // Spawn the child process.
+  status = fdio_spawn_etc(
+      child_job, FDIO_SPAWN_CLONE_ALL, args.Argv()[0], args.Argv(), nullptr,
+      2, spawn_actions, child_process_.reset_and_get_address(), nullptr);
+  GTEST_DEATH_TEST_CHECK_(status == ZX_OK);
+
+  set_spawned(true);
+  return OVERSEE_TEST;
+}
+
+std::string FuchsiaDeathTest::GetErrorLogs() {
+  return captured_stderr_;
+}
+
+#else  // We are neither on Windows, nor on Fuchsia.
+
+// ForkingDeathTest provides implementations for most of the abstract
+// methods of the DeathTest interface.  Only the AssumeRole method is
+// left undefined.
+class ForkingDeathTest : public DeathTestImpl {
+ public:
+  ForkingDeathTest(const char* statement, Matcher<const std::string&> matcher);
+
+  // All of these virtual functions are inherited from DeathTest.
+  int Wait() override;
+
+ protected:
+  void set_child_pid(pid_t child_pid) { child_pid_ = child_pid; }
+
+ private:
+  // PID of child process during death test; 0 in the child process itself.
+  pid_t child_pid_;
+};
+
+// Constructs a ForkingDeathTest.
+ForkingDeathTest::ForkingDeathTest(const char* a_statement,
+                                   Matcher<const std::string&> matcher)
+    : DeathTestImpl(a_statement, std::move(matcher)), child_pid_(-1) {}
+
+// Waits for the child in a death test to exit, returning its exit
+// status, or 0 if no child process exists.  As a side effect, sets the
+// outcome data member.
+int ForkingDeathTest::Wait() {
+  if (!spawned())
+    return 0;
+
+  ReadAndInterpretStatusByte();
+
+  int status_value;
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(waitpid(child_pid_, &status_value, 0));
+  set_status(status_value);
+  return status_value;
+}
+
+// A concrete death test class that forks, then immediately runs the test
+// in the child process.
+class NoExecDeathTest : public ForkingDeathTest {
+ public:
+  NoExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher)
+      : ForkingDeathTest(a_statement, std::move(matcher)) {}
+  TestRole AssumeRole() override;
+};
+
+// The AssumeRole process for a fork-and-run death test.  It implements a
+// straightforward fork, with a simple pipe to transmit the status byte.
+DeathTest::TestRole NoExecDeathTest::AssumeRole() {
+  const size_t thread_count = GetThreadCount();
+  if (thread_count != 1) {
+    GTEST_LOG_(WARNING) << DeathTestThreadWarning(thread_count);
+  }
+
+  int pipe_fd[2];
+  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
+
+  DeathTest::set_last_death_test_message("");
+  CaptureStderr();
+  // When we fork the process below, the log file buffers are copied, but the
+  // file descriptors are shared.  We flush all log files here so that closing
+  // the file descriptors in the child process doesn't throw off the
+  // synchronization between descriptors and buffers in the parent process.
+  // This is as close to the fork as possible to avoid a race condition in case
+  // there are multiple threads running before the death test, and another
+  // thread writes to the log file.
+  FlushInfoLog();
+
+  const pid_t child_pid = fork();
+  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
+  set_child_pid(child_pid);
+  if (child_pid == 0) {
+    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[0]));
+    set_write_fd(pipe_fd[1]);
+    // Redirects all logging to stderr in the child process to prevent
+    // concurrent writes to the log files.  We capture stderr in the parent
+    // process and append the child process' output to a log.
+    LogToStderr();
+    // Event forwarding to the listeners of event listener API mush be shut
+    // down in death test subprocesses.
+    GetUnitTestImpl()->listeners()->SuppressEventForwarding();
+    g_in_fast_death_test_child = true;
+    return EXECUTE_TEST;
+  } else {
+    GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
+    set_read_fd(pipe_fd[0]);
+    set_spawned(true);
+    return OVERSEE_TEST;
+  }
+}
+
+// A concrete death test class that forks and re-executes the main
+// program from the beginning, with command-line flags set that cause
+// only this specific death test to be run.
+class ExecDeathTest : public ForkingDeathTest {
+ public:
+  ExecDeathTest(const char* a_statement, Matcher<const std::string&> matcher,
+                const char* file, int line)
+      : ForkingDeathTest(a_statement, std::move(matcher)),
+        file_(file),
+        line_(line) {}
+  TestRole AssumeRole() override;
+
+ private:
+  static ::std::vector<std::string> GetArgvsForDeathTestChildProcess() {
+    ::std::vector<std::string> args = GetInjectableArgvs();
+#  if defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
+    ::std::vector<std::string> extra_args =
+        GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_();
+    args.insert(args.end(), extra_args.begin(), extra_args.end());
+#  endif  // defined(GTEST_EXTRA_DEATH_TEST_COMMAND_LINE_ARGS_)
+    return args;
+  }
+  // The name of the file in which the death test is located.
+  const char* const file_;
+  // The line number on which the death test is located.
+  const int line_;
+};
+
+// Utility class for accumulating command-line arguments.
+class Arguments {
+ public:
+  Arguments() { args_.push_back(nullptr); }
+
+  ~Arguments() {
+    for (std::vector<char*>::iterator i = args_.begin(); i != args_.end();
+         ++i) {
+      free(*i);
+    }
+  }
+  void AddArgument(const char* argument) {
+    args_.insert(args_.end() - 1, posix::StrDup(argument));
+  }
+
+  template <typename Str>
+  void AddArguments(const ::std::vector<Str>& arguments) {
+    for (typename ::std::vector<Str>::const_iterator i = arguments.begin();
+         i != arguments.end();
+         ++i) {
+      args_.insert(args_.end() - 1, posix::StrDup(i->c_str()));
+    }
+  }
+  char* const* Argv() {
+    return &args_[0];
+  }
+
+ private:
+  std::vector<char*> args_;
+};
+
+// A struct that encompasses the arguments to the child process of a
+// threadsafe-style death test process.
+struct ExecDeathTestArgs {
+  char* const* argv;  // Command-line arguments for the child's call to exec
+  int close_fd;       // File descriptor to close; the read end of a pipe
+};
+
+#  if GTEST_OS_MAC
+inline char** GetEnviron() {
+  // When Google Test is built as a framework on MacOS X, the environ variable
+  // is unavailable. Apple's documentation (man environ) recommends using
+  // _NSGetEnviron() instead.
+  return *_NSGetEnviron();
+}
+#  else
+// Some POSIX platforms expect you to declare environ. extern "C" makes
+// it reside in the global namespace.
+extern "C" char** environ;
+inline char** GetEnviron() { return environ; }
+#  endif  // GTEST_OS_MAC
+
+#  if !GTEST_OS_QNX
+// The main function for a threadsafe-style death test child process.
+// This function is called in a clone()-ed process and thus must avoid
+// any potentially unsafe operations like malloc or libc functions.
+static int ExecDeathTestChildMain(void* child_arg) {
+  ExecDeathTestArgs* const args = static_cast<ExecDeathTestArgs*>(child_arg);
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(args->close_fd));
+
+  // We need to execute the test program in the same environment where
+  // it was originally invoked.  Therefore we change to the original
+  // working directory first.
+  const char* const original_dir =
+      UnitTest::GetInstance()->original_working_dir();
+  // We can safely call chdir() as it's a direct system call.
+  if (chdir(original_dir) != 0) {
+    DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
+                   GetLastErrnoDescription());
+    return EXIT_FAILURE;
+  }
+
+  // We can safely call execve() as it's a direct system call.  We
+  // cannot use execvp() as it's a libc function and thus potentially
+  // unsafe.  Since execve() doesn't search the PATH, the user must
+  // invoke the test program via a valid path that contains at least
+  // one path separator.
+  execve(args->argv[0], args->argv, GetEnviron());
+  DeathTestAbort(std::string("execve(") + args->argv[0] + ", ...) in " +
+                 original_dir + " failed: " +
+                 GetLastErrnoDescription());
+  return EXIT_FAILURE;
+}
+#  endif  // !GTEST_OS_QNX
+
+#  if GTEST_HAS_CLONE
+// Two utility routines that together determine the direction the stack
+// grows.
+// This could be accomplished more elegantly by a single recursive
+// function, but we want to guard against the unlikely possibility of
+// a smart compiler optimizing the recursion away.
+//
+// GTEST_NO_INLINE_ is required to prevent GCC 4.6 from inlining
+// StackLowerThanAddress into StackGrowsDown, which then doesn't give
+// correct answer.
+static void StackLowerThanAddress(const void* ptr,
+                                  bool* result) GTEST_NO_INLINE_;
+// HWAddressSanitizer add a random tag to the MSB of the local variable address,
+// making comparison result unpredictable.
+GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+static void StackLowerThanAddress(const void* ptr, bool* result) {
+  int dummy;
+  *result = (&dummy < ptr);
+}
+
+// Make sure AddressSanitizer does not tamper with the stack here.
+GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+static bool StackGrowsDown() {
+  int dummy {};
+  bool result {};
+  StackLowerThanAddress(&dummy, &result);
+  return result;
+}
+#  endif  // GTEST_HAS_CLONE
+
+// Spawns a child process with the same executable as the current process in
+// a thread-safe manner and instructs it to run the death test.  The
+// implementation uses fork(2) + exec.  On systems where clone(2) is
+// available, it is used instead, being slightly more thread-safe.  On QNX,
+// fork supports only single-threaded environments, so this function uses
+// spawn(2) there instead.  The function dies with an error message if
+// anything goes wrong.
+static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
+  ExecDeathTestArgs args = { argv, close_fd };
+  pid_t child_pid = -1;
+
+#  if GTEST_OS_QNX
+  // Obtains the current directory and sets it to be closed in the child
+  // process.
+  const int cwd_fd = open(".", O_RDONLY);
+  GTEST_DEATH_TEST_CHECK_(cwd_fd != -1);
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(cwd_fd, F_SETFD, FD_CLOEXEC));
+  // We need to execute the test program in the same environment where
+  // it was originally invoked.  Therefore we change to the original
+  // working directory first.
+  const char* const original_dir =
+      UnitTest::GetInstance()->original_working_dir();
+  // We can safely call chdir() as it's a direct system call.
+  if (chdir(original_dir) != 0) {
+    DeathTestAbort(std::string("chdir(\"") + original_dir + "\") failed: " +
+                   GetLastErrnoDescription());
+    return EXIT_FAILURE;
+  }
+
+  int fd_flags;
+  // Set close_fd to be closed after spawn.
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(fd_flags = fcntl(close_fd, F_GETFD));
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(fcntl(close_fd, F_SETFD,
+                                        fd_flags | FD_CLOEXEC));
+  struct inheritance inherit = {0};
+  // spawn is a system call.
+  child_pid =
+      spawn(args.argv[0], 0, nullptr, &inherit, args.argv, GetEnviron());
+  // Restores the current working directory.
+  GTEST_DEATH_TEST_CHECK_(fchdir(cwd_fd) != -1);
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(cwd_fd));
+
+#  else   // GTEST_OS_QNX
+#   if GTEST_OS_LINUX
+  // When a SIGPROF signal is received while fork() or clone() are executing,
+  // the process may hang. To avoid this, we ignore SIGPROF here and re-enable
+  // it after the call to fork()/clone() is complete.
+  struct sigaction saved_sigprof_action;
+  struct sigaction ignore_sigprof_action;
+  memset(&ignore_sigprof_action, 0, sizeof(ignore_sigprof_action));
+  sigemptyset(&ignore_sigprof_action.sa_mask);
+  ignore_sigprof_action.sa_handler = SIG_IGN;
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(sigaction(
+      SIGPROF, &ignore_sigprof_action, &saved_sigprof_action));
+#   endif  // GTEST_OS_LINUX
+
+#   if GTEST_HAS_CLONE
+  const bool use_fork = GTEST_FLAG(death_test_use_fork);
+
+  if (!use_fork) {
+    static const bool stack_grows_down = StackGrowsDown();
+    const auto stack_size = static_cast<size_t>(getpagesize());
+    // MMAP_ANONYMOUS is not defined on Mac, so we use MAP_ANON instead.
+    void* const stack = mmap(nullptr, stack_size, PROT_READ | PROT_WRITE,
+                             MAP_ANON | MAP_PRIVATE, -1, 0);
+    GTEST_DEATH_TEST_CHECK_(stack != MAP_FAILED);
+
+    // Maximum stack alignment in bytes:  For a downward-growing stack, this
+    // amount is subtracted from size of the stack space to get an address
+    // that is within the stack space and is aligned on all systems we care
+    // about.  As far as I know there is no ABI with stack alignment greater
+    // than 64.  We assume stack and stack_size already have alignment of
+    // kMaxStackAlignment.
+    const size_t kMaxStackAlignment = 64;
+    void* const stack_top =
+        static_cast<char*>(stack) +
+            (stack_grows_down ? stack_size - kMaxStackAlignment : 0);
+    GTEST_DEATH_TEST_CHECK_(
+        static_cast<size_t>(stack_size) > kMaxStackAlignment &&
+        reinterpret_cast<uintptr_t>(stack_top) % kMaxStackAlignment == 0);
+
+    child_pid = clone(&ExecDeathTestChildMain, stack_top, SIGCHLD, &args);
+
+    GTEST_DEATH_TEST_CHECK_(munmap(stack, stack_size) != -1);
+  }
+#   else
+  const bool use_fork = true;
+#   endif  // GTEST_HAS_CLONE
+
+  if (use_fork && (child_pid = fork()) == 0) {
+      ExecDeathTestChildMain(&args);
+      _exit(0);
+  }
+#  endif  // GTEST_OS_QNX
+#  if GTEST_OS_LINUX
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(
+      sigaction(SIGPROF, &saved_sigprof_action, nullptr));
+#  endif  // GTEST_OS_LINUX
+
+  GTEST_DEATH_TEST_CHECK_(child_pid != -1);
+  return child_pid;
+}
+
+// The AssumeRole process for a fork-and-exec death test.  It re-executes the
+// main program from the beginning, setting the --gtest_filter
+// and --gtest_internal_run_death_test flags to cause only the current
+// death test to be re-run.
+DeathTest::TestRole ExecDeathTest::AssumeRole() {
+  const UnitTestImpl* const impl = GetUnitTestImpl();
+  const InternalRunDeathTestFlag* const flag =
+      impl->internal_run_death_test_flag();
+  const TestInfo* const info = impl->current_test_info();
+  const int death_test_index = info->result()->death_test_count();
+
+  if (flag != nullptr) {
+    set_write_fd(flag->write_fd());
+    return EXECUTE_TEST;
+  }
+
+  int pipe_fd[2];
+  GTEST_DEATH_TEST_CHECK_(pipe(pipe_fd) != -1);
+  // Clear the close-on-exec flag on the write end of the pipe, lest
+  // it be closed when the child process does an exec:
+  GTEST_DEATH_TEST_CHECK_(fcntl(pipe_fd[1], F_SETFD, 0) != -1);
+
+  const std::string filter_flag = std::string("--") + GTEST_FLAG_PREFIX_ +
+                                  kFilterFlag + "=" + info->test_suite_name() +
+                                  "." + info->name();
+  const std::string internal_flag =
+      std::string("--") + GTEST_FLAG_PREFIX_ + kInternalRunDeathTestFlag + "="
+      + file_ + "|" + StreamableToString(line_) + "|"
+      + StreamableToString(death_test_index) + "|"
+      + StreamableToString(pipe_fd[1]);
+  Arguments args;
+  args.AddArguments(GetArgvsForDeathTestChildProcess());
+  args.AddArgument(filter_flag.c_str());
+  args.AddArgument(internal_flag.c_str());
+
+  DeathTest::set_last_death_test_message("");
+
+  CaptureStderr();
+  // See the comment in NoExecDeathTest::AssumeRole for why the next line
+  // is necessary.
+  FlushInfoLog();
+
+  const pid_t child_pid = ExecDeathTestSpawnChild(args.Argv(), pipe_fd[0]);
+  GTEST_DEATH_TEST_CHECK_SYSCALL_(close(pipe_fd[1]));
+  set_child_pid(child_pid);
+  set_read_fd(pipe_fd[0]);
+  set_spawned(true);
+  return OVERSEE_TEST;
+}
+
+# endif  // !GTEST_OS_WINDOWS
+
+// Creates a concrete DeathTest-derived class that depends on the
+// --gtest_death_test_style flag, and sets the pointer pointed to
+// by the "test" argument to its address.  If the test should be
+// skipped, sets that pointer to NULL.  Returns true, unless the
+// flag is set to an invalid value.
+bool DefaultDeathTestFactory::Create(const char* statement,
+                                     Matcher<const std::string&> matcher,
+                                     const char* file, int line,
+                                     DeathTest** test) {
+  UnitTestImpl* const impl = GetUnitTestImpl();
+  const InternalRunDeathTestFlag* const flag =
+      impl->internal_run_death_test_flag();
+  const int death_test_index = impl->current_test_info()
+      ->increment_death_test_count();
+
+  if (flag != nullptr) {
+    if (death_test_index > flag->index()) {
+      DeathTest::set_last_death_test_message(
+          "Death test count (" + StreamableToString(death_test_index)
+          + ") somehow exceeded expected maximum ("
+          + StreamableToString(flag->index()) + ")");
+      return false;
+    }
+
+    if (!(flag->file() == file && flag->line() == line &&
+          flag->index() == death_test_index)) {
+      *test = nullptr;
+      return true;
+    }
+  }
+
+# if GTEST_OS_WINDOWS
+
+  if (GTEST_FLAG(death_test_style) == "threadsafe" ||
+      GTEST_FLAG(death_test_style) == "fast") {
+    *test = new WindowsDeathTest(statement, std::move(matcher), file, line);
+  }
+
+# elif GTEST_OS_FUCHSIA
+
+  if (GTEST_FLAG(death_test_style) == "threadsafe" ||
+      GTEST_FLAG(death_test_style) == "fast") {
+    *test = new FuchsiaDeathTest(statement, std::move(matcher), file, line);
+  }
+
+# else
+
+  if (GTEST_FLAG(death_test_style) == "threadsafe") {
+    *test = new ExecDeathTest(statement, std::move(matcher), file, line);
+  } else if (GTEST_FLAG(death_test_style) == "fast") {
+    *test = new NoExecDeathTest(statement, std::move(matcher));
+  }
+
+# endif  // GTEST_OS_WINDOWS
+
+  else {  // NOLINT - this is more readable than unbalanced brackets inside #if.
+    DeathTest::set_last_death_test_message(
+        "Unknown death test style \"" + GTEST_FLAG(death_test_style)
+        + "\" encountered");
+    return false;
+  }
+
+  return true;
+}
+
+# if GTEST_OS_WINDOWS
+// Recreates the pipe and event handles from the provided parameters,
+// signals the event, and returns a file descriptor wrapped around the pipe
+// handle. This function is called in the child process only.
+static int GetStatusFileDescriptor(unsigned int parent_process_id,
+                            size_t write_handle_as_size_t,
+                            size_t event_handle_as_size_t) {
+  AutoHandle parent_process_handle(::OpenProcess(PROCESS_DUP_HANDLE,
+                                                   FALSE,  // Non-inheritable.
+                                                   parent_process_id));
+  if (parent_process_handle.Get() == INVALID_HANDLE_VALUE) {
+    DeathTestAbort("Unable to open parent process " +
+                   StreamableToString(parent_process_id));
+  }
+
+  GTEST_CHECK_(sizeof(HANDLE) <= sizeof(size_t));
+
+  const HANDLE write_handle =
+      reinterpret_cast<HANDLE>(write_handle_as_size_t);
+  HANDLE dup_write_handle;
+
+  // The newly initialized handle is accessible only in the parent
+  // process. To obtain one accessible within the child, we need to use
+  // DuplicateHandle.
+  if (!::DuplicateHandle(parent_process_handle.Get(), write_handle,
+                         ::GetCurrentProcess(), &dup_write_handle,
+                         0x0,    // Requested privileges ignored since
+                                 // DUPLICATE_SAME_ACCESS is used.
+                         FALSE,  // Request non-inheritable handler.
+                         DUPLICATE_SAME_ACCESS)) {
+    DeathTestAbort("Unable to duplicate the pipe handle " +
+                   StreamableToString(write_handle_as_size_t) +
+                   " from the parent process " +
+                   StreamableToString(parent_process_id));
+  }
+
+  const HANDLE event_handle = reinterpret_cast<HANDLE>(event_handle_as_size_t);
+  HANDLE dup_event_handle;
+
+  if (!::DuplicateHandle(parent_process_handle.Get(), event_handle,
+                         ::GetCurrentProcess(), &dup_event_handle,
+                         0x0,
+                         FALSE,
+                         DUPLICATE_SAME_ACCESS)) {
+    DeathTestAbort("Unable to duplicate the event handle " +
+                   StreamableToString(event_handle_as_size_t) +
+                   " from the parent process " +
+                   StreamableToString(parent_process_id));
+  }
+
+  const int write_fd =
+      ::_open_osfhandle(reinterpret_cast<intptr_t>(dup_write_handle), O_APPEND);
+  if (write_fd == -1) {
+    DeathTestAbort("Unable to convert pipe handle " +
+                   StreamableToString(write_handle_as_size_t) +
+                   " to a file descriptor");
+  }
+
+  // Signals the parent that the write end of the pipe has been acquired
+  // so the parent can release its own write end.
+  ::SetEvent(dup_event_handle);
+
+  return write_fd;
+}
+# endif  // GTEST_OS_WINDOWS
+
+// Returns a newly created InternalRunDeathTestFlag object with fields
+// initialized from the GTEST_FLAG(internal_run_death_test) flag if
+// the flag is specified; otherwise returns NULL.
+InternalRunDeathTestFlag* ParseInternalRunDeathTestFlag() {
+  if (GTEST_FLAG(internal_run_death_test) == "") return nullptr;
+
+  // GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we
+  // can use it here.
+  int line = -1;
+  int index = -1;
+  ::std::vector< ::std::string> fields;
+  SplitString(GTEST_FLAG(internal_run_death_test).c_str(), '|', &fields);
+  int write_fd = -1;
+
+# if GTEST_OS_WINDOWS
+
+  unsigned int parent_process_id = 0;
+  size_t write_handle_as_size_t = 0;
+  size_t event_handle_as_size_t = 0;
+
+  if (fields.size() != 6
+      || !ParseNaturalNumber(fields[1], &line)
+      || !ParseNaturalNumber(fields[2], &index)
+      || !ParseNaturalNumber(fields[3], &parent_process_id)
+      || !ParseNaturalNumber(fields[4], &write_handle_as_size_t)
+      || !ParseNaturalNumber(fields[5], &event_handle_as_size_t)) {
+    DeathTestAbort("Bad --gtest_internal_run_death_test flag: " +
+                   GTEST_FLAG(internal_run_death_test));
+  }
+  write_fd = GetStatusFileDescriptor(parent_process_id,
+                                     write_handle_as_size_t,
+                                     event_handle_as_size_t);
+
+# elif GTEST_OS_FUCHSIA
+
+  if (fields.size() != 3
+      || !ParseNaturalNumber(fields[1], &line)
+      || !ParseNaturalNumber(fields[2], &index)) {
+    DeathTestAbort("Bad --gtest_internal_run_death_test flag: "
+        + GTEST_FLAG(internal_run_death_test));
+  }
+
+# else
+
+  if (fields.size() != 4
+      || !ParseNaturalNumber(fields[1], &line)
+      || !ParseNaturalNumber(fields[2], &index)
+      || !ParseNaturalNumber(fields[3], &write_fd)) {
+    DeathTestAbort("Bad --gtest_internal_run_death_test flag: "
+        + GTEST_FLAG(internal_run_death_test));
+  }
+
+# endif  // GTEST_OS_WINDOWS
+
+  return new InternalRunDeathTestFlag(fields[0], line, index, write_fd);
+}
+
+}  // namespace internal
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+}  // namespace testing
diff --git a/3rdparty/gtest/src/gtest-filepath.cc b/3rdparty/gtest/src/gtest-filepath.cc
new file mode 100644
index 0000000..bd7b99f
--- /dev/null
+++ b/3rdparty/gtest/src/gtest-filepath.cc
@@ -0,0 +1,379 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "gtest/internal/gtest-filepath.h"
+
+#include <stdlib.h>
+#include "gtest/internal/gtest-port.h"
+#include "gtest/gtest-message.h"
+
+#if GTEST_OS_WINDOWS_MOBILE
+# include <windows.h>
+#elif GTEST_OS_WINDOWS
+# include <direct.h>
+# include <io.h>
+#else
+# include <limits.h>
+# include <climits>  // Some Linux distributions define PATH_MAX here.
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+#include "gtest/internal/gtest-string.h"
+
+#if GTEST_OS_WINDOWS
+# define GTEST_PATH_MAX_ _MAX_PATH
+#elif defined(PATH_MAX)
+# define GTEST_PATH_MAX_ PATH_MAX
+#elif defined(_XOPEN_PATH_MAX)
+# define GTEST_PATH_MAX_ _XOPEN_PATH_MAX
+#else
+# define GTEST_PATH_MAX_ _POSIX_PATH_MAX
+#endif  // GTEST_OS_WINDOWS
+
+namespace testing {
+namespace internal {
+
+#if GTEST_OS_WINDOWS
+// On Windows, '\\' is the standard path separator, but many tools and the
+// Windows API also accept '/' as an alternate path separator. Unless otherwise
+// noted, a file path can contain either kind of path separators, or a mixture
+// of them.
+const char kPathSeparator = '\\';
+const char kAlternatePathSeparator = '/';
+const char kAlternatePathSeparatorString[] = "/";
+# if GTEST_OS_WINDOWS_MOBILE
+// Windows CE doesn't have a current directory. You should not use
+// the current directory in tests on Windows CE, but this at least
+// provides a reasonable fallback.
+const char kCurrentDirectoryString[] = "\\";
+// Windows CE doesn't define INVALID_FILE_ATTRIBUTES
+const DWORD kInvalidFileAttributes = 0xffffffff;
+# else
+const char kCurrentDirectoryString[] = ".\\";
+# endif  // GTEST_OS_WINDOWS_MOBILE
+#else
+const char kPathSeparator = '/';
+const char kCurrentDirectoryString[] = "./";
+#endif  // GTEST_OS_WINDOWS
+
+// Returns whether the given character is a valid path separator.
+static bool IsPathSeparator(char c) {
+#if GTEST_HAS_ALT_PATH_SEP_
+  return (c == kPathSeparator) || (c == kAlternatePathSeparator);
+#else
+  return c == kPathSeparator;
+#endif
+}
+
+// Returns the current working directory, or "" if unsuccessful.
+FilePath FilePath::GetCurrentDir() {
+#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_PHONE || \
+    GTEST_OS_WINDOWS_RT || ARDUINO || defined(ESP_PLATFORM)
+  // These platforms do not have a current directory, so we just return
+  // something reasonable.
+  return FilePath(kCurrentDirectoryString);
+#elif GTEST_OS_WINDOWS
+  char cwd[GTEST_PATH_MAX_ + 1] = { '\0' };
+  return FilePath(_getcwd(cwd, sizeof(cwd)) == nullptr ? "" : cwd);
+#else
+  char cwd[GTEST_PATH_MAX_ + 1] = { '\0' };
+  char* result = getcwd(cwd, sizeof(cwd));
+# if GTEST_OS_NACL
+  // getcwd will likely fail in NaCl due to the sandbox, so return something
+  // reasonable. The user may have provided a shim implementation for getcwd,
+  // however, so fallback only when failure is detected.
+  return FilePath(result == nullptr ? kCurrentDirectoryString : cwd);
+# endif  // GTEST_OS_NACL
+  return FilePath(result == nullptr ? "" : cwd);
+#endif  // GTEST_OS_WINDOWS_MOBILE
+}
+
+// Returns a copy of the FilePath with the case-insensitive extension removed.
+// Example: FilePath("dir/file.exe").RemoveExtension("EXE") returns
+// FilePath("dir/file"). If a case-insensitive extension is not
+// found, returns a copy of the original FilePath.
+FilePath FilePath::RemoveExtension(const char* extension) const {
+  const std::string dot_extension = std::string(".") + extension;
+  if (String::EndsWithCaseInsensitive(pathname_, dot_extension)) {
+    return FilePath(pathname_.substr(
+        0, pathname_.length() - dot_extension.length()));
+  }
+  return *this;
+}
+
+// Returns a pointer to the last occurrence of a valid path separator in
+// the FilePath. On Windows, for example, both '/' and '\' are valid path
+// separators. Returns NULL if no path separator was found.
+const char* FilePath::FindLastPathSeparator() const {
+  const char* const last_sep = strrchr(c_str(), kPathSeparator);
+#if GTEST_HAS_ALT_PATH_SEP_
+  const char* const last_alt_sep = strrchr(c_str(), kAlternatePathSeparator);
+  // Comparing two pointers of which only one is NULL is undefined.
+  if (last_alt_sep != nullptr &&
+      (last_sep == nullptr || last_alt_sep > last_sep)) {
+    return last_alt_sep;
+  }
+#endif
+  return last_sep;
+}
+
+// Returns a copy of the FilePath with the directory part removed.
+// Example: FilePath("path/to/file").RemoveDirectoryName() returns
+// FilePath("file"). If there is no directory part ("just_a_file"), it returns
+// the FilePath unmodified. If there is no file part ("just_a_dir/") it
+// returns an empty FilePath ("").
+// On Windows platform, '\' is the path separator, otherwise it is '/'.
+FilePath FilePath::RemoveDirectoryName() const {
+  const char* const last_sep = FindLastPathSeparator();
+  return last_sep ? FilePath(last_sep + 1) : *this;
+}
+
+// RemoveFileName returns the directory path with the filename removed.
+// Example: FilePath("path/to/file").RemoveFileName() returns "path/to/".
+// If the FilePath is "a_file" or "/a_file", RemoveFileName returns
+// FilePath("./") or, on Windows, FilePath(".\\"). If the filepath does
+// not have a file, like "just/a/dir/", it returns the FilePath unmodified.
+// On Windows platform, '\' is the path separator, otherwise it is '/'.
+FilePath FilePath::RemoveFileName() const {
+  const char* const last_sep = FindLastPathSeparator();
+  std::string dir;
+  if (last_sep) {
+    dir = std::string(c_str(), static_cast<size_t>(last_sep + 1 - c_str()));
+  } else {
+    dir = kCurrentDirectoryString;
+  }
+  return FilePath(dir);
+}
+
+// Helper functions for naming files in a directory for xml output.
+
+// Given directory = "dir", base_name = "test", number = 0,
+// extension = "xml", returns "dir/test.xml". If number is greater
+// than zero (e.g., 12), returns "dir/test_12.xml".
+// On Windows platform, uses \ as the separator rather than /.
+FilePath FilePath::MakeFileName(const FilePath& directory,
+                                const FilePath& base_name,
+                                int number,
+                                const char* extension) {
+  std::string file;
+  if (number == 0) {
+    file = base_name.string() + "." + extension;
+  } else {
+    file = base_name.string() + "_" + StreamableToString(number)
+        + "." + extension;
+  }
+  return ConcatPaths(directory, FilePath(file));
+}
+
+// Given directory = "dir", relative_path = "test.xml", returns "dir/test.xml".
+// On Windows, uses \ as the separator rather than /.
+FilePath FilePath::ConcatPaths(const FilePath& directory,
+                               const FilePath& relative_path) {
+  if (directory.IsEmpty())
+    return relative_path;
+  const FilePath dir(directory.RemoveTrailingPathSeparator());
+  return FilePath(dir.string() + kPathSeparator + relative_path.string());
+}
+
+// Returns true if pathname describes something findable in the file-system,
+// either a file, directory, or whatever.
+bool FilePath::FileOrDirectoryExists() const {
+#if GTEST_OS_WINDOWS_MOBILE
+  LPCWSTR unicode = String::AnsiToUtf16(pathname_.c_str());
+  const DWORD attributes = GetFileAttributes(unicode);
+  delete [] unicode;
+  return attributes != kInvalidFileAttributes;
+#else
+  posix::StatStruct file_stat;
+  return posix::Stat(pathname_.c_str(), &file_stat) == 0;
+#endif  // GTEST_OS_WINDOWS_MOBILE
+}
+
+// Returns true if pathname describes a directory in the file-system
+// that exists.
+bool FilePath::DirectoryExists() const {
+  bool result = false;
+#if GTEST_OS_WINDOWS
+  // Don't strip off trailing separator if path is a root directory on
+  // Windows (like "C:\\").
+  const FilePath& path(IsRootDirectory() ? *this :
+                                           RemoveTrailingPathSeparator());
+#else
+  const FilePath& path(*this);
+#endif
+
+#if GTEST_OS_WINDOWS_MOBILE
+  LPCWSTR unicode = String::AnsiToUtf16(path.c_str());
+  const DWORD attributes = GetFileAttributes(unicode);
+  delete [] unicode;
+  if ((attributes != kInvalidFileAttributes) &&
+      (attributes & FILE_ATTRIBUTE_DIRECTORY)) {
+    result = true;
+  }
+#else
+  posix::StatStruct file_stat;
+  result = posix::Stat(path.c_str(), &file_stat) == 0 &&
+      posix::IsDir(file_stat);
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+  return result;
+}
+
+// Returns true if pathname describes a root directory. (Windows has one
+// root directory per disk drive.)
+bool FilePath::IsRootDirectory() const {
+#if GTEST_OS_WINDOWS
+  return pathname_.length() == 3 && IsAbsolutePath();
+#else
+  return pathname_.length() == 1 && IsPathSeparator(pathname_.c_str()[0]);
+#endif
+}
+
+// Returns true if pathname describes an absolute path.
+bool FilePath::IsAbsolutePath() const {
+  const char* const name = pathname_.c_str();
+#if GTEST_OS_WINDOWS
+  return pathname_.length() >= 3 &&
+     ((name[0] >= 'a' && name[0] <= 'z') ||
+      (name[0] >= 'A' && name[0] <= 'Z')) &&
+     name[1] == ':' &&
+     IsPathSeparator(name[2]);
+#else
+  return IsPathSeparator(name[0]);
+#endif
+}
+
+// Returns a pathname for a file that does not currently exist. The pathname
+// will be directory/base_name.extension or
+// directory/base_name_<number>.extension if directory/base_name.extension
+// already exists. The number will be incremented until a pathname is found
+// that does not already exist.
+// Examples: 'dir/foo_test.xml' or 'dir/foo_test_1.xml'.
+// There could be a race condition if two or more processes are calling this
+// function at the same time -- they could both pick the same filename.
+FilePath FilePath::GenerateUniqueFileName(const FilePath& directory,
+                                          const FilePath& base_name,
+                                          const char* extension) {
+  FilePath full_pathname;
+  int number = 0;
+  do {
+    full_pathname.Set(MakeFileName(directory, base_name, number++, extension));
+  } while (full_pathname.FileOrDirectoryExists());
+  return full_pathname;
+}
+
+// Returns true if FilePath ends with a path separator, which indicates that
+// it is intended to represent a directory. Returns false otherwise.
+// This does NOT check that a directory (or file) actually exists.
+bool FilePath::IsDirectory() const {
+  return !pathname_.empty() &&
+         IsPathSeparator(pathname_.c_str()[pathname_.length() - 1]);
+}
+
+// Create directories so that path exists. Returns true if successful or if
+// the directories already exist; returns false if unable to create directories
+// for any reason.
+bool FilePath::CreateDirectoriesRecursively() const {
+  if (!this->IsDirectory()) {
+    return false;
+  }
+
+  if (pathname_.length() == 0 || this->DirectoryExists()) {
+    return true;
+  }
+
+  const FilePath parent(this->RemoveTrailingPathSeparator().RemoveFileName());
+  return parent.CreateDirectoriesRecursively() && this->CreateFolder();
+}
+
+// Create the directory so that path exists. Returns true if successful or
+// if the directory already exists; returns false if unable to create the
+// directory for any reason, including if the parent directory does not
+// exist. Not named "CreateDirectory" because that's a macro on Windows.
+bool FilePath::CreateFolder() const {
+#if GTEST_OS_WINDOWS_MOBILE
+  FilePath removed_sep(this->RemoveTrailingPathSeparator());
+  LPCWSTR unicode = String::AnsiToUtf16(removed_sep.c_str());
+  int result = CreateDirectory(unicode, nullptr) ? 0 : -1;
+  delete [] unicode;
+#elif GTEST_OS_WINDOWS
+  int result = _mkdir(pathname_.c_str());
+#else
+  int result = mkdir(pathname_.c_str(), 0777);
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+  if (result == -1) {
+    return this->DirectoryExists();  // An error is OK if the directory exists.
+  }
+  return true;  // No error.
+}
+
+// If input name has a trailing separator character, remove it and return the
+// name, otherwise return the name string unmodified.
+// On Windows platform, uses \ as the separator, other platforms use /.
+FilePath FilePath::RemoveTrailingPathSeparator() const {
+  return IsDirectory()
+      ? FilePath(pathname_.substr(0, pathname_.length() - 1))
+      : *this;
+}
+
+// Removes any redundant separators that might be in the pathname.
+// For example, "bar///foo" becomes "bar/foo". Does not eliminate other
+// redundancies that might be in a pathname involving "." or "..".
+void FilePath::Normalize() {
+  if (pathname_.c_str() == nullptr) {
+    pathname_ = "";
+    return;
+  }
+  const char* src = pathname_.c_str();
+  char* const dest = new char[pathname_.length() + 1];
+  char* dest_ptr = dest;
+  memset(dest_ptr, 0, pathname_.length() + 1);
+
+  while (*src != '\0') {
+    *dest_ptr = *src;
+    if (!IsPathSeparator(*src)) {
+      src++;
+    } else {
+#if GTEST_HAS_ALT_PATH_SEP_
+      if (*dest_ptr == kAlternatePathSeparator) {
+        *dest_ptr = kPathSeparator;
+      }
+#endif
+      while (IsPathSeparator(*src))
+        src++;
+    }
+    dest_ptr++;
+  }
+  *dest_ptr = '\0';
+  pathname_ = dest;
+  delete[] dest;
+}
+
+}  // namespace internal
+}  // namespace testing
diff --git a/3rdparty/gtest/src/gtest-internal-inl.h b/3rdparty/gtest/src/gtest-internal-inl.h
new file mode 100644
index 0000000..8ed70da
--- /dev/null
+++ b/3rdparty/gtest/src/gtest-internal-inl.h
@@ -0,0 +1,1211 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Utility functions and classes used by the Google C++ testing framework.//
+// This file contains purely Google Test's internal implementation.  Please
+// DO NOT #INCLUDE IT IN A USER PROGRAM.
+
+#ifndef GTEST_SRC_GTEST_INTERNAL_INL_H_
+#define GTEST_SRC_GTEST_INTERNAL_INL_H_
+
+#ifndef _WIN32_WCE
+# include <errno.h>
+#endif  // !_WIN32_WCE
+#include <stddef.h>
+#include <stdlib.h>  // For strtoll/_strtoul64/malloc/free.
+#include <string.h>  // For memmove.
+
+#include <algorithm>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "gtest/internal/gtest-port.h"
+
+#if GTEST_CAN_STREAM_RESULTS_
+# include <arpa/inet.h>  // NOLINT
+# include <netdb.h>  // NOLINT
+#endif
+
+#if GTEST_OS_WINDOWS
+# include <windows.h>  // NOLINT
+#endif  // GTEST_OS_WINDOWS
+
+#include "gtest/gtest.h"
+#include "gtest/gtest-spi.h"
+
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
+namespace testing {
+
+// Declares the flags.
+//
+// We don't want the users to modify this flag in the code, but want
+// Google Test's own unit tests to be able to access it. Therefore we
+// declare it here as opposed to in gtest.h.
+GTEST_DECLARE_bool_(death_test_use_fork);
+
+namespace internal {
+
+// The value of GetTestTypeId() as seen from within the Google Test
+// library.  This is solely for testing GetTestTypeId().
+GTEST_API_ extern const TypeId kTestTypeIdInGoogleTest;
+
+// Names of the flags (needed for parsing Google Test flags).
+const char kAlsoRunDisabledTestsFlag[] = "also_run_disabled_tests";
+const char kBreakOnFailureFlag[] = "break_on_failure";
+const char kCatchExceptionsFlag[] = "catch_exceptions";
+const char kColorFlag[] = "color";
+const char kFilterFlag[] = "filter";
+const char kListTestsFlag[] = "list_tests";
+const char kOutputFlag[] = "output";
+const char kPrintTimeFlag[] = "print_time";
+const char kPrintUTF8Flag[] = "print_utf8";
+const char kRandomSeedFlag[] = "random_seed";
+const char kRepeatFlag[] = "repeat";
+const char kShuffleFlag[] = "shuffle";
+const char kStackTraceDepthFlag[] = "stack_trace_depth";
+const char kStreamResultToFlag[] = "stream_result_to";
+const char kThrowOnFailureFlag[] = "throw_on_failure";
+const char kFlagfileFlag[] = "flagfile";
+
+// A valid random seed must be in [1, kMaxRandomSeed].
+const int kMaxRandomSeed = 99999;
+
+// g_help_flag is true if and only if the --help flag or an equivalent form
+// is specified on the command line.
+GTEST_API_ extern bool g_help_flag;
+
+// Returns the current time in milliseconds.
+GTEST_API_ TimeInMillis GetTimeInMillis();
+
+// Returns true if and only if Google Test should use colors in the output.
+GTEST_API_ bool ShouldUseColor(bool stdout_is_tty);
+
+// Formats the given time in milliseconds as seconds.
+GTEST_API_ std::string FormatTimeInMillisAsSeconds(TimeInMillis ms);
+
+// Converts the given time in milliseconds to a date string in the ISO 8601
+// format, without the timezone information.  N.B.: due to the use the
+// non-reentrant localtime() function, this function is not thread safe.  Do
+// not use it in any code that can be called from multiple threads.
+GTEST_API_ std::string FormatEpochTimeInMillisAsIso8601(TimeInMillis ms);
+
+// Parses a string for an Int32 flag, in the form of "--flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+GTEST_API_ bool ParseInt32Flag(
+    const char* str, const char* flag, Int32* value);
+
+// Returns a random seed in range [1, kMaxRandomSeed] based on the
+// given --gtest_random_seed flag value.
+inline int GetRandomSeedFromFlag(Int32 random_seed_flag) {
+  const unsigned int raw_seed = (random_seed_flag == 0) ?
+      static_cast<unsigned int>(GetTimeInMillis()) :
+      static_cast<unsigned int>(random_seed_flag);
+
+  // Normalizes the actual seed to range [1, kMaxRandomSeed] such that
+  // it's easy to type.
+  const int normalized_seed =
+      static_cast<int>((raw_seed - 1U) %
+                       static_cast<unsigned int>(kMaxRandomSeed)) + 1;
+  return normalized_seed;
+}
+
+// Returns the first valid random seed after 'seed'.  The behavior is
+// undefined if 'seed' is invalid.  The seed after kMaxRandomSeed is
+// considered to be 1.
+inline int GetNextRandomSeed(int seed) {
+  GTEST_CHECK_(1 <= seed && seed <= kMaxRandomSeed)
+      << "Invalid random seed " << seed << " - must be in [1, "
+      << kMaxRandomSeed << "].";
+  const int next_seed = seed + 1;
+  return (next_seed > kMaxRandomSeed) ? 1 : next_seed;
+}
+
+// This class saves the values of all Google Test flags in its c'tor, and
+// restores them in its d'tor.
+class GTestFlagSaver {
+ public:
+  // The c'tor.
+  GTestFlagSaver() {
+    also_run_disabled_tests_ = GTEST_FLAG(also_run_disabled_tests);
+    break_on_failure_ = GTEST_FLAG(break_on_failure);
+    catch_exceptions_ = GTEST_FLAG(catch_exceptions);
+    color_ = GTEST_FLAG(color);
+    death_test_style_ = GTEST_FLAG(death_test_style);
+    death_test_use_fork_ = GTEST_FLAG(death_test_use_fork);
+    filter_ = GTEST_FLAG(filter);
+    internal_run_death_test_ = GTEST_FLAG(internal_run_death_test);
+    list_tests_ = GTEST_FLAG(list_tests);
+    output_ = GTEST_FLAG(output);
+    print_time_ = GTEST_FLAG(print_time);
+    print_utf8_ = GTEST_FLAG(print_utf8);
+    random_seed_ = GTEST_FLAG(random_seed);
+    repeat_ = GTEST_FLAG(repeat);
+    shuffle_ = GTEST_FLAG(shuffle);
+    stack_trace_depth_ = GTEST_FLAG(stack_trace_depth);
+    stream_result_to_ = GTEST_FLAG(stream_result_to);
+    throw_on_failure_ = GTEST_FLAG(throw_on_failure);
+  }
+
+  // The d'tor is not virtual.  DO NOT INHERIT FROM THIS CLASS.
+  ~GTestFlagSaver() {
+    GTEST_FLAG(also_run_disabled_tests) = also_run_disabled_tests_;
+    GTEST_FLAG(break_on_failure) = break_on_failure_;
+    GTEST_FLAG(catch_exceptions) = catch_exceptions_;
+    GTEST_FLAG(color) = color_;
+    GTEST_FLAG(death_test_style) = death_test_style_;
+    GTEST_FLAG(death_test_use_fork) = death_test_use_fork_;
+    GTEST_FLAG(filter) = filter_;
+    GTEST_FLAG(internal_run_death_test) = internal_run_death_test_;
+    GTEST_FLAG(list_tests) = list_tests_;
+    GTEST_FLAG(output) = output_;
+    GTEST_FLAG(print_time) = print_time_;
+    GTEST_FLAG(print_utf8) = print_utf8_;
+    GTEST_FLAG(random_seed) = random_seed_;
+    GTEST_FLAG(repeat) = repeat_;
+    GTEST_FLAG(shuffle) = shuffle_;
+    GTEST_FLAG(stack_trace_depth) = stack_trace_depth_;
+    GTEST_FLAG(stream_result_to) = stream_result_to_;
+    GTEST_FLAG(throw_on_failure) = throw_on_failure_;
+  }
+
+ private:
+  // Fields for saving the original values of flags.
+  bool also_run_disabled_tests_;
+  bool break_on_failure_;
+  bool catch_exceptions_;
+  std::string color_;
+  std::string death_test_style_;
+  bool death_test_use_fork_;
+  std::string filter_;
+  std::string internal_run_death_test_;
+  bool list_tests_;
+  std::string output_;
+  bool print_time_;
+  bool print_utf8_;
+  internal::Int32 random_seed_;
+  internal::Int32 repeat_;
+  bool shuffle_;
+  internal::Int32 stack_trace_depth_;
+  std::string stream_result_to_;
+  bool throw_on_failure_;
+} GTEST_ATTRIBUTE_UNUSED_;
+
+// Converts a Unicode code point to a narrow string in UTF-8 encoding.
+// code_point parameter is of type UInt32 because wchar_t may not be
+// wide enough to contain a code point.
+// If the code_point is not a valid Unicode code point
+// (i.e. outside of Unicode range U+0 to U+10FFFF) it will be converted
+// to "(Invalid Unicode 0xXXXXXXXX)".
+GTEST_API_ std::string CodePointToUtf8(UInt32 code_point);
+
+// Converts a wide string to a narrow string in UTF-8 encoding.
+// The wide string is assumed to have the following encoding:
+//   UTF-16 if sizeof(wchar_t) == 2 (on Windows, Cygwin)
+//   UTF-32 if sizeof(wchar_t) == 4 (on Linux)
+// Parameter str points to a null-terminated wide string.
+// Parameter num_chars may additionally limit the number
+// of wchar_t characters processed. -1 is used when the entire string
+// should be processed.
+// If the string contains code points that are not valid Unicode code points
+// (i.e. outside of Unicode range U+0 to U+10FFFF) they will be output
+// as '(Invalid Unicode 0xXXXXXXXX)'. If the string is in UTF16 encoding
+// and contains invalid UTF-16 surrogate pairs, values in those pairs
+// will be encoded as individual Unicode characters from Basic Normal Plane.
+GTEST_API_ std::string WideStringToUtf8(const wchar_t* str, int num_chars);
+
+// Reads the GTEST_SHARD_STATUS_FILE environment variable, and creates the file
+// if the variable is present. If a file already exists at this location, this
+// function will write over it. If the variable is present, but the file cannot
+// be created, prints an error and exits.
+void WriteToShardStatusFileIfNeeded();
+
+// Checks whether sharding is enabled by examining the relevant
+// environment variable values. If the variables are present,
+// but inconsistent (e.g., shard_index >= total_shards), prints
+// an error and exits. If in_subprocess_for_death_test, sharding is
+// disabled because it must only be applied to the original test
+// process. Otherwise, we could filter out death tests we intended to execute.
+GTEST_API_ bool ShouldShard(const char* total_shards_str,
+                            const char* shard_index_str,
+                            bool in_subprocess_for_death_test);
+
+// Parses the environment variable var as an Int32. If it is unset,
+// returns default_val. If it is not an Int32, prints an error and
+// and aborts.
+GTEST_API_ Int32 Int32FromEnvOrDie(const char* env_var, Int32 default_val);
+
+// Given the total number of shards, the shard index, and the test id,
+// returns true if and only if the test should be run on this shard. The test id
+// is some arbitrary but unique non-negative integer assigned to each test
+// method. Assumes that 0 <= shard_index < total_shards.
+GTEST_API_ bool ShouldRunTestOnShard(
+    int total_shards, int shard_index, int test_id);
+
+// STL container utilities.
+
+// Returns the number of elements in the given container that satisfy
+// the given predicate.
+template <class Container, typename Predicate>
+inline int CountIf(const Container& c, Predicate predicate) {
+  // Implemented as an explicit loop since std::count_if() in libCstd on
+  // Solaris has a non-standard signature.
+  int count = 0;
+  for (typename Container::const_iterator it = c.begin(); it != c.end(); ++it) {
+    if (predicate(*it))
+      ++count;
+  }
+  return count;
+}
+
+// Applies a function/functor to each element in the container.
+template <class Container, typename Functor>
+void ForEach(const Container& c, Functor functor) {
+  std::for_each(c.begin(), c.end(), functor);
+}
+
+// Returns the i-th element of the vector, or default_value if i is not
+// in range [0, v.size()).
+template <typename E>
+inline E GetElementOr(const std::vector<E>& v, int i, E default_value) {
+  return (i < 0 || i >= static_cast<int>(v.size())) ? default_value
+                                                    : v[static_cast<size_t>(i)];
+}
+
+// Performs an in-place shuffle of a range of the vector's elements.
+// 'begin' and 'end' are element indices as an STL-style range;
+// i.e. [begin, end) are shuffled, where 'end' == size() means to
+// shuffle to the end of the vector.
+template <typename E>
+void ShuffleRange(internal::Random* random, int begin, int end,
+                  std::vector<E>* v) {
+  const int size = static_cast<int>(v->size());
+  GTEST_CHECK_(0 <= begin && begin <= size)
+      << "Invalid shuffle range start " << begin << ": must be in range [0, "
+      << size << "].";
+  GTEST_CHECK_(begin <= end && end <= size)
+      << "Invalid shuffle range finish " << end << ": must be in range ["
+      << begin << ", " << size << "].";
+
+  // Fisher-Yates shuffle, from
+  // http://en.wikipedia.org/wiki/Fisher-Yates_shuffle
+  for (int range_width = end - begin; range_width >= 2; range_width--) {
+    const int last_in_range = begin + range_width - 1;
+    const int selected =
+        begin +
+        static_cast<int>(random->Generate(static_cast<UInt32>(range_width)));
+    std::swap((*v)[static_cast<size_t>(selected)],
+              (*v)[static_cast<size_t>(last_in_range)]);
+  }
+}
+
+// Performs an in-place shuffle of the vector's elements.
+template <typename E>
+inline void Shuffle(internal::Random* random, std::vector<E>* v) {
+  ShuffleRange(random, 0, static_cast<int>(v->size()), v);
+}
+
+// A function for deleting an object.  Handy for being used as a
+// functor.
+template <typename T>
+static void Delete(T* x) {
+  delete x;
+}
+
+// A predicate that checks the key of a TestProperty against a known key.
+//
+// TestPropertyKeyIs is copyable.
+class TestPropertyKeyIs {
+ public:
+  // Constructor.
+  //
+  // TestPropertyKeyIs has NO default constructor.
+  explicit TestPropertyKeyIs(const std::string& key) : key_(key) {}
+
+  // Returns true if and only if the test name of test property matches on key_.
+  bool operator()(const TestProperty& test_property) const {
+    return test_property.key() == key_;
+  }
+
+ private:
+  std::string key_;
+};
+
+// Class UnitTestOptions.
+//
+// This class contains functions for processing options the user
+// specifies when running the tests.  It has only static members.
+//
+// In most cases, the user can specify an option using either an
+// environment variable or a command line flag.  E.g. you can set the
+// test filter using either GTEST_FILTER or --gtest_filter.  If both
+// the variable and the flag are present, the latter overrides the
+// former.
+class GTEST_API_ UnitTestOptions {
+ public:
+  // Functions for processing the gtest_output flag.
+
+  // Returns the output format, or "" for normal printed output.
+  static std::string GetOutputFormat();
+
+  // Returns the absolute path of the requested output file, or the
+  // default (test_detail.xml in the original working directory) if
+  // none was explicitly specified.
+  static std::string GetAbsolutePathToOutputFile();
+
+  // Functions for processing the gtest_filter flag.
+
+  // Returns true if and only if the wildcard pattern matches the string.
+  // The first ':' or '\0' character in pattern marks the end of it.
+  //
+  // This recursive algorithm isn't very efficient, but is clear and
+  // works well enough for matching test names, which are short.
+  static bool PatternMatchesString(const char *pattern, const char *str);
+
+  // Returns true if and only if the user-specified filter matches the test
+  // suite name and the test name.
+  static bool FilterMatchesTest(const std::string& test_suite_name,
+                                const std::string& test_name);
+
+#if GTEST_OS_WINDOWS
+  // Function for supporting the gtest_catch_exception flag.
+
+  // Returns EXCEPTION_EXECUTE_HANDLER if Google Test should handle the
+  // given SEH exception, or EXCEPTION_CONTINUE_SEARCH otherwise.
+  // This function is useful as an __except condition.
+  static int GTestShouldProcessSEH(DWORD exception_code);
+#endif  // GTEST_OS_WINDOWS
+
+  // Returns true if "name" matches the ':' separated list of glob-style
+  // filters in "filter".
+  static bool MatchesFilter(const std::string& name, const char* filter);
+};
+
+// Returns the current application's name, removing directory path if that
+// is present.  Used by UnitTestOptions::GetOutputFile.
+GTEST_API_ FilePath GetCurrentExecutableName();
+
+// The role interface for getting the OS stack trace as a string.
+class OsStackTraceGetterInterface {
+ public:
+  OsStackTraceGetterInterface() {}
+  virtual ~OsStackTraceGetterInterface() {}
+
+  // Returns the current OS stack trace as an std::string.  Parameters:
+  //
+  //   max_depth  - the maximum number of stack frames to be included
+  //                in the trace.
+  //   skip_count - the number of top frames to be skipped; doesn't count
+  //                against max_depth.
+  virtual std::string CurrentStackTrace(int max_depth, int skip_count) = 0;
+
+  // UponLeavingGTest() should be called immediately before Google Test calls
+  // user code. It saves some information about the current stack that
+  // CurrentStackTrace() will use to find and hide Google Test stack frames.
+  virtual void UponLeavingGTest() = 0;
+
+  // This string is inserted in place of stack frames that are part of
+  // Google Test's implementation.
+  static const char* const kElidedFramesMarker;
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(OsStackTraceGetterInterface);
+};
+
+// A working implementation of the OsStackTraceGetterInterface interface.
+class OsStackTraceGetter : public OsStackTraceGetterInterface {
+ public:
+  OsStackTraceGetter() {}
+
+  std::string CurrentStackTrace(int max_depth, int skip_count) override;
+  void UponLeavingGTest() override;
+
+ private:
+#if GTEST_HAS_ABSL
+  Mutex mutex_;  // Protects all internal state.
+
+  // We save the stack frame below the frame that calls user code.
+  // We do this because the address of the frame immediately below
+  // the user code changes between the call to UponLeavingGTest()
+  // and any calls to the stack trace code from within the user code.
+  void* caller_frame_ = nullptr;
+#endif  // GTEST_HAS_ABSL
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(OsStackTraceGetter);
+};
+
+// Information about a Google Test trace point.
+struct TraceInfo {
+  const char* file;
+  int line;
+  std::string message;
+};
+
+// This is the default global test part result reporter used in UnitTestImpl.
+// This class should only be used by UnitTestImpl.
+class DefaultGlobalTestPartResultReporter
+  : public TestPartResultReporterInterface {
+ public:
+  explicit DefaultGlobalTestPartResultReporter(UnitTestImpl* unit_test);
+  // Implements the TestPartResultReporterInterface. Reports the test part
+  // result in the current test.
+  void ReportTestPartResult(const TestPartResult& result) override;
+
+ private:
+  UnitTestImpl* const unit_test_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultGlobalTestPartResultReporter);
+};
+
+// This is the default per thread test part result reporter used in
+// UnitTestImpl. This class should only be used by UnitTestImpl.
+class DefaultPerThreadTestPartResultReporter
+    : public TestPartResultReporterInterface {
+ public:
+  explicit DefaultPerThreadTestPartResultReporter(UnitTestImpl* unit_test);
+  // Implements the TestPartResultReporterInterface. The implementation just
+  // delegates to the current global test part result reporter of *unit_test_.
+  void ReportTestPartResult(const TestPartResult& result) override;
+
+ private:
+  UnitTestImpl* const unit_test_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultPerThreadTestPartResultReporter);
+};
+
+// The private implementation of the UnitTest class.  We don't protect
+// the methods under a mutex, as this class is not accessible by a
+// user and the UnitTest class that delegates work to this class does
+// proper locking.
+class GTEST_API_ UnitTestImpl {
+ public:
+  explicit UnitTestImpl(UnitTest* parent);
+  virtual ~UnitTestImpl();
+
+  // There are two different ways to register your own TestPartResultReporter.
+  // You can register your own repoter to listen either only for test results
+  // from the current thread or for results from all threads.
+  // By default, each per-thread test result repoter just passes a new
+  // TestPartResult to the global test result reporter, which registers the
+  // test part result for the currently running test.
+
+  // Returns the global test part result reporter.
+  TestPartResultReporterInterface* GetGlobalTestPartResultReporter();
+
+  // Sets the global test part result reporter.
+  void SetGlobalTestPartResultReporter(
+      TestPartResultReporterInterface* reporter);
+
+  // Returns the test part result reporter for the current thread.
+  TestPartResultReporterInterface* GetTestPartResultReporterForCurrentThread();
+
+  // Sets the test part result reporter for the current thread.
+  void SetTestPartResultReporterForCurrentThread(
+      TestPartResultReporterInterface* reporter);
+
+  // Gets the number of successful test suites.
+  int successful_test_suite_count() const;
+
+  // Gets the number of failed test suites.
+  int failed_test_suite_count() const;
+
+  // Gets the number of all test suites.
+  int total_test_suite_count() const;
+
+  // Gets the number of all test suites that contain at least one test
+  // that should run.
+  int test_suite_to_run_count() const;
+
+  // Gets the number of successful tests.
+  int successful_test_count() const;
+
+  // Gets the number of skipped tests.
+  int skipped_test_count() const;
+
+  // Gets the number of failed tests.
+  int failed_test_count() const;
+
+  // Gets the number of disabled tests that will be reported in the XML report.
+  int reportable_disabled_test_count() const;
+
+  // Gets the number of disabled tests.
+  int disabled_test_count() const;
+
+  // Gets the number of tests to be printed in the XML report.
+  int reportable_test_count() const;
+
+  // Gets the number of all tests.
+  int total_test_count() const;
+
+  // Gets the number of tests that should run.
+  int test_to_run_count() const;
+
+  // Gets the time of the test program start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp() const { return start_timestamp_; }
+
+  // Gets the elapsed time, in milliseconds.
+  TimeInMillis elapsed_time() const { return elapsed_time_; }
+
+  // Returns true if and only if the unit test passed (i.e. all test suites
+  // passed).
+  bool Passed() const { return !Failed(); }
+
+  // Returns true if and only if the unit test failed (i.e. some test suite
+  // failed or something outside of all tests failed).
+  bool Failed() const {
+    return failed_test_suite_count() > 0 || ad_hoc_test_result()->Failed();
+  }
+
+  // Gets the i-th test suite among all the test suites. i can range from 0 to
+  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
+  const TestSuite* GetTestSuite(int i) const {
+    const int index = GetElementOr(test_suite_indices_, i, -1);
+    return index < 0 ? nullptr : test_suites_[static_cast<size_t>(i)];
+  }
+
+  //  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  const TestCase* GetTestCase(int i) const { return GetTestSuite(i); }
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Gets the i-th test suite among all the test suites. i can range from 0 to
+  // total_test_suite_count() - 1. If i is not in that range, returns NULL.
+  TestSuite* GetMutableSuiteCase(int i) {
+    const int index = GetElementOr(test_suite_indices_, i, -1);
+    return index < 0 ? nullptr : test_suites_[static_cast<size_t>(index)];
+  }
+
+  // Provides access to the event listener list.
+  TestEventListeners* listeners() { return &listeners_; }
+
+  // Returns the TestResult for the test that's currently running, or
+  // the TestResult for the ad hoc test if no test is running.
+  TestResult* current_test_result();
+
+  // Returns the TestResult for the ad hoc test.
+  const TestResult* ad_hoc_test_result() const { return &ad_hoc_test_result_; }
+
+  // Sets the OS stack trace getter.
+  //
+  // Does nothing if the input and the current OS stack trace getter
+  // are the same; otherwise, deletes the old getter and makes the
+  // input the current getter.
+  void set_os_stack_trace_getter(OsStackTraceGetterInterface* getter);
+
+  // Returns the current OS stack trace getter if it is not NULL;
+  // otherwise, creates an OsStackTraceGetter, makes it the current
+  // getter, and returns it.
+  OsStackTraceGetterInterface* os_stack_trace_getter();
+
+  // Returns the current OS stack trace as an std::string.
+  //
+  // The maximum number of stack frames to be included is specified by
+  // the gtest_stack_trace_depth flag.  The skip_count parameter
+  // specifies the number of top frames to be skipped, which doesn't
+  // count against the number of frames to be included.
+  //
+  // For example, if Foo() calls Bar(), which in turn calls
+  // CurrentOsStackTraceExceptTop(1), Foo() will be included in the
+  // trace but Bar() and CurrentOsStackTraceExceptTop() won't.
+  std::string CurrentOsStackTraceExceptTop(int skip_count) GTEST_NO_INLINE_;
+
+  // Finds and returns a TestSuite with the given name.  If one doesn't
+  // exist, creates one and returns it.
+  //
+  // Arguments:
+  //
+  //   test_suite_name: name of the test suite
+  //   type_param:     the name of the test's type parameter, or NULL if
+  //                   this is not a typed or a type-parameterized test.
+  //   set_up_tc:      pointer to the function that sets up the test suite
+  //   tear_down_tc:   pointer to the function that tears down the test suite
+  TestSuite* GetTestSuite(const char* test_suite_name, const char* type_param,
+                          internal::SetUpTestSuiteFunc set_up_tc,
+                          internal::TearDownTestSuiteFunc tear_down_tc);
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  TestCase* GetTestCase(const char* test_case_name, const char* type_param,
+                        internal::SetUpTestSuiteFunc set_up_tc,
+                        internal::TearDownTestSuiteFunc tear_down_tc) {
+    return GetTestSuite(test_case_name, type_param, set_up_tc, tear_down_tc);
+  }
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // Adds a TestInfo to the unit test.
+  //
+  // Arguments:
+  //
+  //   set_up_tc:    pointer to the function that sets up the test suite
+  //   tear_down_tc: pointer to the function that tears down the test suite
+  //   test_info:    the TestInfo object
+  void AddTestInfo(internal::SetUpTestSuiteFunc set_up_tc,
+                   internal::TearDownTestSuiteFunc tear_down_tc,
+                   TestInfo* test_info) {
+    // In order to support thread-safe death tests, we need to
+    // remember the original working directory when the test program
+    // was first invoked.  We cannot do this in RUN_ALL_TESTS(), as
+    // the user may have changed the current directory before calling
+    // RUN_ALL_TESTS().  Therefore we capture the current directory in
+    // AddTestInfo(), which is called to register a TEST or TEST_F
+    // before main() is reached.
+    if (original_working_dir_.IsEmpty()) {
+      original_working_dir_.Set(FilePath::GetCurrentDir());
+      GTEST_CHECK_(!original_working_dir_.IsEmpty())
+          << "Failed to get the current working directory.";
+    }
+
+    GetTestSuite(test_info->test_suite_name(), test_info->type_param(),
+                 set_up_tc, tear_down_tc)
+        ->AddTestInfo(test_info);
+  }
+
+  // Returns ParameterizedTestSuiteRegistry object used to keep track of
+  // value-parameterized tests and instantiate and register them.
+  internal::ParameterizedTestSuiteRegistry& parameterized_test_registry() {
+    return parameterized_test_registry_;
+  }
+
+  // Sets the TestSuite object for the test that's currently running.
+  void set_current_test_suite(TestSuite* a_current_test_suite) {
+    current_test_suite_ = a_current_test_suite;
+  }
+
+  // Sets the TestInfo object for the test that's currently running.  If
+  // current_test_info is NULL, the assertion results will be stored in
+  // ad_hoc_test_result_.
+  void set_current_test_info(TestInfo* a_current_test_info) {
+    current_test_info_ = a_current_test_info;
+  }
+
+  // Registers all parameterized tests defined using TEST_P and
+  // INSTANTIATE_TEST_SUITE_P, creating regular tests for each test/parameter
+  // combination. This method can be called more then once; it has guards
+  // protecting from registering the tests more then once.  If
+  // value-parameterized tests are disabled, RegisterParameterizedTests is
+  // present but does nothing.
+  void RegisterParameterizedTests();
+
+  // Runs all tests in this UnitTest object, prints the result, and
+  // returns true if all tests are successful.  If any exception is
+  // thrown during a test, this test is considered to be failed, but
+  // the rest of the tests will still be run.
+  bool RunAllTests();
+
+  // Clears the results of all tests, except the ad hoc tests.
+  void ClearNonAdHocTestResult() {
+    ForEach(test_suites_, TestSuite::ClearTestSuiteResult);
+  }
+
+  // Clears the results of ad-hoc test assertions.
+  void ClearAdHocTestResult() {
+    ad_hoc_test_result_.Clear();
+  }
+
+  // Adds a TestProperty to the current TestResult object when invoked in a
+  // context of a test or a test suite, or to the global property set. If the
+  // result already contains a property with the same key, the value will be
+  // updated.
+  void RecordProperty(const TestProperty& test_property);
+
+  enum ReactionToSharding {
+    HONOR_SHARDING_PROTOCOL,
+    IGNORE_SHARDING_PROTOCOL
+  };
+
+  // Matches the full name of each test against the user-specified
+  // filter to decide whether the test should run, then records the
+  // result in each TestSuite and TestInfo object.
+  // If shard_tests == HONOR_SHARDING_PROTOCOL, further filters tests
+  // based on sharding variables in the environment.
+  // Returns the number of tests that should run.
+  int FilterTests(ReactionToSharding shard_tests);
+
+  // Prints the names of the tests matching the user-specified filter flag.
+  void ListTestsMatchingFilter();
+
+  const TestSuite* current_test_suite() const { return current_test_suite_; }
+  TestInfo* current_test_info() { return current_test_info_; }
+  const TestInfo* current_test_info() const { return current_test_info_; }
+
+  // Returns the vector of environments that need to be set-up/torn-down
+  // before/after the tests are run.
+  std::vector<Environment*>& environments() { return environments_; }
+
+  // Getters for the per-thread Google Test trace stack.
+  std::vector<TraceInfo>& gtest_trace_stack() {
+    return *(gtest_trace_stack_.pointer());
+  }
+  const std::vector<TraceInfo>& gtest_trace_stack() const {
+    return gtest_trace_stack_.get();
+  }
+
+#if GTEST_HAS_DEATH_TEST
+  void InitDeathTestSubprocessControlInfo() {
+    internal_run_death_test_flag_.reset(ParseInternalRunDeathTestFlag());
+  }
+  // Returns a pointer to the parsed --gtest_internal_run_death_test
+  // flag, or NULL if that flag was not specified.
+  // This information is useful only in a death test child process.
+  // Must not be called before a call to InitGoogleTest.
+  const InternalRunDeathTestFlag* internal_run_death_test_flag() const {
+    return internal_run_death_test_flag_.get();
+  }
+
+  // Returns a pointer to the current death test factory.
+  internal::DeathTestFactory* death_test_factory() {
+    return death_test_factory_.get();
+  }
+
+  void SuppressTestEventsIfInSubprocess();
+
+  friend class ReplaceDeathTestFactory;
+#endif  // GTEST_HAS_DEATH_TEST
+
+  // Initializes the event listener performing XML output as specified by
+  // UnitTestOptions. Must not be called before InitGoogleTest.
+  void ConfigureXmlOutput();
+
+#if GTEST_CAN_STREAM_RESULTS_
+  // Initializes the event listener for streaming test results to a socket.
+  // Must not be called before InitGoogleTest.
+  void ConfigureStreamingOutput();
+#endif
+
+  // Performs initialization dependent upon flag values obtained in
+  // ParseGoogleTestFlagsOnly.  Is called from InitGoogleTest after the call to
+  // ParseGoogleTestFlagsOnly.  In case a user neglects to call InitGoogleTest
+  // this function is also called from RunAllTests.  Since this function can be
+  // called more than once, it has to be idempotent.
+  void PostFlagParsingInit();
+
+  // Gets the random seed used at the start of the current test iteration.
+  int random_seed() const { return random_seed_; }
+
+  // Gets the random number generator.
+  internal::Random* random() { return &random_; }
+
+  // Shuffles all test suites, and the tests within each test suite,
+  // making sure that death tests are still run first.
+  void ShuffleTests();
+
+  // Restores the test suites and tests to their order before the first shuffle.
+  void UnshuffleTests();
+
+  // Returns the value of GTEST_FLAG(catch_exceptions) at the moment
+  // UnitTest::Run() starts.
+  bool catch_exceptions() const { return catch_exceptions_; }
+
+ private:
+  friend class ::testing::UnitTest;
+
+  // Used by UnitTest::Run() to capture the state of
+  // GTEST_FLAG(catch_exceptions) at the moment it starts.
+  void set_catch_exceptions(bool value) { catch_exceptions_ = value; }
+
+  // The UnitTest object that owns this implementation object.
+  UnitTest* const parent_;
+
+  // The working directory when the first TEST() or TEST_F() was
+  // executed.
+  internal::FilePath original_working_dir_;
+
+  // The default test part result reporters.
+  DefaultGlobalTestPartResultReporter default_global_test_part_result_reporter_;
+  DefaultPerThreadTestPartResultReporter
+      default_per_thread_test_part_result_reporter_;
+
+  // Points to (but doesn't own) the global test part result reporter.
+  TestPartResultReporterInterface* global_test_part_result_repoter_;
+
+  // Protects read and write access to global_test_part_result_reporter_.
+  internal::Mutex global_test_part_result_reporter_mutex_;
+
+  // Points to (but doesn't own) the per-thread test part result reporter.
+  internal::ThreadLocal<TestPartResultReporterInterface*>
+      per_thread_test_part_result_reporter_;
+
+  // The vector of environments that need to be set-up/torn-down
+  // before/after the tests are run.
+  std::vector<Environment*> environments_;
+
+  // The vector of TestSuites in their original order.  It owns the
+  // elements in the vector.
+  std::vector<TestSuite*> test_suites_;
+
+  // Provides a level of indirection for the test suite list to allow
+  // easy shuffling and restoring the test suite order.  The i-th
+  // element of this vector is the index of the i-th test suite in the
+  // shuffled order.
+  std::vector<int> test_suite_indices_;
+
+  // ParameterizedTestRegistry object used to register value-parameterized
+  // tests.
+  internal::ParameterizedTestSuiteRegistry parameterized_test_registry_;
+
+  // Indicates whether RegisterParameterizedTests() has been called already.
+  bool parameterized_tests_registered_;
+
+  // Index of the last death test suite registered.  Initially -1.
+  int last_death_test_suite_;
+
+  // This points to the TestSuite for the currently running test.  It
+  // changes as Google Test goes through one test suite after another.
+  // When no test is running, this is set to NULL and Google Test
+  // stores assertion results in ad_hoc_test_result_.  Initially NULL.
+  TestSuite* current_test_suite_;
+
+  // This points to the TestInfo for the currently running test.  It
+  // changes as Google Test goes through one test after another.  When
+  // no test is running, this is set to NULL and Google Test stores
+  // assertion results in ad_hoc_test_result_.  Initially NULL.
+  TestInfo* current_test_info_;
+
+  // Normally, a user only writes assertions inside a TEST or TEST_F,
+  // or inside a function called by a TEST or TEST_F.  Since Google
+  // Test keeps track of which test is current running, it can
+  // associate such an assertion with the test it belongs to.
+  //
+  // If an assertion is encountered when no TEST or TEST_F is running,
+  // Google Test attributes the assertion result to an imaginary "ad hoc"
+  // test, and records the result in ad_hoc_test_result_.
+  TestResult ad_hoc_test_result_;
+
+  // The list of event listeners that can be used to track events inside
+  // Google Test.
+  TestEventListeners listeners_;
+
+  // The OS stack trace getter.  Will be deleted when the UnitTest
+  // object is destructed.  By default, an OsStackTraceGetter is used,
+  // but the user can set this field to use a custom getter if that is
+  // desired.
+  OsStackTraceGetterInterface* os_stack_trace_getter_;
+
+  // True if and only if PostFlagParsingInit() has been called.
+  bool post_flag_parse_init_performed_;
+
+  // The random number seed used at the beginning of the test run.
+  int random_seed_;
+
+  // Our random number generator.
+  internal::Random random_;
+
+  // The time of the test program start, in ms from the start of the
+  // UNIX epoch.
+  TimeInMillis start_timestamp_;
+
+  // How long the test took to run, in milliseconds.
+  TimeInMillis elapsed_time_;
+
+#if GTEST_HAS_DEATH_TEST
+  // The decomposed components of the gtest_internal_run_death_test flag,
+  // parsed when RUN_ALL_TESTS is called.
+  std::unique_ptr<InternalRunDeathTestFlag> internal_run_death_test_flag_;
+  std::unique_ptr<internal::DeathTestFactory> death_test_factory_;
+#endif  // GTEST_HAS_DEATH_TEST
+
+  // A per-thread stack of traces created by the SCOPED_TRACE() macro.
+  internal::ThreadLocal<std::vector<TraceInfo> > gtest_trace_stack_;
+
+  // The value of GTEST_FLAG(catch_exceptions) at the moment RunAllTests()
+  // starts.
+  bool catch_exceptions_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(UnitTestImpl);
+};  // class UnitTestImpl
+
+// Convenience function for accessing the global UnitTest
+// implementation object.
+inline UnitTestImpl* GetUnitTestImpl() {
+  return UnitTest::GetInstance()->impl();
+}
+
+#if GTEST_USES_SIMPLE_RE
+
+// Internal helper functions for implementing the simple regular
+// expression matcher.
+GTEST_API_ bool IsInSet(char ch, const char* str);
+GTEST_API_ bool IsAsciiDigit(char ch);
+GTEST_API_ bool IsAsciiPunct(char ch);
+GTEST_API_ bool IsRepeat(char ch);
+GTEST_API_ bool IsAsciiWhiteSpace(char ch);
+GTEST_API_ bool IsAsciiWordChar(char ch);
+GTEST_API_ bool IsValidEscape(char ch);
+GTEST_API_ bool AtomMatchesChar(bool escaped, char pattern, char ch);
+GTEST_API_ bool ValidateRegex(const char* regex);
+GTEST_API_ bool MatchRegexAtHead(const char* regex, const char* str);
+GTEST_API_ bool MatchRepetitionAndRegexAtHead(
+    bool escaped, char ch, char repeat, const char* regex, const char* str);
+GTEST_API_ bool MatchRegexAnywhere(const char* regex, const char* str);
+
+#endif  // GTEST_USES_SIMPLE_RE
+
+// Parses the command line for Google Test flags, without initializing
+// other parts of Google Test.
+GTEST_API_ void ParseGoogleTestFlagsOnly(int* argc, char** argv);
+GTEST_API_ void ParseGoogleTestFlagsOnly(int* argc, wchar_t** argv);
+
+#if GTEST_HAS_DEATH_TEST
+
+// Returns the message describing the last system error, regardless of the
+// platform.
+GTEST_API_ std::string GetLastErrnoDescription();
+
+// Attempts to parse a string into a positive integer pointed to by the
+// number parameter.  Returns true if that is possible.
+// GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we can use
+// it here.
+template <typename Integer>
+bool ParseNaturalNumber(const ::std::string& str, Integer* number) {
+  // Fail fast if the given string does not begin with a digit;
+  // this bypasses strtoXXX's "optional leading whitespace and plus
+  // or minus sign" semantics, which are undesirable here.
+  if (str.empty() || !IsDigit(str[0])) {
+    return false;
+  }
+  errno = 0;
+
+  char* end;
+  // BiggestConvertible is the largest integer type that system-provided
+  // string-to-number conversion routines can return.
+
+# if GTEST_OS_WINDOWS && !defined(__GNUC__)
+
+  // MSVC and C++ Builder define __int64 instead of the standard long long.
+  typedef unsigned __int64 BiggestConvertible;
+  const BiggestConvertible parsed = _strtoui64(str.c_str(), &end, 10);
+
+# else
+
+  typedef unsigned long long BiggestConvertible;  // NOLINT
+  const BiggestConvertible parsed = strtoull(str.c_str(), &end, 10);
+
+# endif  // GTEST_OS_WINDOWS && !defined(__GNUC__)
+
+  const bool parse_success = *end == '\0' && errno == 0;
+
+  GTEST_CHECK_(sizeof(Integer) <= sizeof(parsed));
+
+  const Integer result = static_cast<Integer>(parsed);
+  if (parse_success && static_cast<BiggestConvertible>(result) == parsed) {
+    *number = result;
+    return true;
+  }
+  return false;
+}
+#endif  // GTEST_HAS_DEATH_TEST
+
+// TestResult contains some private methods that should be hidden from
+// Google Test user but are required for testing. This class allow our tests
+// to access them.
+//
+// This class is supplied only for the purpose of testing Google Test's own
+// constructs. Do not use it in user tests, either directly or indirectly.
+class TestResultAccessor {
+ public:
+  static void RecordProperty(TestResult* test_result,
+                             const std::string& xml_element,
+                             const TestProperty& property) {
+    test_result->RecordProperty(xml_element, property);
+  }
+
+  static void ClearTestPartResults(TestResult* test_result) {
+    test_result->ClearTestPartResults();
+  }
+
+  static const std::vector<testing::TestPartResult>& test_part_results(
+      const TestResult& test_result) {
+    return test_result.test_part_results();
+  }
+};
+
+#if GTEST_CAN_STREAM_RESULTS_
+
+// Streams test results to the given port on the given host machine.
+class StreamingListener : public EmptyTestEventListener {
+ public:
+  // Abstract base class for writing strings to a socket.
+  class AbstractSocketWriter {
+   public:
+    virtual ~AbstractSocketWriter() {}
+
+    // Sends a string to the socket.
+    virtual void Send(const std::string& message) = 0;
+
+    // Closes the socket.
+    virtual void CloseConnection() {}
+
+    // Sends a string and a newline to the socket.
+    void SendLn(const std::string& message) { Send(message + "\n"); }
+  };
+
+  // Concrete class for actually writing strings to a socket.
+  class SocketWriter : public AbstractSocketWriter {
+   public:
+    SocketWriter(const std::string& host, const std::string& port)
+        : sockfd_(-1), host_name_(host), port_num_(port) {
+      MakeConnection();
+    }
+
+    ~SocketWriter() override {
+      if (sockfd_ != -1)
+        CloseConnection();
+    }
+
+    // Sends a string to the socket.
+    void Send(const std::string& message) override {
+      GTEST_CHECK_(sockfd_ != -1)
+          << "Send() can be called only when there is a connection.";
+
+      const auto len = static_cast<size_t>(message.length());
+      if (write(sockfd_, message.c_str(), len) != static_cast<ssize_t>(len)) {
+        GTEST_LOG_(WARNING)
+            << "stream_result_to: failed to stream to "
+            << host_name_ << ":" << port_num_;
+      }
+    }
+
+   private:
+    // Creates a client socket and connects to the server.
+    void MakeConnection();
+
+    // Closes the socket.
+    void CloseConnection() override {
+      GTEST_CHECK_(sockfd_ != -1)
+          << "CloseConnection() can be called only when there is a connection.";
+
+      close(sockfd_);
+      sockfd_ = -1;
+    }
+
+    int sockfd_;  // socket file descriptor
+    const std::string host_name_;
+    const std::string port_num_;
+
+    GTEST_DISALLOW_COPY_AND_ASSIGN_(SocketWriter);
+  };  // class SocketWriter
+
+  // Escapes '=', '&', '%', and '\n' characters in str as "%xx".
+  static std::string UrlEncode(const char* str);
+
+  StreamingListener(const std::string& host, const std::string& port)
+      : socket_writer_(new SocketWriter(host, port)) {
+    Start();
+  }
+
+  explicit StreamingListener(AbstractSocketWriter* socket_writer)
+      : socket_writer_(socket_writer) { Start(); }
+
+  void OnTestProgramStart(const UnitTest& /* unit_test */) override {
+    SendLn("event=TestProgramStart");
+  }
+
+  void OnTestProgramEnd(const UnitTest& unit_test) override {
+    // Note that Google Test current only report elapsed time for each
+    // test iteration, not for the entire test program.
+    SendLn("event=TestProgramEnd&passed=" + FormatBool(unit_test.Passed()));
+
+    // Notify the streaming server to stop.
+    socket_writer_->CloseConnection();
+  }
+
+  void OnTestIterationStart(const UnitTest& /* unit_test */,
+                            int iteration) override {
+    SendLn("event=TestIterationStart&iteration=" +
+           StreamableToString(iteration));
+  }
+
+  void OnTestIterationEnd(const UnitTest& unit_test,
+                          int /* iteration */) override {
+    SendLn("event=TestIterationEnd&passed=" +
+           FormatBool(unit_test.Passed()) + "&elapsed_time=" +
+           StreamableToString(unit_test.elapsed_time()) + "ms");
+  }
+
+  // Note that "event=TestCaseStart" is a wire format and has to remain
+  // "case" for compatibilty
+  void OnTestCaseStart(const TestCase& test_case) override {
+    SendLn(std::string("event=TestCaseStart&name=") + test_case.name());
+  }
+
+  // Note that "event=TestCaseEnd" is a wire format and has to remain
+  // "case" for compatibilty
+  void OnTestCaseEnd(const TestCase& test_case) override {
+    SendLn("event=TestCaseEnd&passed=" + FormatBool(test_case.Passed()) +
+           "&elapsed_time=" + StreamableToString(test_case.elapsed_time()) +
+           "ms");
+  }
+
+  void OnTestStart(const TestInfo& test_info) override {
+    SendLn(std::string("event=TestStart&name=") + test_info.name());
+  }
+
+  void OnTestEnd(const TestInfo& test_info) override {
+    SendLn("event=TestEnd&passed=" +
+           FormatBool((test_info.result())->Passed()) +
+           "&elapsed_time=" +
+           StreamableToString((test_info.result())->elapsed_time()) + "ms");
+  }
+
+  void OnTestPartResult(const TestPartResult& test_part_result) override {
+    const char* file_name = test_part_result.file_name();
+    if (file_name == nullptr) file_name = "";
+    SendLn("event=TestPartResult&file=" + UrlEncode(file_name) +
+           "&line=" + StreamableToString(test_part_result.line_number()) +
+           "&message=" + UrlEncode(test_part_result.message()));
+  }
+
+ private:
+  // Sends the given message and a newline to the socket.
+  void SendLn(const std::string& message) { socket_writer_->SendLn(message); }
+
+  // Called at the start of streaming to notify the receiver what
+  // protocol we are using.
+  void Start() { SendLn("gtest_streaming_protocol_version=1.0"); }
+
+  std::string FormatBool(bool value) { return value ? "1" : "0"; }
+
+  const std::unique_ptr<AbstractSocketWriter> socket_writer_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(StreamingListener);
+};  // class StreamingListener
+
+#endif  // GTEST_CAN_STREAM_RESULTS_
+
+}  // namespace internal
+}  // namespace testing
+
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
+#endif  // GTEST_SRC_GTEST_INTERNAL_INL_H_
diff --git a/3rdparty/gtest/src/gtest-matchers.cc b/3rdparty/gtest/src/gtest-matchers.cc
new file mode 100644
index 0000000..7d2fb68
--- /dev/null
+++ b/3rdparty/gtest/src/gtest-matchers.cc
@@ -0,0 +1,97 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This file implements just enough of the matcher interface to allow
+// EXPECT_DEATH and friends to accept a matcher argument.
+
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
+#include "gtest/gtest-matchers.h"
+
+#include <string>
+
+namespace testing {
+
+// Constructs a matcher that matches a const std::string& whose value is
+// equal to s.
+Matcher<const std::string&>::Matcher(const std::string& s) { *this = Eq(s); }
+
+// Constructs a matcher that matches a const std::string& whose value is
+// equal to s.
+Matcher<const std::string&>::Matcher(const char* s) {
+  *this = Eq(std::string(s));
+}
+
+// Constructs a matcher that matches a std::string whose value is equal to
+// s.
+Matcher<std::string>::Matcher(const std::string& s) { *this = Eq(s); }
+
+// Constructs a matcher that matches a std::string whose value is equal to
+// s.
+Matcher<std::string>::Matcher(const char* s) { *this = Eq(std::string(s)); }
+
+#if GTEST_HAS_ABSL
+// Constructs a matcher that matches a const absl::string_view& whose value is
+// equal to s.
+Matcher<const absl::string_view&>::Matcher(const std::string& s) {
+  *this = Eq(s);
+}
+
+// Constructs a matcher that matches a const absl::string_view& whose value is
+// equal to s.
+Matcher<const absl::string_view&>::Matcher(const char* s) {
+  *this = Eq(std::string(s));
+}
+
+// Constructs a matcher that matches a const absl::string_view& whose value is
+// equal to s.
+Matcher<const absl::string_view&>::Matcher(absl::string_view s) {
+  *this = Eq(std::string(s));
+}
+
+// Constructs a matcher that matches a absl::string_view whose value is equal to
+// s.
+Matcher<absl::string_view>::Matcher(const std::string& s) { *this = Eq(s); }
+
+// Constructs a matcher that matches a absl::string_view whose value is equal to
+// s.
+Matcher<absl::string_view>::Matcher(const char* s) {
+  *this = Eq(std::string(s));
+}
+
+// Constructs a matcher that matches a absl::string_view whose value is equal to
+// s.
+Matcher<absl::string_view>::Matcher(absl::string_view s) {
+  *this = Eq(std::string(s));
+}
+#endif  // GTEST_HAS_ABSL
+
+}  // namespace testing
diff --git a/3rdparty/gtest/src/gtest-port.cc b/3rdparty/gtest/src/gtest-port.cc
new file mode 100644
index 0000000..fc5ba6b
--- /dev/null
+++ b/3rdparty/gtest/src/gtest-port.cc
@@ -0,0 +1,1399 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include "gtest/internal/gtest-port.h"
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fstream>
+#include <memory>
+
+#if GTEST_OS_WINDOWS
+# include <windows.h>
+# include <io.h>
+# include <sys/stat.h>
+# include <map>  // Used in ThreadLocal.
+# ifdef _MSC_VER
+#  include <crtdbg.h>
+# endif  // _MSC_VER
+#else
+# include <unistd.h>
+#endif  // GTEST_OS_WINDOWS
+
+#if GTEST_OS_MAC
+# include <mach/mach_init.h>
+# include <mach/task.h>
+# include <mach/vm_map.h>
+#endif  // GTEST_OS_MAC
+
+#if GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD || \
+    GTEST_OS_NETBSD || GTEST_OS_OPENBSD
+# include <sys/sysctl.h>
+# if GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD
+#  include <sys/user.h>
+# endif
+#endif
+
+#if GTEST_OS_QNX
+# include <devctl.h>
+# include <fcntl.h>
+# include <sys/procfs.h>
+#endif  // GTEST_OS_QNX
+
+#if GTEST_OS_AIX
+# include <procinfo.h>
+# include <sys/types.h>
+#endif  // GTEST_OS_AIX
+
+#if GTEST_OS_FUCHSIA
+# include <zircon/process.h>
+# include <zircon/syscalls.h>
+#endif  // GTEST_OS_FUCHSIA
+
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest-message.h"
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-string.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+namespace internal {
+
+#if defined(_MSC_VER) || defined(__BORLANDC__)
+// MSVC and C++Builder do not provide a definition of STDERR_FILENO.
+const int kStdOutFileno = 1;
+const int kStdErrFileno = 2;
+#else
+const int kStdOutFileno = STDOUT_FILENO;
+const int kStdErrFileno = STDERR_FILENO;
+#endif  // _MSC_VER
+
+#if GTEST_OS_LINUX
+
+namespace {
+template <typename T>
+T ReadProcFileField(const std::string& filename, int field) {
+  std::string dummy;
+  std::ifstream file(filename.c_str());
+  while (field-- > 0) {
+    file >> dummy;
+  }
+  T output = 0;
+  file >> output;
+  return output;
+}
+}  // namespace
+
+// Returns the number of active threads, or 0 when there is an error.
+size_t GetThreadCount() {
+  const std::string filename =
+      (Message() << "/proc/" << getpid() << "/stat").GetString();
+  return ReadProcFileField<size_t>(filename, 19);
+}
+
+#elif GTEST_OS_MAC
+
+size_t GetThreadCount() {
+  const task_t task = mach_task_self();
+  mach_msg_type_number_t thread_count;
+  thread_act_array_t thread_list;
+  const kern_return_t status = task_threads(task, &thread_list, &thread_count);
+  if (status == KERN_SUCCESS) {
+    // task_threads allocates resources in thread_list and we need to free them
+    // to avoid leaks.
+    vm_deallocate(task,
+                  reinterpret_cast<vm_address_t>(thread_list),
+                  sizeof(thread_t) * thread_count);
+    return static_cast<size_t>(thread_count);
+  } else {
+    return 0;
+  }
+}
+
+#elif GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD || \
+      GTEST_OS_NETBSD
+
+#if GTEST_OS_NETBSD
+#undef KERN_PROC
+#define KERN_PROC KERN_PROC2
+#define kinfo_proc kinfo_proc2
+#endif
+
+#if GTEST_OS_DRAGONFLY
+#define KP_NLWP(kp) (kp.kp_nthreads)
+#elif GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD
+#define KP_NLWP(kp) (kp.ki_numthreads)
+#elif GTEST_OS_NETBSD
+#define KP_NLWP(kp) (kp.p_nlwps)
+#endif
+
+// Returns the number of threads running in the process, or 0 to indicate that
+// we cannot detect it.
+size_t GetThreadCount() {
+  int mib[] = {
+    CTL_KERN,
+    KERN_PROC,
+    KERN_PROC_PID,
+    getpid(),
+#if GTEST_OS_NETBSD
+    sizeof(struct kinfo_proc),
+    1,
+#endif
+  };
+  u_int miblen = sizeof(mib) / sizeof(mib[0]);
+  struct kinfo_proc info;
+  size_t size = sizeof(info);
+  if (sysctl(mib, miblen, &info, &size, NULL, 0)) {
+    return 0;
+  }
+  return static_cast<size_t>(KP_NLWP(info));
+}
+#elif GTEST_OS_OPENBSD
+
+// Returns the number of threads running in the process, or 0 to indicate that
+// we cannot detect it.
+size_t GetThreadCount() {
+  int mib[] = {
+    CTL_KERN,
+    KERN_PROC,
+    KERN_PROC_PID | KERN_PROC_SHOW_THREADS,
+    getpid(),
+    sizeof(struct kinfo_proc),
+    0,
+  };
+  u_int miblen = sizeof(mib) / sizeof(mib[0]);
+
+  // get number of structs
+  size_t size;
+  if (sysctl(mib, miblen, NULL, &size, NULL, 0)) {
+    return 0;
+  }
+  mib[5] = size / mib[4];
+
+  // populate array of structs
+  struct kinfo_proc info[mib[5]];
+  if (sysctl(mib, miblen, &info, &size, NULL, 0)) {
+    return 0;
+  }
+
+  // exclude empty members
+  int nthreads = 0;
+  for (int i = 0; i < size / mib[4]; i++) {
+    if (info[i].p_tid != -1)
+      nthreads++;
+  }
+  return nthreads;
+}
+
+#elif GTEST_OS_QNX
+
+// Returns the number of threads running in the process, or 0 to indicate that
+// we cannot detect it.
+size_t GetThreadCount() {
+  const int fd = open("/proc/self/as", O_RDONLY);
+  if (fd < 0) {
+    return 0;
+  }
+  procfs_info process_info;
+  const int status =
+      devctl(fd, DCMD_PROC_INFO, &process_info, sizeof(process_info), nullptr);
+  close(fd);
+  if (status == EOK) {
+    return static_cast<size_t>(process_info.num_threads);
+  } else {
+    return 0;
+  }
+}
+
+#elif GTEST_OS_AIX
+
+size_t GetThreadCount() {
+  struct procentry64 entry;
+  pid_t pid = getpid();
+  int status = getprocs64(&entry, sizeof(entry), nullptr, 0, &pid, 1);
+  if (status == 1) {
+    return entry.pi_thcount;
+  } else {
+    return 0;
+  }
+}
+
+#elif GTEST_OS_FUCHSIA
+
+size_t GetThreadCount() {
+  int dummy_buffer;
+  size_t avail;
+  zx_status_t status = zx_object_get_info(
+      zx_process_self(),
+      ZX_INFO_PROCESS_THREADS,
+      &dummy_buffer,
+      0,
+      nullptr,
+      &avail);
+  if (status == ZX_OK) {
+    return avail;
+  } else {
+    return 0;
+  }
+}
+
+#else
+
+size_t GetThreadCount() {
+  // There's no portable way to detect the number of threads, so we just
+  // return 0 to indicate that we cannot detect it.
+  return 0;
+}
+
+#endif  // GTEST_OS_LINUX
+
+#if GTEST_IS_THREADSAFE && GTEST_OS_WINDOWS
+
+void SleepMilliseconds(int n) {
+  ::Sleep(static_cast<DWORD>(n));
+}
+
+AutoHandle::AutoHandle()
+    : handle_(INVALID_HANDLE_VALUE) {}
+
+AutoHandle::AutoHandle(Handle handle)
+    : handle_(handle) {}
+
+AutoHandle::~AutoHandle() {
+  Reset();
+}
+
+AutoHandle::Handle AutoHandle::Get() const {
+  return handle_;
+}
+
+void AutoHandle::Reset() {
+  Reset(INVALID_HANDLE_VALUE);
+}
+
+void AutoHandle::Reset(HANDLE handle) {
+  // Resetting with the same handle we already own is invalid.
+  if (handle_ != handle) {
+    if (IsCloseable()) {
+      ::CloseHandle(handle_);
+    }
+    handle_ = handle;
+  } else {
+    GTEST_CHECK_(!IsCloseable())
+        << "Resetting a valid handle to itself is likely a programmer error "
+            "and thus not allowed.";
+  }
+}
+
+bool AutoHandle::IsCloseable() const {
+  // Different Windows APIs may use either of these values to represent an
+  // invalid handle.
+  return handle_ != nullptr && handle_ != INVALID_HANDLE_VALUE;
+}
+
+Notification::Notification()
+    : event_(::CreateEvent(nullptr,     // Default security attributes.
+                           TRUE,        // Do not reset automatically.
+                           FALSE,       // Initially unset.
+                           nullptr)) {  // Anonymous event.
+  GTEST_CHECK_(event_.Get() != nullptr);
+}
+
+void Notification::Notify() {
+  GTEST_CHECK_(::SetEvent(event_.Get()) != FALSE);
+}
+
+void Notification::WaitForNotification() {
+  GTEST_CHECK_(
+      ::WaitForSingleObject(event_.Get(), INFINITE) == WAIT_OBJECT_0);
+}
+
+Mutex::Mutex()
+    : owner_thread_id_(0),
+      type_(kDynamic),
+      critical_section_init_phase_(0),
+      critical_section_(new CRITICAL_SECTION) {
+  ::InitializeCriticalSection(critical_section_);
+}
+
+Mutex::~Mutex() {
+  // Static mutexes are leaked intentionally. It is not thread-safe to try
+  // to clean them up.
+  if (type_ == kDynamic) {
+    ::DeleteCriticalSection(critical_section_);
+    delete critical_section_;
+    critical_section_ = nullptr;
+  }
+}
+
+void Mutex::Lock() {
+  ThreadSafeLazyInit();
+  ::EnterCriticalSection(critical_section_);
+  owner_thread_id_ = ::GetCurrentThreadId();
+}
+
+void Mutex::Unlock() {
+  ThreadSafeLazyInit();
+  // We don't protect writing to owner_thread_id_ here, as it's the
+  // caller's responsibility to ensure that the current thread holds the
+  // mutex when this is called.
+  owner_thread_id_ = 0;
+  ::LeaveCriticalSection(critical_section_);
+}
+
+// Does nothing if the current thread holds the mutex. Otherwise, crashes
+// with high probability.
+void Mutex::AssertHeld() {
+  ThreadSafeLazyInit();
+  GTEST_CHECK_(owner_thread_id_ == ::GetCurrentThreadId())
+      << "The current thread is not holding the mutex @" << this;
+}
+
+namespace {
+
+#ifdef _MSC_VER
+// Use the RAII idiom to flag mem allocs that are intentionally never
+// deallocated. The motivation is to silence the false positive mem leaks
+// that are reported by the debug version of MS's CRT which can only detect
+// if an alloc is missing a matching deallocation.
+// Example:
+//    MemoryIsNotDeallocated memory_is_not_deallocated;
+//    critical_section_ = new CRITICAL_SECTION;
+//
+class MemoryIsNotDeallocated
+{
+ public:
+  MemoryIsNotDeallocated() : old_crtdbg_flag_(0) {
+    old_crtdbg_flag_ = _CrtSetDbgFlag(_CRTDBG_REPORT_FLAG);
+    // Set heap allocation block type to _IGNORE_BLOCK so that MS debug CRT
+    // doesn't report mem leak if there's no matching deallocation.
+    _CrtSetDbgFlag(old_crtdbg_flag_ & ~_CRTDBG_ALLOC_MEM_DF);
+  }
+
+  ~MemoryIsNotDeallocated() {
+    // Restore the original _CRTDBG_ALLOC_MEM_DF flag
+    _CrtSetDbgFlag(old_crtdbg_flag_);
+  }
+
+ private:
+  int old_crtdbg_flag_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(MemoryIsNotDeallocated);
+};
+#endif  // _MSC_VER
+
+}  // namespace
+
+// Initializes owner_thread_id_ and critical_section_ in static mutexes.
+void Mutex::ThreadSafeLazyInit() {
+  // Dynamic mutexes are initialized in the constructor.
+  if (type_ == kStatic) {
+    switch (
+        ::InterlockedCompareExchange(&critical_section_init_phase_, 1L, 0L)) {
+      case 0:
+        // If critical_section_init_phase_ was 0 before the exchange, we
+        // are the first to test it and need to perform the initialization.
+        owner_thread_id_ = 0;
+        {
+          // Use RAII to flag that following mem alloc is never deallocated.
+#ifdef _MSC_VER
+          MemoryIsNotDeallocated memory_is_not_deallocated;
+#endif  // _MSC_VER
+          critical_section_ = new CRITICAL_SECTION;
+        }
+        ::InitializeCriticalSection(critical_section_);
+        // Updates the critical_section_init_phase_ to 2 to signal
+        // initialization complete.
+        GTEST_CHECK_(::InterlockedCompareExchange(
+                          &critical_section_init_phase_, 2L, 1L) ==
+                      1L);
+        break;
+      case 1:
+        // Somebody else is already initializing the mutex; spin until they
+        // are done.
+        while (::InterlockedCompareExchange(&critical_section_init_phase_,
+                                            2L,
+                                            2L) != 2L) {
+          // Possibly yields the rest of the thread's time slice to other
+          // threads.
+          ::Sleep(0);
+        }
+        break;
+
+      case 2:
+        break;  // The mutex is already initialized and ready for use.
+
+      default:
+        GTEST_CHECK_(false)
+            << "Unexpected value of critical_section_init_phase_ "
+            << "while initializing a static mutex.";
+    }
+  }
+}
+
+namespace {
+
+class ThreadWithParamSupport : public ThreadWithParamBase {
+ public:
+  static HANDLE CreateThread(Runnable* runnable,
+                             Notification* thread_can_start) {
+    ThreadMainParam* param = new ThreadMainParam(runnable, thread_can_start);
+    DWORD thread_id;
+    HANDLE thread_handle = ::CreateThread(
+        nullptr,  // Default security.
+        0,        // Default stack size.
+        &ThreadWithParamSupport::ThreadMain,
+        param,        // Parameter to ThreadMainStatic
+        0x0,          // Default creation flags.
+        &thread_id);  // Need a valid pointer for the call to work under Win98.
+    GTEST_CHECK_(thread_handle != nullptr)
+        << "CreateThread failed with error " << ::GetLastError() << ".";
+    if (thread_handle == nullptr) {
+      delete param;
+    }
+    return thread_handle;
+  }
+
+ private:
+  struct ThreadMainParam {
+    ThreadMainParam(Runnable* runnable, Notification* thread_can_start)
+        : runnable_(runnable),
+          thread_can_start_(thread_can_start) {
+    }
+    std::unique_ptr<Runnable> runnable_;
+    // Does not own.
+    Notification* thread_can_start_;
+  };
+
+  static DWORD WINAPI ThreadMain(void* ptr) {
+    // Transfers ownership.
+    std::unique_ptr<ThreadMainParam> param(static_cast<ThreadMainParam*>(ptr));
+    if (param->thread_can_start_ != nullptr)
+      param->thread_can_start_->WaitForNotification();
+    param->runnable_->Run();
+    return 0;
+  }
+
+  // Prohibit instantiation.
+  ThreadWithParamSupport();
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParamSupport);
+};
+
+}  // namespace
+
+ThreadWithParamBase::ThreadWithParamBase(Runnable *runnable,
+                                         Notification* thread_can_start)
+      : thread_(ThreadWithParamSupport::CreateThread(runnable,
+                                                     thread_can_start)) {
+}
+
+ThreadWithParamBase::~ThreadWithParamBase() {
+  Join();
+}
+
+void ThreadWithParamBase::Join() {
+  GTEST_CHECK_(::WaitForSingleObject(thread_.Get(), INFINITE) == WAIT_OBJECT_0)
+      << "Failed to join the thread with error " << ::GetLastError() << ".";
+}
+
+// Maps a thread to a set of ThreadIdToThreadLocals that have values
+// instantiated on that thread and notifies them when the thread exits.  A
+// ThreadLocal instance is expected to persist until all threads it has
+// values on have terminated.
+class ThreadLocalRegistryImpl {
+ public:
+  // Registers thread_local_instance as having value on the current thread.
+  // Returns a value that can be used to identify the thread from other threads.
+  static ThreadLocalValueHolderBase* GetValueOnCurrentThread(
+      const ThreadLocalBase* thread_local_instance) {
+    DWORD current_thread = ::GetCurrentThreadId();
+    MutexLock lock(&mutex_);
+    ThreadIdToThreadLocals* const thread_to_thread_locals =
+        GetThreadLocalsMapLocked();
+    ThreadIdToThreadLocals::iterator thread_local_pos =
+        thread_to_thread_locals->find(current_thread);
+    if (thread_local_pos == thread_to_thread_locals->end()) {
+      thread_local_pos = thread_to_thread_locals->insert(
+          std::make_pair(current_thread, ThreadLocalValues())).first;
+      StartWatcherThreadFor(current_thread);
+    }
+    ThreadLocalValues& thread_local_values = thread_local_pos->second;
+    ThreadLocalValues::iterator value_pos =
+        thread_local_values.find(thread_local_instance);
+    if (value_pos == thread_local_values.end()) {
+      value_pos =
+          thread_local_values
+              .insert(std::make_pair(
+                  thread_local_instance,
+                  std::shared_ptr<ThreadLocalValueHolderBase>(
+                      thread_local_instance->NewValueForCurrentThread())))
+              .first;
+    }
+    return value_pos->second.get();
+  }
+
+  static void OnThreadLocalDestroyed(
+      const ThreadLocalBase* thread_local_instance) {
+    std::vector<std::shared_ptr<ThreadLocalValueHolderBase> > value_holders;
+    // Clean up the ThreadLocalValues data structure while holding the lock, but
+    // defer the destruction of the ThreadLocalValueHolderBases.
+    {
+      MutexLock lock(&mutex_);
+      ThreadIdToThreadLocals* const thread_to_thread_locals =
+          GetThreadLocalsMapLocked();
+      for (ThreadIdToThreadLocals::iterator it =
+          thread_to_thread_locals->begin();
+          it != thread_to_thread_locals->end();
+          ++it) {
+        ThreadLocalValues& thread_local_values = it->second;
+        ThreadLocalValues::iterator value_pos =
+            thread_local_values.find(thread_local_instance);
+        if (value_pos != thread_local_values.end()) {
+          value_holders.push_back(value_pos->second);
+          thread_local_values.erase(value_pos);
+          // This 'if' can only be successful at most once, so theoretically we
+          // could break out of the loop here, but we don't bother doing so.
+        }
+      }
+    }
+    // Outside the lock, let the destructor for 'value_holders' deallocate the
+    // ThreadLocalValueHolderBases.
+  }
+
+  static void OnThreadExit(DWORD thread_id) {
+    GTEST_CHECK_(thread_id != 0) << ::GetLastError();
+    std::vector<std::shared_ptr<ThreadLocalValueHolderBase> > value_holders;
+    // Clean up the ThreadIdToThreadLocals data structure while holding the
+    // lock, but defer the destruction of the ThreadLocalValueHolderBases.
+    {
+      MutexLock lock(&mutex_);
+      ThreadIdToThreadLocals* const thread_to_thread_locals =
+          GetThreadLocalsMapLocked();
+      ThreadIdToThreadLocals::iterator thread_local_pos =
+          thread_to_thread_locals->find(thread_id);
+      if (thread_local_pos != thread_to_thread_locals->end()) {
+        ThreadLocalValues& thread_local_values = thread_local_pos->second;
+        for (ThreadLocalValues::iterator value_pos =
+            thread_local_values.begin();
+            value_pos != thread_local_values.end();
+            ++value_pos) {
+          value_holders.push_back(value_pos->second);
+        }
+        thread_to_thread_locals->erase(thread_local_pos);
+      }
+    }
+    // Outside the lock, let the destructor for 'value_holders' deallocate the
+    // ThreadLocalValueHolderBases.
+  }
+
+ private:
+  // In a particular thread, maps a ThreadLocal object to its value.
+  typedef std::map<const ThreadLocalBase*,
+                   std::shared_ptr<ThreadLocalValueHolderBase> >
+      ThreadLocalValues;
+  // Stores all ThreadIdToThreadLocals having values in a thread, indexed by
+  // thread's ID.
+  typedef std::map<DWORD, ThreadLocalValues> ThreadIdToThreadLocals;
+
+  // Holds the thread id and thread handle that we pass from
+  // StartWatcherThreadFor to WatcherThreadFunc.
+  typedef std::pair<DWORD, HANDLE> ThreadIdAndHandle;
+
+  static void StartWatcherThreadFor(DWORD thread_id) {
+    // The returned handle will be kept in thread_map and closed by
+    // watcher_thread in WatcherThreadFunc.
+    HANDLE thread = ::OpenThread(SYNCHRONIZE | THREAD_QUERY_INFORMATION,
+                                 FALSE,
+                                 thread_id);
+    GTEST_CHECK_(thread != nullptr);
+    // We need to pass a valid thread ID pointer into CreateThread for it
+    // to work correctly under Win98.
+    DWORD watcher_thread_id;
+    HANDLE watcher_thread = ::CreateThread(
+        nullptr,  // Default security.
+        0,        // Default stack size
+        &ThreadLocalRegistryImpl::WatcherThreadFunc,
+        reinterpret_cast<LPVOID>(new ThreadIdAndHandle(thread_id, thread)),
+        CREATE_SUSPENDED, &watcher_thread_id);
+    GTEST_CHECK_(watcher_thread != nullptr);
+    // Give the watcher thread the same priority as ours to avoid being
+    // blocked by it.
+    ::SetThreadPriority(watcher_thread,
+                        ::GetThreadPriority(::GetCurrentThread()));
+    ::ResumeThread(watcher_thread);
+    ::CloseHandle(watcher_thread);
+  }
+
+  // Monitors exit from a given thread and notifies those
+  // ThreadIdToThreadLocals about thread termination.
+  static DWORD WINAPI WatcherThreadFunc(LPVOID param) {
+    const ThreadIdAndHandle* tah =
+        reinterpret_cast<const ThreadIdAndHandle*>(param);
+    GTEST_CHECK_(
+        ::WaitForSingleObject(tah->second, INFINITE) == WAIT_OBJECT_0);
+    OnThreadExit(tah->first);
+    ::CloseHandle(tah->second);
+    delete tah;
+    return 0;
+  }
+
+  // Returns map of thread local instances.
+  static ThreadIdToThreadLocals* GetThreadLocalsMapLocked() {
+    mutex_.AssertHeld();
+#ifdef _MSC_VER
+    MemoryIsNotDeallocated memory_is_not_deallocated;
+#endif  // _MSC_VER
+    static ThreadIdToThreadLocals* map = new ThreadIdToThreadLocals();
+    return map;
+  }
+
+  // Protects access to GetThreadLocalsMapLocked() and its return value.
+  static Mutex mutex_;
+  // Protects access to GetThreadMapLocked() and its return value.
+  static Mutex thread_map_mutex_;
+};
+
+Mutex ThreadLocalRegistryImpl::mutex_(Mutex::kStaticMutex);
+Mutex ThreadLocalRegistryImpl::thread_map_mutex_(Mutex::kStaticMutex);
+
+ThreadLocalValueHolderBase* ThreadLocalRegistry::GetValueOnCurrentThread(
+      const ThreadLocalBase* thread_local_instance) {
+  return ThreadLocalRegistryImpl::GetValueOnCurrentThread(
+      thread_local_instance);
+}
+
+void ThreadLocalRegistry::OnThreadLocalDestroyed(
+      const ThreadLocalBase* thread_local_instance) {
+  ThreadLocalRegistryImpl::OnThreadLocalDestroyed(thread_local_instance);
+}
+
+#endif  // GTEST_IS_THREADSAFE && GTEST_OS_WINDOWS
+
+#if GTEST_USES_POSIX_RE
+
+// Implements RE.  Currently only needed for death tests.
+
+RE::~RE() {
+  if (is_valid_) {
+    // regfree'ing an invalid regex might crash because the content
+    // of the regex is undefined. Since the regex's are essentially
+    // the same, one cannot be valid (or invalid) without the other
+    // being so too.
+    regfree(&partial_regex_);
+    regfree(&full_regex_);
+  }
+  free(const_cast<char*>(pattern_));
+}
+
+// Returns true if and only if regular expression re matches the entire str.
+bool RE::FullMatch(const char* str, const RE& re) {
+  if (!re.is_valid_) return false;
+
+  regmatch_t match;
+  return regexec(&re.full_regex_, str, 1, &match, 0) == 0;
+}
+
+// Returns true if and only if regular expression re matches a substring of
+// str (including str itself).
+bool RE::PartialMatch(const char* str, const RE& re) {
+  if (!re.is_valid_) return false;
+
+  regmatch_t match;
+  return regexec(&re.partial_regex_, str, 1, &match, 0) == 0;
+}
+
+// Initializes an RE from its string representation.
+void RE::Init(const char* regex) {
+  pattern_ = posix::StrDup(regex);
+
+  // Reserves enough bytes to hold the regular expression used for a
+  // full match.
+  const size_t full_regex_len = strlen(regex) + 10;
+  char* const full_pattern = new char[full_regex_len];
+
+  snprintf(full_pattern, full_regex_len, "^(%s)$", regex);
+  is_valid_ = regcomp(&full_regex_, full_pattern, REG_EXTENDED) == 0;
+  // We want to call regcomp(&partial_regex_, ...) even if the
+  // previous expression returns false.  Otherwise partial_regex_ may
+  // not be properly initialized can may cause trouble when it's
+  // freed.
+  //
+  // Some implementation of POSIX regex (e.g. on at least some
+  // versions of Cygwin) doesn't accept the empty string as a valid
+  // regex.  We change it to an equivalent form "()" to be safe.
+  if (is_valid_) {
+    const char* const partial_regex = (*regex == '\0') ? "()" : regex;
+    is_valid_ = regcomp(&partial_regex_, partial_regex, REG_EXTENDED) == 0;
+  }
+  EXPECT_TRUE(is_valid_)
+      << "Regular expression \"" << regex
+      << "\" is not a valid POSIX Extended regular expression.";
+
+  delete[] full_pattern;
+}
+
+#elif GTEST_USES_SIMPLE_RE
+
+// Returns true if and only if ch appears anywhere in str (excluding the
+// terminating '\0' character).
+bool IsInSet(char ch, const char* str) {
+  return ch != '\0' && strchr(str, ch) != nullptr;
+}
+
+// Returns true if and only if ch belongs to the given classification.
+// Unlike similar functions in <ctype.h>, these aren't affected by the
+// current locale.
+bool IsAsciiDigit(char ch) { return '0' <= ch && ch <= '9'; }
+bool IsAsciiPunct(char ch) {
+  return IsInSet(ch, "^-!\"#$%&'()*+,./:;<=>?@[\\]_`{|}~");
+}
+bool IsRepeat(char ch) { return IsInSet(ch, "?*+"); }
+bool IsAsciiWhiteSpace(char ch) { return IsInSet(ch, " \f\n\r\t\v"); }
+bool IsAsciiWordChar(char ch) {
+  return ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') ||
+      ('0' <= ch && ch <= '9') || ch == '_';
+}
+
+// Returns true if and only if "\\c" is a supported escape sequence.
+bool IsValidEscape(char c) {
+  return (IsAsciiPunct(c) || IsInSet(c, "dDfnrsStvwW"));
+}
+
+// Returns true if and only if the given atom (specified by escaped and
+// pattern) matches ch.  The result is undefined if the atom is invalid.
+bool AtomMatchesChar(bool escaped, char pattern_char, char ch) {
+  if (escaped) {  // "\\p" where p is pattern_char.
+    switch (pattern_char) {
+      case 'd': return IsAsciiDigit(ch);
+      case 'D': return !IsAsciiDigit(ch);
+      case 'f': return ch == '\f';
+      case 'n': return ch == '\n';
+      case 'r': return ch == '\r';
+      case 's': return IsAsciiWhiteSpace(ch);
+      case 'S': return !IsAsciiWhiteSpace(ch);
+      case 't': return ch == '\t';
+      case 'v': return ch == '\v';
+      case 'w': return IsAsciiWordChar(ch);
+      case 'W': return !IsAsciiWordChar(ch);
+    }
+    return IsAsciiPunct(pattern_char) && pattern_char == ch;
+  }
+
+  return (pattern_char == '.' && ch != '\n') || pattern_char == ch;
+}
+
+// Helper function used by ValidateRegex() to format error messages.
+static std::string FormatRegexSyntaxError(const char* regex, int index) {
+  return (Message() << "Syntax error at index " << index
+          << " in simple regular expression \"" << regex << "\": ").GetString();
+}
+
+// Generates non-fatal failures and returns false if regex is invalid;
+// otherwise returns true.
+bool ValidateRegex(const char* regex) {
+  if (regex == nullptr) {
+    ADD_FAILURE() << "NULL is not a valid simple regular expression.";
+    return false;
+  }
+
+  bool is_valid = true;
+
+  // True if and only if ?, *, or + can follow the previous atom.
+  bool prev_repeatable = false;
+  for (int i = 0; regex[i]; i++) {
+    if (regex[i] == '\\') {  // An escape sequence
+      i++;
+      if (regex[i] == '\0') {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
+                      << "'\\' cannot appear at the end.";
+        return false;
+      }
+
+      if (!IsValidEscape(regex[i])) {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i - 1)
+                      << "invalid escape sequence \"\\" << regex[i] << "\".";
+        is_valid = false;
+      }
+      prev_repeatable = true;
+    } else {  // Not an escape sequence.
+      const char ch = regex[i];
+
+      if (ch == '^' && i > 0) {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
+                      << "'^' can only appear at the beginning.";
+        is_valid = false;
+      } else if (ch == '$' && regex[i + 1] != '\0') {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
+                      << "'$' can only appear at the end.";
+        is_valid = false;
+      } else if (IsInSet(ch, "()[]{}|")) {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
+                      << "'" << ch << "' is unsupported.";
+        is_valid = false;
+      } else if (IsRepeat(ch) && !prev_repeatable) {
+        ADD_FAILURE() << FormatRegexSyntaxError(regex, i)
+                      << "'" << ch << "' can only follow a repeatable token.";
+        is_valid = false;
+      }
+
+      prev_repeatable = !IsInSet(ch, "^$?*+");
+    }
+  }
+
+  return is_valid;
+}
+
+// Matches a repeated regex atom followed by a valid simple regular
+// expression.  The regex atom is defined as c if escaped is false,
+// or \c otherwise.  repeat is the repetition meta character (?, *,
+// or +).  The behavior is undefined if str contains too many
+// characters to be indexable by size_t, in which case the test will
+// probably time out anyway.  We are fine with this limitation as
+// std::string has it too.
+bool MatchRepetitionAndRegexAtHead(
+    bool escaped, char c, char repeat, const char* regex,
+    const char* str) {
+  const size_t min_count = (repeat == '+') ? 1 : 0;
+  const size_t max_count = (repeat == '?') ? 1 :
+      static_cast<size_t>(-1) - 1;
+  // We cannot call numeric_limits::max() as it conflicts with the
+  // max() macro on Windows.
+
+  for (size_t i = 0; i <= max_count; ++i) {
+    // We know that the atom matches each of the first i characters in str.
+    if (i >= min_count && MatchRegexAtHead(regex, str + i)) {
+      // We have enough matches at the head, and the tail matches too.
+      // Since we only care about *whether* the pattern matches str
+      // (as opposed to *how* it matches), there is no need to find a
+      // greedy match.
+      return true;
+    }
+    if (str[i] == '\0' || !AtomMatchesChar(escaped, c, str[i]))
+      return false;
+  }
+  return false;
+}
+
+// Returns true if and only if regex matches a prefix of str. regex must
+// be a valid simple regular expression and not start with "^", or the
+// result is undefined.
+bool MatchRegexAtHead(const char* regex, const char* str) {
+  if (*regex == '\0')  // An empty regex matches a prefix of anything.
+    return true;
+
+  // "$" only matches the end of a string.  Note that regex being
+  // valid guarantees that there's nothing after "$" in it.
+  if (*regex == '$')
+    return *str == '\0';
+
+  // Is the first thing in regex an escape sequence?
+  const bool escaped = *regex == '\\';
+  if (escaped)
+    ++regex;
+  if (IsRepeat(regex[1])) {
+    // MatchRepetitionAndRegexAtHead() calls MatchRegexAtHead(), so
+    // here's an indirect recursion.  It terminates as the regex gets
+    // shorter in each recursion.
+    return MatchRepetitionAndRegexAtHead(
+        escaped, regex[0], regex[1], regex + 2, str);
+  } else {
+    // regex isn't empty, isn't "$", and doesn't start with a
+    // repetition.  We match the first atom of regex with the first
+    // character of str and recurse.
+    return (*str != '\0') && AtomMatchesChar(escaped, *regex, *str) &&
+        MatchRegexAtHead(regex + 1, str + 1);
+  }
+}
+
+// Returns true if and only if regex matches any substring of str.  regex must
+// be a valid simple regular expression, or the result is undefined.
+//
+// The algorithm is recursive, but the recursion depth doesn't exceed
+// the regex length, so we won't need to worry about running out of
+// stack space normally.  In rare cases the time complexity can be
+// exponential with respect to the regex length + the string length,
+// but usually it's must faster (often close to linear).
+bool MatchRegexAnywhere(const char* regex, const char* str) {
+  if (regex == nullptr || str == nullptr) return false;
+
+  if (*regex == '^')
+    return MatchRegexAtHead(regex + 1, str);
+
+  // A successful match can be anywhere in str.
+  do {
+    if (MatchRegexAtHead(regex, str))
+      return true;
+  } while (*str++ != '\0');
+  return false;
+}
+
+// Implements the RE class.
+
+RE::~RE() {
+  free(const_cast<char*>(pattern_));
+  free(const_cast<char*>(full_pattern_));
+}
+
+// Returns true if and only if regular expression re matches the entire str.
+bool RE::FullMatch(const char* str, const RE& re) {
+  return re.is_valid_ && MatchRegexAnywhere(re.full_pattern_, str);
+}
+
+// Returns true if and only if regular expression re matches a substring of
+// str (including str itself).
+bool RE::PartialMatch(const char* str, const RE& re) {
+  return re.is_valid_ && MatchRegexAnywhere(re.pattern_, str);
+}
+
+// Initializes an RE from its string representation.
+void RE::Init(const char* regex) {
+  pattern_ = full_pattern_ = nullptr;
+  if (regex != nullptr) {
+    pattern_ = posix::StrDup(regex);
+  }
+
+  is_valid_ = ValidateRegex(regex);
+  if (!is_valid_) {
+    // No need to calculate the full pattern when the regex is invalid.
+    return;
+  }
+
+  const size_t len = strlen(regex);
+  // Reserves enough bytes to hold the regular expression used for a
+  // full match: we need space to prepend a '^', append a '$', and
+  // terminate the string with '\0'.
+  char* buffer = static_cast<char*>(malloc(len + 3));
+  full_pattern_ = buffer;
+
+  if (*regex != '^')
+    *buffer++ = '^';  // Makes sure full_pattern_ starts with '^'.
+
+  // We don't use snprintf or strncpy, as they trigger a warning when
+  // compiled with VC++ 8.0.
+  memcpy(buffer, regex, len);
+  buffer += len;
+
+  if (len == 0 || regex[len - 1] != '$')
+    *buffer++ = '$';  // Makes sure full_pattern_ ends with '$'.
+
+  *buffer = '\0';
+}
+
+#endif  // GTEST_USES_POSIX_RE
+
+const char kUnknownFile[] = "unknown file";
+
+// Formats a source file path and a line number as they would appear
+// in an error message from the compiler used to compile this code.
+GTEST_API_ ::std::string FormatFileLocation(const char* file, int line) {
+  const std::string file_name(file == nullptr ? kUnknownFile : file);
+
+  if (line < 0) {
+    return file_name + ":";
+  }
+#ifdef _MSC_VER
+  return file_name + "(" + StreamableToString(line) + "):";
+#else
+  return file_name + ":" + StreamableToString(line) + ":";
+#endif  // _MSC_VER
+}
+
+// Formats a file location for compiler-independent XML output.
+// Although this function is not platform dependent, we put it next to
+// FormatFileLocation in order to contrast the two functions.
+// Note that FormatCompilerIndependentFileLocation() does NOT append colon
+// to the file location it produces, unlike FormatFileLocation().
+GTEST_API_ ::std::string FormatCompilerIndependentFileLocation(
+    const char* file, int line) {
+  const std::string file_name(file == nullptr ? kUnknownFile : file);
+
+  if (line < 0)
+    return file_name;
+  else
+    return file_name + ":" + StreamableToString(line);
+}
+
+GTestLog::GTestLog(GTestLogSeverity severity, const char* file, int line)
+    : severity_(severity) {
+  const char* const marker =
+      severity == GTEST_INFO ?    "[  INFO ]" :
+      severity == GTEST_WARNING ? "[WARNING]" :
+      severity == GTEST_ERROR ?   "[ ERROR ]" : "[ FATAL ]";
+  GetStream() << ::std::endl << marker << " "
+              << FormatFileLocation(file, line).c_str() << ": ";
+}
+
+// Flushes the buffers and, if severity is GTEST_FATAL, aborts the program.
+GTestLog::~GTestLog() {
+  GetStream() << ::std::endl;
+  if (severity_ == GTEST_FATAL) {
+    fflush(stderr);
+    posix::Abort();
+  }
+}
+
+// Disable Microsoft deprecation warnings for POSIX functions called from
+// this class (creat, dup, dup2, and close)
+GTEST_DISABLE_MSC_DEPRECATED_PUSH_()
+
+#if GTEST_HAS_STREAM_REDIRECTION
+
+// Object that captures an output stream (stdout/stderr).
+class CapturedStream {
+ public:
+  // The ctor redirects the stream to a temporary file.
+  explicit CapturedStream(int fd) : fd_(fd), uncaptured_fd_(dup(fd)) {
+# if GTEST_OS_WINDOWS
+    char temp_dir_path[MAX_PATH + 1] = { '\0' };  // NOLINT
+    char temp_file_path[MAX_PATH + 1] = { '\0' };  // NOLINT
+
+    ::GetTempPathA(sizeof(temp_dir_path), temp_dir_path);
+    const UINT success = ::GetTempFileNameA(temp_dir_path,
+                                            "gtest_redir",
+                                            0,  // Generate unique file name.
+                                            temp_file_path);
+    GTEST_CHECK_(success != 0)
+        << "Unable to create a temporary file in " << temp_dir_path;
+    const int captured_fd = creat(temp_file_path, _S_IREAD | _S_IWRITE);
+    GTEST_CHECK_(captured_fd != -1) << "Unable to open temporary file "
+                                    << temp_file_path;
+    filename_ = temp_file_path;
+# else
+    // There's no guarantee that a test has write access to the current
+    // directory, so we create the temporary file in the /tmp directory
+    // instead. We use /tmp on most systems, and /sdcard on Android.
+    // That's because Android doesn't have /tmp.
+#  if GTEST_OS_LINUX_ANDROID
+    // Note: Android applications are expected to call the framework's
+    // Context.getExternalStorageDirectory() method through JNI to get
+    // the location of the world-writable SD Card directory. However,
+    // this requires a Context handle, which cannot be retrieved
+    // globally from native code. Doing so also precludes running the
+    // code as part of a regular standalone executable, which doesn't
+    // run in a Dalvik process (e.g. when running it through 'adb shell').
+    //
+    // The location /data/local/tmp is directly accessible from native code.
+    // '/sdcard' and other variants cannot be relied on, as they are not
+    // guaranteed to be mounted, or may have a delay in mounting.
+    char name_template[] = "/data/local/tmp/gtest_captured_stream.XXXXXX";
+#  else
+    char name_template[] = "/tmp/captured_stream.XXXXXX";
+#  endif  // GTEST_OS_LINUX_ANDROID
+    const int captured_fd = mkstemp(name_template);
+    if (captured_fd == -1) {
+      GTEST_LOG_(WARNING)
+          << "Failed to create tmp file " << name_template
+          << " for test; does the test have access to the /tmp directory?";
+    }
+    filename_ = name_template;
+# endif  // GTEST_OS_WINDOWS
+    fflush(nullptr);
+    dup2(captured_fd, fd_);
+    close(captured_fd);
+  }
+
+  ~CapturedStream() {
+    remove(filename_.c_str());
+  }
+
+  std::string GetCapturedString() {
+    if (uncaptured_fd_ != -1) {
+      // Restores the original stream.
+      fflush(nullptr);
+      dup2(uncaptured_fd_, fd_);
+      close(uncaptured_fd_);
+      uncaptured_fd_ = -1;
+    }
+
+    FILE* const file = posix::FOpen(filename_.c_str(), "r");
+    if (file == nullptr) {
+      GTEST_LOG_(FATAL) << "Failed to open tmp file " << filename_
+                        << " for capturing stream.";
+    }
+    const std::string content = ReadEntireFile(file);
+    posix::FClose(file);
+    return content;
+  }
+
+ private:
+  const int fd_;  // A stream to capture.
+  int uncaptured_fd_;
+  // Name of the temporary file holding the stderr output.
+  ::std::string filename_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(CapturedStream);
+};
+
+GTEST_DISABLE_MSC_DEPRECATED_POP_()
+
+static CapturedStream* g_captured_stderr = nullptr;
+static CapturedStream* g_captured_stdout = nullptr;
+
+// Starts capturing an output stream (stdout/stderr).
+static void CaptureStream(int fd, const char* stream_name,
+                          CapturedStream** stream) {
+  if (*stream != nullptr) {
+    GTEST_LOG_(FATAL) << "Only one " << stream_name
+                      << " capturer can exist at a time.";
+  }
+  *stream = new CapturedStream(fd);
+}
+
+// Stops capturing the output stream and returns the captured string.
+static std::string GetCapturedStream(CapturedStream** captured_stream) {
+  const std::string content = (*captured_stream)->GetCapturedString();
+
+  delete *captured_stream;
+  *captured_stream = nullptr;
+
+  return content;
+}
+
+// Starts capturing stdout.
+void CaptureStdout() {
+  CaptureStream(kStdOutFileno, "stdout", &g_captured_stdout);
+}
+
+// Starts capturing stderr.
+void CaptureStderr() {
+  CaptureStream(kStdErrFileno, "stderr", &g_captured_stderr);
+}
+
+// Stops capturing stdout and returns the captured string.
+std::string GetCapturedStdout() {
+  return GetCapturedStream(&g_captured_stdout);
+}
+
+// Stops capturing stderr and returns the captured string.
+std::string GetCapturedStderr() {
+  return GetCapturedStream(&g_captured_stderr);
+}
+
+#endif  // GTEST_HAS_STREAM_REDIRECTION
+
+
+
+
+
+size_t GetFileSize(FILE* file) {
+  fseek(file, 0, SEEK_END);
+  return static_cast<size_t>(ftell(file));
+}
+
+std::string ReadEntireFile(FILE* file) {
+  const size_t file_size = GetFileSize(file);
+  char* const buffer = new char[file_size];
+
+  size_t bytes_last_read = 0;  // # of bytes read in the last fread()
+  size_t bytes_read = 0;       // # of bytes read so far
+
+  fseek(file, 0, SEEK_SET);
+
+  // Keeps reading the file until we cannot read further or the
+  // pre-determined file size is reached.
+  do {
+    bytes_last_read = fread(buffer+bytes_read, 1, file_size-bytes_read, file);
+    bytes_read += bytes_last_read;
+  } while (bytes_last_read > 0 && bytes_read < file_size);
+
+  const std::string content(buffer, bytes_read);
+  delete[] buffer;
+
+  return content;
+}
+
+#if GTEST_HAS_DEATH_TEST
+static const std::vector<std::string>* g_injected_test_argvs =
+    nullptr;  // Owned.
+
+std::vector<std::string> GetInjectableArgvs() {
+  if (g_injected_test_argvs != nullptr) {
+    return *g_injected_test_argvs;
+  }
+  return GetArgvs();
+}
+
+void SetInjectableArgvs(const std::vector<std::string>* new_argvs) {
+  if (g_injected_test_argvs != new_argvs) delete g_injected_test_argvs;
+  g_injected_test_argvs = new_argvs;
+}
+
+void SetInjectableArgvs(const std::vector<std::string>& new_argvs) {
+  SetInjectableArgvs(
+      new std::vector<std::string>(new_argvs.begin(), new_argvs.end()));
+}
+
+void ClearInjectableArgvs() {
+  delete g_injected_test_argvs;
+  g_injected_test_argvs = nullptr;
+}
+#endif  // GTEST_HAS_DEATH_TEST
+
+#if GTEST_OS_WINDOWS_MOBILE
+namespace posix {
+void Abort() {
+  DebugBreak();
+  TerminateProcess(GetCurrentProcess(), 1);
+}
+}  // namespace posix
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+// Returns the name of the environment variable corresponding to the
+// given flag.  For example, FlagToEnvVar("foo") will return
+// "GTEST_FOO" in the open-source version.
+static std::string FlagToEnvVar(const char* flag) {
+  const std::string full_flag =
+      (Message() << GTEST_FLAG_PREFIX_ << flag).GetString();
+
+  Message env_var;
+  for (size_t i = 0; i != full_flag.length(); i++) {
+    env_var << ToUpper(full_flag.c_str()[i]);
+  }
+
+  return env_var.GetString();
+}
+
+// Parses 'str' for a 32-bit signed integer.  If successful, writes
+// the result to *value and returns true; otherwise leaves *value
+// unchanged and returns false.
+bool ParseInt32(const Message& src_text, const char* str, Int32* value) {
+  // Parses the environment variable as a decimal integer.
+  char* end = nullptr;
+  const long long_value = strtol(str, &end, 10);  // NOLINT
+
+  // Has strtol() consumed all characters in the string?
+  if (*end != '\0') {
+    // No - an invalid character was encountered.
+    Message msg;
+    msg << "WARNING: " << src_text
+        << " is expected to be a 32-bit integer, but actually"
+        << " has value \"" << str << "\".\n";
+    printf("%s", msg.GetString().c_str());
+    fflush(stdout);
+    return false;
+  }
+
+  // Is the parsed value in the range of an Int32?
+  const Int32 result = static_cast<Int32>(long_value);
+  if (long_value == LONG_MAX || long_value == LONG_MIN ||
+      // The parsed value overflows as a long.  (strtol() returns
+      // LONG_MAX or LONG_MIN when the input overflows.)
+      result != long_value
+      // The parsed value overflows as an Int32.
+      ) {
+    Message msg;
+    msg << "WARNING: " << src_text
+        << " is expected to be a 32-bit integer, but actually"
+        << " has value " << str << ", which overflows.\n";
+    printf("%s", msg.GetString().c_str());
+    fflush(stdout);
+    return false;
+  }
+
+  *value = result;
+  return true;
+}
+
+// Reads and returns the Boolean environment variable corresponding to
+// the given flag; if it's not set, returns default_value.
+//
+// The value is considered true if and only if it's not "0".
+bool BoolFromGTestEnv(const char* flag, bool default_value) {
+#if defined(GTEST_GET_BOOL_FROM_ENV_)
+  return GTEST_GET_BOOL_FROM_ENV_(flag, default_value);
+#else
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const string_value = posix::GetEnv(env_var.c_str());
+  return string_value == nullptr ? default_value
+                                 : strcmp(string_value, "0") != 0;
+#endif  // defined(GTEST_GET_BOOL_FROM_ENV_)
+}
+
+// Reads and returns a 32-bit integer stored in the environment
+// variable corresponding to the given flag; if it isn't set or
+// doesn't represent a valid 32-bit integer, returns default_value.
+Int32 Int32FromGTestEnv(const char* flag, Int32 default_value) {
+#if defined(GTEST_GET_INT32_FROM_ENV_)
+  return GTEST_GET_INT32_FROM_ENV_(flag, default_value);
+#else
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const string_value = posix::GetEnv(env_var.c_str());
+  if (string_value == nullptr) {
+    // The environment variable is not set.
+    return default_value;
+  }
+
+  Int32 result = default_value;
+  if (!ParseInt32(Message() << "Environment variable " << env_var,
+                  string_value, &result)) {
+    printf("The default value %s is used.\n",
+           (Message() << default_value).GetString().c_str());
+    fflush(stdout);
+    return default_value;
+  }
+
+  return result;
+#endif  // defined(GTEST_GET_INT32_FROM_ENV_)
+}
+
+// As a special case for the 'output' flag, if GTEST_OUTPUT is not
+// set, we look for XML_OUTPUT_FILE, which is set by the Bazel build
+// system.  The value of XML_OUTPUT_FILE is a filename without the
+// "xml:" prefix of GTEST_OUTPUT.
+// Note that this is meant to be called at the call site so it does
+// not check that the flag is 'output'
+// In essence this checks an env variable called XML_OUTPUT_FILE
+// and if it is set we prepend "xml:" to its value, if it not set we return ""
+std::string OutputFlagAlsoCheckEnvVar(){
+  std::string default_value_for_output_flag = "";
+  const char* xml_output_file_env = posix::GetEnv("XML_OUTPUT_FILE");
+  if (nullptr != xml_output_file_env) {
+    default_value_for_output_flag = std::string("xml:") + xml_output_file_env;
+  }
+  return default_value_for_output_flag;
+}
+
+// Reads and returns the string environment variable corresponding to
+// the given flag; if it's not set, returns default_value.
+const char* StringFromGTestEnv(const char* flag, const char* default_value) {
+#if defined(GTEST_GET_STRING_FROM_ENV_)
+  return GTEST_GET_STRING_FROM_ENV_(flag, default_value);
+#else
+  const std::string env_var = FlagToEnvVar(flag);
+  const char* const value = posix::GetEnv(env_var.c_str());
+  return value == nullptr ? default_value : value;
+#endif  // defined(GTEST_GET_STRING_FROM_ENV_)
+}
+
+}  // namespace internal
+}  // namespace testing
diff --git a/3rdparty/gtest/src/gtest-printers.cc b/3rdparty/gtest/src/gtest-printers.cc
new file mode 100644
index 0000000..3337be3
--- /dev/null
+++ b/3rdparty/gtest/src/gtest-printers.cc
@@ -0,0 +1,442 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Google Test - The Google C++ Testing and Mocking Framework
+//
+// This file implements a universal value printer that can print a
+// value of any type T:
+//
+//   void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
+//
+// It uses the << operator when possible, and prints the bytes in the
+// object otherwise.  A user can override its behavior for a class
+// type Foo by defining either operator<<(::std::ostream&, const Foo&)
+// or void PrintTo(const Foo&, ::std::ostream*) in the namespace that
+// defines Foo.
+
+#include "gtest/gtest-printers.h"
+#include <stdio.h>
+#include <cctype>
+#include <cwchar>
+#include <ostream>  // NOLINT
+#include <string>
+#include "gtest/internal/gtest-port.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+
+namespace {
+
+using ::std::ostream;
+
+// Prints a segment of bytes in the given object.
+GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
+GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
+void PrintByteSegmentInObjectTo(const unsigned char* obj_bytes, size_t start,
+                                size_t count, ostream* os) {
+  char text[5] = "";
+  for (size_t i = 0; i != count; i++) {
+    const size_t j = start + i;
+    if (i != 0) {
+      // Organizes the bytes into groups of 2 for easy parsing by
+      // human.
+      if ((j % 2) == 0)
+        *os << ' ';
+      else
+        *os << '-';
+    }
+    GTEST_SNPRINTF_(text, sizeof(text), "%02X", obj_bytes[j]);
+    *os << text;
+  }
+}
+
+// Prints the bytes in the given value to the given ostream.
+void PrintBytesInObjectToImpl(const unsigned char* obj_bytes, size_t count,
+                              ostream* os) {
+  // Tells the user how big the object is.
+  *os << count << "-byte object <";
+
+  const size_t kThreshold = 132;
+  const size_t kChunkSize = 64;
+  // If the object size is bigger than kThreshold, we'll have to omit
+  // some details by printing only the first and the last kChunkSize
+  // bytes.
+  if (count < kThreshold) {
+    PrintByteSegmentInObjectTo(obj_bytes, 0, count, os);
+  } else {
+    PrintByteSegmentInObjectTo(obj_bytes, 0, kChunkSize, os);
+    *os << " ... ";
+    // Rounds up to 2-byte boundary.
+    const size_t resume_pos = (count - kChunkSize + 1)/2*2;
+    PrintByteSegmentInObjectTo(obj_bytes, resume_pos, count - resume_pos, os);
+  }
+  *os << ">";
+}
+
+}  // namespace
+
+namespace internal2 {
+
+// Delegates to PrintBytesInObjectToImpl() to print the bytes in the
+// given object.  The delegation simplifies the implementation, which
+// uses the << operator and thus is easier done outside of the
+// ::testing::internal namespace, which contains a << operator that
+// sometimes conflicts with the one in STL.
+void PrintBytesInObjectTo(const unsigned char* obj_bytes, size_t count,
+                          ostream* os) {
+  PrintBytesInObjectToImpl(obj_bytes, count, os);
+}
+
+}  // namespace internal2
+
+namespace internal {
+
+// Depending on the value of a char (or wchar_t), we print it in one
+// of three formats:
+//   - as is if it's a printable ASCII (e.g. 'a', '2', ' '),
+//   - as a hexadecimal escape sequence (e.g. '\x7F'), or
+//   - as a special escape sequence (e.g. '\r', '\n').
+enum CharFormat {
+  kAsIs,
+  kHexEscape,
+  kSpecialEscape
+};
+
+// Returns true if c is a printable ASCII character.  We test the
+// value of c directly instead of calling isprint(), which is buggy on
+// Windows Mobile.
+inline bool IsPrintableAscii(wchar_t c) {
+  return 0x20 <= c && c <= 0x7E;
+}
+
+// Prints a wide or narrow char c as a character literal without the
+// quotes, escaping it when necessary; returns how c was formatted.
+// The template argument UnsignedChar is the unsigned version of Char,
+// which is the type of c.
+template <typename UnsignedChar, typename Char>
+static CharFormat PrintAsCharLiteralTo(Char c, ostream* os) {
+  wchar_t w_c = static_cast<wchar_t>(c);
+  switch (w_c) {
+    case L'\0':
+      *os << "\\0";
+      break;
+    case L'\'':
+      *os << "\\'";
+      break;
+    case L'\\':
+      *os << "\\\\";
+      break;
+    case L'\a':
+      *os << "\\a";
+      break;
+    case L'\b':
+      *os << "\\b";
+      break;
+    case L'\f':
+      *os << "\\f";
+      break;
+    case L'\n':
+      *os << "\\n";
+      break;
+    case L'\r':
+      *os << "\\r";
+      break;
+    case L'\t':
+      *os << "\\t";
+      break;
+    case L'\v':
+      *os << "\\v";
+      break;
+    default:
+      if (IsPrintableAscii(w_c)) {
+        *os << static_cast<char>(c);
+        return kAsIs;
+      } else {
+        ostream::fmtflags flags = os->flags();
+        *os << "\\x" << std::hex << std::uppercase
+            << static_cast<int>(static_cast<UnsignedChar>(c));
+        os->flags(flags);
+        return kHexEscape;
+      }
+  }
+  return kSpecialEscape;
+}
+
+// Prints a wchar_t c as if it's part of a string literal, escaping it when
+// necessary; returns how c was formatted.
+static CharFormat PrintAsStringLiteralTo(wchar_t c, ostream* os) {
+  switch (c) {
+    case L'\'':
+      *os << "'";
+      return kAsIs;
+    case L'"':
+      *os << "\\\"";
+      return kSpecialEscape;
+    default:
+      return PrintAsCharLiteralTo<wchar_t>(c, os);
+  }
+}
+
+// Prints a char c as if it's part of a string literal, escaping it when
+// necessary; returns how c was formatted.
+static CharFormat PrintAsStringLiteralTo(char c, ostream* os) {
+  return PrintAsStringLiteralTo(
+      static_cast<wchar_t>(static_cast<unsigned char>(c)), os);
+}
+
+// Prints a wide or narrow character c and its code.  '\0' is printed
+// as "'\\0'", other unprintable characters are also properly escaped
+// using the standard C++ escape sequence.  The template argument
+// UnsignedChar is the unsigned version of Char, which is the type of c.
+template <typename UnsignedChar, typename Char>
+void PrintCharAndCodeTo(Char c, ostream* os) {
+  // First, print c as a literal in the most readable form we can find.
+  *os << ((sizeof(c) > 1) ? "L'" : "'");
+  const CharFormat format = PrintAsCharLiteralTo<UnsignedChar>(c, os);
+  *os << "'";
+
+  // To aid user debugging, we also print c's code in decimal, unless
+  // it's 0 (in which case c was printed as '\\0', making the code
+  // obvious).
+  if (c == 0)
+    return;
+  *os << " (" << static_cast<int>(c);
+
+  // For more convenience, we print c's code again in hexadecimal,
+  // unless c was already printed in the form '\x##' or the code is in
+  // [1, 9].
+  if (format == kHexEscape || (1 <= c && c <= 9)) {
+    // Do nothing.
+  } else {
+    *os << ", 0x" << String::FormatHexInt(static_cast<int>(c));
+  }
+  *os << ")";
+}
+
+void PrintTo(unsigned char c, ::std::ostream* os) {
+  PrintCharAndCodeTo<unsigned char>(c, os);
+}
+void PrintTo(signed char c, ::std::ostream* os) {
+  PrintCharAndCodeTo<unsigned char>(c, os);
+}
+
+// Prints a wchar_t as a symbol if it is printable or as its internal
+// code otherwise and also as its code.  L'\0' is printed as "L'\\0'".
+void PrintTo(wchar_t wc, ostream* os) {
+  PrintCharAndCodeTo<wchar_t>(wc, os);
+}
+
+// Prints the given array of characters to the ostream.  CharType must be either
+// char or wchar_t.
+// The array starts at begin, the length is len, it may include '\0' characters
+// and may not be NUL-terminated.
+template <typename CharType>
+GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
+GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
+static CharFormat PrintCharsAsStringTo(
+    const CharType* begin, size_t len, ostream* os) {
+  const char* const kQuoteBegin = sizeof(CharType) == 1 ? "\"" : "L\"";
+  *os << kQuoteBegin;
+  bool is_previous_hex = false;
+  CharFormat print_format = kAsIs;
+  for (size_t index = 0; index < len; ++index) {
+    const CharType cur = begin[index];
+    if (is_previous_hex && IsXDigit(cur)) {
+      // Previous character is of '\x..' form and this character can be
+      // interpreted as another hexadecimal digit in its number. Break string to
+      // disambiguate.
+      *os << "\" " << kQuoteBegin;
+    }
+    is_previous_hex = PrintAsStringLiteralTo(cur, os) == kHexEscape;
+    // Remember if any characters required hex escaping.
+    if (is_previous_hex) {
+      print_format = kHexEscape;
+    }
+  }
+  *os << "\"";
+  return print_format;
+}
+
+// Prints a (const) char/wchar_t array of 'len' elements, starting at address
+// 'begin'.  CharType must be either char or wchar_t.
+template <typename CharType>
+GTEST_ATTRIBUTE_NO_SANITIZE_MEMORY_
+GTEST_ATTRIBUTE_NO_SANITIZE_ADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_HWADDRESS_
+GTEST_ATTRIBUTE_NO_SANITIZE_THREAD_
+static void UniversalPrintCharArray(
+    const CharType* begin, size_t len, ostream* os) {
+  // The code
+  //   const char kFoo[] = "foo";
+  // generates an array of 4, not 3, elements, with the last one being '\0'.
+  //
+  // Therefore when printing a char array, we don't print the last element if
+  // it's '\0', such that the output matches the string literal as it's
+  // written in the source code.
+  if (len > 0 && begin[len - 1] == '\0') {
+    PrintCharsAsStringTo(begin, len - 1, os);
+    return;
+  }
+
+  // If, however, the last element in the array is not '\0', e.g.
+  //    const char kFoo[] = { 'f', 'o', 'o' };
+  // we must print the entire array.  We also print a message to indicate
+  // that the array is not NUL-terminated.
+  PrintCharsAsStringTo(begin, len, os);
+  *os << " (no terminating NUL)";
+}
+
+// Prints a (const) char array of 'len' elements, starting at address 'begin'.
+void UniversalPrintArray(const char* begin, size_t len, ostream* os) {
+  UniversalPrintCharArray(begin, len, os);
+}
+
+// Prints a (const) wchar_t array of 'len' elements, starting at address
+// 'begin'.
+void UniversalPrintArray(const wchar_t* begin, size_t len, ostream* os) {
+  UniversalPrintCharArray(begin, len, os);
+}
+
+// Prints the given C string to the ostream.
+void PrintTo(const char* s, ostream* os) {
+  if (s == nullptr) {
+    *os << "NULL";
+  } else {
+    *os << ImplicitCast_<const void*>(s) << " pointing to ";
+    PrintCharsAsStringTo(s, strlen(s), os);
+  }
+}
+
+// MSVC compiler can be configured to define whar_t as a typedef
+// of unsigned short. Defining an overload for const wchar_t* in that case
+// would cause pointers to unsigned shorts be printed as wide strings,
+// possibly accessing more memory than intended and causing invalid
+// memory accesses. MSVC defines _NATIVE_WCHAR_T_DEFINED symbol when
+// wchar_t is implemented as a native type.
+#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
+// Prints the given wide C string to the ostream.
+void PrintTo(const wchar_t* s, ostream* os) {
+  if (s == nullptr) {
+    *os << "NULL";
+  } else {
+    *os << ImplicitCast_<const void*>(s) << " pointing to ";
+    PrintCharsAsStringTo(s, wcslen(s), os);
+  }
+}
+#endif  // wchar_t is native
+
+namespace {
+
+bool ContainsUnprintableControlCodes(const char* str, size_t length) {
+  const unsigned char *s = reinterpret_cast<const unsigned char *>(str);
+
+  for (size_t i = 0; i < length; i++) {
+    unsigned char ch = *s++;
+    if (std::iscntrl(ch)) {
+        switch (ch) {
+        case '\t':
+        case '\n':
+        case '\r':
+          break;
+        default:
+          return true;
+        }
+      }
+  }
+  return false;
+}
+
+bool IsUTF8TrailByte(unsigned char t) { return 0x80 <= t && t<= 0xbf; }
+
+bool IsValidUTF8(const char* str, size_t length) {
+  const unsigned char *s = reinterpret_cast<const unsigned char *>(str);
+
+  for (size_t i = 0; i < length;) {
+    unsigned char lead = s[i++];
+
+    if (lead <= 0x7f) {
+      continue;  // single-byte character (ASCII) 0..7F
+    }
+    if (lead < 0xc2) {
+      return false;  // trail byte or non-shortest form
+    } else if (lead <= 0xdf && (i + 1) <= length && IsUTF8TrailByte(s[i])) {
+      ++i;  // 2-byte character
+    } else if (0xe0 <= lead && lead <= 0xef && (i + 2) <= length &&
+               IsUTF8TrailByte(s[i]) &&
+               IsUTF8TrailByte(s[i + 1]) &&
+               // check for non-shortest form and surrogate
+               (lead != 0xe0 || s[i] >= 0xa0) &&
+               (lead != 0xed || s[i] < 0xa0)) {
+      i += 2;  // 3-byte character
+    } else if (0xf0 <= lead && lead <= 0xf4 && (i + 3) <= length &&
+               IsUTF8TrailByte(s[i]) &&
+               IsUTF8TrailByte(s[i + 1]) &&
+               IsUTF8TrailByte(s[i + 2]) &&
+               // check for non-shortest form
+               (lead != 0xf0 || s[i] >= 0x90) &&
+               (lead != 0xf4 || s[i] < 0x90)) {
+      i += 3;  // 4-byte character
+    } else {
+      return false;
+    }
+  }
+  return true;
+}
+
+void ConditionalPrintAsText(const char* str, size_t length, ostream* os) {
+  if (!ContainsUnprintableControlCodes(str, length) &&
+      IsValidUTF8(str, length)) {
+    *os << "\n    As Text: \"" << str << "\"";
+  }
+}
+
+}  // anonymous namespace
+
+void PrintStringTo(const ::std::string& s, ostream* os) {
+  if (PrintCharsAsStringTo(s.data(), s.size(), os) == kHexEscape) {
+    if (GTEST_FLAG(print_utf8)) {
+      ConditionalPrintAsText(s.data(), s.size(), os);
+    }
+  }
+}
+
+#if GTEST_HAS_STD_WSTRING
+void PrintWideStringTo(const ::std::wstring& s, ostream* os) {
+  PrintCharsAsStringTo(s.data(), s.size(), os);
+}
+#endif  // GTEST_HAS_STD_WSTRING
+
+}  // namespace internal
+
+}  // namespace testing
diff --git a/3rdparty/gtest/src/gtest-test-part.cc b/3rdparty/gtest/src/gtest-test-part.cc
new file mode 100644
index 0000000..178317a
--- /dev/null
+++ b/3rdparty/gtest/src/gtest-test-part.cc
@@ -0,0 +1,104 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+
+#include "gtest/gtest-test-part.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+
+using internal::GetUnitTestImpl;
+
+// Gets the summary of the failure message by omitting the stack trace
+// in it.
+std::string TestPartResult::ExtractSummary(const char* message) {
+  const char* const stack_trace = strstr(message, internal::kStackTraceMarker);
+  return stack_trace == nullptr ? message : std::string(message, stack_trace);
+}
+
+// Prints a TestPartResult object.
+std::ostream& operator<<(std::ostream& os, const TestPartResult& result) {
+  return os << result.file_name() << ":" << result.line_number() << ": "
+            << (result.type() == TestPartResult::kSuccess
+                    ? "Success"
+                    : result.type() == TestPartResult::kSkip
+                          ? "Skipped"
+                          : result.type() == TestPartResult::kFatalFailure
+                                ? "Fatal failure"
+                                : "Non-fatal failure")
+            << ":\n"
+            << result.message() << std::endl;
+}
+
+// Appends a TestPartResult to the array.
+void TestPartResultArray::Append(const TestPartResult& result) {
+  array_.push_back(result);
+}
+
+// Returns the TestPartResult at the given index (0-based).
+const TestPartResult& TestPartResultArray::GetTestPartResult(int index) const {
+  if (index < 0 || index >= size()) {
+    printf("\nInvalid index (%d) into TestPartResultArray.\n", index);
+    internal::posix::Abort();
+  }
+
+  return array_[static_cast<size_t>(index)];
+}
+
+// Returns the number of TestPartResult objects in the array.
+int TestPartResultArray::size() const {
+  return static_cast<int>(array_.size());
+}
+
+namespace internal {
+
+HasNewFatalFailureHelper::HasNewFatalFailureHelper()
+    : has_new_fatal_failure_(false),
+      original_reporter_(GetUnitTestImpl()->
+                         GetTestPartResultReporterForCurrentThread()) {
+  GetUnitTestImpl()->SetTestPartResultReporterForCurrentThread(this);
+}
+
+HasNewFatalFailureHelper::~HasNewFatalFailureHelper() {
+  GetUnitTestImpl()->SetTestPartResultReporterForCurrentThread(
+      original_reporter_);
+}
+
+void HasNewFatalFailureHelper::ReportTestPartResult(
+    const TestPartResult& result) {
+  if (result.fatally_failed())
+    has_new_fatal_failure_ = true;
+  original_reporter_->ReportTestPartResult(result);
+}
+
+}  // namespace internal
+
+}  // namespace testing
diff --git a/3rdparty/gtest/src/gtest-typed-test.cc b/3rdparty/gtest/src/gtest-typed-test.cc
new file mode 100644
index 0000000..8677caf
--- /dev/null
+++ b/3rdparty/gtest/src/gtest-typed-test.cc
@@ -0,0 +1,118 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include "gtest/gtest-typed-test.h"
+
+#include "gtest/gtest.h"
+
+namespace testing {
+namespace internal {
+
+#if GTEST_HAS_TYPED_TEST_P
+
+// Skips to the first non-space char in str. Returns an empty string if str
+// contains only whitespace characters.
+static const char* SkipSpaces(const char* str) {
+  while (IsSpace(*str))
+    str++;
+  return str;
+}
+
+static std::vector<std::string> SplitIntoTestNames(const char* src) {
+  std::vector<std::string> name_vec;
+  src = SkipSpaces(src);
+  for (; src != nullptr; src = SkipComma(src)) {
+    name_vec.push_back(StripTrailingSpaces(GetPrefixUntilComma(src)));
+  }
+  return name_vec;
+}
+
+// Verifies that registered_tests match the test names in
+// registered_tests_; returns registered_tests if successful, or
+// aborts the program otherwise.
+const char* TypedTestSuitePState::VerifyRegisteredTestNames(
+    const char* file, int line, const char* registered_tests) {
+  typedef RegisteredTestsMap::const_iterator RegisteredTestIter;
+  registered_ = true;
+
+  std::vector<std::string> name_vec = SplitIntoTestNames(registered_tests);
+
+  Message errors;
+
+  std::set<std::string> tests;
+  for (std::vector<std::string>::const_iterator name_it = name_vec.begin();
+       name_it != name_vec.end(); ++name_it) {
+    const std::string& name = *name_it;
+    if (tests.count(name) != 0) {
+      errors << "Test " << name << " is listed more than once.\n";
+      continue;
+    }
+
+    bool found = false;
+    for (RegisteredTestIter it = registered_tests_.begin();
+         it != registered_tests_.end();
+         ++it) {
+      if (name == it->first) {
+        found = true;
+        break;
+      }
+    }
+
+    if (found) {
+      tests.insert(name);
+    } else {
+      errors << "No test named " << name
+             << " can be found in this test suite.\n";
+    }
+  }
+
+  for (RegisteredTestIter it = registered_tests_.begin();
+       it != registered_tests_.end();
+       ++it) {
+    if (tests.count(it->first) == 0) {
+      errors << "You forgot to list test " << it->first << ".\n";
+    }
+  }
+
+  const std::string& errors_str = errors.GetString();
+  if (errors_str != "") {
+    fprintf(stderr, "%s %s", FormatFileLocation(file, line).c_str(),
+            errors_str.c_str());
+    fflush(stderr);
+    posix::Abort();
+  }
+
+  return registered_tests;
+}
+
+#endif  // GTEST_HAS_TYPED_TEST_P
+
+}  // namespace internal
+}  // namespace testing
diff --git a/3rdparty/gtest/src/gtest.cc b/3rdparty/gtest/src/gtest.cc
new file mode 100644
index 0000000..a5b4e5a
--- /dev/null
+++ b/3rdparty/gtest/src/gtest.cc
@@ -0,0 +1,6177 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+
+#include "gtest/gtest.h"
+#include "gtest/internal/custom/gtest.h"
+#include "gtest/gtest-spi.h"
+
+#include <ctype.h>
+#include <math.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <wchar.h>
+#include <wctype.h>
+
+#include <algorithm>
+#include <iomanip>
+#include <limits>
+#include <list>
+#include <map>
+#include <ostream>  // NOLINT
+#include <sstream>
+#include <vector>
+
+#if GTEST_OS_LINUX
+
+# define GTEST_HAS_GETTIMEOFDAY_ 1
+
+# include <fcntl.h>  // NOLINT
+# include <limits.h>  // NOLINT
+# include <sched.h>  // NOLINT
+// Declares vsnprintf().  This header is not available on Windows.
+# include <strings.h>  // NOLINT
+# include <sys/mman.h>  // NOLINT
+# include <sys/time.h>  // NOLINT
+# include <unistd.h>  // NOLINT
+# include <string>
+
+#elif GTEST_OS_ZOS
+# define GTEST_HAS_GETTIMEOFDAY_ 1
+# include <sys/time.h>  // NOLINT
+
+// On z/OS we additionally need strings.h for strcasecmp.
+# include <strings.h>  // NOLINT
+
+#elif GTEST_OS_WINDOWS_MOBILE  // We are on Windows CE.
+
+# include <windows.h>  // NOLINT
+# undef min
+
+#elif GTEST_OS_WINDOWS  // We are on Windows proper.
+
+# include <windows.h>  // NOLINT
+# undef min
+
+# include <crtdbg.h>  // NOLINT
+# include <debugapi.h>  // NOLINT
+# include <io.h>  // NOLINT
+# include <sys/timeb.h>  // NOLINT
+# include <sys/types.h>  // NOLINT
+# include <sys/stat.h>  // NOLINT
+
+# if GTEST_OS_WINDOWS_MINGW
+// MinGW has gettimeofday() but not _ftime64().
+#  define GTEST_HAS_GETTIMEOFDAY_ 1
+#  include <sys/time.h>  // NOLINT
+# endif  // GTEST_OS_WINDOWS_MINGW
+
+#else
+
+// Assume other platforms have gettimeofday().
+# define GTEST_HAS_GETTIMEOFDAY_ 1
+
+// cpplint thinks that the header is already included, so we want to
+// silence it.
+# include <sys/time.h>  // NOLINT
+# include <unistd.h>  // NOLINT
+
+#endif  // GTEST_OS_LINUX
+
+#if GTEST_HAS_EXCEPTIONS
+# include <stdexcept>
+#endif
+
+#if GTEST_CAN_STREAM_RESULTS_
+# include <arpa/inet.h>  // NOLINT
+# include <netdb.h>  // NOLINT
+# include <sys/socket.h>  // NOLINT
+# include <sys/types.h>  // NOLINT
+#endif
+
+#include "src/gtest-internal-inl.h"
+
+#if GTEST_OS_WINDOWS
+# define vsnprintf _vsnprintf
+#endif  // GTEST_OS_WINDOWS
+
+#if GTEST_OS_MAC
+#ifndef GTEST_OS_IOS
+#include <crt_externs.h>
+#endif
+#endif
+
+#if GTEST_HAS_ABSL
+#include "absl/debugging/failure_signal_handler.h"
+#include "absl/debugging/stacktrace.h"
+#include "absl/debugging/symbolize.h"
+#include "absl/strings/str_cat.h"
+#endif  // GTEST_HAS_ABSL
+
+namespace testing {
+
+using internal::CountIf;
+using internal::ForEach;
+using internal::GetElementOr;
+using internal::Shuffle;
+
+// Constants.
+
+// A test whose test suite name or test name matches this filter is
+// disabled and not run.
+static const char kDisableTestFilter[] = "DISABLED_*:*/DISABLED_*";
+
+// A test suite whose name matches this filter is considered a death
+// test suite and will be run before test suites whose name doesn't
+// match this filter.
+static const char kDeathTestSuiteFilter[] = "*DeathTest:*DeathTest/*";
+
+// A test filter that matches everything.
+static const char kUniversalFilter[] = "*";
+
+// The default output format.
+static const char kDefaultOutputFormat[] = "xml";
+// The default output file.
+static const char kDefaultOutputFile[] = "test_detail";
+
+// The environment variable name for the test shard index.
+static const char kTestShardIndex[] = "GTEST_SHARD_INDEX";
+// The environment variable name for the total number of test shards.
+static const char kTestTotalShards[] = "GTEST_TOTAL_SHARDS";
+// The environment variable name for the test shard status file.
+static const char kTestShardStatusFile[] = "GTEST_SHARD_STATUS_FILE";
+
+namespace internal {
+
+// The text used in failure messages to indicate the start of the
+// stack trace.
+const char kStackTraceMarker[] = "\nStack trace:\n";
+
+// g_help_flag is true if and only if the --help flag or an equivalent form
+// is specified on the command line.
+bool g_help_flag = false;
+
+// Utilty function to Open File for Writing
+static FILE* OpenFileForWriting(const std::string& output_file) {
+  FILE* fileout = nullptr;
+  FilePath output_file_path(output_file);
+  FilePath output_dir(output_file_path.RemoveFileName());
+
+  if (output_dir.CreateDirectoriesRecursively()) {
+    fileout = posix::FOpen(output_file.c_str(), "w");
+  }
+  if (fileout == nullptr) {
+    GTEST_LOG_(FATAL) << "Unable to open file \"" << output_file << "\"";
+  }
+  return fileout;
+}
+
+}  // namespace internal
+
+// Bazel passes in the argument to '--test_filter' via the TESTBRIDGE_TEST_ONLY
+// environment variable.
+static const char* GetDefaultFilter() {
+  const char* const testbridge_test_only =
+      internal::posix::GetEnv("TESTBRIDGE_TEST_ONLY");
+  if (testbridge_test_only != nullptr) {
+    return testbridge_test_only;
+  }
+  return kUniversalFilter;
+}
+
+GTEST_DEFINE_bool_(
+    also_run_disabled_tests,
+    internal::BoolFromGTestEnv("also_run_disabled_tests", false),
+    "Run disabled tests too, in addition to the tests normally being run.");
+
+GTEST_DEFINE_bool_(
+    break_on_failure, internal::BoolFromGTestEnv("break_on_failure", false),
+    "True if and only if a failed assertion should be a debugger "
+    "break-point.");
+
+GTEST_DEFINE_bool_(catch_exceptions,
+                   internal::BoolFromGTestEnv("catch_exceptions", true),
+                   "True if and only if " GTEST_NAME_
+                   " should catch exceptions and treat them as test failures.");
+
+GTEST_DEFINE_string_(
+    color,
+    internal::StringFromGTestEnv("color", "auto"),
+    "Whether to use colors in the output.  Valid values: yes, no, "
+    "and auto.  'auto' means to use colors if the output is "
+    "being sent to a terminal and the TERM environment variable "
+    "is set to a terminal type that supports colors.");
+
+GTEST_DEFINE_string_(
+    filter,
+    internal::StringFromGTestEnv("filter", GetDefaultFilter()),
+    "A colon-separated list of glob (not regex) patterns "
+    "for filtering the tests to run, optionally followed by a "
+    "'-' and a : separated list of negative patterns (tests to "
+    "exclude).  A test is run if it matches one of the positive "
+    "patterns and does not match any of the negative patterns.");
+
+GTEST_DEFINE_bool_(
+    install_failure_signal_handler,
+    internal::BoolFromGTestEnv("install_failure_signal_handler", false),
+    "If true and supported on the current platform, " GTEST_NAME_ " should "
+    "install a signal handler that dumps debugging information when fatal "
+    "signals are raised.");
+
+GTEST_DEFINE_bool_(list_tests, false,
+                   "List all tests without running them.");
+
+// The net priority order after flag processing is thus:
+//   --gtest_output command line flag
+//   GTEST_OUTPUT environment variable
+//   XML_OUTPUT_FILE environment variable
+//   ''
+GTEST_DEFINE_string_(
+    output,
+    internal::StringFromGTestEnv("output",
+      internal::OutputFlagAlsoCheckEnvVar().c_str()),
+    "A format (defaults to \"xml\" but can be specified to be \"json\"), "
+    "optionally followed by a colon and an output file name or directory. "
+    "A directory is indicated by a trailing pathname separator. "
+    "Examples: \"xml:filename.xml\", \"xml::directoryname/\". "
+    "If a directory is specified, output files will be created "
+    "within that directory, with file-names based on the test "
+    "executable's name and, if necessary, made unique by adding "
+    "digits.");
+
+GTEST_DEFINE_bool_(print_time, internal::BoolFromGTestEnv("print_time", true),
+                   "True if and only if " GTEST_NAME_
+                   " should display elapsed time in text output.");
+
+GTEST_DEFINE_bool_(print_utf8, internal::BoolFromGTestEnv("print_utf8", true),
+                   "True if and only if " GTEST_NAME_
+                   " prints UTF8 characters as text.");
+
+GTEST_DEFINE_int32_(
+    random_seed,
+    internal::Int32FromGTestEnv("random_seed", 0),
+    "Random number seed to use when shuffling test orders.  Must be in range "
+    "[1, 99999], or 0 to use a seed based on the current time.");
+
+GTEST_DEFINE_int32_(
+    repeat,
+    internal::Int32FromGTestEnv("repeat", 1),
+    "How many times to repeat each test.  Specify a negative number "
+    "for repeating forever.  Useful for shaking out flaky tests.");
+
+GTEST_DEFINE_bool_(show_internal_stack_frames, false,
+                   "True if and only if " GTEST_NAME_
+                   " should include internal stack frames when "
+                   "printing test failure stack traces.");
+
+GTEST_DEFINE_bool_(shuffle, internal::BoolFromGTestEnv("shuffle", false),
+                   "True if and only if " GTEST_NAME_
+                   " should randomize tests' order on every run.");
+
+GTEST_DEFINE_int32_(
+    stack_trace_depth,
+    internal::Int32FromGTestEnv("stack_trace_depth", kMaxStackTraceDepth),
+    "The maximum number of stack frames to print when an "
+    "assertion fails.  The valid range is 0 through 100, inclusive.");
+
+GTEST_DEFINE_string_(
+    stream_result_to,
+    internal::StringFromGTestEnv("stream_result_to", ""),
+    "This flag specifies the host name and the port number on which to stream "
+    "test results. Example: \"localhost:555\". The flag is effective only on "
+    "Linux.");
+
+GTEST_DEFINE_bool_(
+    throw_on_failure,
+    internal::BoolFromGTestEnv("throw_on_failure", false),
+    "When this flag is specified, a failed assertion will throw an exception "
+    "if exceptions are enabled or exit the program with a non-zero code "
+    "otherwise. For use with an external test framework.");
+
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+GTEST_DEFINE_string_(
+    flagfile,
+    internal::StringFromGTestEnv("flagfile", ""),
+    "This flag specifies the flagfile to read command-line flags from.");
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+
+namespace internal {
+
+// Generates a random number from [0, range), using a Linear
+// Congruential Generator (LCG).  Crashes if 'range' is 0 or greater
+// than kMaxRange.
+UInt32 Random::Generate(UInt32 range) {
+  // These constants are the same as are used in glibc's rand(3).
+  // Use wider types than necessary to prevent unsigned overflow diagnostics.
+  state_ = static_cast<UInt32>(1103515245ULL*state_ + 12345U) % kMaxRange;
+
+  GTEST_CHECK_(range > 0)
+      << "Cannot generate a number in the range [0, 0).";
+  GTEST_CHECK_(range <= kMaxRange)
+      << "Generation of a number in [0, " << range << ") was requested, "
+      << "but this can only generate numbers in [0, " << kMaxRange << ").";
+
+  // Converting via modulus introduces a bit of downward bias, but
+  // it's simple, and a linear congruential generator isn't too good
+  // to begin with.
+  return state_ % range;
+}
+
+// GTestIsInitialized() returns true if and only if the user has initialized
+// Google Test.  Useful for catching the user mistake of not initializing
+// Google Test before calling RUN_ALL_TESTS().
+static bool GTestIsInitialized() { return GetArgvs().size() > 0; }
+
+// Iterates over a vector of TestSuites, keeping a running sum of the
+// results of calling a given int-returning method on each.
+// Returns the sum.
+static int SumOverTestSuiteList(const std::vector<TestSuite*>& case_list,
+                                int (TestSuite::*method)() const) {
+  int sum = 0;
+  for (size_t i = 0; i < case_list.size(); i++) {
+    sum += (case_list[i]->*method)();
+  }
+  return sum;
+}
+
+// Returns true if and only if the test suite passed.
+static bool TestSuitePassed(const TestSuite* test_suite) {
+  return test_suite->should_run() && test_suite->Passed();
+}
+
+// Returns true if and only if the test suite failed.
+static bool TestSuiteFailed(const TestSuite* test_suite) {
+  return test_suite->should_run() && test_suite->Failed();
+}
+
+// Returns true if and only if test_suite contains at least one test that
+// should run.
+static bool ShouldRunTestSuite(const TestSuite* test_suite) {
+  return test_suite->should_run();
+}
+
+// AssertHelper constructor.
+AssertHelper::AssertHelper(TestPartResult::Type type,
+                           const char* file,
+                           int line,
+                           const char* message)
+    : data_(new AssertHelperData(type, file, line, message)) {
+}
+
+AssertHelper::~AssertHelper() {
+  delete data_;
+}
+
+// Message assignment, for assertion streaming support.
+void AssertHelper::operator=(const Message& message) const {
+  UnitTest::GetInstance()->
+    AddTestPartResult(data_->type, data_->file, data_->line,
+                      AppendUserMessage(data_->message, message),
+                      UnitTest::GetInstance()->impl()
+                      ->CurrentOsStackTraceExceptTop(1)
+                      // Skips the stack frame for this function itself.
+                      );  // NOLINT
+}
+
+// A copy of all command line arguments.  Set by InitGoogleTest().
+static ::std::vector<std::string> g_argvs;
+
+::std::vector<std::string> GetArgvs() {
+#if defined(GTEST_CUSTOM_GET_ARGVS_)
+  // GTEST_CUSTOM_GET_ARGVS_() may return a container of std::string or
+  // ::string. This code converts it to the appropriate type.
+  const auto& custom = GTEST_CUSTOM_GET_ARGVS_();
+  return ::std::vector<std::string>(custom.begin(), custom.end());
+#else   // defined(GTEST_CUSTOM_GET_ARGVS_)
+  return g_argvs;
+#endif  // defined(GTEST_CUSTOM_GET_ARGVS_)
+}
+
+// Returns the current application's name, removing directory path if that
+// is present.
+FilePath GetCurrentExecutableName() {
+  FilePath result;
+
+#if GTEST_OS_WINDOWS || GTEST_OS_OS2
+  result.Set(FilePath(GetArgvs()[0]).RemoveExtension("exe"));
+#else
+  result.Set(FilePath(GetArgvs()[0]));
+#endif  // GTEST_OS_WINDOWS
+
+  return result.RemoveDirectoryName();
+}
+
+// Functions for processing the gtest_output flag.
+
+// Returns the output format, or "" for normal printed output.
+std::string UnitTestOptions::GetOutputFormat() {
+  const char* const gtest_output_flag = GTEST_FLAG(output).c_str();
+  const char* const colon = strchr(gtest_output_flag, ':');
+  return (colon == nullptr)
+             ? std::string(gtest_output_flag)
+             : std::string(gtest_output_flag,
+                           static_cast<size_t>(colon - gtest_output_flag));
+}
+
+// Returns the name of the requested output file, or the default if none
+// was explicitly specified.
+std::string UnitTestOptions::GetAbsolutePathToOutputFile() {
+  const char* const gtest_output_flag = GTEST_FLAG(output).c_str();
+
+  std::string format = GetOutputFormat();
+  if (format.empty())
+    format = std::string(kDefaultOutputFormat);
+
+  const char* const colon = strchr(gtest_output_flag, ':');
+  if (colon == nullptr)
+    return internal::FilePath::MakeFileName(
+        internal::FilePath(
+            UnitTest::GetInstance()->original_working_dir()),
+        internal::FilePath(kDefaultOutputFile), 0,
+        format.c_str()).string();
+
+  internal::FilePath output_name(colon + 1);
+  if (!output_name.IsAbsolutePath())
+    output_name = internal::FilePath::ConcatPaths(
+        internal::FilePath(UnitTest::GetInstance()->original_working_dir()),
+        internal::FilePath(colon + 1));
+
+  if (!output_name.IsDirectory())
+    return output_name.string();
+
+  internal::FilePath result(internal::FilePath::GenerateUniqueFileName(
+      output_name, internal::GetCurrentExecutableName(),
+      GetOutputFormat().c_str()));
+  return result.string();
+}
+
+// Returns true if and only if the wildcard pattern matches the string.
+// The first ':' or '\0' character in pattern marks the end of it.
+//
+// This recursive algorithm isn't very efficient, but is clear and
+// works well enough for matching test names, which are short.
+bool UnitTestOptions::PatternMatchesString(const char *pattern,
+                                           const char *str) {
+  switch (*pattern) {
+    case '\0':
+    case ':':  // Either ':' or '\0' marks the end of the pattern.
+      return *str == '\0';
+    case '?':  // Matches any single character.
+      return *str != '\0' && PatternMatchesString(pattern + 1, str + 1);
+    case '*':  // Matches any string (possibly empty) of characters.
+      return (*str != '\0' && PatternMatchesString(pattern, str + 1)) ||
+          PatternMatchesString(pattern + 1, str);
+    default:  // Non-special character.  Matches itself.
+      return *pattern == *str &&
+          PatternMatchesString(pattern + 1, str + 1);
+  }
+}
+
+bool UnitTestOptions::MatchesFilter(
+    const std::string& name, const char* filter) {
+  const char *cur_pattern = filter;
+  for (;;) {
+    if (PatternMatchesString(cur_pattern, name.c_str())) {
+      return true;
+    }
+
+    // Finds the next pattern in the filter.
+    cur_pattern = strchr(cur_pattern, ':');
+
+    // Returns if no more pattern can be found.
+    if (cur_pattern == nullptr) {
+      return false;
+    }
+
+    // Skips the pattern separater (the ':' character).
+    cur_pattern++;
+  }
+}
+
+// Returns true if and only if the user-specified filter matches the test
+// suite name and the test name.
+bool UnitTestOptions::FilterMatchesTest(const std::string& test_suite_name,
+                                        const std::string& test_name) {
+  const std::string& full_name = test_suite_name + "." + test_name.c_str();
+
+  // Split --gtest_filter at '-', if there is one, to separate into
+  // positive filter and negative filter portions
+  const char* const p = GTEST_FLAG(filter).c_str();
+  const char* const dash = strchr(p, '-');
+  std::string positive;
+  std::string negative;
+  if (dash == nullptr) {
+    positive = GTEST_FLAG(filter).c_str();  // Whole string is a positive filter
+    negative = "";
+  } else {
+    positive = std::string(p, dash);   // Everything up to the dash
+    negative = std::string(dash + 1);  // Everything after the dash
+    if (positive.empty()) {
+      // Treat '-test1' as the same as '*-test1'
+      positive = kUniversalFilter;
+    }
+  }
+
+  // A filter is a colon-separated list of patterns.  It matches a
+  // test if any pattern in it matches the test.
+  return (MatchesFilter(full_name, positive.c_str()) &&
+          !MatchesFilter(full_name, negative.c_str()));
+}
+
+#if GTEST_HAS_SEH
+// Returns EXCEPTION_EXECUTE_HANDLER if Google Test should handle the
+// given SEH exception, or EXCEPTION_CONTINUE_SEARCH otherwise.
+// This function is useful as an __except condition.
+int UnitTestOptions::GTestShouldProcessSEH(DWORD exception_code) {
+  // Google Test should handle a SEH exception if:
+  //   1. the user wants it to, AND
+  //   2. this is not a breakpoint exception, AND
+  //   3. this is not a C++ exception (VC++ implements them via SEH,
+  //      apparently).
+  //
+  // SEH exception code for C++ exceptions.
+  // (see http://support.microsoft.com/kb/185294 for more information).
+  const DWORD kCxxExceptionCode = 0xe06d7363;
+
+  bool should_handle = true;
+
+  if (!GTEST_FLAG(catch_exceptions))
+    should_handle = false;
+  else if (exception_code == EXCEPTION_BREAKPOINT)
+    should_handle = false;
+  else if (exception_code == kCxxExceptionCode)
+    should_handle = false;
+
+  return should_handle ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH;
+}
+#endif  // GTEST_HAS_SEH
+
+}  // namespace internal
+
+// The c'tor sets this object as the test part result reporter used by
+// Google Test.  The 'result' parameter specifies where to report the
+// results. Intercepts only failures from the current thread.
+ScopedFakeTestPartResultReporter::ScopedFakeTestPartResultReporter(
+    TestPartResultArray* result)
+    : intercept_mode_(INTERCEPT_ONLY_CURRENT_THREAD),
+      result_(result) {
+  Init();
+}
+
+// The c'tor sets this object as the test part result reporter used by
+// Google Test.  The 'result' parameter specifies where to report the
+// results.
+ScopedFakeTestPartResultReporter::ScopedFakeTestPartResultReporter(
+    InterceptMode intercept_mode, TestPartResultArray* result)
+    : intercept_mode_(intercept_mode),
+      result_(result) {
+  Init();
+}
+
+void ScopedFakeTestPartResultReporter::Init() {
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  if (intercept_mode_ == INTERCEPT_ALL_THREADS) {
+    old_reporter_ = impl->GetGlobalTestPartResultReporter();
+    impl->SetGlobalTestPartResultReporter(this);
+  } else {
+    old_reporter_ = impl->GetTestPartResultReporterForCurrentThread();
+    impl->SetTestPartResultReporterForCurrentThread(this);
+  }
+}
+
+// The d'tor restores the test part result reporter used by Google Test
+// before.
+ScopedFakeTestPartResultReporter::~ScopedFakeTestPartResultReporter() {
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  if (intercept_mode_ == INTERCEPT_ALL_THREADS) {
+    impl->SetGlobalTestPartResultReporter(old_reporter_);
+  } else {
+    impl->SetTestPartResultReporterForCurrentThread(old_reporter_);
+  }
+}
+
+// Increments the test part result count and remembers the result.
+// This method is from the TestPartResultReporterInterface interface.
+void ScopedFakeTestPartResultReporter::ReportTestPartResult(
+    const TestPartResult& result) {
+  result_->Append(result);
+}
+
+namespace internal {
+
+// Returns the type ID of ::testing::Test.  We should always call this
+// instead of GetTypeId< ::testing::Test>() to get the type ID of
+// testing::Test.  This is to work around a suspected linker bug when
+// using Google Test as a framework on Mac OS X.  The bug causes
+// GetTypeId< ::testing::Test>() to return different values depending
+// on whether the call is from the Google Test framework itself or
+// from user test code.  GetTestTypeId() is guaranteed to always
+// return the same value, as it always calls GetTypeId<>() from the
+// gtest.cc, which is within the Google Test framework.
+TypeId GetTestTypeId() {
+  return GetTypeId<Test>();
+}
+
+// The value of GetTestTypeId() as seen from within the Google Test
+// library.  This is solely for testing GetTestTypeId().
+extern const TypeId kTestTypeIdInGoogleTest = GetTestTypeId();
+
+// This predicate-formatter checks that 'results' contains a test part
+// failure of the given type and that the failure message contains the
+// given substring.
+static AssertionResult HasOneFailure(const char* /* results_expr */,
+                                     const char* /* type_expr */,
+                                     const char* /* substr_expr */,
+                                     const TestPartResultArray& results,
+                                     TestPartResult::Type type,
+                                     const std::string& substr) {
+  const std::string expected(type == TestPartResult::kFatalFailure ?
+                        "1 fatal failure" :
+                        "1 non-fatal failure");
+  Message msg;
+  if (results.size() != 1) {
+    msg << "Expected: " << expected << "\n"
+        << "  Actual: " << results.size() << " failures";
+    for (int i = 0; i < results.size(); i++) {
+      msg << "\n" << results.GetTestPartResult(i);
+    }
+    return AssertionFailure() << msg;
+  }
+
+  const TestPartResult& r = results.GetTestPartResult(0);
+  if (r.type() != type) {
+    return AssertionFailure() << "Expected: " << expected << "\n"
+                              << "  Actual:\n"
+                              << r;
+  }
+
+  if (strstr(r.message(), substr.c_str()) == nullptr) {
+    return AssertionFailure() << "Expected: " << expected << " containing \""
+                              << substr << "\"\n"
+                              << "  Actual:\n"
+                              << r;
+  }
+
+  return AssertionSuccess();
+}
+
+// The constructor of SingleFailureChecker remembers where to look up
+// test part results, what type of failure we expect, and what
+// substring the failure message should contain.
+SingleFailureChecker::SingleFailureChecker(const TestPartResultArray* results,
+                                           TestPartResult::Type type,
+                                           const std::string& substr)
+    : results_(results), type_(type), substr_(substr) {}
+
+// The destructor of SingleFailureChecker verifies that the given
+// TestPartResultArray contains exactly one failure that has the given
+// type and contains the given substring.  If that's not the case, a
+// non-fatal failure will be generated.
+SingleFailureChecker::~SingleFailureChecker() {
+  EXPECT_PRED_FORMAT3(HasOneFailure, *results_, type_, substr_);
+}
+
+DefaultGlobalTestPartResultReporter::DefaultGlobalTestPartResultReporter(
+    UnitTestImpl* unit_test) : unit_test_(unit_test) {}
+
+void DefaultGlobalTestPartResultReporter::ReportTestPartResult(
+    const TestPartResult& result) {
+  unit_test_->current_test_result()->AddTestPartResult(result);
+  unit_test_->listeners()->repeater()->OnTestPartResult(result);
+}
+
+DefaultPerThreadTestPartResultReporter::DefaultPerThreadTestPartResultReporter(
+    UnitTestImpl* unit_test) : unit_test_(unit_test) {}
+
+void DefaultPerThreadTestPartResultReporter::ReportTestPartResult(
+    const TestPartResult& result) {
+  unit_test_->GetGlobalTestPartResultReporter()->ReportTestPartResult(result);
+}
+
+// Returns the global test part result reporter.
+TestPartResultReporterInterface*
+UnitTestImpl::GetGlobalTestPartResultReporter() {
+  internal::MutexLock lock(&global_test_part_result_reporter_mutex_);
+  return global_test_part_result_repoter_;
+}
+
+// Sets the global test part result reporter.
+void UnitTestImpl::SetGlobalTestPartResultReporter(
+    TestPartResultReporterInterface* reporter) {
+  internal::MutexLock lock(&global_test_part_result_reporter_mutex_);
+  global_test_part_result_repoter_ = reporter;
+}
+
+// Returns the test part result reporter for the current thread.
+TestPartResultReporterInterface*
+UnitTestImpl::GetTestPartResultReporterForCurrentThread() {
+  return per_thread_test_part_result_reporter_.get();
+}
+
+// Sets the test part result reporter for the current thread.
+void UnitTestImpl::SetTestPartResultReporterForCurrentThread(
+    TestPartResultReporterInterface* reporter) {
+  per_thread_test_part_result_reporter_.set(reporter);
+}
+
+// Gets the number of successful test suites.
+int UnitTestImpl::successful_test_suite_count() const {
+  return CountIf(test_suites_, TestSuitePassed);
+}
+
+// Gets the number of failed test suites.
+int UnitTestImpl::failed_test_suite_count() const {
+  return CountIf(test_suites_, TestSuiteFailed);
+}
+
+// Gets the number of all test suites.
+int UnitTestImpl::total_test_suite_count() const {
+  return static_cast<int>(test_suites_.size());
+}
+
+// Gets the number of all test suites that contain at least one test
+// that should run.
+int UnitTestImpl::test_suite_to_run_count() const {
+  return CountIf(test_suites_, ShouldRunTestSuite);
+}
+
+// Gets the number of successful tests.
+int UnitTestImpl::successful_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::successful_test_count);
+}
+
+// Gets the number of skipped tests.
+int UnitTestImpl::skipped_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::skipped_test_count);
+}
+
+// Gets the number of failed tests.
+int UnitTestImpl::failed_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::failed_test_count);
+}
+
+// Gets the number of disabled tests that will be reported in the XML report.
+int UnitTestImpl::reportable_disabled_test_count() const {
+  return SumOverTestSuiteList(test_suites_,
+                              &TestSuite::reportable_disabled_test_count);
+}
+
+// Gets the number of disabled tests.
+int UnitTestImpl::disabled_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::disabled_test_count);
+}
+
+// Gets the number of tests to be printed in the XML report.
+int UnitTestImpl::reportable_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::reportable_test_count);
+}
+
+// Gets the number of all tests.
+int UnitTestImpl::total_test_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::total_test_count);
+}
+
+// Gets the number of tests that should run.
+int UnitTestImpl::test_to_run_count() const {
+  return SumOverTestSuiteList(test_suites_, &TestSuite::test_to_run_count);
+}
+
+// Returns the current OS stack trace as an std::string.
+//
+// The maximum number of stack frames to be included is specified by
+// the gtest_stack_trace_depth flag.  The skip_count parameter
+// specifies the number of top frames to be skipped, which doesn't
+// count against the number of frames to be included.
+//
+// For example, if Foo() calls Bar(), which in turn calls
+// CurrentOsStackTraceExceptTop(1), Foo() will be included in the
+// trace but Bar() and CurrentOsStackTraceExceptTop() won't.
+std::string UnitTestImpl::CurrentOsStackTraceExceptTop(int skip_count) {
+  return os_stack_trace_getter()->CurrentStackTrace(
+      static_cast<int>(GTEST_FLAG(stack_trace_depth)),
+      skip_count + 1
+      // Skips the user-specified number of frames plus this function
+      // itself.
+      );  // NOLINT
+}
+
+// Returns the current time in milliseconds.
+TimeInMillis GetTimeInMillis() {
+#if GTEST_OS_WINDOWS_MOBILE || defined(__BORLANDC__)
+  // Difference between 1970-01-01 and 1601-01-01 in milliseconds.
+  // http://analogous.blogspot.com/2005/04/epoch.html
+  const TimeInMillis kJavaEpochToWinFileTimeDelta =
+    static_cast<TimeInMillis>(116444736UL) * 100000UL;
+  const DWORD kTenthMicrosInMilliSecond = 10000;
+
+  SYSTEMTIME now_systime;
+  FILETIME now_filetime;
+  ULARGE_INTEGER now_int64;
+  GetSystemTime(&now_systime);
+  if (SystemTimeToFileTime(&now_systime, &now_filetime)) {
+    now_int64.LowPart = now_filetime.dwLowDateTime;
+    now_int64.HighPart = now_filetime.dwHighDateTime;
+    now_int64.QuadPart = (now_int64.QuadPart / kTenthMicrosInMilliSecond) -
+      kJavaEpochToWinFileTimeDelta;
+    return now_int64.QuadPart;
+  }
+  return 0;
+#elif GTEST_OS_WINDOWS && !GTEST_HAS_GETTIMEOFDAY_
+  __timeb64 now;
+
+  // MSVC 8 deprecates _ftime64(), so we want to suppress warning 4996
+  // (deprecated function) there.
+  GTEST_DISABLE_MSC_DEPRECATED_PUSH_()
+  _ftime64(&now);
+  GTEST_DISABLE_MSC_DEPRECATED_POP_()
+
+  return static_cast<TimeInMillis>(now.time) * 1000 + now.millitm;
+#elif GTEST_HAS_GETTIMEOFDAY_
+  struct timeval now;
+  gettimeofday(&now, nullptr);
+  return static_cast<TimeInMillis>(now.tv_sec) * 1000 + now.tv_usec / 1000;
+#else
+# error "Don't know how to get the current time on your system."
+#endif
+}
+
+// Utilities
+
+// class String.
+
+#if GTEST_OS_WINDOWS_MOBILE
+// Creates a UTF-16 wide string from the given ANSI string, allocating
+// memory using new. The caller is responsible for deleting the return
+// value using delete[]. Returns the wide string, or NULL if the
+// input is NULL.
+LPCWSTR String::AnsiToUtf16(const char* ansi) {
+  if (!ansi) return nullptr;
+  const int length = strlen(ansi);
+  const int unicode_length =
+      MultiByteToWideChar(CP_ACP, 0, ansi, length, nullptr, 0);
+  WCHAR* unicode = new WCHAR[unicode_length + 1];
+  MultiByteToWideChar(CP_ACP, 0, ansi, length,
+                      unicode, unicode_length);
+  unicode[unicode_length] = 0;
+  return unicode;
+}
+
+// Creates an ANSI string from the given wide string, allocating
+// memory using new. The caller is responsible for deleting the return
+// value using delete[]. Returns the ANSI string, or NULL if the
+// input is NULL.
+const char* String::Utf16ToAnsi(LPCWSTR utf16_str)  {
+  if (!utf16_str) return nullptr;
+  const int ansi_length = WideCharToMultiByte(CP_ACP, 0, utf16_str, -1, nullptr,
+                                              0, nullptr, nullptr);
+  char* ansi = new char[ansi_length + 1];
+  WideCharToMultiByte(CP_ACP, 0, utf16_str, -1, ansi, ansi_length, nullptr,
+                      nullptr);
+  ansi[ansi_length] = 0;
+  return ansi;
+}
+
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+// Compares two C strings.  Returns true if and only if they have the same
+// content.
+//
+// Unlike strcmp(), this function can handle NULL argument(s).  A NULL
+// C string is considered different to any non-NULL C string,
+// including the empty string.
+bool String::CStringEquals(const char * lhs, const char * rhs) {
+  if (lhs == nullptr) return rhs == nullptr;
+
+  if (rhs == nullptr) return false;
+
+  return strcmp(lhs, rhs) == 0;
+}
+
+#if GTEST_HAS_STD_WSTRING
+
+// Converts an array of wide chars to a narrow string using the UTF-8
+// encoding, and streams the result to the given Message object.
+static void StreamWideCharsToMessage(const wchar_t* wstr, size_t length,
+                                     Message* msg) {
+  for (size_t i = 0; i != length; ) {  // NOLINT
+    if (wstr[i] != L'\0') {
+      *msg << WideStringToUtf8(wstr + i, static_cast<int>(length - i));
+      while (i != length && wstr[i] != L'\0')
+        i++;
+    } else {
+      *msg << '\0';
+      i++;
+    }
+  }
+}
+
+#endif  // GTEST_HAS_STD_WSTRING
+
+void SplitString(const ::std::string& str, char delimiter,
+                 ::std::vector< ::std::string>* dest) {
+  ::std::vector< ::std::string> parsed;
+  ::std::string::size_type pos = 0;
+  while (::testing::internal::AlwaysTrue()) {
+    const ::std::string::size_type colon = str.find(delimiter, pos);
+    if (colon == ::std::string::npos) {
+      parsed.push_back(str.substr(pos));
+      break;
+    } else {
+      parsed.push_back(str.substr(pos, colon - pos));
+      pos = colon + 1;
+    }
+  }
+  dest->swap(parsed);
+}
+
+}  // namespace internal
+
+// Constructs an empty Message.
+// We allocate the stringstream separately because otherwise each use of
+// ASSERT/EXPECT in a procedure adds over 200 bytes to the procedure's
+// stack frame leading to huge stack frames in some cases; gcc does not reuse
+// the stack space.
+Message::Message() : ss_(new ::std::stringstream) {
+  // By default, we want there to be enough precision when printing
+  // a double to a Message.
+  *ss_ << std::setprecision(std::numeric_limits<double>::digits10 + 2);
+}
+
+// These two overloads allow streaming a wide C string to a Message
+// using the UTF-8 encoding.
+Message& Message::operator <<(const wchar_t* wide_c_str) {
+  return *this << internal::String::ShowWideCString(wide_c_str);
+}
+Message& Message::operator <<(wchar_t* wide_c_str) {
+  return *this << internal::String::ShowWideCString(wide_c_str);
+}
+
+#if GTEST_HAS_STD_WSTRING
+// Converts the given wide string to a narrow string using the UTF-8
+// encoding, and streams the result to this Message object.
+Message& Message::operator <<(const ::std::wstring& wstr) {
+  internal::StreamWideCharsToMessage(wstr.c_str(), wstr.length(), this);
+  return *this;
+}
+#endif  // GTEST_HAS_STD_WSTRING
+
+// Gets the text streamed to this object so far as an std::string.
+// Each '\0' character in the buffer is replaced with "\\0".
+std::string Message::GetString() const {
+  return internal::StringStreamToString(ss_.get());
+}
+
+// AssertionResult constructors.
+// Used in EXPECT_TRUE/FALSE(assertion_result).
+AssertionResult::AssertionResult(const AssertionResult& other)
+    : success_(other.success_),
+      message_(other.message_.get() != nullptr
+                   ? new ::std::string(*other.message_)
+                   : static_cast< ::std::string*>(nullptr)) {}
+
+// Swaps two AssertionResults.
+void AssertionResult::swap(AssertionResult& other) {
+  using std::swap;
+  swap(success_, other.success_);
+  swap(message_, other.message_);
+}
+
+// Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
+AssertionResult AssertionResult::operator!() const {
+  AssertionResult negation(!success_);
+  if (message_.get() != nullptr) negation << *message_;
+  return negation;
+}
+
+// Makes a successful assertion result.
+AssertionResult AssertionSuccess() {
+  return AssertionResult(true);
+}
+
+// Makes a failed assertion result.
+AssertionResult AssertionFailure() {
+  return AssertionResult(false);
+}
+
+// Makes a failed assertion result with the given failure message.
+// Deprecated; use AssertionFailure() << message.
+AssertionResult AssertionFailure(const Message& message) {
+  return AssertionFailure() << message;
+}
+
+namespace internal {
+
+namespace edit_distance {
+std::vector<EditType> CalculateOptimalEdits(const std::vector<size_t>& left,
+                                            const std::vector<size_t>& right) {
+  std::vector<std::vector<double> > costs(
+      left.size() + 1, std::vector<double>(right.size() + 1));
+  std::vector<std::vector<EditType> > best_move(
+      left.size() + 1, std::vector<EditType>(right.size() + 1));
+
+  // Populate for empty right.
+  for (size_t l_i = 0; l_i < costs.size(); ++l_i) {
+    costs[l_i][0] = static_cast<double>(l_i);
+    best_move[l_i][0] = kRemove;
+  }
+  // Populate for empty left.
+  for (size_t r_i = 1; r_i < costs[0].size(); ++r_i) {
+    costs[0][r_i] = static_cast<double>(r_i);
+    best_move[0][r_i] = kAdd;
+  }
+
+  for (size_t l_i = 0; l_i < left.size(); ++l_i) {
+    for (size_t r_i = 0; r_i < right.size(); ++r_i) {
+      if (left[l_i] == right[r_i]) {
+        // Found a match. Consume it.
+        costs[l_i + 1][r_i + 1] = costs[l_i][r_i];
+        best_move[l_i + 1][r_i + 1] = kMatch;
+        continue;
+      }
+
+      const double add = costs[l_i + 1][r_i];
+      const double remove = costs[l_i][r_i + 1];
+      const double replace = costs[l_i][r_i];
+      if (add < remove && add < replace) {
+        costs[l_i + 1][r_i + 1] = add + 1;
+        best_move[l_i + 1][r_i + 1] = kAdd;
+      } else if (remove < add && remove < replace) {
+        costs[l_i + 1][r_i + 1] = remove + 1;
+        best_move[l_i + 1][r_i + 1] = kRemove;
+      } else {
+        // We make replace a little more expensive than add/remove to lower
+        // their priority.
+        costs[l_i + 1][r_i + 1] = replace + 1.00001;
+        best_move[l_i + 1][r_i + 1] = kReplace;
+      }
+    }
+  }
+
+  // Reconstruct the best path. We do it in reverse order.
+  std::vector<EditType> best_path;
+  for (size_t l_i = left.size(), r_i = right.size(); l_i > 0 || r_i > 0;) {
+    EditType move = best_move[l_i][r_i];
+    best_path.push_back(move);
+    l_i -= move != kAdd;
+    r_i -= move != kRemove;
+  }
+  std::reverse(best_path.begin(), best_path.end());
+  return best_path;
+}
+
+namespace {
+
+// Helper class to convert string into ids with deduplication.
+class InternalStrings {
+ public:
+  size_t GetId(const std::string& str) {
+    IdMap::iterator it = ids_.find(str);
+    if (it != ids_.end()) return it->second;
+    size_t id = ids_.size();
+    return ids_[str] = id;
+  }
+
+ private:
+  typedef std::map<std::string, size_t> IdMap;
+  IdMap ids_;
+};
+
+}  // namespace
+
+std::vector<EditType> CalculateOptimalEdits(
+    const std::vector<std::string>& left,
+    const std::vector<std::string>& right) {
+  std::vector<size_t> left_ids, right_ids;
+  {
+    InternalStrings intern_table;
+    for (size_t i = 0; i < left.size(); ++i) {
+      left_ids.push_back(intern_table.GetId(left[i]));
+    }
+    for (size_t i = 0; i < right.size(); ++i) {
+      right_ids.push_back(intern_table.GetId(right[i]));
+    }
+  }
+  return CalculateOptimalEdits(left_ids, right_ids);
+}
+
+namespace {
+
+// Helper class that holds the state for one hunk and prints it out to the
+// stream.
+// It reorders adds/removes when possible to group all removes before all
+// adds. It also adds the hunk header before printint into the stream.
+class Hunk {
+ public:
+  Hunk(size_t left_start, size_t right_start)
+      : left_start_(left_start),
+        right_start_(right_start),
+        adds_(),
+        removes_(),
+        common_() {}
+
+  void PushLine(char edit, const char* line) {
+    switch (edit) {
+      case ' ':
+        ++common_;
+        FlushEdits();
+        hunk_.push_back(std::make_pair(' ', line));
+        break;
+      case '-':
+        ++removes_;
+        hunk_removes_.push_back(std::make_pair('-', line));
+        break;
+      case '+':
+        ++adds_;
+        hunk_adds_.push_back(std::make_pair('+', line));
+        break;
+    }
+  }
+
+  void PrintTo(std::ostream* os) {
+    PrintHeader(os);
+    FlushEdits();
+    for (std::list<std::pair<char, const char*> >::const_iterator it =
+             hunk_.begin();
+         it != hunk_.end(); ++it) {
+      *os << it->first << it->second << "\n";
+    }
+  }
+
+  bool has_edits() const { return adds_ || removes_; }
+
+ private:
+  void FlushEdits() {
+    hunk_.splice(hunk_.end(), hunk_removes_);
+    hunk_.splice(hunk_.end(), hunk_adds_);
+  }
+
+  // Print a unified diff header for one hunk.
+  // The format is
+  //   "@@ -<left_start>,<left_length> +<right_start>,<right_length> @@"
+  // where the left/right parts are omitted if unnecessary.
+  void PrintHeader(std::ostream* ss) const {
+    *ss << "@@ ";
+    if (removes_) {
+      *ss << "-" << left_start_ << "," << (removes_ + common_);
+    }
+    if (removes_ && adds_) {
+      *ss << " ";
+    }
+    if (adds_) {
+      *ss << "+" << right_start_ << "," << (adds_ + common_);
+    }
+    *ss << " @@\n";
+  }
+
+  size_t left_start_, right_start_;
+  size_t adds_, removes_, common_;
+  std::list<std::pair<char, const char*> > hunk_, hunk_adds_, hunk_removes_;
+};
+
+}  // namespace
+
+// Create a list of diff hunks in Unified diff format.
+// Each hunk has a header generated by PrintHeader above plus a body with
+// lines prefixed with ' ' for no change, '-' for deletion and '+' for
+// addition.
+// 'context' represents the desired unchanged prefix/suffix around the diff.
+// If two hunks are close enough that their contexts overlap, then they are
+// joined into one hunk.
+std::string CreateUnifiedDiff(const std::vector<std::string>& left,
+                              const std::vector<std::string>& right,
+                              size_t context) {
+  const std::vector<EditType> edits = CalculateOptimalEdits(left, right);
+
+  size_t l_i = 0, r_i = 0, edit_i = 0;
+  std::stringstream ss;
+  while (edit_i < edits.size()) {
+    // Find first edit.
+    while (edit_i < edits.size() && edits[edit_i] == kMatch) {
+      ++l_i;
+      ++r_i;
+      ++edit_i;
+    }
+
+    // Find the first line to include in the hunk.
+    const size_t prefix_context = std::min(l_i, context);
+    Hunk hunk(l_i - prefix_context + 1, r_i - prefix_context + 1);
+    for (size_t i = prefix_context; i > 0; --i) {
+      hunk.PushLine(' ', left[l_i - i].c_str());
+    }
+
+    // Iterate the edits until we found enough suffix for the hunk or the input
+    // is over.
+    size_t n_suffix = 0;
+    for (; edit_i < edits.size(); ++edit_i) {
+      if (n_suffix >= context) {
+        // Continue only if the next hunk is very close.
+        auto it = edits.begin() + static_cast<int>(edit_i);
+        while (it != edits.end() && *it == kMatch) ++it;
+        if (it == edits.end() ||
+            static_cast<size_t>(it - edits.begin()) - edit_i >= context) {
+          // There is no next edit or it is too far away.
+          break;
+        }
+      }
+
+      EditType edit = edits[edit_i];
+      // Reset count when a non match is found.
+      n_suffix = edit == kMatch ? n_suffix + 1 : 0;
+
+      if (edit == kMatch || edit == kRemove || edit == kReplace) {
+        hunk.PushLine(edit == kMatch ? ' ' : '-', left[l_i].c_str());
+      }
+      if (edit == kAdd || edit == kReplace) {
+        hunk.PushLine('+', right[r_i].c_str());
+      }
+
+      // Advance indices, depending on edit type.
+      l_i += edit != kAdd;
+      r_i += edit != kRemove;
+    }
+
+    if (!hunk.has_edits()) {
+      // We are done. We don't want this hunk.
+      break;
+    }
+
+    hunk.PrintTo(&ss);
+  }
+  return ss.str();
+}
+
+}  // namespace edit_distance
+
+namespace {
+
+// The string representation of the values received in EqFailure() are already
+// escaped. Split them on escaped '\n' boundaries. Leave all other escaped
+// characters the same.
+std::vector<std::string> SplitEscapedString(const std::string& str) {
+  std::vector<std::string> lines;
+  size_t start = 0, end = str.size();
+  if (end > 2 && str[0] == '"' && str[end - 1] == '"') {
+    ++start;
+    --end;
+  }
+  bool escaped = false;
+  for (size_t i = start; i + 1 < end; ++i) {
+    if (escaped) {
+      escaped = false;
+      if (str[i] == 'n') {
+        lines.push_back(str.substr(start, i - start - 1));
+        start = i + 1;
+      }
+    } else {
+      escaped = str[i] == '\\';
+    }
+  }
+  lines.push_back(str.substr(start, end - start));
+  return lines;
+}
+
+}  // namespace
+
+// Constructs and returns the message for an equality assertion
+// (e.g. ASSERT_EQ, EXPECT_STREQ, etc) failure.
+//
+// The first four parameters are the expressions used in the assertion
+// and their values, as strings.  For example, for ASSERT_EQ(foo, bar)
+// where foo is 5 and bar is 6, we have:
+//
+//   lhs_expression: "foo"
+//   rhs_expression: "bar"
+//   lhs_value:      "5"
+//   rhs_value:      "6"
+//
+// The ignoring_case parameter is true if and only if the assertion is a
+// *_STRCASEEQ*.  When it's true, the string "Ignoring case" will
+// be inserted into the message.
+AssertionResult EqFailure(const char* lhs_expression,
+                          const char* rhs_expression,
+                          const std::string& lhs_value,
+                          const std::string& rhs_value,
+                          bool ignoring_case) {
+  Message msg;
+  msg << "Expected equality of these values:";
+  msg << "\n  " << lhs_expression;
+  if (lhs_value != lhs_expression) {
+    msg << "\n    Which is: " << lhs_value;
+  }
+  msg << "\n  " << rhs_expression;
+  if (rhs_value != rhs_expression) {
+    msg << "\n    Which is: " << rhs_value;
+  }
+
+  if (ignoring_case) {
+    msg << "\nIgnoring case";
+  }
+
+  if (!lhs_value.empty() && !rhs_value.empty()) {
+    const std::vector<std::string> lhs_lines =
+        SplitEscapedString(lhs_value);
+    const std::vector<std::string> rhs_lines =
+        SplitEscapedString(rhs_value);
+    if (lhs_lines.size() > 1 || rhs_lines.size() > 1) {
+      msg << "\nWith diff:\n"
+          << edit_distance::CreateUnifiedDiff(lhs_lines, rhs_lines);
+    }
+  }
+
+  return AssertionFailure() << msg;
+}
+
+// Constructs a failure message for Boolean assertions such as EXPECT_TRUE.
+std::string GetBoolAssertionFailureMessage(
+    const AssertionResult& assertion_result,
+    const char* expression_text,
+    const char* actual_predicate_value,
+    const char* expected_predicate_value) {
+  const char* actual_message = assertion_result.message();
+  Message msg;
+  msg << "Value of: " << expression_text
+      << "\n  Actual: " << actual_predicate_value;
+  if (actual_message[0] != '\0')
+    msg << " (" << actual_message << ")";
+  msg << "\nExpected: " << expected_predicate_value;
+  return msg.GetString();
+}
+
+// Helper function for implementing ASSERT_NEAR.
+AssertionResult DoubleNearPredFormat(const char* expr1,
+                                     const char* expr2,
+                                     const char* abs_error_expr,
+                                     double val1,
+                                     double val2,
+                                     double abs_error) {
+  const double diff = fabs(val1 - val2);
+  if (diff <= abs_error) return AssertionSuccess();
+
+  return AssertionFailure()
+      << "The difference between " << expr1 << " and " << expr2
+      << " is " << diff << ", which exceeds " << abs_error_expr << ", where\n"
+      << expr1 << " evaluates to " << val1 << ",\n"
+      << expr2 << " evaluates to " << val2 << ", and\n"
+      << abs_error_expr << " evaluates to " << abs_error << ".";
+}
+
+
+// Helper template for implementing FloatLE() and DoubleLE().
+template <typename RawType>
+AssertionResult FloatingPointLE(const char* expr1,
+                                const char* expr2,
+                                RawType val1,
+                                RawType val2) {
+  // Returns success if val1 is less than val2,
+  if (val1 < val2) {
+    return AssertionSuccess();
+  }
+
+  // or if val1 is almost equal to val2.
+  const FloatingPoint<RawType> lhs(val1), rhs(val2);
+  if (lhs.AlmostEquals(rhs)) {
+    return AssertionSuccess();
+  }
+
+  // Note that the above two checks will both fail if either val1 or
+  // val2 is NaN, as the IEEE floating-point standard requires that
+  // any predicate involving a NaN must return false.
+
+  ::std::stringstream val1_ss;
+  val1_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
+          << val1;
+
+  ::std::stringstream val2_ss;
+  val2_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
+          << val2;
+
+  return AssertionFailure()
+      << "Expected: (" << expr1 << ") <= (" << expr2 << ")\n"
+      << "  Actual: " << StringStreamToString(&val1_ss) << " vs "
+      << StringStreamToString(&val2_ss);
+}
+
+}  // namespace internal
+
+// Asserts that val1 is less than, or almost equal to, val2.  Fails
+// otherwise.  In particular, it fails if either val1 or val2 is NaN.
+AssertionResult FloatLE(const char* expr1, const char* expr2,
+                        float val1, float val2) {
+  return internal::FloatingPointLE<float>(expr1, expr2, val1, val2);
+}
+
+// Asserts that val1 is less than, or almost equal to, val2.  Fails
+// otherwise.  In particular, it fails if either val1 or val2 is NaN.
+AssertionResult DoubleLE(const char* expr1, const char* expr2,
+                         double val1, double val2) {
+  return internal::FloatingPointLE<double>(expr1, expr2, val1, val2);
+}
+
+namespace internal {
+
+// The helper function for {ASSERT|EXPECT}_EQ with int or enum
+// arguments.
+AssertionResult CmpHelperEQ(const char* lhs_expression,
+                            const char* rhs_expression,
+                            BiggestInt lhs,
+                            BiggestInt rhs) {
+  if (lhs == rhs) {
+    return AssertionSuccess();
+  }
+
+  return EqFailure(lhs_expression,
+                   rhs_expression,
+                   FormatForComparisonFailureMessage(lhs, rhs),
+                   FormatForComparisonFailureMessage(rhs, lhs),
+                   false);
+}
+
+// A macro for implementing the helper functions needed to implement
+// ASSERT_?? and EXPECT_?? with integer or enum arguments.  It is here
+// just to avoid copy-and-paste of similar code.
+#define GTEST_IMPL_CMP_HELPER_(op_name, op)\
+AssertionResult CmpHelper##op_name(const char* expr1, const char* expr2, \
+                                   BiggestInt val1, BiggestInt val2) {\
+  if (val1 op val2) {\
+    return AssertionSuccess();\
+  } else {\
+    return AssertionFailure() \
+        << "Expected: (" << expr1 << ") " #op " (" << expr2\
+        << "), actual: " << FormatForComparisonFailureMessage(val1, val2)\
+        << " vs " << FormatForComparisonFailureMessage(val2, val1);\
+  }\
+}
+
+// Implements the helper function for {ASSERT|EXPECT}_NE with int or
+// enum arguments.
+GTEST_IMPL_CMP_HELPER_(NE, !=)
+// Implements the helper function for {ASSERT|EXPECT}_LE with int or
+// enum arguments.
+GTEST_IMPL_CMP_HELPER_(LE, <=)
+// Implements the helper function for {ASSERT|EXPECT}_LT with int or
+// enum arguments.
+GTEST_IMPL_CMP_HELPER_(LT, < )
+// Implements the helper function for {ASSERT|EXPECT}_GE with int or
+// enum arguments.
+GTEST_IMPL_CMP_HELPER_(GE, >=)
+// Implements the helper function for {ASSERT|EXPECT}_GT with int or
+// enum arguments.
+GTEST_IMPL_CMP_HELPER_(GT, > )
+
+#undef GTEST_IMPL_CMP_HELPER_
+
+// The helper function for {ASSERT|EXPECT}_STREQ.
+AssertionResult CmpHelperSTREQ(const char* lhs_expression,
+                               const char* rhs_expression,
+                               const char* lhs,
+                               const char* rhs) {
+  if (String::CStringEquals(lhs, rhs)) {
+    return AssertionSuccess();
+  }
+
+  return EqFailure(lhs_expression,
+                   rhs_expression,
+                   PrintToString(lhs),
+                   PrintToString(rhs),
+                   false);
+}
+
+// The helper function for {ASSERT|EXPECT}_STRCASEEQ.
+AssertionResult CmpHelperSTRCASEEQ(const char* lhs_expression,
+                                   const char* rhs_expression,
+                                   const char* lhs,
+                                   const char* rhs) {
+  if (String::CaseInsensitiveCStringEquals(lhs, rhs)) {
+    return AssertionSuccess();
+  }
+
+  return EqFailure(lhs_expression,
+                   rhs_expression,
+                   PrintToString(lhs),
+                   PrintToString(rhs),
+                   true);
+}
+
+// The helper function for {ASSERT|EXPECT}_STRNE.
+AssertionResult CmpHelperSTRNE(const char* s1_expression,
+                               const char* s2_expression,
+                               const char* s1,
+                               const char* s2) {
+  if (!String::CStringEquals(s1, s2)) {
+    return AssertionSuccess();
+  } else {
+    return AssertionFailure() << "Expected: (" << s1_expression << ") != ("
+                              << s2_expression << "), actual: \""
+                              << s1 << "\" vs \"" << s2 << "\"";
+  }
+}
+
+// The helper function for {ASSERT|EXPECT}_STRCASENE.
+AssertionResult CmpHelperSTRCASENE(const char* s1_expression,
+                                   const char* s2_expression,
+                                   const char* s1,
+                                   const char* s2) {
+  if (!String::CaseInsensitiveCStringEquals(s1, s2)) {
+    return AssertionSuccess();
+  } else {
+    return AssertionFailure()
+        << "Expected: (" << s1_expression << ") != ("
+        << s2_expression << ") (ignoring case), actual: \""
+        << s1 << "\" vs \"" << s2 << "\"";
+  }
+}
+
+}  // namespace internal
+
+namespace {
+
+// Helper functions for implementing IsSubString() and IsNotSubstring().
+
+// This group of overloaded functions return true if and only if needle
+// is a substring of haystack.  NULL is considered a substring of
+// itself only.
+
+bool IsSubstringPred(const char* needle, const char* haystack) {
+  if (needle == nullptr || haystack == nullptr) return needle == haystack;
+
+  return strstr(haystack, needle) != nullptr;
+}
+
+bool IsSubstringPred(const wchar_t* needle, const wchar_t* haystack) {
+  if (needle == nullptr || haystack == nullptr) return needle == haystack;
+
+  return wcsstr(haystack, needle) != nullptr;
+}
+
+// StringType here can be either ::std::string or ::std::wstring.
+template <typename StringType>
+bool IsSubstringPred(const StringType& needle,
+                     const StringType& haystack) {
+  return haystack.find(needle) != StringType::npos;
+}
+
+// This function implements either IsSubstring() or IsNotSubstring(),
+// depending on the value of the expected_to_be_substring parameter.
+// StringType here can be const char*, const wchar_t*, ::std::string,
+// or ::std::wstring.
+template <typename StringType>
+AssertionResult IsSubstringImpl(
+    bool expected_to_be_substring,
+    const char* needle_expr, const char* haystack_expr,
+    const StringType& needle, const StringType& haystack) {
+  if (IsSubstringPred(needle, haystack) == expected_to_be_substring)
+    return AssertionSuccess();
+
+  const bool is_wide_string = sizeof(needle[0]) > 1;
+  const char* const begin_string_quote = is_wide_string ? "L\"" : "\"";
+  return AssertionFailure()
+      << "Value of: " << needle_expr << "\n"
+      << "  Actual: " << begin_string_quote << needle << "\"\n"
+      << "Expected: " << (expected_to_be_substring ? "" : "not ")
+      << "a substring of " << haystack_expr << "\n"
+      << "Which is: " << begin_string_quote << haystack << "\"";
+}
+
+}  // namespace
+
+// IsSubstring() and IsNotSubstring() check whether needle is a
+// substring of haystack (NULL is considered a substring of itself
+// only), and return an appropriate error message when they fail.
+
+AssertionResult IsSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const char* needle, const char* haystack) {
+  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const wchar_t* needle, const wchar_t* haystack) {
+  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsNotSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const char* needle, const char* haystack) {
+  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsNotSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const wchar_t* needle, const wchar_t* haystack) {
+  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const ::std::string& needle, const ::std::string& haystack) {
+  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsNotSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const ::std::string& needle, const ::std::string& haystack) {
+  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
+}
+
+#if GTEST_HAS_STD_WSTRING
+AssertionResult IsSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const ::std::wstring& needle, const ::std::wstring& haystack) {
+  return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
+}
+
+AssertionResult IsNotSubstring(
+    const char* needle_expr, const char* haystack_expr,
+    const ::std::wstring& needle, const ::std::wstring& haystack) {
+  return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
+}
+#endif  // GTEST_HAS_STD_WSTRING
+
+namespace internal {
+
+#if GTEST_OS_WINDOWS
+
+namespace {
+
+// Helper function for IsHRESULT{SuccessFailure} predicates
+AssertionResult HRESULTFailureHelper(const char* expr,
+                                     const char* expected,
+                                     long hr) {  // NOLINT
+# if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_TV_TITLE
+
+  // Windows CE doesn't support FormatMessage.
+  const char error_text[] = "";
+
+# else
+
+  // Looks up the human-readable system message for the HRESULT code
+  // and since we're not passing any params to FormatMessage, we don't
+  // want inserts expanded.
+  const DWORD kFlags = FORMAT_MESSAGE_FROM_SYSTEM |
+                       FORMAT_MESSAGE_IGNORE_INSERTS;
+  const DWORD kBufSize = 4096;
+  // Gets the system's human readable message string for this HRESULT.
+  char error_text[kBufSize] = { '\0' };
+  DWORD message_length = ::FormatMessageA(kFlags,
+                                          0,   // no source, we're asking system
+                                          static_cast<DWORD>(hr),  // the error
+                                          0,   // no line width restrictions
+                                          error_text,  // output buffer
+                                          kBufSize,    // buf size
+                                          nullptr);  // no arguments for inserts
+  // Trims tailing white space (FormatMessage leaves a trailing CR-LF)
+  for (; message_length && IsSpace(error_text[message_length - 1]);
+          --message_length) {
+    error_text[message_length - 1] = '\0';
+  }
+
+# endif  // GTEST_OS_WINDOWS_MOBILE
+
+  const std::string error_hex("0x" + String::FormatHexInt(hr));
+  return ::testing::AssertionFailure()
+      << "Expected: " << expr << " " << expected << ".\n"
+      << "  Actual: " << error_hex << " " << error_text << "\n";
+}
+
+}  // namespace
+
+AssertionResult IsHRESULTSuccess(const char* expr, long hr) {  // NOLINT
+  if (SUCCEEDED(hr)) {
+    return AssertionSuccess();
+  }
+  return HRESULTFailureHelper(expr, "succeeds", hr);
+}
+
+AssertionResult IsHRESULTFailure(const char* expr, long hr) {  // NOLINT
+  if (FAILED(hr)) {
+    return AssertionSuccess();
+  }
+  return HRESULTFailureHelper(expr, "fails", hr);
+}
+
+#endif  // GTEST_OS_WINDOWS
+
+// Utility functions for encoding Unicode text (wide strings) in
+// UTF-8.
+
+// A Unicode code-point can have up to 21 bits, and is encoded in UTF-8
+// like this:
+//
+// Code-point length   Encoding
+//   0 -  7 bits       0xxxxxxx
+//   8 - 11 bits       110xxxxx 10xxxxxx
+//  12 - 16 bits       1110xxxx 10xxxxxx 10xxxxxx
+//  17 - 21 bits       11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+
+// The maximum code-point a one-byte UTF-8 sequence can represent.
+const UInt32 kMaxCodePoint1 = (static_cast<UInt32>(1) <<  7) - 1;
+
+// The maximum code-point a two-byte UTF-8 sequence can represent.
+const UInt32 kMaxCodePoint2 = (static_cast<UInt32>(1) << (5 + 6)) - 1;
+
+// The maximum code-point a three-byte UTF-8 sequence can represent.
+const UInt32 kMaxCodePoint3 = (static_cast<UInt32>(1) << (4 + 2*6)) - 1;
+
+// The maximum code-point a four-byte UTF-8 sequence can represent.
+const UInt32 kMaxCodePoint4 = (static_cast<UInt32>(1) << (3 + 3*6)) - 1;
+
+// Chops off the n lowest bits from a bit pattern.  Returns the n
+// lowest bits.  As a side effect, the original bit pattern will be
+// shifted to the right by n bits.
+inline UInt32 ChopLowBits(UInt32* bits, int n) {
+  const UInt32 low_bits = *bits & ((static_cast<UInt32>(1) << n) - 1);
+  *bits >>= n;
+  return low_bits;
+}
+
+// Converts a Unicode code point to a narrow string in UTF-8 encoding.
+// code_point parameter is of type UInt32 because wchar_t may not be
+// wide enough to contain a code point.
+// If the code_point is not a valid Unicode code point
+// (i.e. outside of Unicode range U+0 to U+10FFFF) it will be converted
+// to "(Invalid Unicode 0xXXXXXXXX)".
+std::string CodePointToUtf8(UInt32 code_point) {
+  if (code_point > kMaxCodePoint4) {
+    return "(Invalid Unicode 0x" + String::FormatHexUInt32(code_point) + ")";
+  }
+
+  char str[5];  // Big enough for the largest valid code point.
+  if (code_point <= kMaxCodePoint1) {
+    str[1] = '\0';
+    str[0] = static_cast<char>(code_point);                          // 0xxxxxxx
+  } else if (code_point <= kMaxCodePoint2) {
+    str[2] = '\0';
+    str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[0] = static_cast<char>(0xC0 | code_point);                   // 110xxxxx
+  } else if (code_point <= kMaxCodePoint3) {
+    str[3] = '\0';
+    str[2] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[0] = static_cast<char>(0xE0 | code_point);                   // 1110xxxx
+  } else {  // code_point <= kMaxCodePoint4
+    str[4] = '\0';
+    str[3] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[2] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
+    str[0] = static_cast<char>(0xF0 | code_point);                   // 11110xxx
+  }
+  return str;
+}
+
+// The following two functions only make sense if the system
+// uses UTF-16 for wide string encoding. All supported systems
+// with 16 bit wchar_t (Windows, Cygwin) do use UTF-16.
+
+// Determines if the arguments constitute UTF-16 surrogate pair
+// and thus should be combined into a single Unicode code point
+// using CreateCodePointFromUtf16SurrogatePair.
+inline bool IsUtf16SurrogatePair(wchar_t first, wchar_t second) {
+  return sizeof(wchar_t) == 2 &&
+      (first & 0xFC00) == 0xD800 && (second & 0xFC00) == 0xDC00;
+}
+
+// Creates a Unicode code point from UTF16 surrogate pair.
+inline UInt32 CreateCodePointFromUtf16SurrogatePair(wchar_t first,
+                                                    wchar_t second) {
+  const auto first_u = static_cast<UInt32>(first);
+  const auto second_u = static_cast<UInt32>(second);
+  const UInt32 mask = (1 << 10) - 1;
+  return (sizeof(wchar_t) == 2)
+             ? (((first_u & mask) << 10) | (second_u & mask)) + 0x10000
+             :
+             // This function should not be called when the condition is
+             // false, but we provide a sensible default in case it is.
+             first_u;
+}
+
+// Converts a wide string to a narrow string in UTF-8 encoding.
+// The wide string is assumed to have the following encoding:
+//   UTF-16 if sizeof(wchar_t) == 2 (on Windows, Cygwin)
+//   UTF-32 if sizeof(wchar_t) == 4 (on Linux)
+// Parameter str points to a null-terminated wide string.
+// Parameter num_chars may additionally limit the number
+// of wchar_t characters processed. -1 is used when the entire string
+// should be processed.
+// If the string contains code points that are not valid Unicode code points
+// (i.e. outside of Unicode range U+0 to U+10FFFF) they will be output
+// as '(Invalid Unicode 0xXXXXXXXX)'. If the string is in UTF16 encoding
+// and contains invalid UTF-16 surrogate pairs, values in those pairs
+// will be encoded as individual Unicode characters from Basic Normal Plane.
+std::string WideStringToUtf8(const wchar_t* str, int num_chars) {
+  if (num_chars == -1)
+    num_chars = static_cast<int>(wcslen(str));
+
+  ::std::stringstream stream;
+  for (int i = 0; i < num_chars; ++i) {
+    UInt32 unicode_code_point;
+
+    if (str[i] == L'\0') {
+      break;
+    } else if (i + 1 < num_chars && IsUtf16SurrogatePair(str[i], str[i + 1])) {
+      unicode_code_point = CreateCodePointFromUtf16SurrogatePair(str[i],
+                                                                 str[i + 1]);
+      i++;
+    } else {
+      unicode_code_point = static_cast<UInt32>(str[i]);
+    }
+
+    stream << CodePointToUtf8(unicode_code_point);
+  }
+  return StringStreamToString(&stream);
+}
+
+// Converts a wide C string to an std::string using the UTF-8 encoding.
+// NULL will be converted to "(null)".
+std::string String::ShowWideCString(const wchar_t * wide_c_str) {
+  if (wide_c_str == nullptr) return "(null)";
+
+  return internal::WideStringToUtf8(wide_c_str, -1);
+}
+
+// Compares two wide C strings.  Returns true if and only if they have the
+// same content.
+//
+// Unlike wcscmp(), this function can handle NULL argument(s).  A NULL
+// C string is considered different to any non-NULL C string,
+// including the empty string.
+bool String::WideCStringEquals(const wchar_t * lhs, const wchar_t * rhs) {
+  if (lhs == nullptr) return rhs == nullptr;
+
+  if (rhs == nullptr) return false;
+
+  return wcscmp(lhs, rhs) == 0;
+}
+
+// Helper function for *_STREQ on wide strings.
+AssertionResult CmpHelperSTREQ(const char* lhs_expression,
+                               const char* rhs_expression,
+                               const wchar_t* lhs,
+                               const wchar_t* rhs) {
+  if (String::WideCStringEquals(lhs, rhs)) {
+    return AssertionSuccess();
+  }
+
+  return EqFailure(lhs_expression,
+                   rhs_expression,
+                   PrintToString(lhs),
+                   PrintToString(rhs),
+                   false);
+}
+
+// Helper function for *_STRNE on wide strings.
+AssertionResult CmpHelperSTRNE(const char* s1_expression,
+                               const char* s2_expression,
+                               const wchar_t* s1,
+                               const wchar_t* s2) {
+  if (!String::WideCStringEquals(s1, s2)) {
+    return AssertionSuccess();
+  }
+
+  return AssertionFailure() << "Expected: (" << s1_expression << ") != ("
+                            << s2_expression << "), actual: "
+                            << PrintToString(s1)
+                            << " vs " << PrintToString(s2);
+}
+
+// Compares two C strings, ignoring case.  Returns true if and only if they have
+// the same content.
+//
+// Unlike strcasecmp(), this function can handle NULL argument(s).  A
+// NULL C string is considered different to any non-NULL C string,
+// including the empty string.
+bool String::CaseInsensitiveCStringEquals(const char * lhs, const char * rhs) {
+  if (lhs == nullptr) return rhs == nullptr;
+  if (rhs == nullptr) return false;
+  return posix::StrCaseCmp(lhs, rhs) == 0;
+}
+
+// Compares two wide C strings, ignoring case.  Returns true if and only if they
+// have the same content.
+//
+// Unlike wcscasecmp(), this function can handle NULL argument(s).
+// A NULL C string is considered different to any non-NULL wide C string,
+// including the empty string.
+// NB: The implementations on different platforms slightly differ.
+// On windows, this method uses _wcsicmp which compares according to LC_CTYPE
+// environment variable. On GNU platform this method uses wcscasecmp
+// which compares according to LC_CTYPE category of the current locale.
+// On MacOS X, it uses towlower, which also uses LC_CTYPE category of the
+// current locale.
+bool String::CaseInsensitiveWideCStringEquals(const wchar_t* lhs,
+                                              const wchar_t* rhs) {
+  if (lhs == nullptr) return rhs == nullptr;
+
+  if (rhs == nullptr) return false;
+
+#if GTEST_OS_WINDOWS
+  return _wcsicmp(lhs, rhs) == 0;
+#elif GTEST_OS_LINUX && !GTEST_OS_LINUX_ANDROID
+  return wcscasecmp(lhs, rhs) == 0;
+#else
+  // Android, Mac OS X and Cygwin don't define wcscasecmp.
+  // Other unknown OSes may not define it either.
+  wint_t left, right;
+  do {
+    left = towlower(static_cast<wint_t>(*lhs++));
+    right = towlower(static_cast<wint_t>(*rhs++));
+  } while (left && left == right);
+  return left == right;
+#endif  // OS selector
+}
+
+// Returns true if and only if str ends with the given suffix, ignoring case.
+// Any string is considered to end with an empty suffix.
+bool String::EndsWithCaseInsensitive(
+    const std::string& str, const std::string& suffix) {
+  const size_t str_len = str.length();
+  const size_t suffix_len = suffix.length();
+  return (str_len >= suffix_len) &&
+         CaseInsensitiveCStringEquals(str.c_str() + str_len - suffix_len,
+                                      suffix.c_str());
+}
+
+// Formats an int value as "%02d".
+std::string String::FormatIntWidth2(int value) {
+  std::stringstream ss;
+  ss << std::setfill('0') << std::setw(2) << value;
+  return ss.str();
+}
+
+// Formats an int value as "%X".
+std::string String::FormatHexUInt32(UInt32 value) {
+  std::stringstream ss;
+  ss << std::hex << std::uppercase << value;
+  return ss.str();
+}
+
+// Formats an int value as "%X".
+std::string String::FormatHexInt(int value) {
+  return FormatHexUInt32(static_cast<UInt32>(value));
+}
+
+// Formats a byte as "%02X".
+std::string String::FormatByte(unsigned char value) {
+  std::stringstream ss;
+  ss << std::setfill('0') << std::setw(2) << std::hex << std::uppercase
+     << static_cast<unsigned int>(value);
+  return ss.str();
+}
+
+// Converts the buffer in a stringstream to an std::string, converting NUL
+// bytes to "\\0" along the way.
+std::string StringStreamToString(::std::stringstream* ss) {
+  const ::std::string& str = ss->str();
+  const char* const start = str.c_str();
+  const char* const end = start + str.length();
+
+  std::string result;
+  result.reserve(static_cast<size_t>(2 * (end - start)));
+  for (const char* ch = start; ch != end; ++ch) {
+    if (*ch == '\0') {
+      result += "\\0";  // Replaces NUL with "\\0";
+    } else {
+      result += *ch;
+    }
+  }
+
+  return result;
+}
+
+// Appends the user-supplied message to the Google-Test-generated message.
+std::string AppendUserMessage(const std::string& gtest_msg,
+                              const Message& user_msg) {
+  // Appends the user message if it's non-empty.
+  const std::string user_msg_string = user_msg.GetString();
+  if (user_msg_string.empty()) {
+    return gtest_msg;
+  }
+
+  return gtest_msg + "\n" + user_msg_string;
+}
+
+}  // namespace internal
+
+// class TestResult
+
+// Creates an empty TestResult.
+TestResult::TestResult()
+    : death_test_count_(0), start_timestamp_(0), elapsed_time_(0) {}
+
+// D'tor.
+TestResult::~TestResult() {
+}
+
+// Returns the i-th test part result among all the results. i can
+// range from 0 to total_part_count() - 1. If i is not in that range,
+// aborts the program.
+const TestPartResult& TestResult::GetTestPartResult(int i) const {
+  if (i < 0 || i >= total_part_count())
+    internal::posix::Abort();
+  return test_part_results_.at(static_cast<size_t>(i));
+}
+
+// Returns the i-th test property. i can range from 0 to
+// test_property_count() - 1. If i is not in that range, aborts the
+// program.
+const TestProperty& TestResult::GetTestProperty(int i) const {
+  if (i < 0 || i >= test_property_count())
+    internal::posix::Abort();
+  return test_properties_.at(static_cast<size_t>(i));
+}
+
+// Clears the test part results.
+void TestResult::ClearTestPartResults() {
+  test_part_results_.clear();
+}
+
+// Adds a test part result to the list.
+void TestResult::AddTestPartResult(const TestPartResult& test_part_result) {
+  test_part_results_.push_back(test_part_result);
+}
+
+// Adds a test property to the list. If a property with the same key as the
+// supplied property is already represented, the value of this test_property
+// replaces the old value for that key.
+void TestResult::RecordProperty(const std::string& xml_element,
+                                const TestProperty& test_property) {
+  if (!ValidateTestProperty(xml_element, test_property)) {
+    return;
+  }
+  internal::MutexLock lock(&test_properites_mutex_);
+  const std::vector<TestProperty>::iterator property_with_matching_key =
+      std::find_if(test_properties_.begin(), test_properties_.end(),
+                   internal::TestPropertyKeyIs(test_property.key()));
+  if (property_with_matching_key == test_properties_.end()) {
+    test_properties_.push_back(test_property);
+    return;
+  }
+  property_with_matching_key->SetValue(test_property.value());
+}
+
+// The list of reserved attributes used in the <testsuites> element of XML
+// output.
+static const char* const kReservedTestSuitesAttributes[] = {
+  "disabled",
+  "errors",
+  "failures",
+  "name",
+  "random_seed",
+  "tests",
+  "time",
+  "timestamp"
+};
+
+// The list of reserved attributes used in the <testsuite> element of XML
+// output.
+static const char* const kReservedTestSuiteAttributes[] = {
+    "disabled", "errors", "failures", "name", "tests", "time", "timestamp"};
+
+// The list of reserved attributes used in the <testcase> element of XML output.
+static const char* const kReservedTestCaseAttributes[] = {
+    "classname",   "name", "status", "time",  "type_param",
+    "value_param", "file", "line"};
+
+// Use a slightly different set for allowed output to ensure existing tests can
+// still RecordProperty("result") or "RecordProperty(timestamp")
+static const char* const kReservedOutputTestCaseAttributes[] = {
+    "classname",   "name", "status", "time",   "type_param",
+    "value_param", "file", "line",   "result", "timestamp"};
+
+template <int kSize>
+std::vector<std::string> ArrayAsVector(const char* const (&array)[kSize]) {
+  return std::vector<std::string>(array, array + kSize);
+}
+
+static std::vector<std::string> GetReservedAttributesForElement(
+    const std::string& xml_element) {
+  if (xml_element == "testsuites") {
+    return ArrayAsVector(kReservedTestSuitesAttributes);
+  } else if (xml_element == "testsuite") {
+    return ArrayAsVector(kReservedTestSuiteAttributes);
+  } else if (xml_element == "testcase") {
+    return ArrayAsVector(kReservedTestCaseAttributes);
+  } else {
+    GTEST_CHECK_(false) << "Unrecognized xml_element provided: " << xml_element;
+  }
+  // This code is unreachable but some compilers may not realizes that.
+  return std::vector<std::string>();
+}
+
+// TODO(jdesprez): Merge the two getReserved attributes once skip is improved
+static std::vector<std::string> GetReservedOutputAttributesForElement(
+    const std::string& xml_element) {
+  if (xml_element == "testsuites") {
+    return ArrayAsVector(kReservedTestSuitesAttributes);
+  } else if (xml_element == "testsuite") {
+    return ArrayAsVector(kReservedTestSuiteAttributes);
+  } else if (xml_element == "testcase") {
+    return ArrayAsVector(kReservedOutputTestCaseAttributes);
+  } else {
+    GTEST_CHECK_(false) << "Unrecognized xml_element provided: " << xml_element;
+  }
+  // This code is unreachable but some compilers may not realizes that.
+  return std::vector<std::string>();
+}
+
+static std::string FormatWordList(const std::vector<std::string>& words) {
+  Message word_list;
+  for (size_t i = 0; i < words.size(); ++i) {
+    if (i > 0 && words.size() > 2) {
+      word_list << ", ";
+    }
+    if (i == words.size() - 1) {
+      word_list << "and ";
+    }
+    word_list << "'" << words[i] << "'";
+  }
+  return word_list.GetString();
+}
+
+static bool ValidateTestPropertyName(
+    const std::string& property_name,
+    const std::vector<std::string>& reserved_names) {
+  if (std::find(reserved_names.begin(), reserved_names.end(), property_name) !=
+          reserved_names.end()) {
+    ADD_FAILURE() << "Reserved key used in RecordProperty(): " << property_name
+                  << " (" << FormatWordList(reserved_names)
+                  << " are reserved by " << GTEST_NAME_ << ")";
+    return false;
+  }
+  return true;
+}
+
+// Adds a failure if the key is a reserved attribute of the element named
+// xml_element.  Returns true if the property is valid.
+bool TestResult::ValidateTestProperty(const std::string& xml_element,
+                                      const TestProperty& test_property) {
+  return ValidateTestPropertyName(test_property.key(),
+                                  GetReservedAttributesForElement(xml_element));
+}
+
+// Clears the object.
+void TestResult::Clear() {
+  test_part_results_.clear();
+  test_properties_.clear();
+  death_test_count_ = 0;
+  elapsed_time_ = 0;
+}
+
+// Returns true off the test part was skipped.
+static bool TestPartSkipped(const TestPartResult& result) {
+  return result.skipped();
+}
+
+// Returns true if and only if the test was skipped.
+bool TestResult::Skipped() const {
+  return !Failed() && CountIf(test_part_results_, TestPartSkipped) > 0;
+}
+
+// Returns true if and only if the test failed.
+bool TestResult::Failed() const {
+  for (int i = 0; i < total_part_count(); ++i) {
+    if (GetTestPartResult(i).failed())
+      return true;
+  }
+  return false;
+}
+
+// Returns true if and only if the test part fatally failed.
+static bool TestPartFatallyFailed(const TestPartResult& result) {
+  return result.fatally_failed();
+}
+
+// Returns true if and only if the test fatally failed.
+bool TestResult::HasFatalFailure() const {
+  return CountIf(test_part_results_, TestPartFatallyFailed) > 0;
+}
+
+// Returns true if and only if the test part non-fatally failed.
+static bool TestPartNonfatallyFailed(const TestPartResult& result) {
+  return result.nonfatally_failed();
+}
+
+// Returns true if and only if the test has a non-fatal failure.
+bool TestResult::HasNonfatalFailure() const {
+  return CountIf(test_part_results_, TestPartNonfatallyFailed) > 0;
+}
+
+// Gets the number of all test parts.  This is the sum of the number
+// of successful test parts and the number of failed test parts.
+int TestResult::total_part_count() const {
+  return static_cast<int>(test_part_results_.size());
+}
+
+// Returns the number of the test properties.
+int TestResult::test_property_count() const {
+  return static_cast<int>(test_properties_.size());
+}
+
+// class Test
+
+// Creates a Test object.
+
+// The c'tor saves the states of all flags.
+Test::Test()
+    : gtest_flag_saver_(new GTEST_FLAG_SAVER_) {
+}
+
+// The d'tor restores the states of all flags.  The actual work is
+// done by the d'tor of the gtest_flag_saver_ field, and thus not
+// visible here.
+Test::~Test() {
+}
+
+// Sets up the test fixture.
+//
+// A sub-class may override this.
+void Test::SetUp() {
+}
+
+// Tears down the test fixture.
+//
+// A sub-class may override this.
+void Test::TearDown() {
+}
+
+// Allows user supplied key value pairs to be recorded for later output.
+void Test::RecordProperty(const std::string& key, const std::string& value) {
+  UnitTest::GetInstance()->RecordProperty(key, value);
+}
+
+// Allows user supplied key value pairs to be recorded for later output.
+void Test::RecordProperty(const std::string& key, int value) {
+  Message value_message;
+  value_message << value;
+  RecordProperty(key, value_message.GetString().c_str());
+}
+
+namespace internal {
+
+void ReportFailureInUnknownLocation(TestPartResult::Type result_type,
+                                    const std::string& message) {
+  // This function is a friend of UnitTest and as such has access to
+  // AddTestPartResult.
+  UnitTest::GetInstance()->AddTestPartResult(
+      result_type,
+      nullptr,  // No info about the source file where the exception occurred.
+      -1,       // We have no info on which line caused the exception.
+      message,
+      "");  // No stack trace, either.
+}
+
+}  // namespace internal
+
+// Google Test requires all tests in the same test suite to use the same test
+// fixture class.  This function checks if the current test has the
+// same fixture class as the first test in the current test suite.  If
+// yes, it returns true; otherwise it generates a Google Test failure and
+// returns false.
+bool Test::HasSameFixtureClass() {
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  const TestSuite* const test_suite = impl->current_test_suite();
+
+  // Info about the first test in the current test suite.
+  const TestInfo* const first_test_info = test_suite->test_info_list()[0];
+  const internal::TypeId first_fixture_id = first_test_info->fixture_class_id_;
+  const char* const first_test_name = first_test_info->name();
+
+  // Info about the current test.
+  const TestInfo* const this_test_info = impl->current_test_info();
+  const internal::TypeId this_fixture_id = this_test_info->fixture_class_id_;
+  const char* const this_test_name = this_test_info->name();
+
+  if (this_fixture_id != first_fixture_id) {
+    // Is the first test defined using TEST?
+    const bool first_is_TEST = first_fixture_id == internal::GetTestTypeId();
+    // Is this test defined using TEST?
+    const bool this_is_TEST = this_fixture_id == internal::GetTestTypeId();
+
+    if (first_is_TEST || this_is_TEST) {
+      // Both TEST and TEST_F appear in same test suite, which is incorrect.
+      // Tell the user how to fix this.
+
+      // Gets the name of the TEST and the name of the TEST_F.  Note
+      // that first_is_TEST and this_is_TEST cannot both be true, as
+      // the fixture IDs are different for the two tests.
+      const char* const TEST_name =
+          first_is_TEST ? first_test_name : this_test_name;
+      const char* const TEST_F_name =
+          first_is_TEST ? this_test_name : first_test_name;
+
+      ADD_FAILURE()
+          << "All tests in the same test suite must use the same test fixture\n"
+          << "class, so mixing TEST_F and TEST in the same test suite is\n"
+          << "illegal.  In test suite " << this_test_info->test_suite_name()
+          << ",\n"
+          << "test " << TEST_F_name << " is defined using TEST_F but\n"
+          << "test " << TEST_name << " is defined using TEST.  You probably\n"
+          << "want to change the TEST to TEST_F or move it to another test\n"
+          << "case.";
+    } else {
+      // Two fixture classes with the same name appear in two different
+      // namespaces, which is not allowed. Tell the user how to fix this.
+      ADD_FAILURE()
+          << "All tests in the same test suite must use the same test fixture\n"
+          << "class.  However, in test suite "
+          << this_test_info->test_suite_name() << ",\n"
+          << "you defined test " << first_test_name << " and test "
+          << this_test_name << "\n"
+          << "using two different test fixture classes.  This can happen if\n"
+          << "the two classes are from different namespaces or translation\n"
+          << "units and have the same name.  You should probably rename one\n"
+          << "of the classes to put the tests into different test suites.";
+    }
+    return false;
+  }
+
+  return true;
+}
+
+#if GTEST_HAS_SEH
+
+// Adds an "exception thrown" fatal failure to the current test.  This
+// function returns its result via an output parameter pointer because VC++
+// prohibits creation of objects with destructors on stack in functions
+// using __try (see error C2712).
+static std::string* FormatSehExceptionMessage(DWORD exception_code,
+                                              const char* location) {
+  Message message;
+  message << "SEH exception with code 0x" << std::setbase(16) <<
+    exception_code << std::setbase(10) << " thrown in " << location << ".";
+
+  return new std::string(message.GetString());
+}
+
+#endif  // GTEST_HAS_SEH
+
+namespace internal {
+
+#if GTEST_HAS_EXCEPTIONS
+
+// Adds an "exception thrown" fatal failure to the current test.
+static std::string FormatCxxExceptionMessage(const char* description,
+                                             const char* location) {
+  Message message;
+  if (description != nullptr) {
+    message << "C++ exception with description \"" << description << "\"";
+  } else {
+    message << "Unknown C++ exception";
+  }
+  message << " thrown in " << location << ".";
+
+  return message.GetString();
+}
+
+static std::string PrintTestPartResultToString(
+    const TestPartResult& test_part_result);
+
+GoogleTestFailureException::GoogleTestFailureException(
+    const TestPartResult& failure)
+    : ::std::runtime_error(PrintTestPartResultToString(failure).c_str()) {}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// We put these helper functions in the internal namespace as IBM's xlC
+// compiler rejects the code if they were declared static.
+
+// Runs the given method and handles SEH exceptions it throws, when
+// SEH is supported; returns the 0-value for type Result in case of an
+// SEH exception.  (Microsoft compilers cannot handle SEH and C++
+// exceptions in the same function.  Therefore, we provide a separate
+// wrapper function for handling SEH exceptions.)
+template <class T, typename Result>
+Result HandleSehExceptionsInMethodIfSupported(
+    T* object, Result (T::*method)(), const char* location) {
+#if GTEST_HAS_SEH
+  __try {
+    return (object->*method)();
+  } __except (internal::UnitTestOptions::GTestShouldProcessSEH(  // NOLINT
+      GetExceptionCode())) {
+    // We create the exception message on the heap because VC++ prohibits
+    // creation of objects with destructors on stack in functions using __try
+    // (see error C2712).
+    std::string* exception_message = FormatSehExceptionMessage(
+        GetExceptionCode(), location);
+    internal::ReportFailureInUnknownLocation(TestPartResult::kFatalFailure,
+                                             *exception_message);
+    delete exception_message;
+    return static_cast<Result>(0);
+  }
+#else
+  (void)location;
+  return (object->*method)();
+#endif  // GTEST_HAS_SEH
+}
+
+// Runs the given method and catches and reports C++ and/or SEH-style
+// exceptions, if they are supported; returns the 0-value for type
+// Result in case of an SEH exception.
+template <class T, typename Result>
+Result HandleExceptionsInMethodIfSupported(
+    T* object, Result (T::*method)(), const char* location) {
+  // NOTE: The user code can affect the way in which Google Test handles
+  // exceptions by setting GTEST_FLAG(catch_exceptions), but only before
+  // RUN_ALL_TESTS() starts. It is technically possible to check the flag
+  // after the exception is caught and either report or re-throw the
+  // exception based on the flag's value:
+  //
+  // try {
+  //   // Perform the test method.
+  // } catch (...) {
+  //   if (GTEST_FLAG(catch_exceptions))
+  //     // Report the exception as failure.
+  //   else
+  //     throw;  // Re-throws the original exception.
+  // }
+  //
+  // However, the purpose of this flag is to allow the program to drop into
+  // the debugger when the exception is thrown. On most platforms, once the
+  // control enters the catch block, the exception origin information is
+  // lost and the debugger will stop the program at the point of the
+  // re-throw in this function -- instead of at the point of the original
+  // throw statement in the code under test.  For this reason, we perform
+  // the check early, sacrificing the ability to affect Google Test's
+  // exception handling in the method where the exception is thrown.
+  if (internal::GetUnitTestImpl()->catch_exceptions()) {
+#if GTEST_HAS_EXCEPTIONS
+    try {
+      return HandleSehExceptionsInMethodIfSupported(object, method, location);
+    } catch (const AssertionException&) {  // NOLINT
+      // This failure was reported already.
+    } catch (const internal::GoogleTestFailureException&) {  // NOLINT
+      // This exception type can only be thrown by a failed Google
+      // Test assertion with the intention of letting another testing
+      // framework catch it.  Therefore we just re-throw it.
+      throw;
+    } catch (const std::exception& e) {  // NOLINT
+      internal::ReportFailureInUnknownLocation(
+          TestPartResult::kFatalFailure,
+          FormatCxxExceptionMessage(e.what(), location));
+    } catch (...) {  // NOLINT
+      internal::ReportFailureInUnknownLocation(
+          TestPartResult::kFatalFailure,
+          FormatCxxExceptionMessage(nullptr, location));
+    }
+    return static_cast<Result>(0);
+#else
+    return HandleSehExceptionsInMethodIfSupported(object, method, location);
+#endif  // GTEST_HAS_EXCEPTIONS
+  } else {
+    return (object->*method)();
+  }
+}
+
+}  // namespace internal
+
+// Runs the test and updates the test result.
+void Test::Run() {
+  if (!HasSameFixtureClass()) return;
+
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+  internal::HandleExceptionsInMethodIfSupported(this, &Test::SetUp, "SetUp()");
+  // We will run the test only if SetUp() was successful and didn't call
+  // GTEST_SKIP().
+  if (!HasFatalFailure() && !IsSkipped()) {
+    impl->os_stack_trace_getter()->UponLeavingGTest();
+    internal::HandleExceptionsInMethodIfSupported(
+        this, &Test::TestBody, "the test body");
+  }
+
+  // However, we want to clean up as much as possible.  Hence we will
+  // always call TearDown(), even if SetUp() or the test body has
+  // failed.
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+  internal::HandleExceptionsInMethodIfSupported(
+      this, &Test::TearDown, "TearDown()");
+}
+
+// Returns true if and only if the current test has a fatal failure.
+bool Test::HasFatalFailure() {
+  return internal::GetUnitTestImpl()->current_test_result()->HasFatalFailure();
+}
+
+// Returns true if and only if the current test has a non-fatal failure.
+bool Test::HasNonfatalFailure() {
+  return internal::GetUnitTestImpl()->current_test_result()->
+      HasNonfatalFailure();
+}
+
+// Returns true if and only if the current test was skipped.
+bool Test::IsSkipped() {
+  return internal::GetUnitTestImpl()->current_test_result()->Skipped();
+}
+
+// class TestInfo
+
+// Constructs a TestInfo object. It assumes ownership of the test factory
+// object.
+TestInfo::TestInfo(const std::string& a_test_suite_name,
+                   const std::string& a_name, const char* a_type_param,
+                   const char* a_value_param,
+                   internal::CodeLocation a_code_location,
+                   internal::TypeId fixture_class_id,
+                   internal::TestFactoryBase* factory)
+    : test_suite_name_(a_test_suite_name),
+      name_(a_name),
+      type_param_(a_type_param ? new std::string(a_type_param) : nullptr),
+      value_param_(a_value_param ? new std::string(a_value_param) : nullptr),
+      location_(a_code_location),
+      fixture_class_id_(fixture_class_id),
+      should_run_(false),
+      is_disabled_(false),
+      matches_filter_(false),
+      factory_(factory),
+      result_() {}
+
+// Destructs a TestInfo object.
+TestInfo::~TestInfo() { delete factory_; }
+
+namespace internal {
+
+// Creates a new TestInfo object and registers it with Google Test;
+// returns the created object.
+//
+// Arguments:
+//
+//   test_suite_name:   name of the test suite
+//   name:             name of the test
+//   type_param:       the name of the test's type parameter, or NULL if
+//                     this is not a typed or a type-parameterized test.
+//   value_param:      text representation of the test's value parameter,
+//                     or NULL if this is not a value-parameterized test.
+//   code_location:    code location where the test is defined
+//   fixture_class_id: ID of the test fixture class
+//   set_up_tc:        pointer to the function that sets up the test suite
+//   tear_down_tc:     pointer to the function that tears down the test suite
+//   factory:          pointer to the factory that creates a test object.
+//                     The newly created TestInfo instance will assume
+//                     ownership of the factory object.
+TestInfo* MakeAndRegisterTestInfo(
+    const char* test_suite_name, const char* name, const char* type_param,
+    const char* value_param, CodeLocation code_location,
+    TypeId fixture_class_id, SetUpTestSuiteFunc set_up_tc,
+    TearDownTestSuiteFunc tear_down_tc, TestFactoryBase* factory) {
+  TestInfo* const test_info =
+      new TestInfo(test_suite_name, name, type_param, value_param,
+                   code_location, fixture_class_id, factory);
+  GetUnitTestImpl()->AddTestInfo(set_up_tc, tear_down_tc, test_info);
+  return test_info;
+}
+
+void ReportInvalidTestSuiteType(const char* test_suite_name,
+                                CodeLocation code_location) {
+  Message errors;
+  errors
+      << "Attempted redefinition of test suite " << test_suite_name << ".\n"
+      << "All tests in the same test suite must use the same test fixture\n"
+      << "class.  However, in test suite " << test_suite_name << ", you tried\n"
+      << "to define a test using a fixture class different from the one\n"
+      << "used earlier. This can happen if the two fixture classes are\n"
+      << "from different namespaces and have the same name. You should\n"
+      << "probably rename one of the classes to put the tests into different\n"
+      << "test suites.";
+
+  GTEST_LOG_(ERROR) << FormatFileLocation(code_location.file.c_str(),
+                                          code_location.line)
+                    << " " << errors.GetString();
+}
+}  // namespace internal
+
+namespace {
+
+// A predicate that checks the test name of a TestInfo against a known
+// value.
+//
+// This is used for implementation of the TestSuite class only.  We put
+// it in the anonymous namespace to prevent polluting the outer
+// namespace.
+//
+// TestNameIs is copyable.
+class TestNameIs {
+ public:
+  // Constructor.
+  //
+  // TestNameIs has NO default constructor.
+  explicit TestNameIs(const char* name)
+      : name_(name) {}
+
+  // Returns true if and only if the test name of test_info matches name_.
+  bool operator()(const TestInfo * test_info) const {
+    return test_info && test_info->name() == name_;
+  }
+
+ private:
+  std::string name_;
+};
+
+}  // namespace
+
+namespace internal {
+
+// This method expands all parameterized tests registered with macros TEST_P
+// and INSTANTIATE_TEST_SUITE_P into regular tests and registers those.
+// This will be done just once during the program runtime.
+void UnitTestImpl::RegisterParameterizedTests() {
+  if (!parameterized_tests_registered_) {
+    parameterized_test_registry_.RegisterTests();
+    parameterized_tests_registered_ = true;
+  }
+}
+
+}  // namespace internal
+
+// Creates the test object, runs it, records its result, and then
+// deletes it.
+void TestInfo::Run() {
+  if (!should_run_) return;
+
+  // Tells UnitTest where to store test result.
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  impl->set_current_test_info(this);
+
+  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
+
+  // Notifies the unit test event listeners that a test is about to start.
+  repeater->OnTestStart(*this);
+
+  const TimeInMillis start = internal::GetTimeInMillis();
+
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+
+  // Creates the test object.
+  Test* const test = internal::HandleExceptionsInMethodIfSupported(
+      factory_, &internal::TestFactoryBase::CreateTest,
+      "the test fixture's constructor");
+
+  // Runs the test if the constructor didn't generate a fatal failure or invoke
+  // GTEST_SKIP().
+  // Note that the object will not be null
+  if (!Test::HasFatalFailure() && !Test::IsSkipped()) {
+    // This doesn't throw as all user code that can throw are wrapped into
+    // exception handling code.
+    test->Run();
+  }
+
+  if (test != nullptr) {
+    // Deletes the test object.
+    impl->os_stack_trace_getter()->UponLeavingGTest();
+    internal::HandleExceptionsInMethodIfSupported(
+        test, &Test::DeleteSelf_, "the test fixture's destructor");
+  }
+
+  result_.set_start_timestamp(start);
+  result_.set_elapsed_time(internal::GetTimeInMillis() - start);
+
+  // Notifies the unit test event listener that a test has just finished.
+  repeater->OnTestEnd(*this);
+
+  // Tells UnitTest to stop associating assertion results to this
+  // test.
+  impl->set_current_test_info(nullptr);
+}
+
+// class TestSuite
+
+// Gets the number of successful tests in this test suite.
+int TestSuite::successful_test_count() const {
+  return CountIf(test_info_list_, TestPassed);
+}
+
+// Gets the number of successful tests in this test suite.
+int TestSuite::skipped_test_count() const {
+  return CountIf(test_info_list_, TestSkipped);
+}
+
+// Gets the number of failed tests in this test suite.
+int TestSuite::failed_test_count() const {
+  return CountIf(test_info_list_, TestFailed);
+}
+
+// Gets the number of disabled tests that will be reported in the XML report.
+int TestSuite::reportable_disabled_test_count() const {
+  return CountIf(test_info_list_, TestReportableDisabled);
+}
+
+// Gets the number of disabled tests in this test suite.
+int TestSuite::disabled_test_count() const {
+  return CountIf(test_info_list_, TestDisabled);
+}
+
+// Gets the number of tests to be printed in the XML report.
+int TestSuite::reportable_test_count() const {
+  return CountIf(test_info_list_, TestReportable);
+}
+
+// Get the number of tests in this test suite that should run.
+int TestSuite::test_to_run_count() const {
+  return CountIf(test_info_list_, ShouldRunTest);
+}
+
+// Gets the number of all tests.
+int TestSuite::total_test_count() const {
+  return static_cast<int>(test_info_list_.size());
+}
+
+// Creates a TestSuite with the given name.
+//
+// Arguments:
+//
+//   name:         name of the test suite
+//   a_type_param: the name of the test suite's type parameter, or NULL if
+//                 this is not a typed or a type-parameterized test suite.
+//   set_up_tc:    pointer to the function that sets up the test suite
+//   tear_down_tc: pointer to the function that tears down the test suite
+TestSuite::TestSuite(const char* a_name, const char* a_type_param,
+                     internal::SetUpTestSuiteFunc set_up_tc,
+                     internal::TearDownTestSuiteFunc tear_down_tc)
+    : name_(a_name),
+      type_param_(a_type_param ? new std::string(a_type_param) : nullptr),
+      set_up_tc_(set_up_tc),
+      tear_down_tc_(tear_down_tc),
+      should_run_(false),
+      start_timestamp_(0),
+      elapsed_time_(0) {}
+
+// Destructor of TestSuite.
+TestSuite::~TestSuite() {
+  // Deletes every Test in the collection.
+  ForEach(test_info_list_, internal::Delete<TestInfo>);
+}
+
+// Returns the i-th test among all the tests. i can range from 0 to
+// total_test_count() - 1. If i is not in that range, returns NULL.
+const TestInfo* TestSuite::GetTestInfo(int i) const {
+  const int index = GetElementOr(test_indices_, i, -1);
+  return index < 0 ? nullptr : test_info_list_[static_cast<size_t>(index)];
+}
+
+// Returns the i-th test among all the tests. i can range from 0 to
+// total_test_count() - 1. If i is not in that range, returns NULL.
+TestInfo* TestSuite::GetMutableTestInfo(int i) {
+  const int index = GetElementOr(test_indices_, i, -1);
+  return index < 0 ? nullptr : test_info_list_[static_cast<size_t>(index)];
+}
+
+// Adds a test to this test suite.  Will delete the test upon
+// destruction of the TestSuite object.
+void TestSuite::AddTestInfo(TestInfo* test_info) {
+  test_info_list_.push_back(test_info);
+  test_indices_.push_back(static_cast<int>(test_indices_.size()));
+}
+
+// Runs every test in this TestSuite.
+void TestSuite::Run() {
+  if (!should_run_) return;
+
+  internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
+  impl->set_current_test_suite(this);
+
+  TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
+
+  // Call both legacy and the new API
+  repeater->OnTestSuiteStart(*this);
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI
+  repeater->OnTestCaseStart(*this);
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI
+
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+  internal::HandleExceptionsInMethodIfSupported(
+      this, &TestSuite::RunSetUpTestSuite, "SetUpTestSuite()");
+
+  start_timestamp_ = internal::GetTimeInMillis();
+  for (int i = 0; i < total_test_count(); i++) {
+    GetMutableTestInfo(i)->Run();
+  }
+  elapsed_time_ = internal::GetTimeInMillis() - start_timestamp_;
+
+  impl->os_stack_trace_getter()->UponLeavingGTest();
+  internal::HandleExceptionsInMethodIfSupported(
+      this, &TestSuite::RunTearDownTestSuite, "TearDownTestSuite()");
+
+  // Call both legacy and the new API
+  repeater->OnTestSuiteEnd(*this);
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI
+  repeater->OnTestCaseEnd(*this);
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI
+
+  impl->set_current_test_suite(nullptr);
+}
+
+// Clears the results of all tests in this test suite.
+void TestSuite::ClearResult() {
+  ad_hoc_test_result_.Clear();
+  ForEach(test_info_list_, TestInfo::ClearTestResult);
+}
+
+// Shuffles the tests in this test suite.
+void TestSuite::ShuffleTests(internal::Random* random) {
+  Shuffle(random, &test_indices_);
+}
+
+// Restores the test order to before the first shuffle.
+void TestSuite::UnshuffleTests() {
+  for (size_t i = 0; i < test_indices_.size(); i++) {
+    test_indices_[i] = static_cast<int>(i);
+  }
+}
+
+// Formats a countable noun.  Depending on its quantity, either the
+// singular form or the plural form is used. e.g.
+//
+// FormatCountableNoun(1, "formula", "formuli") returns "1 formula".
+// FormatCountableNoun(5, "book", "books") returns "5 books".
+static std::string FormatCountableNoun(int count,
+                                       const char * singular_form,
+                                       const char * plural_form) {
+  return internal::StreamableToString(count) + " " +
+      (count == 1 ? singular_form : plural_form);
+}
+
+// Formats the count of tests.
+static std::string FormatTestCount(int test_count) {
+  return FormatCountableNoun(test_count, "test", "tests");
+}
+
+// Formats the count of test suites.
+static std::string FormatTestSuiteCount(int test_suite_count) {
+  return FormatCountableNoun(test_suite_count, "test suite", "test suites");
+}
+
+// Converts a TestPartResult::Type enum to human-friendly string
+// representation.  Both kNonFatalFailure and kFatalFailure are translated
+// to "Failure", as the user usually doesn't care about the difference
+// between the two when viewing the test result.
+static const char * TestPartResultTypeToString(TestPartResult::Type type) {
+  switch (type) {
+    case TestPartResult::kSkip:
+      return "Skipped";
+    case TestPartResult::kSuccess:
+      return "Success";
+
+    case TestPartResult::kNonFatalFailure:
+    case TestPartResult::kFatalFailure:
+#ifdef _MSC_VER
+      return "error: ";
+#else
+      return "Failure\n";
+#endif
+    default:
+      return "Unknown result type";
+  }
+}
+
+namespace internal {
+
+// Prints a TestPartResult to an std::string.
+static std::string PrintTestPartResultToString(
+    const TestPartResult& test_part_result) {
+  return (Message()
+          << internal::FormatFileLocation(test_part_result.file_name(),
+                                          test_part_result.line_number())
+          << " " << TestPartResultTypeToString(test_part_result.type())
+          << test_part_result.message()).GetString();
+}
+
+// Prints a TestPartResult.
+static void PrintTestPartResult(const TestPartResult& test_part_result) {
+  const std::string& result =
+      PrintTestPartResultToString(test_part_result);
+  printf("%s\n", result.c_str());
+  fflush(stdout);
+  // If the test program runs in Visual Studio or a debugger, the
+  // following statements add the test part result message to the Output
+  // window such that the user can double-click on it to jump to the
+  // corresponding source code location; otherwise they do nothing.
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
+  // We don't call OutputDebugString*() on Windows Mobile, as printing
+  // to stdout is done by OutputDebugString() there already - we don't
+  // want the same message printed twice.
+  ::OutputDebugStringA(result.c_str());
+  ::OutputDebugStringA("\n");
+#endif
+}
+
+// class PrettyUnitTestResultPrinter
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE && \
+    !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT && !GTEST_OS_WINDOWS_MINGW
+
+// Returns the character attribute for the given color.
+static WORD GetColorAttribute(GTestColor color) {
+  switch (color) {
+    case COLOR_RED:    return FOREGROUND_RED;
+    case COLOR_GREEN:  return FOREGROUND_GREEN;
+    case COLOR_YELLOW: return FOREGROUND_RED | FOREGROUND_GREEN;
+    default:           return 0;
+  }
+}
+
+static int GetBitOffset(WORD color_mask) {
+  if (color_mask == 0) return 0;
+
+  int bitOffset = 0;
+  while ((color_mask & 1) == 0) {
+    color_mask >>= 1;
+    ++bitOffset;
+  }
+  return bitOffset;
+}
+
+static WORD GetNewColor(GTestColor color, WORD old_color_attrs) {
+  // Let's reuse the BG
+  static const WORD background_mask = BACKGROUND_BLUE | BACKGROUND_GREEN |
+                                      BACKGROUND_RED | BACKGROUND_INTENSITY;
+  static const WORD foreground_mask = FOREGROUND_BLUE | FOREGROUND_GREEN |
+                                      FOREGROUND_RED | FOREGROUND_INTENSITY;
+  const WORD existing_bg = old_color_attrs & background_mask;
+
+  WORD new_color =
+      GetColorAttribute(color) | existing_bg | FOREGROUND_INTENSITY;
+  static const int bg_bitOffset = GetBitOffset(background_mask);
+  static const int fg_bitOffset = GetBitOffset(foreground_mask);
+
+  if (((new_color & background_mask) >> bg_bitOffset) ==
+      ((new_color & foreground_mask) >> fg_bitOffset)) {
+    new_color ^= FOREGROUND_INTENSITY;  // invert intensity
+  }
+  return new_color;
+}
+
+#else
+
+// Returns the ANSI color code for the given color.  COLOR_DEFAULT is
+// an invalid input.
+static const char* GetAnsiColorCode(GTestColor color) {
+  switch (color) {
+    case COLOR_RED:     return "1";
+    case COLOR_GREEN:   return "2";
+    case COLOR_YELLOW:  return "3";
+    default:
+      return nullptr;
+  }
+}
+
+#endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
+
+// Returns true if and only if Google Test should use colors in the output.
+bool ShouldUseColor(bool stdout_is_tty) {
+  const char* const gtest_color = GTEST_FLAG(color).c_str();
+
+  if (String::CaseInsensitiveCStringEquals(gtest_color, "auto")) {
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
+    // On Windows the TERM variable is usually not set, but the
+    // console there does support colors.
+    return stdout_is_tty;
+#else
+    // On non-Windows platforms, we rely on the TERM variable.
+    const char* const term = posix::GetEnv("TERM");
+    const bool term_supports_color =
+        String::CStringEquals(term, "xterm") ||
+        String::CStringEquals(term, "xterm-color") ||
+        String::CStringEquals(term, "xterm-256color") ||
+        String::CStringEquals(term, "screen") ||
+        String::CStringEquals(term, "screen-256color") ||
+        String::CStringEquals(term, "tmux") ||
+        String::CStringEquals(term, "tmux-256color") ||
+        String::CStringEquals(term, "rxvt-unicode") ||
+        String::CStringEquals(term, "rxvt-unicode-256color") ||
+        String::CStringEquals(term, "linux") ||
+        String::CStringEquals(term, "cygwin");
+    return stdout_is_tty && term_supports_color;
+#endif  // GTEST_OS_WINDOWS
+  }
+
+  return String::CaseInsensitiveCStringEquals(gtest_color, "yes") ||
+      String::CaseInsensitiveCStringEquals(gtest_color, "true") ||
+      String::CaseInsensitiveCStringEquals(gtest_color, "t") ||
+      String::CStringEquals(gtest_color, "1");
+  // We take "yes", "true", "t", and "1" as meaning "yes".  If the
+  // value is neither one of these nor "auto", we treat it as "no" to
+  // be conservative.
+}
+
+// Helpers for printing colored strings to stdout. Note that on Windows, we
+// cannot simply emit special characters and have the terminal change colors.
+// This routine must actually emit the characters rather than return a string
+// that would be colored when printed, as can be done on Linux.
+void ColoredPrintf(GTestColor color, const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+
+#if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_ZOS || GTEST_OS_IOS || \
+    GTEST_OS_WINDOWS_PHONE || GTEST_OS_WINDOWS_RT || defined(ESP_PLATFORM)
+  const bool use_color = AlwaysFalse();
+#else
+  static const bool in_color_mode =
+      ShouldUseColor(posix::IsATTY(posix::FileNo(stdout)) != 0);
+  const bool use_color = in_color_mode && (color != COLOR_DEFAULT);
+#endif  // GTEST_OS_WINDOWS_MOBILE || GTEST_OS_ZOS
+
+  if (!use_color) {
+    vprintf(fmt, args);
+    va_end(args);
+    return;
+  }
+
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE && \
+    !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT && !GTEST_OS_WINDOWS_MINGW
+  const HANDLE stdout_handle = GetStdHandle(STD_OUTPUT_HANDLE);
+
+  // Gets the current text color.
+  CONSOLE_SCREEN_BUFFER_INFO buffer_info;
+  GetConsoleScreenBufferInfo(stdout_handle, &buffer_info);
+  const WORD old_color_attrs = buffer_info.wAttributes;
+  const WORD new_color = GetNewColor(color, old_color_attrs);
+
+  // We need to flush the stream buffers into the console before each
+  // SetConsoleTextAttribute call lest it affect the text that is already
+  // printed but has not yet reached the console.
+  fflush(stdout);
+  SetConsoleTextAttribute(stdout_handle, new_color);
+
+  vprintf(fmt, args);
+
+  fflush(stdout);
+  // Restores the text color.
+  SetConsoleTextAttribute(stdout_handle, old_color_attrs);
+#else
+  printf("\033[0;3%sm", GetAnsiColorCode(color));
+  vprintf(fmt, args);
+  printf("\033[m");  // Resets the terminal to default.
+#endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
+  va_end(args);
+}
+
+// Text printed in Google Test's text output and --gtest_list_tests
+// output to label the type parameter and value parameter for a test.
+static const char kTypeParamLabel[] = "TypeParam";
+static const char kValueParamLabel[] = "GetParam()";
+
+static void PrintFullTestCommentIfPresent(const TestInfo& test_info) {
+  const char* const type_param = test_info.type_param();
+  const char* const value_param = test_info.value_param();
+
+  if (type_param != nullptr || value_param != nullptr) {
+    printf(", where ");
+    if (type_param != nullptr) {
+      printf("%s = %s", kTypeParamLabel, type_param);
+      if (value_param != nullptr) printf(" and ");
+    }
+    if (value_param != nullptr) {
+      printf("%s = %s", kValueParamLabel, value_param);
+    }
+  }
+}
+
+// This class implements the TestEventListener interface.
+//
+// Class PrettyUnitTestResultPrinter is copyable.
+class PrettyUnitTestResultPrinter : public TestEventListener {
+ public:
+  PrettyUnitTestResultPrinter() {}
+  static void PrintTestName(const char* test_suite, const char* test) {
+    printf("%s.%s", test_suite, test);
+  }
+
+  // The following methods override what's in the TestEventListener class.
+  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationStart(const UnitTest& unit_test, int iteration) override;
+  void OnEnvironmentsSetUpStart(const UnitTest& unit_test) override;
+  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseStart(const TestCase& test_case) override;
+#else
+  void OnTestSuiteStart(const TestSuite& test_suite) override;
+#endif  // OnTestCaseStart
+
+  void OnTestStart(const TestInfo& test_info) override;
+
+  void OnTestPartResult(const TestPartResult& result) override;
+  void OnTestEnd(const TestInfo& test_info) override;
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseEnd(const TestCase& test_case) override;
+#else
+  void OnTestSuiteEnd(const TestSuite& test_suite) override;
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  void OnEnvironmentsTearDownStart(const UnitTest& unit_test) override;
+  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
+
+ private:
+  static void PrintFailedTests(const UnitTest& unit_test);
+  static void PrintSkippedTests(const UnitTest& unit_test);
+};
+
+  // Fired before each iteration of tests starts.
+void PrettyUnitTestResultPrinter::OnTestIterationStart(
+    const UnitTest& unit_test, int iteration) {
+  if (GTEST_FLAG(repeat) != 1)
+    printf("\nRepeating all tests (iteration %d) . . .\n\n", iteration + 1);
+
+  const char* const filter = GTEST_FLAG(filter).c_str();
+
+  // Prints the filter if it's not *.  This reminds the user that some
+  // tests may be skipped.
+  if (!String::CStringEquals(filter, kUniversalFilter)) {
+    ColoredPrintf(COLOR_YELLOW,
+                  "Note: %s filter = %s\n", GTEST_NAME_, filter);
+  }
+
+  if (internal::ShouldShard(kTestTotalShards, kTestShardIndex, false)) {
+    const Int32 shard_index = Int32FromEnvOrDie(kTestShardIndex, -1);
+    ColoredPrintf(COLOR_YELLOW,
+                  "Note: This is test shard %d of %s.\n",
+                  static_cast<int>(shard_index) + 1,
+                  internal::posix::GetEnv(kTestTotalShards));
+  }
+
+  if (GTEST_FLAG(shuffle)) {
+    ColoredPrintf(COLOR_YELLOW,
+                  "Note: Randomizing tests' orders with a seed of %d .\n",
+                  unit_test.random_seed());
+  }
+
+  ColoredPrintf(COLOR_GREEN,  "[==========] ");
+  printf("Running %s from %s.\n",
+         FormatTestCount(unit_test.test_to_run_count()).c_str(),
+         FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
+  fflush(stdout);
+}
+
+void PrettyUnitTestResultPrinter::OnEnvironmentsSetUpStart(
+    const UnitTest& /*unit_test*/) {
+  ColoredPrintf(COLOR_GREEN,  "[----------] ");
+  printf("Global test environment set-up.\n");
+  fflush(stdout);
+}
+
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+void PrettyUnitTestResultPrinter::OnTestCaseStart(const TestCase& test_case) {
+  const std::string counts =
+      FormatCountableNoun(test_case.test_to_run_count(), "test", "tests");
+  ColoredPrintf(COLOR_GREEN, "[----------] ");
+  printf("%s from %s", counts.c_str(), test_case.name());
+  if (test_case.type_param() == nullptr) {
+    printf("\n");
+  } else {
+    printf(", where %s = %s\n", kTypeParamLabel, test_case.type_param());
+  }
+  fflush(stdout);
+}
+#else
+void PrettyUnitTestResultPrinter::OnTestSuiteStart(
+    const TestSuite& test_suite) {
+  const std::string counts =
+      FormatCountableNoun(test_suite.test_to_run_count(), "test", "tests");
+  ColoredPrintf(COLOR_GREEN, "[----------] ");
+  printf("%s from %s", counts.c_str(), test_suite.name());
+  if (test_suite.type_param() == nullptr) {
+    printf("\n");
+  } else {
+    printf(", where %s = %s\n", kTypeParamLabel, test_suite.type_param());
+  }
+  fflush(stdout);
+}
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+void PrettyUnitTestResultPrinter::OnTestStart(const TestInfo& test_info) {
+  ColoredPrintf(COLOR_GREEN,  "[ RUN      ] ");
+  PrintTestName(test_info.test_suite_name(), test_info.name());
+  printf("\n");
+  fflush(stdout);
+}
+
+// Called after an assertion failure.
+void PrettyUnitTestResultPrinter::OnTestPartResult(
+    const TestPartResult& result) {
+  switch (result.type()) {
+    // If the test part succeeded, or was skipped,
+    // we don't need to do anything.
+    case TestPartResult::kSkip:
+    case TestPartResult::kSuccess:
+      return;
+    default:
+      // Print failure message from the assertion
+      // (e.g. expected this and got that).
+      PrintTestPartResult(result);
+      fflush(stdout);
+  }
+}
+
+void PrettyUnitTestResultPrinter::OnTestEnd(const TestInfo& test_info) {
+  if (test_info.result()->Passed()) {
+    ColoredPrintf(COLOR_GREEN, "[       OK ] ");
+  } else if (test_info.result()->Skipped()) {
+    ColoredPrintf(COLOR_GREEN, "[  SKIPPED ] ");
+  } else {
+    ColoredPrintf(COLOR_RED, "[  FAILED  ] ");
+  }
+  PrintTestName(test_info.test_suite_name(), test_info.name());
+  if (test_info.result()->Failed())
+    PrintFullTestCommentIfPresent(test_info);
+
+  if (GTEST_FLAG(print_time)) {
+    printf(" (%s ms)\n", internal::StreamableToString(
+           test_info.result()->elapsed_time()).c_str());
+  } else {
+    printf("\n");
+  }
+  fflush(stdout);
+}
+
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+void PrettyUnitTestResultPrinter::OnTestCaseEnd(const TestCase& test_case) {
+  if (!GTEST_FLAG(print_time)) return;
+
+  const std::string counts =
+      FormatCountableNoun(test_case.test_to_run_count(), "test", "tests");
+  ColoredPrintf(COLOR_GREEN, "[----------] ");
+  printf("%s from %s (%s ms total)\n\n", counts.c_str(), test_case.name(),
+         internal::StreamableToString(test_case.elapsed_time()).c_str());
+  fflush(stdout);
+}
+#else
+void PrettyUnitTestResultPrinter::OnTestSuiteEnd(const TestSuite& test_suite) {
+  if (!GTEST_FLAG(print_time)) return;
+
+  const std::string counts =
+      FormatCountableNoun(test_suite.test_to_run_count(), "test", "tests");
+  ColoredPrintf(COLOR_GREEN, "[----------] ");
+  printf("%s from %s (%s ms total)\n\n", counts.c_str(), test_suite.name(),
+         internal::StreamableToString(test_suite.elapsed_time()).c_str());
+  fflush(stdout);
+}
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+void PrettyUnitTestResultPrinter::OnEnvironmentsTearDownStart(
+    const UnitTest& /*unit_test*/) {
+  ColoredPrintf(COLOR_GREEN,  "[----------] ");
+  printf("Global test environment tear-down\n");
+  fflush(stdout);
+}
+
+// Internal helper for printing the list of failed tests.
+void PrettyUnitTestResultPrinter::PrintFailedTests(const UnitTest& unit_test) {
+  const int failed_test_count = unit_test.failed_test_count();
+  if (failed_test_count == 0) {
+    return;
+  }
+
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    const TestSuite& test_suite = *unit_test.GetTestSuite(i);
+    if (!test_suite.should_run() || (test_suite.failed_test_count() == 0)) {
+      continue;
+    }
+    for (int j = 0; j < test_suite.total_test_count(); ++j) {
+      const TestInfo& test_info = *test_suite.GetTestInfo(j);
+      if (!test_info.should_run() || !test_info.result()->Failed()) {
+        continue;
+      }
+      ColoredPrintf(COLOR_RED, "[  FAILED  ] ");
+      printf("%s.%s", test_suite.name(), test_info.name());
+      PrintFullTestCommentIfPresent(test_info);
+      printf("\n");
+    }
+  }
+}
+
+// Internal helper for printing the list of skipped tests.
+void PrettyUnitTestResultPrinter::PrintSkippedTests(const UnitTest& unit_test) {
+  const int skipped_test_count = unit_test.skipped_test_count();
+  if (skipped_test_count == 0) {
+    return;
+  }
+
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    const TestSuite& test_suite = *unit_test.GetTestSuite(i);
+    if (!test_suite.should_run() || (test_suite.skipped_test_count() == 0)) {
+      continue;
+    }
+    for (int j = 0; j < test_suite.total_test_count(); ++j) {
+      const TestInfo& test_info = *test_suite.GetTestInfo(j);
+      if (!test_info.should_run() || !test_info.result()->Skipped()) {
+        continue;
+      }
+      ColoredPrintf(COLOR_GREEN, "[  SKIPPED ] ");
+      printf("%s.%s", test_suite.name(), test_info.name());
+      printf("\n");
+    }
+  }
+}
+
+void PrettyUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
+                                                     int /*iteration*/) {
+  ColoredPrintf(COLOR_GREEN,  "[==========] ");
+  printf("%s from %s ran.",
+         FormatTestCount(unit_test.test_to_run_count()).c_str(),
+         FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
+  if (GTEST_FLAG(print_time)) {
+    printf(" (%s ms total)",
+           internal::StreamableToString(unit_test.elapsed_time()).c_str());
+  }
+  printf("\n");
+  ColoredPrintf(COLOR_GREEN,  "[  PASSED  ] ");
+  printf("%s.\n", FormatTestCount(unit_test.successful_test_count()).c_str());
+
+  const int skipped_test_count = unit_test.skipped_test_count();
+  if (skipped_test_count > 0) {
+    ColoredPrintf(COLOR_GREEN, "[  SKIPPED ] ");
+    printf("%s, listed below:\n", FormatTestCount(skipped_test_count).c_str());
+    PrintSkippedTests(unit_test);
+  }
+
+  int num_failures = unit_test.failed_test_count();
+  if (!unit_test.Passed()) {
+    const int failed_test_count = unit_test.failed_test_count();
+    ColoredPrintf(COLOR_RED,  "[  FAILED  ] ");
+    printf("%s, listed below:\n", FormatTestCount(failed_test_count).c_str());
+    PrintFailedTests(unit_test);
+    printf("\n%2d FAILED %s\n", num_failures,
+                        num_failures == 1 ? "TEST" : "TESTS");
+  }
+
+  int num_disabled = unit_test.reportable_disabled_test_count();
+  if (num_disabled && !GTEST_FLAG(also_run_disabled_tests)) {
+    if (!num_failures) {
+      printf("\n");  // Add a spacer if no FAILURE banner is displayed.
+    }
+    ColoredPrintf(COLOR_YELLOW,
+                  "  YOU HAVE %d DISABLED %s\n\n",
+                  num_disabled,
+                  num_disabled == 1 ? "TEST" : "TESTS");
+  }
+  // Ensure that Google Test output is printed before, e.g., heapchecker output.
+  fflush(stdout);
+}
+
+// End PrettyUnitTestResultPrinter
+
+// class TestEventRepeater
+//
+// This class forwards events to other event listeners.
+class TestEventRepeater : public TestEventListener {
+ public:
+  TestEventRepeater() : forwarding_enabled_(true) {}
+  ~TestEventRepeater() override;
+  void Append(TestEventListener *listener);
+  TestEventListener* Release(TestEventListener* listener);
+
+  // Controls whether events will be forwarded to listeners_. Set to false
+  // in death test child processes.
+  bool forwarding_enabled() const { return forwarding_enabled_; }
+  void set_forwarding_enabled(bool enable) { forwarding_enabled_ = enable; }
+
+  void OnTestProgramStart(const UnitTest& unit_test) override;
+  void OnTestIterationStart(const UnitTest& unit_test, int iteration) override;
+  void OnEnvironmentsSetUpStart(const UnitTest& unit_test) override;
+  void OnEnvironmentsSetUpEnd(const UnitTest& unit_test) override;
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseStart(const TestSuite& parameter) override;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestSuiteStart(const TestSuite& parameter) override;
+  void OnTestStart(const TestInfo& test_info) override;
+  void OnTestPartResult(const TestPartResult& result) override;
+  void OnTestEnd(const TestInfo& test_info) override;
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseEnd(const TestCase& parameter) override;
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestSuiteEnd(const TestSuite& parameter) override;
+  void OnEnvironmentsTearDownStart(const UnitTest& unit_test) override;
+  void OnEnvironmentsTearDownEnd(const UnitTest& unit_test) override;
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+  void OnTestProgramEnd(const UnitTest& unit_test) override;
+
+ private:
+  // Controls whether events will be forwarded to listeners_. Set to false
+  // in death test child processes.
+  bool forwarding_enabled_;
+  // The list of listeners that receive events.
+  std::vector<TestEventListener*> listeners_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestEventRepeater);
+};
+
+TestEventRepeater::~TestEventRepeater() {
+  ForEach(listeners_, Delete<TestEventListener>);
+}
+
+void TestEventRepeater::Append(TestEventListener *listener) {
+  listeners_.push_back(listener);
+}
+
+TestEventListener* TestEventRepeater::Release(TestEventListener *listener) {
+  for (size_t i = 0; i < listeners_.size(); ++i) {
+    if (listeners_[i] == listener) {
+      listeners_.erase(listeners_.begin() + static_cast<int>(i));
+      return listener;
+    }
+  }
+
+  return nullptr;
+}
+
+// Since most methods are very similar, use macros to reduce boilerplate.
+// This defines a member that forwards the call to all listeners.
+#define GTEST_REPEATER_METHOD_(Name, Type) \
+void TestEventRepeater::Name(const Type& parameter) { \
+  if (forwarding_enabled_) { \
+    for (size_t i = 0; i < listeners_.size(); i++) { \
+      listeners_[i]->Name(parameter); \
+    } \
+  } \
+}
+// This defines a member that forwards the call to all listeners in reverse
+// order.
+#define GTEST_REVERSE_REPEATER_METHOD_(Name, Type)      \
+  void TestEventRepeater::Name(const Type& parameter) { \
+    if (forwarding_enabled_) {                          \
+      for (size_t i = listeners_.size(); i != 0; i--) { \
+        listeners_[i - 1]->Name(parameter);             \
+      }                                                 \
+    }                                                   \
+  }
+
+GTEST_REPEATER_METHOD_(OnTestProgramStart, UnitTest)
+GTEST_REPEATER_METHOD_(OnEnvironmentsSetUpStart, UnitTest)
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+GTEST_REPEATER_METHOD_(OnTestCaseStart, TestSuite)
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+GTEST_REPEATER_METHOD_(OnTestSuiteStart, TestSuite)
+GTEST_REPEATER_METHOD_(OnTestStart, TestInfo)
+GTEST_REPEATER_METHOD_(OnTestPartResult, TestPartResult)
+GTEST_REPEATER_METHOD_(OnEnvironmentsTearDownStart, UnitTest)
+GTEST_REVERSE_REPEATER_METHOD_(OnEnvironmentsSetUpEnd, UnitTest)
+GTEST_REVERSE_REPEATER_METHOD_(OnEnvironmentsTearDownEnd, UnitTest)
+GTEST_REVERSE_REPEATER_METHOD_(OnTestEnd, TestInfo)
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+GTEST_REVERSE_REPEATER_METHOD_(OnTestCaseEnd, TestSuite)
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+GTEST_REVERSE_REPEATER_METHOD_(OnTestSuiteEnd, TestSuite)
+GTEST_REVERSE_REPEATER_METHOD_(OnTestProgramEnd, UnitTest)
+
+#undef GTEST_REPEATER_METHOD_
+#undef GTEST_REVERSE_REPEATER_METHOD_
+
+void TestEventRepeater::OnTestIterationStart(const UnitTest& unit_test,
+                                             int iteration) {
+  if (forwarding_enabled_) {
+    for (size_t i = 0; i < listeners_.size(); i++) {
+      listeners_[i]->OnTestIterationStart(unit_test, iteration);
+    }
+  }
+}
+
+void TestEventRepeater::OnTestIterationEnd(const UnitTest& unit_test,
+                                           int iteration) {
+  if (forwarding_enabled_) {
+    for (size_t i = listeners_.size(); i > 0; i--) {
+      listeners_[i - 1]->OnTestIterationEnd(unit_test, iteration);
+    }
+  }
+}
+
+// End TestEventRepeater
+
+// This class generates an XML output file.
+class XmlUnitTestResultPrinter : public EmptyTestEventListener {
+ public:
+  explicit XmlUnitTestResultPrinter(const char* output_file);
+
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+  void ListTestsMatchingFilter(const std::vector<TestSuite*>& test_suites);
+
+  // Prints an XML summary of all unit tests.
+  static void PrintXmlTestsList(std::ostream* stream,
+                                const std::vector<TestSuite*>& test_suites);
+
+ private:
+  // Is c a whitespace character that is normalized to a space character
+  // when it appears in an XML attribute value?
+  static bool IsNormalizableWhitespace(char c) {
+    return c == 0x9 || c == 0xA || c == 0xD;
+  }
+
+  // May c appear in a well-formed XML document?
+  static bool IsValidXmlCharacter(char c) {
+    return IsNormalizableWhitespace(c) || c >= 0x20;
+  }
+
+  // Returns an XML-escaped copy of the input string str.  If
+  // is_attribute is true, the text is meant to appear as an attribute
+  // value, and normalizable whitespace is preserved by replacing it
+  // with character references.
+  static std::string EscapeXml(const std::string& str, bool is_attribute);
+
+  // Returns the given string with all characters invalid in XML removed.
+  static std::string RemoveInvalidXmlCharacters(const std::string& str);
+
+  // Convenience wrapper around EscapeXml when str is an attribute value.
+  static std::string EscapeXmlAttribute(const std::string& str) {
+    return EscapeXml(str, true);
+  }
+
+  // Convenience wrapper around EscapeXml when str is not an attribute value.
+  static std::string EscapeXmlText(const char* str) {
+    return EscapeXml(str, false);
+  }
+
+  // Verifies that the given attribute belongs to the given element and
+  // streams the attribute as XML.
+  static void OutputXmlAttribute(std::ostream* stream,
+                                 const std::string& element_name,
+                                 const std::string& name,
+                                 const std::string& value);
+
+  // Streams an XML CDATA section, escaping invalid CDATA sequences as needed.
+  static void OutputXmlCDataSection(::std::ostream* stream, const char* data);
+
+  // Streams an XML representation of a TestInfo object.
+  static void OutputXmlTestInfo(::std::ostream* stream,
+                                const char* test_suite_name,
+                                const TestInfo& test_info);
+
+  // Prints an XML representation of a TestSuite object
+  static void PrintXmlTestSuite(::std::ostream* stream,
+                                const TestSuite& test_suite);
+
+  // Prints an XML summary of unit_test to output stream out.
+  static void PrintXmlUnitTest(::std::ostream* stream,
+                               const UnitTest& unit_test);
+
+  // Produces a string representing the test properties in a result as space
+  // delimited XML attributes based on the property key="value" pairs.
+  // When the std::string is not empty, it includes a space at the beginning,
+  // to delimit this attribute from prior attributes.
+  static std::string TestPropertiesAsXmlAttributes(const TestResult& result);
+
+  // Streams an XML representation of the test properties of a TestResult
+  // object.
+  static void OutputXmlTestProperties(std::ostream* stream,
+                                      const TestResult& result);
+
+  // The output file.
+  const std::string output_file_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(XmlUnitTestResultPrinter);
+};
+
+// Creates a new XmlUnitTestResultPrinter.
+XmlUnitTestResultPrinter::XmlUnitTestResultPrinter(const char* output_file)
+    : output_file_(output_file) {
+  if (output_file_.empty()) {
+    GTEST_LOG_(FATAL) << "XML output file may not be null";
+  }
+}
+
+// Called after the unit test ends.
+void XmlUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
+                                                  int /*iteration*/) {
+  FILE* xmlout = OpenFileForWriting(output_file_);
+  std::stringstream stream;
+  PrintXmlUnitTest(&stream, unit_test);
+  fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
+  fclose(xmlout);
+}
+
+void XmlUnitTestResultPrinter::ListTestsMatchingFilter(
+    const std::vector<TestSuite*>& test_suites) {
+  FILE* xmlout = OpenFileForWriting(output_file_);
+  std::stringstream stream;
+  PrintXmlTestsList(&stream, test_suites);
+  fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
+  fclose(xmlout);
+}
+
+// Returns an XML-escaped copy of the input string str.  If is_attribute
+// is true, the text is meant to appear as an attribute value, and
+// normalizable whitespace is preserved by replacing it with character
+// references.
+//
+// Invalid XML characters in str, if any, are stripped from the output.
+// It is expected that most, if not all, of the text processed by this
+// module will consist of ordinary English text.
+// If this module is ever modified to produce version 1.1 XML output,
+// most invalid characters can be retained using character references.
+std::string XmlUnitTestResultPrinter::EscapeXml(
+    const std::string& str, bool is_attribute) {
+  Message m;
+
+  for (size_t i = 0; i < str.size(); ++i) {
+    const char ch = str[i];
+    switch (ch) {
+      case '<':
+        m << "&lt;";
+        break;
+      case '>':
+        m << "&gt;";
+        break;
+      case '&':
+        m << "&amp;";
+        break;
+      case '\'':
+        if (is_attribute)
+          m << "&apos;";
+        else
+          m << '\'';
+        break;
+      case '"':
+        if (is_attribute)
+          m << "&quot;";
+        else
+          m << '"';
+        break;
+      default:
+        if (IsValidXmlCharacter(ch)) {
+          if (is_attribute && IsNormalizableWhitespace(ch))
+            m << "&#x" << String::FormatByte(static_cast<unsigned char>(ch))
+              << ";";
+          else
+            m << ch;
+        }
+        break;
+    }
+  }
+
+  return m.GetString();
+}
+
+// Returns the given string with all characters invalid in XML removed.
+// Currently invalid characters are dropped from the string. An
+// alternative is to replace them with certain characters such as . or ?.
+std::string XmlUnitTestResultPrinter::RemoveInvalidXmlCharacters(
+    const std::string& str) {
+  std::string output;
+  output.reserve(str.size());
+  for (std::string::const_iterator it = str.begin(); it != str.end(); ++it)
+    if (IsValidXmlCharacter(*it))
+      output.push_back(*it);
+
+  return output;
+}
+
+// The following routines generate an XML representation of a UnitTest
+// object.
+// GOOGLETEST_CM0009 DO NOT DELETE
+//
+// This is how Google Test concepts map to the DTD:
+//
+// <testsuites name="AllTests">        <-- corresponds to a UnitTest object
+//   <testsuite name="testcase-name">  <-- corresponds to a TestSuite object
+//     <testcase name="test-name">     <-- corresponds to a TestInfo object
+//       <failure message="...">...</failure>
+//       <failure message="...">...</failure>
+//       <failure message="...">...</failure>
+//                                     <-- individual assertion failures
+//     </testcase>
+//   </testsuite>
+// </testsuites>
+
+// Formats the given time in milliseconds as seconds.
+std::string FormatTimeInMillisAsSeconds(TimeInMillis ms) {
+  ::std::stringstream ss;
+  ss << (static_cast<double>(ms) * 1e-3);
+  return ss.str();
+}
+
+static bool PortableLocaltime(time_t seconds, struct tm* out) {
+#if defined(_MSC_VER)
+  return localtime_s(out, &seconds) == 0;
+#elif defined(__MINGW32__) || defined(__MINGW64__)
+  // MINGW <time.h> provides neither localtime_r nor localtime_s, but uses
+  // Windows' localtime(), which has a thread-local tm buffer.
+  struct tm* tm_ptr = localtime(&seconds);  // NOLINT
+  if (tm_ptr == nullptr) return false;
+  *out = *tm_ptr;
+  return true;
+#else
+  return localtime_r(&seconds, out) != nullptr;
+#endif
+}
+
+// Converts the given epoch time in milliseconds to a date string in the ISO
+// 8601 format, without the timezone information.
+std::string FormatEpochTimeInMillisAsIso8601(TimeInMillis ms) {
+  struct tm time_struct;
+  if (!PortableLocaltime(static_cast<time_t>(ms / 1000), &time_struct))
+    return "";
+  // YYYY-MM-DDThh:mm:ss
+  return StreamableToString(time_struct.tm_year + 1900) + "-" +
+      String::FormatIntWidth2(time_struct.tm_mon + 1) + "-" +
+      String::FormatIntWidth2(time_struct.tm_mday) + "T" +
+      String::FormatIntWidth2(time_struct.tm_hour) + ":" +
+      String::FormatIntWidth2(time_struct.tm_min) + ":" +
+      String::FormatIntWidth2(time_struct.tm_sec);
+}
+
+// Streams an XML CDATA section, escaping invalid CDATA sequences as needed.
+void XmlUnitTestResultPrinter::OutputXmlCDataSection(::std::ostream* stream,
+                                                     const char* data) {
+  const char* segment = data;
+  *stream << "<![CDATA[";
+  for (;;) {
+    const char* const next_segment = strstr(segment, "]]>");
+    if (next_segment != nullptr) {
+      stream->write(
+          segment, static_cast<std::streamsize>(next_segment - segment));
+      *stream << "]]>]]&gt;<![CDATA[";
+      segment = next_segment + strlen("]]>");
+    } else {
+      *stream << segment;
+      break;
+    }
+  }
+  *stream << "]]>";
+}
+
+void XmlUnitTestResultPrinter::OutputXmlAttribute(
+    std::ostream* stream,
+    const std::string& element_name,
+    const std::string& name,
+    const std::string& value) {
+  const std::vector<std::string>& allowed_names =
+      GetReservedOutputAttributesForElement(element_name);
+
+  GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
+                   allowed_names.end())
+      << "Attribute " << name << " is not allowed for element <" << element_name
+      << ">.";
+
+  *stream << " " << name << "=\"" << EscapeXmlAttribute(value) << "\"";
+}
+
+// Prints an XML representation of a TestInfo object.
+void XmlUnitTestResultPrinter::OutputXmlTestInfo(::std::ostream* stream,
+                                                 const char* test_suite_name,
+                                                 const TestInfo& test_info) {
+  const TestResult& result = *test_info.result();
+  const std::string kTestsuite = "testcase";
+
+  if (test_info.is_in_another_shard()) {
+    return;
+  }
+
+  *stream << "    <testcase";
+  OutputXmlAttribute(stream, kTestsuite, "name", test_info.name());
+
+  if (test_info.value_param() != nullptr) {
+    OutputXmlAttribute(stream, kTestsuite, "value_param",
+                       test_info.value_param());
+  }
+  if (test_info.type_param() != nullptr) {
+    OutputXmlAttribute(stream, kTestsuite, "type_param",
+                       test_info.type_param());
+  }
+  if (GTEST_FLAG(list_tests)) {
+    OutputXmlAttribute(stream, kTestsuite, "file", test_info.file());
+    OutputXmlAttribute(stream, kTestsuite, "line",
+                       StreamableToString(test_info.line()));
+    *stream << " />\n";
+    return;
+  }
+
+  OutputXmlAttribute(stream, kTestsuite, "status",
+                     test_info.should_run() ? "run" : "notrun");
+  OutputXmlAttribute(stream, kTestsuite, "result",
+                     test_info.should_run()
+                         ? (result.Skipped() ? "skipped" : "completed")
+                         : "suppressed");
+  OutputXmlAttribute(stream, kTestsuite, "time",
+                     FormatTimeInMillisAsSeconds(result.elapsed_time()));
+  OutputXmlAttribute(
+      stream, kTestsuite, "timestamp",
+      FormatEpochTimeInMillisAsIso8601(result.start_timestamp()));
+  OutputXmlAttribute(stream, kTestsuite, "classname", test_suite_name);
+
+  int failures = 0;
+  for (int i = 0; i < result.total_part_count(); ++i) {
+    const TestPartResult& part = result.GetTestPartResult(i);
+    if (part.failed()) {
+      if (++failures == 1) {
+        *stream << ">\n";
+      }
+      const std::string location =
+          internal::FormatCompilerIndependentFileLocation(part.file_name(),
+                                                          part.line_number());
+      const std::string summary = location + "\n" + part.summary();
+      *stream << "      <failure message=\""
+              << EscapeXmlAttribute(summary.c_str())
+              << "\" type=\"\">";
+      const std::string detail = location + "\n" + part.message();
+      OutputXmlCDataSection(stream, RemoveInvalidXmlCharacters(detail).c_str());
+      *stream << "</failure>\n";
+    }
+  }
+
+  if (failures == 0 && result.test_property_count() == 0) {
+    *stream << " />\n";
+  } else {
+    if (failures == 0) {
+      *stream << ">\n";
+    }
+    OutputXmlTestProperties(stream, result);
+    *stream << "    </testcase>\n";
+  }
+}
+
+// Prints an XML representation of a TestSuite object
+void XmlUnitTestResultPrinter::PrintXmlTestSuite(std::ostream* stream,
+                                                 const TestSuite& test_suite) {
+  const std::string kTestsuite = "testsuite";
+  *stream << "  <" << kTestsuite;
+  OutputXmlAttribute(stream, kTestsuite, "name", test_suite.name());
+  OutputXmlAttribute(stream, kTestsuite, "tests",
+                     StreamableToString(test_suite.reportable_test_count()));
+  if (!GTEST_FLAG(list_tests)) {
+    OutputXmlAttribute(stream, kTestsuite, "failures",
+                       StreamableToString(test_suite.failed_test_count()));
+    OutputXmlAttribute(
+        stream, kTestsuite, "disabled",
+        StreamableToString(test_suite.reportable_disabled_test_count()));
+    OutputXmlAttribute(stream, kTestsuite, "errors", "0");
+    OutputXmlAttribute(stream, kTestsuite, "time",
+                       FormatTimeInMillisAsSeconds(test_suite.elapsed_time()));
+    OutputXmlAttribute(
+        stream, kTestsuite, "timestamp",
+        FormatEpochTimeInMillisAsIso8601(test_suite.start_timestamp()));
+    *stream << TestPropertiesAsXmlAttributes(test_suite.ad_hoc_test_result());
+  }
+  *stream << ">\n";
+  for (int i = 0; i < test_suite.total_test_count(); ++i) {
+    if (test_suite.GetTestInfo(i)->is_reportable())
+      OutputXmlTestInfo(stream, test_suite.name(), *test_suite.GetTestInfo(i));
+  }
+  *stream << "  </" << kTestsuite << ">\n";
+}
+
+// Prints an XML summary of unit_test to output stream out.
+void XmlUnitTestResultPrinter::PrintXmlUnitTest(std::ostream* stream,
+                                                const UnitTest& unit_test) {
+  const std::string kTestsuites = "testsuites";
+
+  *stream << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
+  *stream << "<" << kTestsuites;
+
+  OutputXmlAttribute(stream, kTestsuites, "tests",
+                     StreamableToString(unit_test.reportable_test_count()));
+  OutputXmlAttribute(stream, kTestsuites, "failures",
+                     StreamableToString(unit_test.failed_test_count()));
+  OutputXmlAttribute(
+      stream, kTestsuites, "disabled",
+      StreamableToString(unit_test.reportable_disabled_test_count()));
+  OutputXmlAttribute(stream, kTestsuites, "errors", "0");
+  OutputXmlAttribute(stream, kTestsuites, "time",
+                     FormatTimeInMillisAsSeconds(unit_test.elapsed_time()));
+  OutputXmlAttribute(
+      stream, kTestsuites, "timestamp",
+      FormatEpochTimeInMillisAsIso8601(unit_test.start_timestamp()));
+
+  if (GTEST_FLAG(shuffle)) {
+    OutputXmlAttribute(stream, kTestsuites, "random_seed",
+                       StreamableToString(unit_test.random_seed()));
+  }
+  *stream << TestPropertiesAsXmlAttributes(unit_test.ad_hoc_test_result());
+
+  OutputXmlAttribute(stream, kTestsuites, "name", "AllTests");
+  *stream << ">\n";
+
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    if (unit_test.GetTestSuite(i)->reportable_test_count() > 0)
+      PrintXmlTestSuite(stream, *unit_test.GetTestSuite(i));
+  }
+  *stream << "</" << kTestsuites << ">\n";
+}
+
+void XmlUnitTestResultPrinter::PrintXmlTestsList(
+    std::ostream* stream, const std::vector<TestSuite*>& test_suites) {
+  const std::string kTestsuites = "testsuites";
+
+  *stream << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
+  *stream << "<" << kTestsuites;
+
+  int total_tests = 0;
+  for (auto test_suite : test_suites) {
+    total_tests += test_suite->total_test_count();
+  }
+  OutputXmlAttribute(stream, kTestsuites, "tests",
+                     StreamableToString(total_tests));
+  OutputXmlAttribute(stream, kTestsuites, "name", "AllTests");
+  *stream << ">\n";
+
+  for (auto test_suite : test_suites) {
+    PrintXmlTestSuite(stream, *test_suite);
+  }
+  *stream << "</" << kTestsuites << ">\n";
+}
+
+// Produces a string representing the test properties in a result as space
+// delimited XML attributes based on the property key="value" pairs.
+std::string XmlUnitTestResultPrinter::TestPropertiesAsXmlAttributes(
+    const TestResult& result) {
+  Message attributes;
+  for (int i = 0; i < result.test_property_count(); ++i) {
+    const TestProperty& property = result.GetTestProperty(i);
+    attributes << " " << property.key() << "="
+        << "\"" << EscapeXmlAttribute(property.value()) << "\"";
+  }
+  return attributes.GetString();
+}
+
+void XmlUnitTestResultPrinter::OutputXmlTestProperties(
+    std::ostream* stream, const TestResult& result) {
+  const std::string kProperties = "properties";
+  const std::string kProperty = "property";
+
+  if (result.test_property_count() <= 0) {
+    return;
+  }
+
+  *stream << "<" << kProperties << ">\n";
+  for (int i = 0; i < result.test_property_count(); ++i) {
+    const TestProperty& property = result.GetTestProperty(i);
+    *stream << "<" << kProperty;
+    *stream << " name=\"" << EscapeXmlAttribute(property.key()) << "\"";
+    *stream << " value=\"" << EscapeXmlAttribute(property.value()) << "\"";
+    *stream << "/>\n";
+  }
+  *stream << "</" << kProperties << ">\n";
+}
+
+// End XmlUnitTestResultPrinter
+
+// This class generates an JSON output file.
+class JsonUnitTestResultPrinter : public EmptyTestEventListener {
+ public:
+  explicit JsonUnitTestResultPrinter(const char* output_file);
+
+  void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
+
+  // Prints an JSON summary of all unit tests.
+  static void PrintJsonTestList(::std::ostream* stream,
+                                const std::vector<TestSuite*>& test_suites);
+
+ private:
+  // Returns an JSON-escaped copy of the input string str.
+  static std::string EscapeJson(const std::string& str);
+
+  //// Verifies that the given attribute belongs to the given element and
+  //// streams the attribute as JSON.
+  static void OutputJsonKey(std::ostream* stream,
+                            const std::string& element_name,
+                            const std::string& name,
+                            const std::string& value,
+                            const std::string& indent,
+                            bool comma = true);
+  static void OutputJsonKey(std::ostream* stream,
+                            const std::string& element_name,
+                            const std::string& name,
+                            int value,
+                            const std::string& indent,
+                            bool comma = true);
+
+  // Streams a JSON representation of a TestInfo object.
+  static void OutputJsonTestInfo(::std::ostream* stream,
+                                 const char* test_suite_name,
+                                 const TestInfo& test_info);
+
+  // Prints a JSON representation of a TestSuite object
+  static void PrintJsonTestSuite(::std::ostream* stream,
+                                 const TestSuite& test_suite);
+
+  // Prints a JSON summary of unit_test to output stream out.
+  static void PrintJsonUnitTest(::std::ostream* stream,
+                                const UnitTest& unit_test);
+
+  // Produces a string representing the test properties in a result as
+  // a JSON dictionary.
+  static std::string TestPropertiesAsJson(const TestResult& result,
+                                          const std::string& indent);
+
+  // The output file.
+  const std::string output_file_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(JsonUnitTestResultPrinter);
+};
+
+// Creates a new JsonUnitTestResultPrinter.
+JsonUnitTestResultPrinter::JsonUnitTestResultPrinter(const char* output_file)
+    : output_file_(output_file) {
+  if (output_file_.empty()) {
+    GTEST_LOG_(FATAL) << "JSON output file may not be null";
+  }
+}
+
+void JsonUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
+                                                  int /*iteration*/) {
+  FILE* jsonout = OpenFileForWriting(output_file_);
+  std::stringstream stream;
+  PrintJsonUnitTest(&stream, unit_test);
+  fprintf(jsonout, "%s", StringStreamToString(&stream).c_str());
+  fclose(jsonout);
+}
+
+// Returns an JSON-escaped copy of the input string str.
+std::string JsonUnitTestResultPrinter::EscapeJson(const std::string& str) {
+  Message m;
+
+  for (size_t i = 0; i < str.size(); ++i) {
+    const char ch = str[i];
+    switch (ch) {
+      case '\\':
+      case '"':
+      case '/':
+        m << '\\' << ch;
+        break;
+      case '\b':
+        m << "\\b";
+        break;
+      case '\t':
+        m << "\\t";
+        break;
+      case '\n':
+        m << "\\n";
+        break;
+      case '\f':
+        m << "\\f";
+        break;
+      case '\r':
+        m << "\\r";
+        break;
+      default:
+        if (ch < ' ') {
+          m << "\\u00" << String::FormatByte(static_cast<unsigned char>(ch));
+        } else {
+          m << ch;
+        }
+        break;
+    }
+  }
+
+  return m.GetString();
+}
+
+// The following routines generate an JSON representation of a UnitTest
+// object.
+
+// Formats the given time in milliseconds as seconds.
+static std::string FormatTimeInMillisAsDuration(TimeInMillis ms) {
+  ::std::stringstream ss;
+  ss << (static_cast<double>(ms) * 1e-3) << "s";
+  return ss.str();
+}
+
+// Converts the given epoch time in milliseconds to a date string in the
+// RFC3339 format, without the timezone information.
+static std::string FormatEpochTimeInMillisAsRFC3339(TimeInMillis ms) {
+  struct tm time_struct;
+  if (!PortableLocaltime(static_cast<time_t>(ms / 1000), &time_struct))
+    return "";
+  // YYYY-MM-DDThh:mm:ss
+  return StreamableToString(time_struct.tm_year + 1900) + "-" +
+      String::FormatIntWidth2(time_struct.tm_mon + 1) + "-" +
+      String::FormatIntWidth2(time_struct.tm_mday) + "T" +
+      String::FormatIntWidth2(time_struct.tm_hour) + ":" +
+      String::FormatIntWidth2(time_struct.tm_min) + ":" +
+      String::FormatIntWidth2(time_struct.tm_sec) + "Z";
+}
+
+static inline std::string Indent(size_t width) {
+  return std::string(width, ' ');
+}
+
+void JsonUnitTestResultPrinter::OutputJsonKey(
+    std::ostream* stream,
+    const std::string& element_name,
+    const std::string& name,
+    const std::string& value,
+    const std::string& indent,
+    bool comma) {
+  const std::vector<std::string>& allowed_names =
+      GetReservedOutputAttributesForElement(element_name);
+
+  GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
+                   allowed_names.end())
+      << "Key \"" << name << "\" is not allowed for value \"" << element_name
+      << "\".";
+
+  *stream << indent << "\"" << name << "\": \"" << EscapeJson(value) << "\"";
+  if (comma)
+    *stream << ",\n";
+}
+
+void JsonUnitTestResultPrinter::OutputJsonKey(
+    std::ostream* stream,
+    const std::string& element_name,
+    const std::string& name,
+    int value,
+    const std::string& indent,
+    bool comma) {
+  const std::vector<std::string>& allowed_names =
+      GetReservedOutputAttributesForElement(element_name);
+
+  GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
+                   allowed_names.end())
+      << "Key \"" << name << "\" is not allowed for value \"" << element_name
+      << "\".";
+
+  *stream << indent << "\"" << name << "\": " << StreamableToString(value);
+  if (comma)
+    *stream << ",\n";
+}
+
+// Prints a JSON representation of a TestInfo object.
+void JsonUnitTestResultPrinter::OutputJsonTestInfo(::std::ostream* stream,
+                                                   const char* test_suite_name,
+                                                   const TestInfo& test_info) {
+  const TestResult& result = *test_info.result();
+  const std::string kTestsuite = "testcase";
+  const std::string kIndent = Indent(10);
+
+  *stream << Indent(8) << "{\n";
+  OutputJsonKey(stream, kTestsuite, "name", test_info.name(), kIndent);
+
+  if (test_info.value_param() != nullptr) {
+    OutputJsonKey(stream, kTestsuite, "value_param", test_info.value_param(),
+                  kIndent);
+  }
+  if (test_info.type_param() != nullptr) {
+    OutputJsonKey(stream, kTestsuite, "type_param", test_info.type_param(),
+                  kIndent);
+  }
+  if (GTEST_FLAG(list_tests)) {
+    OutputJsonKey(stream, kTestsuite, "file", test_info.file(), kIndent);
+    OutputJsonKey(stream, kTestsuite, "line", test_info.line(), kIndent, false);
+    *stream << "\n" << Indent(8) << "}";
+    return;
+  }
+
+  OutputJsonKey(stream, kTestsuite, "status",
+                test_info.should_run() ? "RUN" : "NOTRUN", kIndent);
+  OutputJsonKey(stream, kTestsuite, "result",
+                test_info.should_run()
+                    ? (result.Skipped() ? "SKIPPED" : "COMPLETED")
+                    : "SUPPRESSED",
+                kIndent);
+  OutputJsonKey(stream, kTestsuite, "timestamp",
+                FormatEpochTimeInMillisAsRFC3339(result.start_timestamp()),
+                kIndent);
+  OutputJsonKey(stream, kTestsuite, "time",
+                FormatTimeInMillisAsDuration(result.elapsed_time()), kIndent);
+  OutputJsonKey(stream, kTestsuite, "classname", test_suite_name, kIndent,
+                false);
+  *stream << TestPropertiesAsJson(result, kIndent);
+
+  int failures = 0;
+  for (int i = 0; i < result.total_part_count(); ++i) {
+    const TestPartResult& part = result.GetTestPartResult(i);
+    if (part.failed()) {
+      *stream << ",\n";
+      if (++failures == 1) {
+        *stream << kIndent << "\"" << "failures" << "\": [\n";
+      }
+      const std::string location =
+          internal::FormatCompilerIndependentFileLocation(part.file_name(),
+                                                          part.line_number());
+      const std::string message = EscapeJson(location + "\n" + part.message());
+      *stream << kIndent << "  {\n"
+              << kIndent << "    \"failure\": \"" << message << "\",\n"
+              << kIndent << "    \"type\": \"\"\n"
+              << kIndent << "  }";
+    }
+  }
+
+  if (failures > 0)
+    *stream << "\n" << kIndent << "]";
+  *stream << "\n" << Indent(8) << "}";
+}
+
+// Prints an JSON representation of a TestSuite object
+void JsonUnitTestResultPrinter::PrintJsonTestSuite(
+    std::ostream* stream, const TestSuite& test_suite) {
+  const std::string kTestsuite = "testsuite";
+  const std::string kIndent = Indent(6);
+
+  *stream << Indent(4) << "{\n";
+  OutputJsonKey(stream, kTestsuite, "name", test_suite.name(), kIndent);
+  OutputJsonKey(stream, kTestsuite, "tests", test_suite.reportable_test_count(),
+                kIndent);
+  if (!GTEST_FLAG(list_tests)) {
+    OutputJsonKey(stream, kTestsuite, "failures",
+                  test_suite.failed_test_count(), kIndent);
+    OutputJsonKey(stream, kTestsuite, "disabled",
+                  test_suite.reportable_disabled_test_count(), kIndent);
+    OutputJsonKey(stream, kTestsuite, "errors", 0, kIndent);
+    OutputJsonKey(
+        stream, kTestsuite, "timestamp",
+        FormatEpochTimeInMillisAsRFC3339(test_suite.start_timestamp()),
+        kIndent);
+    OutputJsonKey(stream, kTestsuite, "time",
+                  FormatTimeInMillisAsDuration(test_suite.elapsed_time()),
+                  kIndent, false);
+    *stream << TestPropertiesAsJson(test_suite.ad_hoc_test_result(), kIndent)
+            << ",\n";
+  }
+
+  *stream << kIndent << "\"" << kTestsuite << "\": [\n";
+
+  bool comma = false;
+  for (int i = 0; i < test_suite.total_test_count(); ++i) {
+    if (test_suite.GetTestInfo(i)->is_reportable()) {
+      if (comma) {
+        *stream << ",\n";
+      } else {
+        comma = true;
+      }
+      OutputJsonTestInfo(stream, test_suite.name(), *test_suite.GetTestInfo(i));
+    }
+  }
+  *stream << "\n" << kIndent << "]\n" << Indent(4) << "}";
+}
+
+// Prints a JSON summary of unit_test to output stream out.
+void JsonUnitTestResultPrinter::PrintJsonUnitTest(std::ostream* stream,
+                                                  const UnitTest& unit_test) {
+  const std::string kTestsuites = "testsuites";
+  const std::string kIndent = Indent(2);
+  *stream << "{\n";
+
+  OutputJsonKey(stream, kTestsuites, "tests", unit_test.reportable_test_count(),
+                kIndent);
+  OutputJsonKey(stream, kTestsuites, "failures", unit_test.failed_test_count(),
+                kIndent);
+  OutputJsonKey(stream, kTestsuites, "disabled",
+                unit_test.reportable_disabled_test_count(), kIndent);
+  OutputJsonKey(stream, kTestsuites, "errors", 0, kIndent);
+  if (GTEST_FLAG(shuffle)) {
+    OutputJsonKey(stream, kTestsuites, "random_seed", unit_test.random_seed(),
+                  kIndent);
+  }
+  OutputJsonKey(stream, kTestsuites, "timestamp",
+                FormatEpochTimeInMillisAsRFC3339(unit_test.start_timestamp()),
+                kIndent);
+  OutputJsonKey(stream, kTestsuites, "time",
+                FormatTimeInMillisAsDuration(unit_test.elapsed_time()), kIndent,
+                false);
+
+  *stream << TestPropertiesAsJson(unit_test.ad_hoc_test_result(), kIndent)
+          << ",\n";
+
+  OutputJsonKey(stream, kTestsuites, "name", "AllTests", kIndent);
+  *stream << kIndent << "\"" << kTestsuites << "\": [\n";
+
+  bool comma = false;
+  for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+    if (unit_test.GetTestSuite(i)->reportable_test_count() > 0) {
+      if (comma) {
+        *stream << ",\n";
+      } else {
+        comma = true;
+      }
+      PrintJsonTestSuite(stream, *unit_test.GetTestSuite(i));
+    }
+  }
+
+  *stream << "\n" << kIndent << "]\n" << "}\n";
+}
+
+void JsonUnitTestResultPrinter::PrintJsonTestList(
+    std::ostream* stream, const std::vector<TestSuite*>& test_suites) {
+  const std::string kTestsuites = "testsuites";
+  const std::string kIndent = Indent(2);
+  *stream << "{\n";
+  int total_tests = 0;
+  for (auto test_suite : test_suites) {
+    total_tests += test_suite->total_test_count();
+  }
+  OutputJsonKey(stream, kTestsuites, "tests", total_tests, kIndent);
+
+  OutputJsonKey(stream, kTestsuites, "name", "AllTests", kIndent);
+  *stream << kIndent << "\"" << kTestsuites << "\": [\n";
+
+  for (size_t i = 0; i < test_suites.size(); ++i) {
+    if (i != 0) {
+      *stream << ",\n";
+    }
+    PrintJsonTestSuite(stream, *test_suites[i]);
+  }
+
+  *stream << "\n"
+          << kIndent << "]\n"
+          << "}\n";
+}
+// Produces a string representing the test properties in a result as
+// a JSON dictionary.
+std::string JsonUnitTestResultPrinter::TestPropertiesAsJson(
+    const TestResult& result, const std::string& indent) {
+  Message attributes;
+  for (int i = 0; i < result.test_property_count(); ++i) {
+    const TestProperty& property = result.GetTestProperty(i);
+    attributes << ",\n" << indent << "\"" << property.key() << "\": "
+               << "\"" << EscapeJson(property.value()) << "\"";
+  }
+  return attributes.GetString();
+}
+
+// End JsonUnitTestResultPrinter
+
+#if GTEST_CAN_STREAM_RESULTS_
+
+// Checks if str contains '=', '&', '%' or '\n' characters. If yes,
+// replaces them by "%xx" where xx is their hexadecimal value. For
+// example, replaces "=" with "%3D".  This algorithm is O(strlen(str))
+// in both time and space -- important as the input str may contain an
+// arbitrarily long test failure message and stack trace.
+std::string StreamingListener::UrlEncode(const char* str) {
+  std::string result;
+  result.reserve(strlen(str) + 1);
+  for (char ch = *str; ch != '\0'; ch = *++str) {
+    switch (ch) {
+      case '%':
+      case '=':
+      case '&':
+      case '\n':
+        result.append("%" + String::FormatByte(static_cast<unsigned char>(ch)));
+        break;
+      default:
+        result.push_back(ch);
+        break;
+    }
+  }
+  return result;
+}
+
+void StreamingListener::SocketWriter::MakeConnection() {
+  GTEST_CHECK_(sockfd_ == -1)
+      << "MakeConnection() can't be called when there is already a connection.";
+
+  addrinfo hints;
+  memset(&hints, 0, sizeof(hints));
+  hints.ai_family = AF_UNSPEC;    // To allow both IPv4 and IPv6 addresses.
+  hints.ai_socktype = SOCK_STREAM;
+  addrinfo* servinfo = nullptr;
+
+  // Use the getaddrinfo() to get a linked list of IP addresses for
+  // the given host name.
+  const int error_num = getaddrinfo(
+      host_name_.c_str(), port_num_.c_str(), &hints, &servinfo);
+  if (error_num != 0) {
+    GTEST_LOG_(WARNING) << "stream_result_to: getaddrinfo() failed: "
+                        << gai_strerror(error_num);
+  }
+
+  // Loop through all the results and connect to the first we can.
+  for (addrinfo* cur_addr = servinfo; sockfd_ == -1 && cur_addr != nullptr;
+       cur_addr = cur_addr->ai_next) {
+    sockfd_ = socket(
+        cur_addr->ai_family, cur_addr->ai_socktype, cur_addr->ai_protocol);
+    if (sockfd_ != -1) {
+      // Connect the client socket to the server socket.
+      if (connect(sockfd_, cur_addr->ai_addr, cur_addr->ai_addrlen) == -1) {
+        close(sockfd_);
+        sockfd_ = -1;
+      }
+    }
+  }
+
+  freeaddrinfo(servinfo);  // all done with this structure
+
+  if (sockfd_ == -1) {
+    GTEST_LOG_(WARNING) << "stream_result_to: failed to connect to "
+                        << host_name_ << ":" << port_num_;
+  }
+}
+
+// End of class Streaming Listener
+#endif  // GTEST_CAN_STREAM_RESULTS__
+
+// class OsStackTraceGetter
+
+const char* const OsStackTraceGetterInterface::kElidedFramesMarker =
+    "... " GTEST_NAME_ " internal frames ...";
+
+std::string OsStackTraceGetter::CurrentStackTrace(int max_depth, int skip_count)
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+#if GTEST_HAS_ABSL
+  std::string result;
+
+  if (max_depth <= 0) {
+    return result;
+  }
+
+  max_depth = std::min(max_depth, kMaxStackTraceDepth);
+
+  std::vector<void*> raw_stack(max_depth);
+  // Skips the frames requested by the caller, plus this function.
+  const int raw_stack_size =
+      absl::GetStackTrace(&raw_stack[0], max_depth, skip_count + 1);
+
+  void* caller_frame = nullptr;
+  {
+    MutexLock lock(&mutex_);
+    caller_frame = caller_frame_;
+  }
+
+  for (int i = 0; i < raw_stack_size; ++i) {
+    if (raw_stack[i] == caller_frame &&
+        !GTEST_FLAG(show_internal_stack_frames)) {
+      // Add a marker to the trace and stop adding frames.
+      absl::StrAppend(&result, kElidedFramesMarker, "\n");
+      break;
+    }
+
+    char tmp[1024];
+    const char* symbol = "(unknown)";
+    if (absl::Symbolize(raw_stack[i], tmp, sizeof(tmp))) {
+      symbol = tmp;
+    }
+
+    char line[1024];
+    snprintf(line, sizeof(line), "  %p: %s\n", raw_stack[i], symbol);
+    result += line;
+  }
+
+  return result;
+
+#else  // !GTEST_HAS_ABSL
+  static_cast<void>(max_depth);
+  static_cast<void>(skip_count);
+  return "";
+#endif  // GTEST_HAS_ABSL
+}
+
+void OsStackTraceGetter::UponLeavingGTest() GTEST_LOCK_EXCLUDED_(mutex_) {
+#if GTEST_HAS_ABSL
+  void* caller_frame = nullptr;
+  if (absl::GetStackTrace(&caller_frame, 1, 3) <= 0) {
+    caller_frame = nullptr;
+  }
+
+  MutexLock lock(&mutex_);
+  caller_frame_ = caller_frame;
+#endif  // GTEST_HAS_ABSL
+}
+
+// A helper class that creates the premature-exit file in its
+// constructor and deletes the file in its destructor.
+class ScopedPrematureExitFile {
+ public:
+  explicit ScopedPrematureExitFile(const char* premature_exit_filepath)
+      : premature_exit_filepath_(premature_exit_filepath ?
+                                 premature_exit_filepath : "") {
+    // If a path to the premature-exit file is specified...
+    if (!premature_exit_filepath_.empty()) {
+      // create the file with a single "0" character in it.  I/O
+      // errors are ignored as there's nothing better we can do and we
+      // don't want to fail the test because of this.
+      FILE* pfile = posix::FOpen(premature_exit_filepath, "w");
+      fwrite("0", 1, 1, pfile);
+      fclose(pfile);
+    }
+  }
+
+  ~ScopedPrematureExitFile() {
+    if (!premature_exit_filepath_.empty()) {
+      int retval = remove(premature_exit_filepath_.c_str());
+      if (retval) {
+        GTEST_LOG_(ERROR) << "Failed to remove premature exit filepath \""
+                          << premature_exit_filepath_ << "\" with error "
+                          << retval;
+      }
+    }
+  }
+
+ private:
+  const std::string premature_exit_filepath_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(ScopedPrematureExitFile);
+};
+
+}  // namespace internal
+
+// class TestEventListeners
+
+TestEventListeners::TestEventListeners()
+    : repeater_(new internal::TestEventRepeater()),
+      default_result_printer_(nullptr),
+      default_xml_generator_(nullptr) {}
+
+TestEventListeners::~TestEventListeners() { delete repeater_; }
+
+// Returns the standard listener responsible for the default console
+// output.  Can be removed from the listeners list to shut down default
+// console output.  Note that removing this object from the listener list
+// with Release transfers its ownership to the user.
+void TestEventListeners::Append(TestEventListener* listener) {
+  repeater_->Append(listener);
+}
+
+// Removes the given event listener from the list and returns it.  It then
+// becomes the caller's responsibility to delete the listener. Returns
+// NULL if the listener is not found in the list.
+TestEventListener* TestEventListeners::Release(TestEventListener* listener) {
+  if (listener == default_result_printer_)
+    default_result_printer_ = nullptr;
+  else if (listener == default_xml_generator_)
+    default_xml_generator_ = nullptr;
+  return repeater_->Release(listener);
+}
+
+// Returns repeater that broadcasts the TestEventListener events to all
+// subscribers.
+TestEventListener* TestEventListeners::repeater() { return repeater_; }
+
+// Sets the default_result_printer attribute to the provided listener.
+// The listener is also added to the listener list and previous
+// default_result_printer is removed from it and deleted. The listener can
+// also be NULL in which case it will not be added to the list. Does
+// nothing if the previous and the current listener objects are the same.
+void TestEventListeners::SetDefaultResultPrinter(TestEventListener* listener) {
+  if (default_result_printer_ != listener) {
+    // It is an error to pass this method a listener that is already in the
+    // list.
+    delete Release(default_result_printer_);
+    default_result_printer_ = listener;
+    if (listener != nullptr) Append(listener);
+  }
+}
+
+// Sets the default_xml_generator attribute to the provided listener.  The
+// listener is also added to the listener list and previous
+// default_xml_generator is removed from it and deleted. The listener can
+// also be NULL in which case it will not be added to the list. Does
+// nothing if the previous and the current listener objects are the same.
+void TestEventListeners::SetDefaultXmlGenerator(TestEventListener* listener) {
+  if (default_xml_generator_ != listener) {
+    // It is an error to pass this method a listener that is already in the
+    // list.
+    delete Release(default_xml_generator_);
+    default_xml_generator_ = listener;
+    if (listener != nullptr) Append(listener);
+  }
+}
+
+// Controls whether events will be forwarded by the repeater to the
+// listeners in the list.
+bool TestEventListeners::EventForwardingEnabled() const {
+  return repeater_->forwarding_enabled();
+}
+
+void TestEventListeners::SuppressEventForwarding() {
+  repeater_->set_forwarding_enabled(false);
+}
+
+// class UnitTest
+
+// Gets the singleton UnitTest object.  The first time this method is
+// called, a UnitTest object is constructed and returned.  Consecutive
+// calls will return the same object.
+//
+// We don't protect this under mutex_ as a user is not supposed to
+// call this before main() starts, from which point on the return
+// value will never change.
+UnitTest* UnitTest::GetInstance() {
+  // CodeGear C++Builder insists on a public destructor for the
+  // default implementation.  Use this implementation to keep good OO
+  // design with private destructor.
+
+#if defined(__BORLANDC__)
+  static UnitTest* const instance = new UnitTest;
+  return instance;
+#else
+  static UnitTest instance;
+  return &instance;
+#endif  // defined(__BORLANDC__)
+}
+
+// Gets the number of successful test suites.
+int UnitTest::successful_test_suite_count() const {
+  return impl()->successful_test_suite_count();
+}
+
+// Gets the number of failed test suites.
+int UnitTest::failed_test_suite_count() const {
+  return impl()->failed_test_suite_count();
+}
+
+// Gets the number of all test suites.
+int UnitTest::total_test_suite_count() const {
+  return impl()->total_test_suite_count();
+}
+
+// Gets the number of all test suites that contain at least one test
+// that should run.
+int UnitTest::test_suite_to_run_count() const {
+  return impl()->test_suite_to_run_count();
+}
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+int UnitTest::successful_test_case_count() const {
+  return impl()->successful_test_suite_count();
+}
+int UnitTest::failed_test_case_count() const {
+  return impl()->failed_test_suite_count();
+}
+int UnitTest::total_test_case_count() const {
+  return impl()->total_test_suite_count();
+}
+int UnitTest::test_case_to_run_count() const {
+  return impl()->test_suite_to_run_count();
+}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+// Gets the number of successful tests.
+int UnitTest::successful_test_count() const {
+  return impl()->successful_test_count();
+}
+
+// Gets the number of skipped tests.
+int UnitTest::skipped_test_count() const {
+  return impl()->skipped_test_count();
+}
+
+// Gets the number of failed tests.
+int UnitTest::failed_test_count() const { return impl()->failed_test_count(); }
+
+// Gets the number of disabled tests that will be reported in the XML report.
+int UnitTest::reportable_disabled_test_count() const {
+  return impl()->reportable_disabled_test_count();
+}
+
+// Gets the number of disabled tests.
+int UnitTest::disabled_test_count() const {
+  return impl()->disabled_test_count();
+}
+
+// Gets the number of tests to be printed in the XML report.
+int UnitTest::reportable_test_count() const {
+  return impl()->reportable_test_count();
+}
+
+// Gets the number of all tests.
+int UnitTest::total_test_count() const { return impl()->total_test_count(); }
+
+// Gets the number of tests that should run.
+int UnitTest::test_to_run_count() const { return impl()->test_to_run_count(); }
+
+// Gets the time of the test program start, in ms from the start of the
+// UNIX epoch.
+internal::TimeInMillis UnitTest::start_timestamp() const {
+    return impl()->start_timestamp();
+}
+
+// Gets the elapsed time, in milliseconds.
+internal::TimeInMillis UnitTest::elapsed_time() const {
+  return impl()->elapsed_time();
+}
+
+// Returns true if and only if the unit test passed (i.e. all test suites
+// passed).
+bool UnitTest::Passed() const { return impl()->Passed(); }
+
+// Returns true if and only if the unit test failed (i.e. some test suite
+// failed or something outside of all tests failed).
+bool UnitTest::Failed() const { return impl()->Failed(); }
+
+// Gets the i-th test suite among all the test suites. i can range from 0 to
+// total_test_suite_count() - 1. If i is not in that range, returns NULL.
+const TestSuite* UnitTest::GetTestSuite(int i) const {
+  return impl()->GetTestSuite(i);
+}
+
+//  Legacy API is deprecated but still available
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+const TestCase* UnitTest::GetTestCase(int i) const {
+  return impl()->GetTestCase(i);
+}
+#endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+// Returns the TestResult containing information on test failures and
+// properties logged outside of individual test suites.
+const TestResult& UnitTest::ad_hoc_test_result() const {
+  return *impl()->ad_hoc_test_result();
+}
+
+// Gets the i-th test suite among all the test suites. i can range from 0 to
+// total_test_suite_count() - 1. If i is not in that range, returns NULL.
+TestSuite* UnitTest::GetMutableTestSuite(int i) {
+  return impl()->GetMutableSuiteCase(i);
+}
+
+// Returns the list of event listeners that can be used to track events
+// inside Google Test.
+TestEventListeners& UnitTest::listeners() {
+  return *impl()->listeners();
+}
+
+// Registers and returns a global test environment.  When a test
+// program is run, all global test environments will be set-up in the
+// order they were registered.  After all tests in the program have
+// finished, all global test environments will be torn-down in the
+// *reverse* order they were registered.
+//
+// The UnitTest object takes ownership of the given environment.
+//
+// We don't protect this under mutex_, as we only support calling it
+// from the main thread.
+Environment* UnitTest::AddEnvironment(Environment* env) {
+  if (env == nullptr) {
+    return nullptr;
+  }
+
+  impl_->environments().push_back(env);
+  return env;
+}
+
+// Adds a TestPartResult to the current TestResult object.  All Google Test
+// assertion macros (e.g. ASSERT_TRUE, EXPECT_EQ, etc) eventually call
+// this to report their results.  The user code should use the
+// assertion macros instead of calling this directly.
+void UnitTest::AddTestPartResult(
+    TestPartResult::Type result_type,
+    const char* file_name,
+    int line_number,
+    const std::string& message,
+    const std::string& os_stack_trace) GTEST_LOCK_EXCLUDED_(mutex_) {
+  Message msg;
+  msg << message;
+
+  internal::MutexLock lock(&mutex_);
+  if (impl_->gtest_trace_stack().size() > 0) {
+    msg << "\n" << GTEST_NAME_ << " trace:";
+
+    for (size_t i = impl_->gtest_trace_stack().size(); i > 0; --i) {
+      const internal::TraceInfo& trace = impl_->gtest_trace_stack()[i - 1];
+      msg << "\n" << internal::FormatFileLocation(trace.file, trace.line)
+          << " " << trace.message;
+    }
+  }
+
+  if (os_stack_trace.c_str() != nullptr && !os_stack_trace.empty()) {
+    msg << internal::kStackTraceMarker << os_stack_trace;
+  }
+
+  const TestPartResult result = TestPartResult(
+      result_type, file_name, line_number, msg.GetString().c_str());
+  impl_->GetTestPartResultReporterForCurrentThread()->
+      ReportTestPartResult(result);
+
+  if (result_type != TestPartResult::kSuccess &&
+      result_type != TestPartResult::kSkip) {
+    // gtest_break_on_failure takes precedence over
+    // gtest_throw_on_failure.  This allows a user to set the latter
+    // in the code (perhaps in order to use Google Test assertions
+    // with another testing framework) and specify the former on the
+    // command line for debugging.
+    if (GTEST_FLAG(break_on_failure)) {
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
+      // Using DebugBreak on Windows allows gtest to still break into a debugger
+      // when a failure happens and both the --gtest_break_on_failure and
+      // the --gtest_catch_exceptions flags are specified.
+      DebugBreak();
+#elif (!defined(__native_client__)) &&            \
+    ((defined(__clang__) || defined(__GNUC__)) && \
+     (defined(__x86_64__) || defined(__i386__)))
+      // with clang/gcc we can achieve the same effect on x86 by invoking int3
+      asm("int3");
+#else
+      // Dereference nullptr through a volatile pointer to prevent the compiler
+      // from removing. We use this rather than abort() or __builtin_trap() for
+      // portability: some debuggers don't correctly trap abort().
+      *static_cast<volatile int*>(nullptr) = 1;
+#endif  // GTEST_OS_WINDOWS
+    } else if (GTEST_FLAG(throw_on_failure)) {
+#if GTEST_HAS_EXCEPTIONS
+      throw internal::GoogleTestFailureException(result);
+#else
+      // We cannot call abort() as it generates a pop-up in debug mode
+      // that cannot be suppressed in VC 7.1 or below.
+      exit(1);
+#endif
+    }
+  }
+}
+
+// Adds a TestProperty to the current TestResult object when invoked from
+// inside a test, to current TestSuite's ad_hoc_test_result_ when invoked
+// from SetUpTestSuite or TearDownTestSuite, or to the global property set
+// when invoked elsewhere.  If the result already contains a property with
+// the same key, the value will be updated.
+void UnitTest::RecordProperty(const std::string& key,
+                              const std::string& value) {
+  impl_->RecordProperty(TestProperty(key, value));
+}
+
+// Runs all tests in this UnitTest object and prints the result.
+// Returns 0 if successful, or 1 otherwise.
+//
+// We don't protect this under mutex_, as we only support calling it
+// from the main thread.
+int UnitTest::Run() {
+  const bool in_death_test_child_process =
+      internal::GTEST_FLAG(internal_run_death_test).length() > 0;
+
+  // Google Test implements this protocol for catching that a test
+  // program exits before returning control to Google Test:
+  //
+  //   1. Upon start, Google Test creates a file whose absolute path
+  //      is specified by the environment variable
+  //      TEST_PREMATURE_EXIT_FILE.
+  //   2. When Google Test has finished its work, it deletes the file.
+  //
+  // This allows a test runner to set TEST_PREMATURE_EXIT_FILE before
+  // running a Google-Test-based test program and check the existence
+  // of the file at the end of the test execution to see if it has
+  // exited prematurely.
+
+  // If we are in the child process of a death test, don't
+  // create/delete the premature exit file, as doing so is unnecessary
+  // and will confuse the parent process.  Otherwise, create/delete
+  // the file upon entering/leaving this function.  If the program
+  // somehow exits before this function has a chance to return, the
+  // premature-exit file will be left undeleted, causing a test runner
+  // that understands the premature-exit-file protocol to report the
+  // test as having failed.
+  const internal::ScopedPrematureExitFile premature_exit_file(
+      in_death_test_child_process
+          ? nullptr
+          : internal::posix::GetEnv("TEST_PREMATURE_EXIT_FILE"));
+
+  // Captures the value of GTEST_FLAG(catch_exceptions).  This value will be
+  // used for the duration of the program.
+  impl()->set_catch_exceptions(GTEST_FLAG(catch_exceptions));
+
+#if GTEST_OS_WINDOWS
+  // Either the user wants Google Test to catch exceptions thrown by the
+  // tests or this is executing in the context of death test child
+  // process. In either case the user does not want to see pop-up dialogs
+  // about crashes - they are expected.
+  if (impl()->catch_exceptions() || in_death_test_child_process) {
+# if !GTEST_OS_WINDOWS_MOBILE && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
+    // SetErrorMode doesn't exist on CE.
+    SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOALIGNMENTFAULTEXCEPT |
+                 SEM_NOGPFAULTERRORBOX | SEM_NOOPENFILEERRORBOX);
+# endif  // !GTEST_OS_WINDOWS_MOBILE
+
+# if (defined(_MSC_VER) || GTEST_OS_WINDOWS_MINGW) && !GTEST_OS_WINDOWS_MOBILE
+    // Death test children can be terminated with _abort().  On Windows,
+    // _abort() can show a dialog with a warning message.  This forces the
+    // abort message to go to stderr instead.
+    _set_error_mode(_OUT_TO_STDERR);
+# endif
+
+# if defined(_MSC_VER) && !GTEST_OS_WINDOWS_MOBILE
+    // In the debug version, Visual Studio pops up a separate dialog
+    // offering a choice to debug the aborted program. We need to suppress
+    // this dialog or it will pop up for every EXPECT/ASSERT_DEATH statement
+    // executed. Google Test will notify the user of any unexpected
+    // failure via stderr.
+    if (!GTEST_FLAG(break_on_failure))
+      _set_abort_behavior(
+          0x0,                                    // Clear the following flags:
+          _WRITE_ABORT_MSG | _CALL_REPORTFAULT);  // pop-up window, core dump.
+# endif
+
+    // In debug mode, the Windows CRT can crash with an assertion over invalid
+    // input (e.g. passing an invalid file descriptor).  The default handling
+    // for these assertions is to pop up a dialog and wait for user input.
+    // Instead ask the CRT to dump such assertions to stderr non-interactively.
+    if (!IsDebuggerPresent()) {
+      (void)_CrtSetReportMode(_CRT_ASSERT,
+                              _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
+      (void)_CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
+    }
+  }
+#endif  // GTEST_OS_WINDOWS
+
+  return internal::HandleExceptionsInMethodIfSupported(
+      impl(),
+      &internal::UnitTestImpl::RunAllTests,
+      "auxiliary test code (environments or event listeners)") ? 0 : 1;
+}
+
+// Returns the working directory when the first TEST() or TEST_F() was
+// executed.
+const char* UnitTest::original_working_dir() const {
+  return impl_->original_working_dir_.c_str();
+}
+
+// Returns the TestSuite object for the test that's currently running,
+// or NULL if no test is running.
+const TestSuite* UnitTest::current_test_suite() const
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  return impl_->current_test_suite();
+}
+
+// Legacy API is still available but deprecated
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+const TestCase* UnitTest::current_test_case() const
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  return impl_->current_test_suite();
+}
+#endif
+
+// Returns the TestInfo object for the test that's currently running,
+// or NULL if no test is running.
+const TestInfo* UnitTest::current_test_info() const
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  return impl_->current_test_info();
+}
+
+// Returns the random seed used at the start of the current test run.
+int UnitTest::random_seed() const { return impl_->random_seed(); }
+
+// Returns ParameterizedTestSuiteRegistry object used to keep track of
+// value-parameterized tests and instantiate and register them.
+internal::ParameterizedTestSuiteRegistry&
+UnitTest::parameterized_test_registry() GTEST_LOCK_EXCLUDED_(mutex_) {
+  return impl_->parameterized_test_registry();
+}
+
+// Creates an empty UnitTest.
+UnitTest::UnitTest() {
+  impl_ = new internal::UnitTestImpl(this);
+}
+
+// Destructor of UnitTest.
+UnitTest::~UnitTest() {
+  delete impl_;
+}
+
+// Pushes a trace defined by SCOPED_TRACE() on to the per-thread
+// Google Test trace stack.
+void UnitTest::PushGTestTrace(const internal::TraceInfo& trace)
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  impl_->gtest_trace_stack().push_back(trace);
+}
+
+// Pops a trace from the per-thread Google Test trace stack.
+void UnitTest::PopGTestTrace()
+    GTEST_LOCK_EXCLUDED_(mutex_) {
+  internal::MutexLock lock(&mutex_);
+  impl_->gtest_trace_stack().pop_back();
+}
+
+namespace internal {
+
+UnitTestImpl::UnitTestImpl(UnitTest* parent)
+    : parent_(parent),
+      GTEST_DISABLE_MSC_WARNINGS_PUSH_(4355 /* using this in initializer */)
+          default_global_test_part_result_reporter_(this),
+      default_per_thread_test_part_result_reporter_(this),
+      GTEST_DISABLE_MSC_WARNINGS_POP_() global_test_part_result_repoter_(
+          &default_global_test_part_result_reporter_),
+      per_thread_test_part_result_reporter_(
+          &default_per_thread_test_part_result_reporter_),
+      parameterized_test_registry_(),
+      parameterized_tests_registered_(false),
+      last_death_test_suite_(-1),
+      current_test_suite_(nullptr),
+      current_test_info_(nullptr),
+      ad_hoc_test_result_(),
+      os_stack_trace_getter_(nullptr),
+      post_flag_parse_init_performed_(false),
+      random_seed_(0),  // Will be overridden by the flag before first use.
+      random_(0),       // Will be reseeded before first use.
+      start_timestamp_(0),
+      elapsed_time_(0),
+#if GTEST_HAS_DEATH_TEST
+      death_test_factory_(new DefaultDeathTestFactory),
+#endif
+      // Will be overridden by the flag before first use.
+      catch_exceptions_(false) {
+  listeners()->SetDefaultResultPrinter(new PrettyUnitTestResultPrinter);
+}
+
+UnitTestImpl::~UnitTestImpl() {
+  // Deletes every TestSuite.
+  ForEach(test_suites_, internal::Delete<TestSuite>);
+
+  // Deletes every Environment.
+  ForEach(environments_, internal::Delete<Environment>);
+
+  delete os_stack_trace_getter_;
+}
+
+// Adds a TestProperty to the current TestResult object when invoked in a
+// context of a test, to current test suite's ad_hoc_test_result when invoke
+// from SetUpTestSuite/TearDownTestSuite, or to the global property set
+// otherwise.  If the result already contains a property with the same key,
+// the value will be updated.
+void UnitTestImpl::RecordProperty(const TestProperty& test_property) {
+  std::string xml_element;
+  TestResult* test_result;  // TestResult appropriate for property recording.
+
+  if (current_test_info_ != nullptr) {
+    xml_element = "testcase";
+    test_result = &(current_test_info_->result_);
+  } else if (current_test_suite_ != nullptr) {
+    xml_element = "testsuite";
+    test_result = &(current_test_suite_->ad_hoc_test_result_);
+  } else {
+    xml_element = "testsuites";
+    test_result = &ad_hoc_test_result_;
+  }
+  test_result->RecordProperty(xml_element, test_property);
+}
+
+#if GTEST_HAS_DEATH_TEST
+// Disables event forwarding if the control is currently in a death test
+// subprocess. Must not be called before InitGoogleTest.
+void UnitTestImpl::SuppressTestEventsIfInSubprocess() {
+  if (internal_run_death_test_flag_.get() != nullptr)
+    listeners()->SuppressEventForwarding();
+}
+#endif  // GTEST_HAS_DEATH_TEST
+
+// Initializes event listeners performing XML output as specified by
+// UnitTestOptions. Must not be called before InitGoogleTest.
+void UnitTestImpl::ConfigureXmlOutput() {
+  const std::string& output_format = UnitTestOptions::GetOutputFormat();
+  if (output_format == "xml") {
+    listeners()->SetDefaultXmlGenerator(new XmlUnitTestResultPrinter(
+        UnitTestOptions::GetAbsolutePathToOutputFile().c_str()));
+  } else if (output_format == "json") {
+    listeners()->SetDefaultXmlGenerator(new JsonUnitTestResultPrinter(
+        UnitTestOptions::GetAbsolutePathToOutputFile().c_str()));
+  } else if (output_format != "") {
+    GTEST_LOG_(WARNING) << "WARNING: unrecognized output format \""
+                        << output_format << "\" ignored.";
+  }
+}
+
+#if GTEST_CAN_STREAM_RESULTS_
+// Initializes event listeners for streaming test results in string form.
+// Must not be called before InitGoogleTest.
+void UnitTestImpl::ConfigureStreamingOutput() {
+  const std::string& target = GTEST_FLAG(stream_result_to);
+  if (!target.empty()) {
+    const size_t pos = target.find(':');
+    if (pos != std::string::npos) {
+      listeners()->Append(new StreamingListener(target.substr(0, pos),
+                                                target.substr(pos+1)));
+    } else {
+      GTEST_LOG_(WARNING) << "unrecognized streaming target \"" << target
+                          << "\" ignored.";
+    }
+  }
+}
+#endif  // GTEST_CAN_STREAM_RESULTS_
+
+// Performs initialization dependent upon flag values obtained in
+// ParseGoogleTestFlagsOnly.  Is called from InitGoogleTest after the call to
+// ParseGoogleTestFlagsOnly.  In case a user neglects to call InitGoogleTest
+// this function is also called from RunAllTests.  Since this function can be
+// called more than once, it has to be idempotent.
+void UnitTestImpl::PostFlagParsingInit() {
+  // Ensures that this function does not execute more than once.
+  if (!post_flag_parse_init_performed_) {
+    post_flag_parse_init_performed_ = true;
+
+#if defined(GTEST_CUSTOM_TEST_EVENT_LISTENER_)
+    // Register to send notifications about key process state changes.
+    listeners()->Append(new GTEST_CUSTOM_TEST_EVENT_LISTENER_());
+#endif  // defined(GTEST_CUSTOM_TEST_EVENT_LISTENER_)
+
+#if GTEST_HAS_DEATH_TEST
+    InitDeathTestSubprocessControlInfo();
+    SuppressTestEventsIfInSubprocess();
+#endif  // GTEST_HAS_DEATH_TEST
+
+    // Registers parameterized tests. This makes parameterized tests
+    // available to the UnitTest reflection API without running
+    // RUN_ALL_TESTS.
+    RegisterParameterizedTests();
+
+    // Configures listeners for XML output. This makes it possible for users
+    // to shut down the default XML output before invoking RUN_ALL_TESTS.
+    ConfigureXmlOutput();
+
+#if GTEST_CAN_STREAM_RESULTS_
+    // Configures listeners for streaming test results to the specified server.
+    ConfigureStreamingOutput();
+#endif  // GTEST_CAN_STREAM_RESULTS_
+
+#if GTEST_HAS_ABSL
+    if (GTEST_FLAG(install_failure_signal_handler)) {
+      absl::FailureSignalHandlerOptions options;
+      absl::InstallFailureSignalHandler(options);
+    }
+#endif  // GTEST_HAS_ABSL
+  }
+}
+
+// A predicate that checks the name of a TestSuite against a known
+// value.
+//
+// This is used for implementation of the UnitTest class only.  We put
+// it in the anonymous namespace to prevent polluting the outer
+// namespace.
+//
+// TestSuiteNameIs is copyable.
+class TestSuiteNameIs {
+ public:
+  // Constructor.
+  explicit TestSuiteNameIs(const std::string& name) : name_(name) {}
+
+  // Returns true if and only if the name of test_suite matches name_.
+  bool operator()(const TestSuite* test_suite) const {
+    return test_suite != nullptr &&
+           strcmp(test_suite->name(), name_.c_str()) == 0;
+  }
+
+ private:
+  std::string name_;
+};
+
+// Finds and returns a TestSuite with the given name.  If one doesn't
+// exist, creates one and returns it.  It's the CALLER'S
+// RESPONSIBILITY to ensure that this function is only called WHEN THE
+// TESTS ARE NOT SHUFFLED.
+//
+// Arguments:
+//
+//   test_suite_name: name of the test suite
+//   type_param:     the name of the test suite's type parameter, or NULL if
+//                   this is not a typed or a type-parameterized test suite.
+//   set_up_tc:      pointer to the function that sets up the test suite
+//   tear_down_tc:   pointer to the function that tears down the test suite
+TestSuite* UnitTestImpl::GetTestSuite(
+    const char* test_suite_name, const char* type_param,
+    internal::SetUpTestSuiteFunc set_up_tc,
+    internal::TearDownTestSuiteFunc tear_down_tc) {
+  // Can we find a TestSuite with the given name?
+  const auto test_suite =
+      std::find_if(test_suites_.rbegin(), test_suites_.rend(),
+                   TestSuiteNameIs(test_suite_name));
+
+  if (test_suite != test_suites_.rend()) return *test_suite;
+
+  // No.  Let's create one.
+  auto* const new_test_suite =
+      new TestSuite(test_suite_name, type_param, set_up_tc, tear_down_tc);
+
+  // Is this a death test suite?
+  if (internal::UnitTestOptions::MatchesFilter(test_suite_name,
+                                               kDeathTestSuiteFilter)) {
+    // Yes.  Inserts the test suite after the last death test suite
+    // defined so far.  This only works when the test suites haven't
+    // been shuffled.  Otherwise we may end up running a death test
+    // after a non-death test.
+    ++last_death_test_suite_;
+    test_suites_.insert(test_suites_.begin() + last_death_test_suite_,
+                        new_test_suite);
+  } else {
+    // No.  Appends to the end of the list.
+    test_suites_.push_back(new_test_suite);
+  }
+
+  test_suite_indices_.push_back(static_cast<int>(test_suite_indices_.size()));
+  return new_test_suite;
+}
+
+// Helpers for setting up / tearing down the given environment.  They
+// are for use in the ForEach() function.
+static void SetUpEnvironment(Environment* env) { env->SetUp(); }
+static void TearDownEnvironment(Environment* env) { env->TearDown(); }
+
+// Runs all tests in this UnitTest object, prints the result, and
+// returns true if all tests are successful.  If any exception is
+// thrown during a test, the test is considered to be failed, but the
+// rest of the tests will still be run.
+//
+// When parameterized tests are enabled, it expands and registers
+// parameterized tests first in RegisterParameterizedTests().
+// All other functions called from RunAllTests() may safely assume that
+// parameterized tests are ready to be counted and run.
+bool UnitTestImpl::RunAllTests() {
+  // True if and only if Google Test is initialized before RUN_ALL_TESTS() is
+  // called.
+  const bool gtest_is_initialized_before_run_all_tests = GTestIsInitialized();
+
+  // Do not run any test if the --help flag was specified.
+  if (g_help_flag)
+    return true;
+
+  // Repeats the call to the post-flag parsing initialization in case the
+  // user didn't call InitGoogleTest.
+  PostFlagParsingInit();
+
+  // Even if sharding is not on, test runners may want to use the
+  // GTEST_SHARD_STATUS_FILE to query whether the test supports the sharding
+  // protocol.
+  internal::WriteToShardStatusFileIfNeeded();
+
+  // True if and only if we are in a subprocess for running a thread-safe-style
+  // death test.
+  bool in_subprocess_for_death_test = false;
+
+#if GTEST_HAS_DEATH_TEST
+  in_subprocess_for_death_test =
+      (internal_run_death_test_flag_.get() != nullptr);
+# if defined(GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_)
+  if (in_subprocess_for_death_test) {
+    GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_();
+  }
+# endif  // defined(GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_)
+#endif  // GTEST_HAS_DEATH_TEST
+
+  const bool should_shard = ShouldShard(kTestTotalShards, kTestShardIndex,
+                                        in_subprocess_for_death_test);
+
+  // Compares the full test names with the filter to decide which
+  // tests to run.
+  const bool has_tests_to_run = FilterTests(should_shard
+                                              ? HONOR_SHARDING_PROTOCOL
+                                              : IGNORE_SHARDING_PROTOCOL) > 0;
+
+  // Lists the tests and exits if the --gtest_list_tests flag was specified.
+  if (GTEST_FLAG(list_tests)) {
+    // This must be called *after* FilterTests() has been called.
+    ListTestsMatchingFilter();
+    return true;
+  }
+
+  random_seed_ = GTEST_FLAG(shuffle) ?
+      GetRandomSeedFromFlag(GTEST_FLAG(random_seed)) : 0;
+
+  // True if and only if at least one test has failed.
+  bool failed = false;
+
+  TestEventListener* repeater = listeners()->repeater();
+
+  start_timestamp_ = GetTimeInMillis();
+  repeater->OnTestProgramStart(*parent_);
+
+  // How many times to repeat the tests?  We don't want to repeat them
+  // when we are inside the subprocess of a death test.
+  const int repeat = in_subprocess_for_death_test ? 1 : GTEST_FLAG(repeat);
+  // Repeats forever if the repeat count is negative.
+  const bool gtest_repeat_forever = repeat < 0;
+  for (int i = 0; gtest_repeat_forever || i != repeat; i++) {
+    // We want to preserve failures generated by ad-hoc test
+    // assertions executed before RUN_ALL_TESTS().
+    ClearNonAdHocTestResult();
+
+    const TimeInMillis start = GetTimeInMillis();
+
+    // Shuffles test suites and tests if requested.
+    if (has_tests_to_run && GTEST_FLAG(shuffle)) {
+      random()->Reseed(static_cast<UInt32>(random_seed_));
+      // This should be done before calling OnTestIterationStart(),
+      // such that a test event listener can see the actual test order
+      // in the event.
+      ShuffleTests();
+    }
+
+    // Tells the unit test event listeners that the tests are about to start.
+    repeater->OnTestIterationStart(*parent_, i);
+
+    // Runs each test suite if there is at least one test to run.
+    if (has_tests_to_run) {
+      // Sets up all environments beforehand.
+      repeater->OnEnvironmentsSetUpStart(*parent_);
+      ForEach(environments_, SetUpEnvironment);
+      repeater->OnEnvironmentsSetUpEnd(*parent_);
+
+      // Runs the tests only if there was no fatal failure or skip triggered
+      // during global set-up.
+      if (Test::IsSkipped()) {
+        // Emit diagnostics when global set-up calls skip, as it will not be
+        // emitted by default.
+        TestResult& test_result =
+            *internal::GetUnitTestImpl()->current_test_result();
+        for (int j = 0; j < test_result.total_part_count(); ++j) {
+          const TestPartResult& test_part_result =
+              test_result.GetTestPartResult(j);
+          if (test_part_result.type() == TestPartResult::kSkip) {
+            const std::string& result = test_part_result.message();
+            printf("%s\n", result.c_str());
+          }
+        }
+        fflush(stdout);
+      } else if (!Test::HasFatalFailure()) {
+        for (int test_index = 0; test_index < total_test_suite_count();
+             test_index++) {
+          GetMutableSuiteCase(test_index)->Run();
+        }
+      }
+
+      // Tears down all environments in reverse order afterwards.
+      repeater->OnEnvironmentsTearDownStart(*parent_);
+      std::for_each(environments_.rbegin(), environments_.rend(),
+                    TearDownEnvironment);
+      repeater->OnEnvironmentsTearDownEnd(*parent_);
+    }
+
+    elapsed_time_ = GetTimeInMillis() - start;
+
+    // Tells the unit test event listener that the tests have just finished.
+    repeater->OnTestIterationEnd(*parent_, i);
+
+    // Gets the result and clears it.
+    if (!Passed()) {
+      failed = true;
+    }
+
+    // Restores the original test order after the iteration.  This
+    // allows the user to quickly repro a failure that happens in the
+    // N-th iteration without repeating the first (N - 1) iterations.
+    // This is not enclosed in "if (GTEST_FLAG(shuffle)) { ... }", in
+    // case the user somehow changes the value of the flag somewhere
+    // (it's always safe to unshuffle the tests).
+    UnshuffleTests();
+
+    if (GTEST_FLAG(shuffle)) {
+      // Picks a new random seed for each iteration.
+      random_seed_ = GetNextRandomSeed(random_seed_);
+    }
+  }
+
+  repeater->OnTestProgramEnd(*parent_);
+
+  if (!gtest_is_initialized_before_run_all_tests) {
+    ColoredPrintf(
+        COLOR_RED,
+        "\nIMPORTANT NOTICE - DO NOT IGNORE:\n"
+        "This test program did NOT call " GTEST_INIT_GOOGLE_TEST_NAME_
+        "() before calling RUN_ALL_TESTS(). This is INVALID. Soon " GTEST_NAME_
+        " will start to enforce the valid usage. "
+        "Please fix it ASAP, or IT WILL START TO FAIL.\n");  // NOLINT
+#if GTEST_FOR_GOOGLE_
+    ColoredPrintf(COLOR_RED,
+                  "For more details, see http://wiki/Main/ValidGUnitMain.\n");
+#endif  // GTEST_FOR_GOOGLE_
+  }
+
+  return !failed;
+}
+
+// Reads the GTEST_SHARD_STATUS_FILE environment variable, and creates the file
+// if the variable is present. If a file already exists at this location, this
+// function will write over it. If the variable is present, but the file cannot
+// be created, prints an error and exits.
+void WriteToShardStatusFileIfNeeded() {
+  const char* const test_shard_file = posix::GetEnv(kTestShardStatusFile);
+  if (test_shard_file != nullptr) {
+    FILE* const file = posix::FOpen(test_shard_file, "w");
+    if (file == nullptr) {
+      ColoredPrintf(COLOR_RED,
+                    "Could not write to the test shard status file \"%s\" "
+                    "specified by the %s environment variable.\n",
+                    test_shard_file, kTestShardStatusFile);
+      fflush(stdout);
+      exit(EXIT_FAILURE);
+    }
+    fclose(file);
+  }
+}
+
+// Checks whether sharding is enabled by examining the relevant
+// environment variable values. If the variables are present,
+// but inconsistent (i.e., shard_index >= total_shards), prints
+// an error and exits. If in_subprocess_for_death_test, sharding is
+// disabled because it must only be applied to the original test
+// process. Otherwise, we could filter out death tests we intended to execute.
+bool ShouldShard(const char* total_shards_env,
+                 const char* shard_index_env,
+                 bool in_subprocess_for_death_test) {
+  if (in_subprocess_for_death_test) {
+    return false;
+  }
+
+  const Int32 total_shards = Int32FromEnvOrDie(total_shards_env, -1);
+  const Int32 shard_index = Int32FromEnvOrDie(shard_index_env, -1);
+
+  if (total_shards == -1 && shard_index == -1) {
+    return false;
+  } else if (total_shards == -1 && shard_index != -1) {
+    const Message msg = Message()
+      << "Invalid environment variables: you have "
+      << kTestShardIndex << " = " << shard_index
+      << ", but have left " << kTestTotalShards << " unset.\n";
+    ColoredPrintf(COLOR_RED, "%s", msg.GetString().c_str());
+    fflush(stdout);
+    exit(EXIT_FAILURE);
+  } else if (total_shards != -1 && shard_index == -1) {
+    const Message msg = Message()
+      << "Invalid environment variables: you have "
+      << kTestTotalShards << " = " << total_shards
+      << ", but have left " << kTestShardIndex << " unset.\n";
+    ColoredPrintf(COLOR_RED, "%s", msg.GetString().c_str());
+    fflush(stdout);
+    exit(EXIT_FAILURE);
+  } else if (shard_index < 0 || shard_index >= total_shards) {
+    const Message msg = Message()
+      << "Invalid environment variables: we require 0 <= "
+      << kTestShardIndex << " < " << kTestTotalShards
+      << ", but you have " << kTestShardIndex << "=" << shard_index
+      << ", " << kTestTotalShards << "=" << total_shards << ".\n";
+    ColoredPrintf(COLOR_RED, "%s", msg.GetString().c_str());
+    fflush(stdout);
+    exit(EXIT_FAILURE);
+  }
+
+  return total_shards > 1;
+}
+
+// Parses the environment variable var as an Int32. If it is unset,
+// returns default_val. If it is not an Int32, prints an error
+// and aborts.
+Int32 Int32FromEnvOrDie(const char* var, Int32 default_val) {
+  const char* str_val = posix::GetEnv(var);
+  if (str_val == nullptr) {
+    return default_val;
+  }
+
+  Int32 result;
+  if (!ParseInt32(Message() << "The value of environment variable " << var,
+                  str_val, &result)) {
+    exit(EXIT_FAILURE);
+  }
+  return result;
+}
+
+// Given the total number of shards, the shard index, and the test id,
+// returns true if and only if the test should be run on this shard. The test id
+// is some arbitrary but unique non-negative integer assigned to each test
+// method. Assumes that 0 <= shard_index < total_shards.
+bool ShouldRunTestOnShard(int total_shards, int shard_index, int test_id) {
+  return (test_id % total_shards) == shard_index;
+}
+
+// Compares the name of each test with the user-specified filter to
+// decide whether the test should be run, then records the result in
+// each TestSuite and TestInfo object.
+// If shard_tests == true, further filters tests based on sharding
+// variables in the environment - see
+// https://github.com/google/googletest/blob/master/googletest/docs/advanced.md
+// . Returns the number of tests that should run.
+int UnitTestImpl::FilterTests(ReactionToSharding shard_tests) {
+  const Int32 total_shards = shard_tests == HONOR_SHARDING_PROTOCOL ?
+      Int32FromEnvOrDie(kTestTotalShards, -1) : -1;
+  const Int32 shard_index = shard_tests == HONOR_SHARDING_PROTOCOL ?
+      Int32FromEnvOrDie(kTestShardIndex, -1) : -1;
+
+  // num_runnable_tests are the number of tests that will
+  // run across all shards (i.e., match filter and are not disabled).
+  // num_selected_tests are the number of tests to be run on
+  // this shard.
+  int num_runnable_tests = 0;
+  int num_selected_tests = 0;
+  for (auto* test_suite : test_suites_) {
+    const std::string& test_suite_name = test_suite->name();
+    test_suite->set_should_run(false);
+
+    for (size_t j = 0; j < test_suite->test_info_list().size(); j++) {
+      TestInfo* const test_info = test_suite->test_info_list()[j];
+      const std::string test_name(test_info->name());
+      // A test is disabled if test suite name or test name matches
+      // kDisableTestFilter.
+      const bool is_disabled = internal::UnitTestOptions::MatchesFilter(
+                                   test_suite_name, kDisableTestFilter) ||
+                               internal::UnitTestOptions::MatchesFilter(
+                                   test_name, kDisableTestFilter);
+      test_info->is_disabled_ = is_disabled;
+
+      const bool matches_filter = internal::UnitTestOptions::FilterMatchesTest(
+          test_suite_name, test_name);
+      test_info->matches_filter_ = matches_filter;
+
+      const bool is_runnable =
+          (GTEST_FLAG(also_run_disabled_tests) || !is_disabled) &&
+          matches_filter;
+
+      const bool is_in_another_shard =
+          shard_tests != IGNORE_SHARDING_PROTOCOL &&
+          !ShouldRunTestOnShard(total_shards, shard_index, num_runnable_tests);
+      test_info->is_in_another_shard_ = is_in_another_shard;
+      const bool is_selected = is_runnable && !is_in_another_shard;
+
+      num_runnable_tests += is_runnable;
+      num_selected_tests += is_selected;
+
+      test_info->should_run_ = is_selected;
+      test_suite->set_should_run(test_suite->should_run() || is_selected);
+    }
+  }
+  return num_selected_tests;
+}
+
+// Prints the given C-string on a single line by replacing all '\n'
+// characters with string "\\n".  If the output takes more than
+// max_length characters, only prints the first max_length characters
+// and "...".
+static void PrintOnOneLine(const char* str, int max_length) {
+  if (str != nullptr) {
+    for (int i = 0; *str != '\0'; ++str) {
+      if (i >= max_length) {
+        printf("...");
+        break;
+      }
+      if (*str == '\n') {
+        printf("\\n");
+        i += 2;
+      } else {
+        printf("%c", *str);
+        ++i;
+      }
+    }
+  }
+}
+
+// Prints the names of the tests matching the user-specified filter flag.
+void UnitTestImpl::ListTestsMatchingFilter() {
+  // Print at most this many characters for each type/value parameter.
+  const int kMaxParamLength = 250;
+
+  for (auto* test_suite : test_suites_) {
+    bool printed_test_suite_name = false;
+
+    for (size_t j = 0; j < test_suite->test_info_list().size(); j++) {
+      const TestInfo* const test_info = test_suite->test_info_list()[j];
+      if (test_info->matches_filter_) {
+        if (!printed_test_suite_name) {
+          printed_test_suite_name = true;
+          printf("%s.", test_suite->name());
+          if (test_suite->type_param() != nullptr) {
+            printf("  # %s = ", kTypeParamLabel);
+            // We print the type parameter on a single line to make
+            // the output easy to parse by a program.
+            PrintOnOneLine(test_suite->type_param(), kMaxParamLength);
+          }
+          printf("\n");
+        }
+        printf("  %s", test_info->name());
+        if (test_info->value_param() != nullptr) {
+          printf("  # %s = ", kValueParamLabel);
+          // We print the value parameter on a single line to make the
+          // output easy to parse by a program.
+          PrintOnOneLine(test_info->value_param(), kMaxParamLength);
+        }
+        printf("\n");
+      }
+    }
+  }
+  fflush(stdout);
+  const std::string& output_format = UnitTestOptions::GetOutputFormat();
+  if (output_format == "xml" || output_format == "json") {
+    FILE* fileout = OpenFileForWriting(
+        UnitTestOptions::GetAbsolutePathToOutputFile().c_str());
+    std::stringstream stream;
+    if (output_format == "xml") {
+      XmlUnitTestResultPrinter(
+          UnitTestOptions::GetAbsolutePathToOutputFile().c_str())
+          .PrintXmlTestsList(&stream, test_suites_);
+    } else if (output_format == "json") {
+      JsonUnitTestResultPrinter(
+          UnitTestOptions::GetAbsolutePathToOutputFile().c_str())
+          .PrintJsonTestList(&stream, test_suites_);
+    }
+    fprintf(fileout, "%s", StringStreamToString(&stream).c_str());
+    fclose(fileout);
+  }
+}
+
+// Sets the OS stack trace getter.
+//
+// Does nothing if the input and the current OS stack trace getter are
+// the same; otherwise, deletes the old getter and makes the input the
+// current getter.
+void UnitTestImpl::set_os_stack_trace_getter(
+    OsStackTraceGetterInterface* getter) {
+  if (os_stack_trace_getter_ != getter) {
+    delete os_stack_trace_getter_;
+    os_stack_trace_getter_ = getter;
+  }
+}
+
+// Returns the current OS stack trace getter if it is not NULL;
+// otherwise, creates an OsStackTraceGetter, makes it the current
+// getter, and returns it.
+OsStackTraceGetterInterface* UnitTestImpl::os_stack_trace_getter() {
+  if (os_stack_trace_getter_ == nullptr) {
+#ifdef GTEST_OS_STACK_TRACE_GETTER_
+    os_stack_trace_getter_ = new GTEST_OS_STACK_TRACE_GETTER_;
+#else
+    os_stack_trace_getter_ = new OsStackTraceGetter;
+#endif  // GTEST_OS_STACK_TRACE_GETTER_
+  }
+
+  return os_stack_trace_getter_;
+}
+
+// Returns the most specific TestResult currently running.
+TestResult* UnitTestImpl::current_test_result() {
+  if (current_test_info_ != nullptr) {
+    return &current_test_info_->result_;
+  }
+  if (current_test_suite_ != nullptr) {
+    return &current_test_suite_->ad_hoc_test_result_;
+  }
+  return &ad_hoc_test_result_;
+}
+
+// Shuffles all test suites, and the tests within each test suite,
+// making sure that death tests are still run first.
+void UnitTestImpl::ShuffleTests() {
+  // Shuffles the death test suites.
+  ShuffleRange(random(), 0, last_death_test_suite_ + 1, &test_suite_indices_);
+
+  // Shuffles the non-death test suites.
+  ShuffleRange(random(), last_death_test_suite_ + 1,
+               static_cast<int>(test_suites_.size()), &test_suite_indices_);
+
+  // Shuffles the tests inside each test suite.
+  for (auto& test_suite : test_suites_) {
+    test_suite->ShuffleTests(random());
+  }
+}
+
+// Restores the test suites and tests to their order before the first shuffle.
+void UnitTestImpl::UnshuffleTests() {
+  for (size_t i = 0; i < test_suites_.size(); i++) {
+    // Unshuffles the tests in each test suite.
+    test_suites_[i]->UnshuffleTests();
+    // Resets the index of each test suite.
+    test_suite_indices_[i] = static_cast<int>(i);
+  }
+}
+
+// Returns the current OS stack trace as an std::string.
+//
+// The maximum number of stack frames to be included is specified by
+// the gtest_stack_trace_depth flag.  The skip_count parameter
+// specifies the number of top frames to be skipped, which doesn't
+// count against the number of frames to be included.
+//
+// For example, if Foo() calls Bar(), which in turn calls
+// GetCurrentOsStackTraceExceptTop(..., 1), Foo() will be included in
+// the trace but Bar() and GetCurrentOsStackTraceExceptTop() won't.
+std::string GetCurrentOsStackTraceExceptTop(UnitTest* /*unit_test*/,
+                                            int skip_count) {
+  // We pass skip_count + 1 to skip this wrapper function in addition
+  // to what the user really wants to skip.
+  return GetUnitTestImpl()->CurrentOsStackTraceExceptTop(skip_count + 1);
+}
+
+// Used by the GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_ macro to
+// suppress unreachable code warnings.
+namespace {
+class ClassUniqueToAlwaysTrue {};
+}
+
+bool IsTrue(bool condition) { return condition; }
+
+bool AlwaysTrue() {
+#if GTEST_HAS_EXCEPTIONS
+  // This condition is always false so AlwaysTrue() never actually throws,
+  // but it makes the compiler think that it may throw.
+  if (IsTrue(false))
+    throw ClassUniqueToAlwaysTrue();
+#endif  // GTEST_HAS_EXCEPTIONS
+  return true;
+}
+
+// If *pstr starts with the given prefix, modifies *pstr to be right
+// past the prefix and returns true; otherwise leaves *pstr unchanged
+// and returns false.  None of pstr, *pstr, and prefix can be NULL.
+bool SkipPrefix(const char* prefix, const char** pstr) {
+  const size_t prefix_len = strlen(prefix);
+  if (strncmp(*pstr, prefix, prefix_len) == 0) {
+    *pstr += prefix_len;
+    return true;
+  }
+  return false;
+}
+
+// Parses a string as a command line flag.  The string should have
+// the format "--flag=value".  When def_optional is true, the "=value"
+// part can be omitted.
+//
+// Returns the value of the flag, or NULL if the parsing failed.
+static const char* ParseFlagValue(const char* str, const char* flag,
+                                  bool def_optional) {
+  // str and flag must not be NULL.
+  if (str == nullptr || flag == nullptr) return nullptr;
+
+  // The flag must start with "--" followed by GTEST_FLAG_PREFIX_.
+  const std::string flag_str = std::string("--") + GTEST_FLAG_PREFIX_ + flag;
+  const size_t flag_len = flag_str.length();
+  if (strncmp(str, flag_str.c_str(), flag_len) != 0) return nullptr;
+
+  // Skips the flag name.
+  const char* flag_end = str + flag_len;
+
+  // When def_optional is true, it's OK to not have a "=value" part.
+  if (def_optional && (flag_end[0] == '\0')) {
+    return flag_end;
+  }
+
+  // If def_optional is true and there are more characters after the
+  // flag name, or if def_optional is false, there must be a '=' after
+  // the flag name.
+  if (flag_end[0] != '=') return nullptr;
+
+  // Returns the string after "=".
+  return flag_end + 1;
+}
+
+// Parses a string for a bool flag, in the form of either
+// "--flag=value" or "--flag".
+//
+// In the former case, the value is taken as true as long as it does
+// not start with '0', 'f', or 'F'.
+//
+// In the latter case, the value is taken as true.
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+static bool ParseBoolFlag(const char* str, const char* flag, bool* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag, true);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Converts the string value to a bool.
+  *value = !(*value_str == '0' || *value_str == 'f' || *value_str == 'F');
+  return true;
+}
+
+// Parses a string for an Int32 flag, in the form of
+// "--flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+bool ParseInt32Flag(const char* str, const char* flag, Int32* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag, false);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Sets *value to the value of the flag.
+  return ParseInt32(Message() << "The value of flag --" << flag,
+                    value_str, value);
+}
+
+// Parses a string for a string flag, in the form of
+// "--flag=value".
+//
+// On success, stores the value of the flag in *value, and returns
+// true.  On failure, returns false without changing *value.
+template <typename String>
+static bool ParseStringFlag(const char* str, const char* flag, String* value) {
+  // Gets the value of the flag as a string.
+  const char* const value_str = ParseFlagValue(str, flag, false);
+
+  // Aborts if the parsing failed.
+  if (value_str == nullptr) return false;
+
+  // Sets *value to the value of the flag.
+  *value = value_str;
+  return true;
+}
+
+// Determines whether a string has a prefix that Google Test uses for its
+// flags, i.e., starts with GTEST_FLAG_PREFIX_ or GTEST_FLAG_PREFIX_DASH_.
+// If Google Test detects that a command line flag has its prefix but is not
+// recognized, it will print its help message. Flags starting with
+// GTEST_INTERNAL_PREFIX_ followed by "internal_" are considered Google Test
+// internal flags and do not trigger the help message.
+static bool HasGoogleTestFlagPrefix(const char* str) {
+  return (SkipPrefix("--", &str) ||
+          SkipPrefix("-", &str) ||
+          SkipPrefix("/", &str)) &&
+         !SkipPrefix(GTEST_FLAG_PREFIX_ "internal_", &str) &&
+         (SkipPrefix(GTEST_FLAG_PREFIX_, &str) ||
+          SkipPrefix(GTEST_FLAG_PREFIX_DASH_, &str));
+}
+
+// Prints a string containing code-encoded text.  The following escape
+// sequences can be used in the string to control the text color:
+//
+//   @@    prints a single '@' character.
+//   @R    changes the color to red.
+//   @G    changes the color to green.
+//   @Y    changes the color to yellow.
+//   @D    changes to the default terminal text color.
+//
+static void PrintColorEncoded(const char* str) {
+  GTestColor color = COLOR_DEFAULT;  // The current color.
+
+  // Conceptually, we split the string into segments divided by escape
+  // sequences.  Then we print one segment at a time.  At the end of
+  // each iteration, the str pointer advances to the beginning of the
+  // next segment.
+  for (;;) {
+    const char* p = strchr(str, '@');
+    if (p == nullptr) {
+      ColoredPrintf(color, "%s", str);
+      return;
+    }
+
+    ColoredPrintf(color, "%s", std::string(str, p).c_str());
+
+    const char ch = p[1];
+    str = p + 2;
+    if (ch == '@') {
+      ColoredPrintf(color, "@");
+    } else if (ch == 'D') {
+      color = COLOR_DEFAULT;
+    } else if (ch == 'R') {
+      color = COLOR_RED;
+    } else if (ch == 'G') {
+      color = COLOR_GREEN;
+    } else if (ch == 'Y') {
+      color = COLOR_YELLOW;
+    } else {
+      --str;
+    }
+  }
+}
+
+static const char kColorEncodedHelpMessage[] =
+"This program contains tests written using " GTEST_NAME_ ". You can use the\n"
+"following command line flags to control its behavior:\n"
+"\n"
+"Test Selection:\n"
+"  @G--" GTEST_FLAG_PREFIX_ "list_tests@D\n"
+"      List the names of all tests instead of running them. The name of\n"
+"      TEST(Foo, Bar) is \"Foo.Bar\".\n"
+"  @G--" GTEST_FLAG_PREFIX_ "filter=@YPOSTIVE_PATTERNS"
+    "[@G-@YNEGATIVE_PATTERNS]@D\n"
+"      Run only the tests whose name matches one of the positive patterns but\n"
+"      none of the negative patterns. '?' matches any single character; '*'\n"
+"      matches any substring; ':' separates two patterns.\n"
+"  @G--" GTEST_FLAG_PREFIX_ "also_run_disabled_tests@D\n"
+"      Run all disabled tests too.\n"
+"\n"
+"Test Execution:\n"
+"  @G--" GTEST_FLAG_PREFIX_ "repeat=@Y[COUNT]@D\n"
+"      Run the tests repeatedly; use a negative count to repeat forever.\n"
+"  @G--" GTEST_FLAG_PREFIX_ "shuffle@D\n"
+"      Randomize tests' orders on every iteration.\n"
+"  @G--" GTEST_FLAG_PREFIX_ "random_seed=@Y[NUMBER]@D\n"
+"      Random number seed to use for shuffling test orders (between 1 and\n"
+"      99999, or 0 to use a seed based on the current time).\n"
+"\n"
+"Test Output:\n"
+"  @G--" GTEST_FLAG_PREFIX_ "color=@Y(@Gyes@Y|@Gno@Y|@Gauto@Y)@D\n"
+"      Enable/disable colored output. The default is @Gauto@D.\n"
+"  -@G-" GTEST_FLAG_PREFIX_ "print_time=0@D\n"
+"      Don't print the elapsed time of each test.\n"
+"  @G--" GTEST_FLAG_PREFIX_ "output=@Y(@Gjson@Y|@Gxml@Y)[@G:@YDIRECTORY_PATH@G"
+    GTEST_PATH_SEP_ "@Y|@G:@YFILE_PATH]@D\n"
+"      Generate a JSON or XML report in the given directory or with the given\n"
+"      file name. @YFILE_PATH@D defaults to @Gtest_detail.xml@D.\n"
+# if GTEST_CAN_STREAM_RESULTS_
+"  @G--" GTEST_FLAG_PREFIX_ "stream_result_to=@YHOST@G:@YPORT@D\n"
+"      Stream test results to the given server.\n"
+# endif  // GTEST_CAN_STREAM_RESULTS_
+"\n"
+"Assertion Behavior:\n"
+# if GTEST_HAS_DEATH_TEST && !GTEST_OS_WINDOWS
+"  @G--" GTEST_FLAG_PREFIX_ "death_test_style=@Y(@Gfast@Y|@Gthreadsafe@Y)@D\n"
+"      Set the default death test style.\n"
+# endif  // GTEST_HAS_DEATH_TEST && !GTEST_OS_WINDOWS
+"  @G--" GTEST_FLAG_PREFIX_ "break_on_failure@D\n"
+"      Turn assertion failures into debugger break-points.\n"
+"  @G--" GTEST_FLAG_PREFIX_ "throw_on_failure@D\n"
+"      Turn assertion failures into C++ exceptions for use by an external\n"
+"      test framework.\n"
+"  @G--" GTEST_FLAG_PREFIX_ "catch_exceptions=0@D\n"
+"      Do not report exceptions as test failures. Instead, allow them\n"
+"      to crash the program or throw a pop-up (on Windows).\n"
+"\n"
+"Except for @G--" GTEST_FLAG_PREFIX_ "list_tests@D, you can alternatively set "
+    "the corresponding\n"
+"environment variable of a flag (all letters in upper-case). For example, to\n"
+"disable colored text output, you can either specify @G--" GTEST_FLAG_PREFIX_
+    "color=no@D or set\n"
+"the @G" GTEST_FLAG_PREFIX_UPPER_ "COLOR@D environment variable to @Gno@D.\n"
+"\n"
+"For more information, please read the " GTEST_NAME_ " documentation at\n"
+"@G" GTEST_PROJECT_URL_ "@D. If you find a bug in " GTEST_NAME_ "\n"
+"(not one in your own code or tests), please report it to\n"
+"@G<" GTEST_DEV_EMAIL_ ">@D.\n";
+
+static bool ParseGoogleTestFlag(const char* const arg) {
+  return ParseBoolFlag(arg, kAlsoRunDisabledTestsFlag,
+                       &GTEST_FLAG(also_run_disabled_tests)) ||
+      ParseBoolFlag(arg, kBreakOnFailureFlag,
+                    &GTEST_FLAG(break_on_failure)) ||
+      ParseBoolFlag(arg, kCatchExceptionsFlag,
+                    &GTEST_FLAG(catch_exceptions)) ||
+      ParseStringFlag(arg, kColorFlag, &GTEST_FLAG(color)) ||
+      ParseStringFlag(arg, kDeathTestStyleFlag,
+                      &GTEST_FLAG(death_test_style)) ||
+      ParseBoolFlag(arg, kDeathTestUseFork,
+                    &GTEST_FLAG(death_test_use_fork)) ||
+      ParseStringFlag(arg, kFilterFlag, &GTEST_FLAG(filter)) ||
+      ParseStringFlag(arg, kInternalRunDeathTestFlag,
+                      &GTEST_FLAG(internal_run_death_test)) ||
+      ParseBoolFlag(arg, kListTestsFlag, &GTEST_FLAG(list_tests)) ||
+      ParseStringFlag(arg, kOutputFlag, &GTEST_FLAG(output)) ||
+      ParseBoolFlag(arg, kPrintTimeFlag, &GTEST_FLAG(print_time)) ||
+      ParseBoolFlag(arg, kPrintUTF8Flag, &GTEST_FLAG(print_utf8)) ||
+      ParseInt32Flag(arg, kRandomSeedFlag, &GTEST_FLAG(random_seed)) ||
+      ParseInt32Flag(arg, kRepeatFlag, &GTEST_FLAG(repeat)) ||
+      ParseBoolFlag(arg, kShuffleFlag, &GTEST_FLAG(shuffle)) ||
+      ParseInt32Flag(arg, kStackTraceDepthFlag,
+                     &GTEST_FLAG(stack_trace_depth)) ||
+      ParseStringFlag(arg, kStreamResultToFlag,
+                      &GTEST_FLAG(stream_result_to)) ||
+      ParseBoolFlag(arg, kThrowOnFailureFlag,
+                    &GTEST_FLAG(throw_on_failure));
+}
+
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+static void LoadFlagsFromFile(const std::string& path) {
+  FILE* flagfile = posix::FOpen(path.c_str(), "r");
+  if (!flagfile) {
+    GTEST_LOG_(FATAL) << "Unable to open file \"" << GTEST_FLAG(flagfile)
+                      << "\"";
+  }
+  std::string contents(ReadEntireFile(flagfile));
+  posix::FClose(flagfile);
+  std::vector<std::string> lines;
+  SplitString(contents, '\n', &lines);
+  for (size_t i = 0; i < lines.size(); ++i) {
+    if (lines[i].empty())
+      continue;
+    if (!ParseGoogleTestFlag(lines[i].c_str()))
+      g_help_flag = true;
+  }
+}
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+
+// Parses the command line for Google Test flags, without initializing
+// other parts of Google Test.  The type parameter CharType can be
+// instantiated to either char or wchar_t.
+template <typename CharType>
+void ParseGoogleTestFlagsOnlyImpl(int* argc, CharType** argv) {
+  for (int i = 1; i < *argc; i++) {
+    const std::string arg_string = StreamableToString(argv[i]);
+    const char* const arg = arg_string.c_str();
+
+    using internal::ParseBoolFlag;
+    using internal::ParseInt32Flag;
+    using internal::ParseStringFlag;
+
+    bool remove_flag = false;
+    if (ParseGoogleTestFlag(arg)) {
+      remove_flag = true;
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+    } else if (ParseStringFlag(arg, kFlagfileFlag, &GTEST_FLAG(flagfile))) {
+      LoadFlagsFromFile(GTEST_FLAG(flagfile));
+      remove_flag = true;
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+    } else if (arg_string == "--help" || arg_string == "-h" ||
+               arg_string == "-?" || arg_string == "/?" ||
+               HasGoogleTestFlagPrefix(arg)) {
+      // Both help flag and unrecognized Google Test flags (excluding
+      // internal ones) trigger help display.
+      g_help_flag = true;
+    }
+
+    if (remove_flag) {
+      // Shift the remainder of the argv list left by one.  Note
+      // that argv has (*argc + 1) elements, the last one always being
+      // NULL.  The following loop moves the trailing NULL element as
+      // well.
+      for (int j = i; j != *argc; j++) {
+        argv[j] = argv[j + 1];
+      }
+
+      // Decrements the argument count.
+      (*argc)--;
+
+      // We also need to decrement the iterator as we just removed
+      // an element.
+      i--;
+    }
+  }
+
+  if (g_help_flag) {
+    // We print the help here instead of in RUN_ALL_TESTS(), as the
+    // latter may not be called at all if the user is using Google
+    // Test with another testing framework.
+    PrintColorEncoded(kColorEncodedHelpMessage);
+  }
+}
+
+// Parses the command line for Google Test flags, without initializing
+// other parts of Google Test.
+void ParseGoogleTestFlagsOnly(int* argc, char** argv) {
+  ParseGoogleTestFlagsOnlyImpl(argc, argv);
+
+  // Fix the value of *_NSGetArgc() on macOS, but if and only if
+  // *_NSGetArgv() == argv
+  // Only applicable to char** version of argv
+#if GTEST_OS_MAC
+#ifndef GTEST_OS_IOS
+  if (*_NSGetArgv() == argv) {
+    *_NSGetArgc() = *argc;
+  }
+#endif
+#endif
+}
+void ParseGoogleTestFlagsOnly(int* argc, wchar_t** argv) {
+  ParseGoogleTestFlagsOnlyImpl(argc, argv);
+}
+
+// The internal implementation of InitGoogleTest().
+//
+// The type parameter CharType can be instantiated to either char or
+// wchar_t.
+template <typename CharType>
+void InitGoogleTestImpl(int* argc, CharType** argv) {
+  // We don't want to run the initialization code twice.
+  if (GTestIsInitialized()) return;
+
+  if (*argc <= 0) return;
+
+  g_argvs.clear();
+  for (int i = 0; i != *argc; i++) {
+    g_argvs.push_back(StreamableToString(argv[i]));
+  }
+
+#if GTEST_HAS_ABSL
+  absl::InitializeSymbolizer(g_argvs[0].c_str());
+#endif  // GTEST_HAS_ABSL
+
+  ParseGoogleTestFlagsOnly(argc, argv);
+  GetUnitTestImpl()->PostFlagParsingInit();
+}
+
+}  // namespace internal
+
+// Initializes Google Test.  This must be called before calling
+// RUN_ALL_TESTS().  In particular, it parses a command line for the
+// flags that Google Test recognizes.  Whenever a Google Test flag is
+// seen, it is removed from argv, and *argc is decremented.
+//
+// No value is returned.  Instead, the Google Test flag variables are
+// updated.
+//
+// Calling the function for the second time has no user-visible effect.
+void InitGoogleTest(int* argc, char** argv) {
+#if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(argc, argv);
+#else  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  internal::InitGoogleTestImpl(argc, argv);
+#endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+}
+
+// This overloaded version can be used in Windows programs compiled in
+// UNICODE mode.
+void InitGoogleTest(int* argc, wchar_t** argv) {
+#if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(argc, argv);
+#else  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  internal::InitGoogleTestImpl(argc, argv);
+#endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+}
+
+// This overloaded version can be used on Arduino/embedded platforms where
+// there is no argc/argv.
+void InitGoogleTest() {
+  // Since Arduino doesn't have a command line, fake out the argc/argv arguments
+  int argc = 1;
+  const auto arg0 = "dummy";
+  char* argv0 = const_cast<char*>(arg0);
+  char** argv = &argv0;
+
+#if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(&argc, argv);
+#else  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+  internal::InitGoogleTestImpl(&argc, argv);
+#endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
+}
+
+std::string TempDir() {
+#if defined(GTEST_CUSTOM_TEMPDIR_FUNCTION_)
+  return GTEST_CUSTOM_TEMPDIR_FUNCTION_();
+#endif
+
+#if GTEST_OS_WINDOWS_MOBILE
+  return "\\temp\\";
+#elif GTEST_OS_WINDOWS
+  const char* temp_dir = internal::posix::GetEnv("TEMP");
+  if (temp_dir == nullptr || temp_dir[0] == '\0')
+    return "\\temp\\";
+  else if (temp_dir[strlen(temp_dir) - 1] == '\\')
+    return temp_dir;
+  else
+    return std::string(temp_dir) + "\\";
+#elif GTEST_OS_LINUX_ANDROID
+  return "/sdcard/";
+#else
+  return "/tmp/";
+#endif  // GTEST_OS_WINDOWS_MOBILE
+}
+
+// Class ScopedTrace
+
+// Pushes the given source file location and message onto a per-thread
+// trace stack maintained by Google Test.
+void ScopedTrace::PushTrace(const char* file, int line, std::string message) {
+  internal::TraceInfo trace;
+  trace.file = file;
+  trace.line = line;
+  trace.message.swap(message);
+
+  UnitTest::GetInstance()->PushGTestTrace(trace);
+}
+
+// Pops the info pushed by the c'tor.
+ScopedTrace::~ScopedTrace()
+    GTEST_LOCK_EXCLUDED_(&UnitTest::mutex_) {
+  UnitTest::GetInstance()->PopGTestTrace();
+}
+
+}  // namespace testing
diff --git a/3rdparty/gtest/src/gtest_main.cc b/3rdparty/gtest/src/gtest_main.cc
new file mode 100644
index 0000000..f6e1dd9
--- /dev/null
+++ b/3rdparty/gtest/src/gtest_main.cc
@@ -0,0 +1,47 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <cstdio>
+#include "gtest/gtest.h"
+
+#ifdef ARDUINO
+void setup() {
+  testing::InitGoogleTest();
+}
+
+void loop() { RUN_ALL_TESTS(); }
+
+#else
+
+GTEST_API_ int main(int argc, char **argv) {
+  printf("Running main() from %s\n", __FILE__);
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+#endif
diff --git a/3rdparty/gtest/test/BUILD.bazel b/3rdparty/gtest/test/BUILD.bazel
new file mode 100644
index 0000000..156d5d4
--- /dev/null
+++ b/3rdparty/gtest/test/BUILD.bazel
@@ -0,0 +1,521 @@
+# Copyright 2017 Google Inc.
+# All Rights Reserved.
+#
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Author: misterg@google.com (Gennadiy Civil)
+#
+# Bazel BUILD for The Google C++ Testing Framework (Google Test)
+
+load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_test")
+load("@rules_python//python:defs.bzl", "py_library", "py_test")
+
+licenses(["notice"])
+
+#on windows exclude gtest-tuple.h
+cc_test(
+    name = "gtest_all_test",
+    size = "small",
+    srcs = glob(
+        include = [
+            "gtest-*.cc",
+            "googletest-*.cc",
+            "*.h",
+            "googletest/include/gtest/**/*.h",
+        ],
+        exclude = [
+            "gtest-unittest-api_test.cc",
+            "googletest/src/gtest-all.cc",
+            "gtest_all_test.cc",
+            "gtest-death-test_ex_test.cc",
+            "gtest-listener_test.cc",
+            "gtest-unittest-api_test.cc",
+            "googletest-param-test-test.cc",
+            "googletest-catch-exceptions-test_.cc",
+            "googletest-color-test_.cc",
+            "googletest-env-var-test_.cc",
+            "googletest-filter-unittest_.cc",
+            "googletest-break-on-failure-unittest_.cc",
+            "googletest-listener-test.cc",
+            "googletest-output-test_.cc",
+            "googletest-list-tests-unittest_.cc",
+            "googletest-shuffle-test_.cc",
+            "googletest-uninitialized-test_.cc",
+            "googletest-death-test_ex_test.cc",
+            "googletest-param-test-test",
+            "googletest-throw-on-failure-test_.cc",
+            "googletest-param-test-invalid-name1-test_.cc",
+            "googletest-param-test-invalid-name2-test_.cc",
+        ],
+    ) + select({
+        "//:windows": [],
+        "//conditions:default": [],
+    }),
+    copts = select({
+        "//:windows": ["-DGTEST_USE_OWN_TR1_TUPLE=0"],
+        "//conditions:default": ["-DGTEST_USE_OWN_TR1_TUPLE=1"],
+    }),
+    includes = [
+        "googletest",
+        "googletest/include",
+        "googletest/include/internal",
+        "googletest/test",
+    ],
+    linkopts = select({
+        "//:windows": [],
+        "//conditions:default": ["-pthread"],
+    }),
+    deps = ["//:gtest_main"],
+)
+
+# Tests death tests.
+cc_test(
+    name = "googletest-death-test-test",
+    size = "medium",
+    srcs = ["googletest-death-test-test.cc"],
+    deps = ["//:gtest_main"],
+)
+
+cc_test(
+    name = "gtest_test_macro_stack_footprint_test",
+    size = "small",
+    srcs = ["gtest_test_macro_stack_footprint_test.cc"],
+    deps = ["//:gtest"],
+)
+
+#These googletest tests have their own main()
+cc_test(
+    name = "googletest-listener-test",
+    size = "small",
+    srcs = ["googletest-listener-test.cc"],
+    deps = ["//:gtest_main"],
+)
+
+cc_test(
+    name = "gtest-unittest-api_test",
+    size = "small",
+    srcs = [
+        "gtest-unittest-api_test.cc",
+    ],
+    deps = [
+        "//:gtest",
+    ],
+)
+
+cc_test(
+    name = "googletest-param-test-test",
+    size = "small",
+    srcs = [
+        "googletest-param-test-test.cc",
+        "googletest-param-test-test.h",
+        "googletest-param-test2-test.cc",
+    ],
+    deps = ["//:gtest"],
+)
+
+cc_test(
+    name = "gtest_unittest",
+    size = "small",
+    srcs = ["gtest_unittest.cc"],
+    args = ["--heap_check=strict"],
+    shard_count = 2,
+    deps = ["//:gtest_main"],
+)
+
+#  Py tests
+
+py_library(
+    name = "gtest_test_utils",
+    testonly = 1,
+    srcs = ["gtest_test_utils.py"],
+)
+
+cc_binary(
+    name = "gtest_help_test_",
+    testonly = 1,
+    srcs = ["gtest_help_test_.cc"],
+    deps = ["//:gtest_main"],
+)
+
+py_test(
+    name = "gtest_help_test",
+    size = "small",
+    srcs = ["gtest_help_test.py"],
+    data = [":gtest_help_test_"],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "googletest-output-test_",
+    testonly = 1,
+    srcs = ["googletest-output-test_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "googletest-output-test",
+    size = "small",
+    srcs = ["googletest-output-test.py"],
+    args = select({
+        "//:has_absl": [],
+        "//conditions:default": ["--no_stacktrace_support"],
+    }),
+    data = [
+        "googletest-output-test-golden-lin.txt",
+        ":googletest-output-test_",
+    ],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "googletest-color-test_",
+    testonly = 1,
+    srcs = ["googletest-color-test_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "googletest-color-test",
+    size = "small",
+    srcs = ["googletest-color-test.py"],
+    data = [":googletest-color-test_"],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "googletest-env-var-test_",
+    testonly = 1,
+    srcs = ["googletest-env-var-test_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "googletest-env-var-test",
+    size = "medium",
+    srcs = ["googletest-env-var-test.py"],
+    data = [":googletest-env-var-test_"],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "googletest-filter-unittest_",
+    testonly = 1,
+    srcs = ["googletest-filter-unittest_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "googletest-filter-unittest",
+    size = "medium",
+    srcs = ["googletest-filter-unittest.py"],
+    data = [":googletest-filter-unittest_"],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "googletest-break-on-failure-unittest_",
+    testonly = 1,
+    srcs = ["googletest-break-on-failure-unittest_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "googletest-break-on-failure-unittest",
+    size = "small",
+    srcs = ["googletest-break-on-failure-unittest.py"],
+    data = [":googletest-break-on-failure-unittest_"],
+    deps = [":gtest_test_utils"],
+)
+
+cc_test(
+    name = "gtest_assert_by_exception_test",
+    size = "small",
+    srcs = ["gtest_assert_by_exception_test.cc"],
+    deps = ["//:gtest"],
+)
+
+cc_binary(
+    name = "googletest-throw-on-failure-test_",
+    testonly = 1,
+    srcs = ["googletest-throw-on-failure-test_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "googletest-throw-on-failure-test",
+    size = "small",
+    srcs = ["googletest-throw-on-failure-test.py"],
+    data = [":googletest-throw-on-failure-test_"],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "googletest-list-tests-unittest_",
+    testonly = 1,
+    srcs = ["googletest-list-tests-unittest_.cc"],
+    deps = ["//:gtest"],
+)
+
+cc_test(
+    name = "gtest_skip_test",
+    size = "small",
+    srcs = ["gtest_skip_test.cc"],
+    deps = ["//:gtest_main"],
+)
+
+cc_test(
+    name = "gtest_skip_in_environment_setup_test",
+    size = "small",
+    srcs = ["gtest_skip_in_environment_setup_test.cc"],
+    deps = ["//:gtest_main"],
+)
+
+py_test(
+    name = "gtest_skip_environment_check_output_test",
+    size = "small",
+    srcs = ["gtest_skip_environment_check_output_test.py"],
+    data = [
+        ":gtest_skip_in_environment_setup_test",
+    ],
+    deps = [":gtest_test_utils"],
+)
+
+py_test(
+    name = "googletest-list-tests-unittest",
+    size = "small",
+    srcs = ["googletest-list-tests-unittest.py"],
+    data = [":googletest-list-tests-unittest_"],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "googletest-shuffle-test_",
+    srcs = ["googletest-shuffle-test_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "googletest-shuffle-test",
+    size = "small",
+    srcs = ["googletest-shuffle-test.py"],
+    data = [":googletest-shuffle-test_"],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "googletest-catch-exceptions-no-ex-test_",
+    testonly = 1,
+    srcs = ["googletest-catch-exceptions-test_.cc"],
+    deps = ["//:gtest_main"],
+)
+
+cc_binary(
+    name = "googletest-catch-exceptions-ex-test_",
+    testonly = 1,
+    srcs = ["googletest-catch-exceptions-test_.cc"],
+    copts = ["-fexceptions"],
+    deps = ["//:gtest_main"],
+)
+
+py_test(
+    name = "googletest-catch-exceptions-test",
+    size = "small",
+    srcs = ["googletest-catch-exceptions-test.py"],
+    data = [
+        ":googletest-catch-exceptions-ex-test_",
+        ":googletest-catch-exceptions-no-ex-test_",
+    ],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "gtest_xml_output_unittest_",
+    testonly = 1,
+    srcs = ["gtest_xml_output_unittest_.cc"],
+    deps = ["//:gtest"],
+)
+
+cc_test(
+    name = "gtest_no_test_unittest",
+    size = "small",
+    srcs = ["gtest_no_test_unittest.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "gtest_xml_output_unittest",
+    size = "small",
+    srcs = [
+        "gtest_xml_output_unittest.py",
+        "gtest_xml_test_utils.py",
+    ],
+    args = select({
+        "//:has_absl": [],
+        "//conditions:default": ["--no_stacktrace_support"],
+    }),
+    data = [
+        # We invoke gtest_no_test_unittest to verify the XML output
+        # when the test program contains no test definition.
+        ":gtest_no_test_unittest",
+        ":gtest_xml_output_unittest_",
+    ],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "gtest_xml_outfile1_test_",
+    testonly = 1,
+    srcs = ["gtest_xml_outfile1_test_.cc"],
+    deps = ["//:gtest_main"],
+)
+
+cc_binary(
+    name = "gtest_xml_outfile2_test_",
+    testonly = 1,
+    srcs = ["gtest_xml_outfile2_test_.cc"],
+    deps = ["//:gtest_main"],
+)
+
+py_test(
+    name = "gtest_xml_outfiles_test",
+    size = "small",
+    srcs = [
+        "gtest_xml_outfiles_test.py",
+        "gtest_xml_test_utils.py",
+    ],
+    data = [
+        ":gtest_xml_outfile1_test_",
+        ":gtest_xml_outfile2_test_",
+    ],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "googletest-uninitialized-test_",
+    testonly = 1,
+    srcs = ["googletest-uninitialized-test_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "googletest-uninitialized-test",
+    size = "medium",
+    srcs = ["googletest-uninitialized-test.py"],
+    data = ["googletest-uninitialized-test_"],
+    deps = [":gtest_test_utils"],
+)
+
+cc_binary(
+    name = "gtest_testbridge_test_",
+    testonly = 1,
+    srcs = ["gtest_testbridge_test_.cc"],
+    deps = ["//:gtest_main"],
+)
+
+# Tests that filtering via testbridge works
+py_test(
+    name = "gtest_testbridge_test",
+    size = "small",
+    srcs = ["gtest_testbridge_test.py"],
+    data = [":gtest_testbridge_test_"],
+    deps = [":gtest_test_utils"],
+)
+
+py_test(
+    name = "googletest-json-outfiles-test",
+    size = "small",
+    srcs = [
+        "googletest-json-outfiles-test.py",
+        "gtest_json_test_utils.py",
+    ],
+    data = [
+        ":gtest_xml_outfile1_test_",
+        ":gtest_xml_outfile2_test_",
+    ],
+    deps = [":gtest_test_utils"],
+)
+
+py_test(
+    name = "googletest-json-output-unittest",
+    size = "medium",
+    srcs = [
+        "googletest-json-output-unittest.py",
+        "gtest_json_test_utils.py",
+    ],
+    args = select({
+        "//:has_absl": [],
+        "//conditions:default": ["--no_stacktrace_support"],
+    }),
+    data = [
+        # We invoke gtest_no_test_unittest to verify the JSON output
+        # when the test program contains no test definition.
+        ":gtest_no_test_unittest",
+        ":gtest_xml_output_unittest_",
+    ],
+    deps = [":gtest_test_utils"],
+)
+
+# Verifies interaction of death tests and exceptions.
+cc_test(
+    name = "googletest-death-test_ex_catch_test",
+    size = "medium",
+    srcs = ["googletest-death-test_ex_test.cc"],
+    copts = ["-fexceptions"],
+    defines = ["GTEST_ENABLE_CATCH_EXCEPTIONS_=1"],
+    deps = ["//:gtest"],
+)
+
+cc_binary(
+    name = "googletest-param-test-invalid-name1-test_",
+    testonly = 1,
+    srcs = ["googletest-param-test-invalid-name1-test_.cc"],
+    deps = ["//:gtest"],
+)
+
+cc_binary(
+    name = "googletest-param-test-invalid-name2-test_",
+    testonly = 1,
+    srcs = ["googletest-param-test-invalid-name2-test_.cc"],
+    deps = ["//:gtest"],
+)
+
+py_test(
+    name = "googletest-param-test-invalid-name1-test",
+    size = "small",
+    srcs = ["googletest-param-test-invalid-name1-test.py"],
+    data = [":googletest-param-test-invalid-name1-test_"],
+    deps = [":gtest_test_utils"],
+)
+
+py_test(
+    name = "googletest-param-test-invalid-name2-test",
+    size = "small",
+    srcs = ["googletest-param-test-invalid-name2-test.py"],
+    data = [":googletest-param-test-invalid-name2-test_"],
+    deps = [":gtest_test_utils"],
+)
diff --git a/3rdparty/gtest/test/googletest-break-on-failure-unittest.py b/3rdparty/gtest/test/googletest-break-on-failure-unittest.py
new file mode 100644
index 0000000..a5dfbc6
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-break-on-failure-unittest.py
@@ -0,0 +1,208 @@
+#!/usr/bin/env python
+#
+# Copyright 2006, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test for Google Test's break-on-failure mode.
+
+A user can ask Google Test to seg-fault when an assertion fails, using
+either the GTEST_BREAK_ON_FAILURE environment variable or the
+--gtest_break_on_failure flag.  This script tests such functionality
+by invoking googletest-break-on-failure-unittest_ (a program written with
+Google Test) with different environments and command line flags.
+"""
+
+import os
+import gtest_test_utils
+
+# Constants.
+
+IS_WINDOWS = os.name == 'nt'
+
+# The environment variable for enabling/disabling the break-on-failure mode.
+BREAK_ON_FAILURE_ENV_VAR = 'GTEST_BREAK_ON_FAILURE'
+
+# The command line flag for enabling/disabling the break-on-failure mode.
+BREAK_ON_FAILURE_FLAG = 'gtest_break_on_failure'
+
+# The environment variable for enabling/disabling the throw-on-failure mode.
+THROW_ON_FAILURE_ENV_VAR = 'GTEST_THROW_ON_FAILURE'
+
+# The environment variable for enabling/disabling the catch-exceptions mode.
+CATCH_EXCEPTIONS_ENV_VAR = 'GTEST_CATCH_EXCEPTIONS'
+
+# Path to the googletest-break-on-failure-unittest_ program.
+EXE_PATH = gtest_test_utils.GetTestExecutablePath(
+    'googletest-break-on-failure-unittest_')
+
+
+environ = gtest_test_utils.environ
+SetEnvVar = gtest_test_utils.SetEnvVar
+
+# Tests in this file run a Google-Test-based test program and expect it
+# to terminate prematurely.  Therefore they are incompatible with
+# the premature-exit-file protocol by design.  Unset the
+# premature-exit filepath to prevent Google Test from creating
+# the file.
+SetEnvVar(gtest_test_utils.PREMATURE_EXIT_FILE_ENV_VAR, None)
+
+
+def Run(command):
+  """Runs a command; returns 1 if it was killed by a signal, or 0 otherwise."""
+
+  p = gtest_test_utils.Subprocess(command, env=environ)
+  if p.terminated_by_signal:
+    return 1
+  else:
+    return 0
+
+
+# The tests.
+
+
+class GTestBreakOnFailureUnitTest(gtest_test_utils.TestCase):
+  """Tests using the GTEST_BREAK_ON_FAILURE environment variable or
+  the --gtest_break_on_failure flag to turn assertion failures into
+  segmentation faults.
+  """
+
+  def RunAndVerify(self, env_var_value, flag_value, expect_seg_fault):
+    """Runs googletest-break-on-failure-unittest_ and verifies that it does
+    (or does not) have a seg-fault.
+
+    Args:
+      env_var_value:    value of the GTEST_BREAK_ON_FAILURE environment
+                        variable; None if the variable should be unset.
+      flag_value:       value of the --gtest_break_on_failure flag;
+                        None if the flag should not be present.
+      expect_seg_fault: 1 if the program is expected to generate a seg-fault;
+                        0 otherwise.
+    """
+
+    SetEnvVar(BREAK_ON_FAILURE_ENV_VAR, env_var_value)
+
+    if env_var_value is None:
+      env_var_value_msg = ' is not set'
+    else:
+      env_var_value_msg = '=' + env_var_value
+
+    if flag_value is None:
+      flag = ''
+    elif flag_value == '0':
+      flag = '--%s=0' % BREAK_ON_FAILURE_FLAG
+    else:
+      flag = '--%s' % BREAK_ON_FAILURE_FLAG
+
+    command = [EXE_PATH]
+    if flag:
+      command.append(flag)
+
+    if expect_seg_fault:
+      should_or_not = 'should'
+    else:
+      should_or_not = 'should not'
+
+    has_seg_fault = Run(command)
+
+    SetEnvVar(BREAK_ON_FAILURE_ENV_VAR, None)
+
+    msg = ('when %s%s, an assertion failure in "%s" %s cause a seg-fault.' %
+           (BREAK_ON_FAILURE_ENV_VAR, env_var_value_msg, ' '.join(command),
+            should_or_not))
+    self.assert_(has_seg_fault == expect_seg_fault, msg)
+
+  def testDefaultBehavior(self):
+    """Tests the behavior of the default mode."""
+
+    self.RunAndVerify(env_var_value=None,
+                      flag_value=None,
+                      expect_seg_fault=0)
+
+  def testEnvVar(self):
+    """Tests using the GTEST_BREAK_ON_FAILURE environment variable."""
+
+    self.RunAndVerify(env_var_value='0',
+                      flag_value=None,
+                      expect_seg_fault=0)
+    self.RunAndVerify(env_var_value='1',
+                      flag_value=None,
+                      expect_seg_fault=1)
+
+  def testFlag(self):
+    """Tests using the --gtest_break_on_failure flag."""
+
+    self.RunAndVerify(env_var_value=None,
+                      flag_value='0',
+                      expect_seg_fault=0)
+    self.RunAndVerify(env_var_value=None,
+                      flag_value='1',
+                      expect_seg_fault=1)
+
+  def testFlagOverridesEnvVar(self):
+    """Tests that the flag overrides the environment variable."""
+
+    self.RunAndVerify(env_var_value='0',
+                      flag_value='0',
+                      expect_seg_fault=0)
+    self.RunAndVerify(env_var_value='0',
+                      flag_value='1',
+                      expect_seg_fault=1)
+    self.RunAndVerify(env_var_value='1',
+                      flag_value='0',
+                      expect_seg_fault=0)
+    self.RunAndVerify(env_var_value='1',
+                      flag_value='1',
+                      expect_seg_fault=1)
+
+  def testBreakOnFailureOverridesThrowOnFailure(self):
+    """Tests that gtest_break_on_failure overrides gtest_throw_on_failure."""
+
+    SetEnvVar(THROW_ON_FAILURE_ENV_VAR, '1')
+    try:
+      self.RunAndVerify(env_var_value=None,
+                        flag_value='1',
+                        expect_seg_fault=1)
+    finally:
+      SetEnvVar(THROW_ON_FAILURE_ENV_VAR, None)
+
+  if IS_WINDOWS:
+    def testCatchExceptionsDoesNotInterfere(self):
+      """Tests that gtest_catch_exceptions doesn't interfere."""
+
+      SetEnvVar(CATCH_EXCEPTIONS_ENV_VAR, '1')
+      try:
+        self.RunAndVerify(env_var_value='1',
+                          flag_value='1',
+                          expect_seg_fault=1)
+      finally:
+        SetEnvVar(CATCH_EXCEPTIONS_ENV_VAR, None)
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-break-on-failure-unittest_.cc b/3rdparty/gtest/test/googletest-break-on-failure-unittest_.cc
new file mode 100644
index 0000000..f84957a
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-break-on-failure-unittest_.cc
@@ -0,0 +1,86 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Unit test for Google Test's break-on-failure mode.
+//
+// A user can ask Google Test to seg-fault when an assertion fails, using
+// either the GTEST_BREAK_ON_FAILURE environment variable or the
+// --gtest_break_on_failure flag.  This file is used for testing such
+// functionality.
+//
+// This program will be invoked from a Python unit test.  It is
+// expected to fail.  Don't run it directly.
+
+#include "gtest/gtest.h"
+
+#if GTEST_OS_WINDOWS
+# include <windows.h>
+# include <stdlib.h>
+#endif
+
+namespace {
+
+// A test that's expected to fail.
+TEST(Foo, Bar) {
+  EXPECT_EQ(2, 3);
+}
+
+#if GTEST_HAS_SEH && !GTEST_OS_WINDOWS_MOBILE
+// On Windows Mobile global exception handlers are not supported.
+LONG WINAPI ExitWithExceptionCode(
+    struct _EXCEPTION_POINTERS* exception_pointers) {
+  exit(exception_pointers->ExceptionRecord->ExceptionCode);
+}
+#endif
+
+}  // namespace
+
+int main(int argc, char **argv) {
+#if GTEST_OS_WINDOWS
+  // Suppresses display of the Windows error dialog upon encountering
+  // a general protection fault (segment violation).
+  SetErrorMode(SEM_NOGPFAULTERRORBOX | SEM_FAILCRITICALERRORS);
+
+# if GTEST_HAS_SEH && !GTEST_OS_WINDOWS_MOBILE
+
+  // The default unhandled exception filter does not always exit
+  // with the exception code as exit code - for example it exits with
+  // 0 for EXCEPTION_ACCESS_VIOLATION and 1 for EXCEPTION_BREAKPOINT
+  // if the application is compiled in debug mode. Thus we use our own
+  // filter which always exits with the exception code for unhandled
+  // exceptions.
+  SetUnhandledExceptionFilter(ExitWithExceptionCode);
+
+# endif
+#endif  // GTEST_OS_WINDOWS
+  testing::InitGoogleTest(&argc, argv);
+
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/googletest-catch-exceptions-test.py b/3rdparty/gtest/test/googletest-catch-exceptions-test.py
new file mode 100644
index 0000000..94a5b33
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-catch-exceptions-test.py
@@ -0,0 +1,236 @@
+#!/usr/bin/env python
+#
+# Copyright 2010 Google Inc.  All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Tests Google Test's exception catching behavior.
+
+This script invokes googletest-catch-exceptions-test_ and
+googletest-catch-exceptions-ex-test_ (programs written with
+Google Test) and verifies their output.
+"""
+
+import gtest_test_utils
+
+# Constants.
+FLAG_PREFIX = '--gtest_'
+LIST_TESTS_FLAG = FLAG_PREFIX + 'list_tests'
+NO_CATCH_EXCEPTIONS_FLAG = FLAG_PREFIX + 'catch_exceptions=0'
+FILTER_FLAG = FLAG_PREFIX + 'filter'
+
+# Path to the googletest-catch-exceptions-ex-test_ binary, compiled with
+# exceptions enabled.
+EX_EXE_PATH = gtest_test_utils.GetTestExecutablePath(
+    'googletest-catch-exceptions-ex-test_')
+
+# Path to the googletest-catch-exceptions-test_ binary, compiled with
+# exceptions disabled.
+EXE_PATH = gtest_test_utils.GetTestExecutablePath(
+    'googletest-catch-exceptions-no-ex-test_')
+
+environ = gtest_test_utils.environ
+SetEnvVar = gtest_test_utils.SetEnvVar
+
+# Tests in this file run a Google-Test-based test program and expect it
+# to terminate prematurely.  Therefore they are incompatible with
+# the premature-exit-file protocol by design.  Unset the
+# premature-exit filepath to prevent Google Test from creating
+# the file.
+SetEnvVar(gtest_test_utils.PREMATURE_EXIT_FILE_ENV_VAR, None)
+
+TEST_LIST = gtest_test_utils.Subprocess(
+    [EXE_PATH, LIST_TESTS_FLAG], env=environ).output
+
+SUPPORTS_SEH_EXCEPTIONS = 'ThrowsSehException' in TEST_LIST
+
+if SUPPORTS_SEH_EXCEPTIONS:
+  BINARY_OUTPUT = gtest_test_utils.Subprocess([EXE_PATH], env=environ).output
+
+EX_BINARY_OUTPUT = gtest_test_utils.Subprocess(
+    [EX_EXE_PATH], env=environ).output
+
+
+# The tests.
+if SUPPORTS_SEH_EXCEPTIONS:
+  # pylint:disable-msg=C6302
+  class CatchSehExceptionsTest(gtest_test_utils.TestCase):
+    """Tests exception-catching behavior."""
+
+
+    def TestSehExceptions(self, test_output):
+      self.assert_('SEH exception with code 0x2a thrown '
+                   'in the test fixture\'s constructor'
+                   in test_output)
+      self.assert_('SEH exception with code 0x2a thrown '
+                   'in the test fixture\'s destructor'
+                   in test_output)
+      self.assert_('SEH exception with code 0x2a thrown in SetUpTestSuite()'
+                   in test_output)
+      self.assert_('SEH exception with code 0x2a thrown in TearDownTestSuite()'
+                   in test_output)
+      self.assert_('SEH exception with code 0x2a thrown in SetUp()'
+                   in test_output)
+      self.assert_('SEH exception with code 0x2a thrown in TearDown()'
+                   in test_output)
+      self.assert_('SEH exception with code 0x2a thrown in the test body'
+                   in test_output)
+
+    def testCatchesSehExceptionsWithCxxExceptionsEnabled(self):
+      self.TestSehExceptions(EX_BINARY_OUTPUT)
+
+    def testCatchesSehExceptionsWithCxxExceptionsDisabled(self):
+      self.TestSehExceptions(BINARY_OUTPUT)
+
+
+class CatchCxxExceptionsTest(gtest_test_utils.TestCase):
+  """Tests C++ exception-catching behavior.
+
+     Tests in this test case verify that:
+     * C++ exceptions are caught and logged as C++ (not SEH) exceptions
+     * Exception thrown affect the remainder of the test work flow in the
+       expected manner.
+  """
+
+  def testCatchesCxxExceptionsInFixtureConstructor(self):
+    self.assertTrue(
+        'C++ exception with description '
+        '"Standard C++ exception" thrown '
+        'in the test fixture\'s constructor' in EX_BINARY_OUTPUT,
+        EX_BINARY_OUTPUT)
+    self.assert_('unexpected' not in EX_BINARY_OUTPUT,
+                 'This failure belongs in this test only if '
+                 '"CxxExceptionInConstructorTest" (no quotes) '
+                 'appears on the same line as words "called unexpectedly"')
+
+  if ('CxxExceptionInDestructorTest.ThrowsExceptionInDestructor' in
+      EX_BINARY_OUTPUT):
+
+    def testCatchesCxxExceptionsInFixtureDestructor(self):
+      self.assertTrue(
+          'C++ exception with description '
+          '"Standard C++ exception" thrown '
+          'in the test fixture\'s destructor' in EX_BINARY_OUTPUT,
+          EX_BINARY_OUTPUT)
+      self.assertTrue(
+          'CxxExceptionInDestructorTest::TearDownTestSuite() '
+          'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+
+  def testCatchesCxxExceptionsInSetUpTestCase(self):
+    self.assertTrue(
+        'C++ exception with description "Standard C++ exception"'
+        ' thrown in SetUpTestSuite()' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInConstructorTest::TearDownTestSuite() '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInSetUpTestSuiteTest constructor '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInSetUpTestSuiteTest destructor '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInSetUpTestSuiteTest::SetUp() '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInSetUpTestSuiteTest::TearDown() '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInSetUpTestSuiteTest test body '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+
+  def testCatchesCxxExceptionsInTearDownTestCase(self):
+    self.assertTrue(
+        'C++ exception with description "Standard C++ exception"'
+        ' thrown in TearDownTestSuite()' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+
+  def testCatchesCxxExceptionsInSetUp(self):
+    self.assertTrue(
+        'C++ exception with description "Standard C++ exception"'
+        ' thrown in SetUp()' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInSetUpTest::TearDownTestSuite() '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInSetUpTest destructor '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInSetUpTest::TearDown() '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assert_('unexpected' not in EX_BINARY_OUTPUT,
+                 'This failure belongs in this test only if '
+                 '"CxxExceptionInSetUpTest" (no quotes) '
+                 'appears on the same line as words "called unexpectedly"')
+
+  def testCatchesCxxExceptionsInTearDown(self):
+    self.assertTrue(
+        'C++ exception with description "Standard C++ exception"'
+        ' thrown in TearDown()' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInTearDownTest::TearDownTestSuite() '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInTearDownTest destructor '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+
+  def testCatchesCxxExceptionsInTestBody(self):
+    self.assertTrue(
+        'C++ exception with description "Standard C++ exception"'
+        ' thrown in the test body' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInTestBodyTest::TearDownTestSuite() '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInTestBodyTest destructor '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+    self.assertTrue(
+        'CxxExceptionInTestBodyTest::TearDown() '
+        'called as expected.' in EX_BINARY_OUTPUT, EX_BINARY_OUTPUT)
+
+  def testCatchesNonStdCxxExceptions(self):
+    self.assertTrue(
+        'Unknown C++ exception thrown in the test body' in EX_BINARY_OUTPUT,
+        EX_BINARY_OUTPUT)
+
+  def testUnhandledCxxExceptionsAbortTheProgram(self):
+    # Filters out SEH exception tests on Windows. Unhandled SEH exceptions
+    # cause tests to show pop-up windows there.
+    FITLER_OUT_SEH_TESTS_FLAG = FILTER_FLAG + '=-*Seh*'
+    # By default, Google Test doesn't catch the exceptions.
+    uncaught_exceptions_ex_binary_output = gtest_test_utils.Subprocess(
+        [EX_EXE_PATH,
+         NO_CATCH_EXCEPTIONS_FLAG,
+         FITLER_OUT_SEH_TESTS_FLAG],
+        env=environ).output
+
+    self.assert_('Unhandled C++ exception terminating the program'
+                 in uncaught_exceptions_ex_binary_output)
+    self.assert_('unexpected' not in uncaught_exceptions_ex_binary_output)
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-catch-exceptions-test_.cc b/3rdparty/gtest/test/googletest-catch-exceptions-test_.cc
new file mode 100644
index 0000000..8c127d4
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-catch-exceptions-test_.cc
@@ -0,0 +1,293 @@
+// Copyright 2010, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests for Google Test itself. Tests in this file throw C++ or SEH
+// exceptions, and the output is verified by
+// googletest-catch-exceptions-test.py.
+
+#include <stdio.h>  // NOLINT
+#include <stdlib.h>  // For exit().
+
+#include "gtest/gtest.h"
+
+#if GTEST_HAS_SEH
+# include <windows.h>
+#endif
+
+#if GTEST_HAS_EXCEPTIONS
+# include <exception>  // For set_terminate().
+# include <stdexcept>
+#endif
+
+using testing::Test;
+
+#if GTEST_HAS_SEH
+
+class SehExceptionInConstructorTest : public Test {
+ public:
+  SehExceptionInConstructorTest() { RaiseException(42, 0, 0, NULL); }
+};
+
+TEST_F(SehExceptionInConstructorTest, ThrowsExceptionInConstructor) {}
+
+class SehExceptionInDestructorTest : public Test {
+ public:
+  ~SehExceptionInDestructorTest() { RaiseException(42, 0, 0, NULL); }
+};
+
+TEST_F(SehExceptionInDestructorTest, ThrowsExceptionInDestructor) {}
+
+class SehExceptionInSetUpTestSuiteTest : public Test {
+ public:
+  static void SetUpTestSuite() { RaiseException(42, 0, 0, NULL); }
+};
+
+TEST_F(SehExceptionInSetUpTestSuiteTest, ThrowsExceptionInSetUpTestSuite) {}
+
+class SehExceptionInTearDownTestSuiteTest : public Test {
+ public:
+  static void TearDownTestSuite() { RaiseException(42, 0, 0, NULL); }
+};
+
+TEST_F(SehExceptionInTearDownTestSuiteTest,
+       ThrowsExceptionInTearDownTestSuite) {}
+
+class SehExceptionInSetUpTest : public Test {
+ protected:
+  virtual void SetUp() { RaiseException(42, 0, 0, NULL); }
+};
+
+TEST_F(SehExceptionInSetUpTest, ThrowsExceptionInSetUp) {}
+
+class SehExceptionInTearDownTest : public Test {
+ protected:
+  virtual void TearDown() { RaiseException(42, 0, 0, NULL); }
+};
+
+TEST_F(SehExceptionInTearDownTest, ThrowsExceptionInTearDown) {}
+
+TEST(SehExceptionTest, ThrowsSehException) {
+  RaiseException(42, 0, 0, NULL);
+}
+
+#endif  // GTEST_HAS_SEH
+
+#if GTEST_HAS_EXCEPTIONS
+
+class CxxExceptionInConstructorTest : public Test {
+ public:
+  CxxExceptionInConstructorTest() {
+    // Without this macro VC++ complains about unreachable code at the end of
+    // the constructor.
+    GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(
+        throw std::runtime_error("Standard C++ exception"));
+  }
+
+  static void TearDownTestSuite() {
+    printf("%s",
+           "CxxExceptionInConstructorTest::TearDownTestSuite() "
+           "called as expected.\n");
+  }
+
+ protected:
+  ~CxxExceptionInConstructorTest() override {
+    ADD_FAILURE() << "CxxExceptionInConstructorTest destructor "
+                  << "called unexpectedly.";
+  }
+
+  void SetUp() override {
+    ADD_FAILURE() << "CxxExceptionInConstructorTest::SetUp() "
+                  << "called unexpectedly.";
+  }
+
+  void TearDown() override {
+    ADD_FAILURE() << "CxxExceptionInConstructorTest::TearDown() "
+                  << "called unexpectedly.";
+  }
+};
+
+TEST_F(CxxExceptionInConstructorTest, ThrowsExceptionInConstructor) {
+  ADD_FAILURE() << "CxxExceptionInConstructorTest test body "
+                << "called unexpectedly.";
+}
+
+class CxxExceptionInSetUpTestSuiteTest : public Test {
+ public:
+  CxxExceptionInSetUpTestSuiteTest() {
+    printf("%s",
+           "CxxExceptionInSetUpTestSuiteTest constructor "
+           "called as expected.\n");
+  }
+
+  static void SetUpTestSuite() {
+    throw std::runtime_error("Standard C++ exception");
+  }
+
+  static void TearDownTestSuite() {
+    printf("%s",
+           "CxxExceptionInSetUpTestSuiteTest::TearDownTestSuite() "
+           "called as expected.\n");
+  }
+
+ protected:
+  ~CxxExceptionInSetUpTestSuiteTest() override {
+    printf("%s",
+           "CxxExceptionInSetUpTestSuiteTest destructor "
+           "called as expected.\n");
+  }
+
+  void SetUp() override {
+    printf("%s",
+           "CxxExceptionInSetUpTestSuiteTest::SetUp() "
+           "called as expected.\n");
+  }
+
+  void TearDown() override {
+    printf("%s",
+           "CxxExceptionInSetUpTestSuiteTest::TearDown() "
+           "called as expected.\n");
+  }
+};
+
+TEST_F(CxxExceptionInSetUpTestSuiteTest, ThrowsExceptionInSetUpTestSuite) {
+  printf("%s",
+         "CxxExceptionInSetUpTestSuiteTest test body "
+         "called as expected.\n");
+}
+
+class CxxExceptionInTearDownTestSuiteTest : public Test {
+ public:
+  static void TearDownTestSuite() {
+    throw std::runtime_error("Standard C++ exception");
+  }
+};
+
+TEST_F(CxxExceptionInTearDownTestSuiteTest,
+       ThrowsExceptionInTearDownTestSuite) {}
+
+class CxxExceptionInSetUpTest : public Test {
+ public:
+  static void TearDownTestSuite() {
+    printf("%s",
+           "CxxExceptionInSetUpTest::TearDownTestSuite() "
+           "called as expected.\n");
+  }
+
+ protected:
+  ~CxxExceptionInSetUpTest() override {
+    printf("%s",
+           "CxxExceptionInSetUpTest destructor "
+           "called as expected.\n");
+  }
+
+  void SetUp() override { throw std::runtime_error("Standard C++ exception"); }
+
+  void TearDown() override {
+    printf("%s",
+           "CxxExceptionInSetUpTest::TearDown() "
+           "called as expected.\n");
+  }
+};
+
+TEST_F(CxxExceptionInSetUpTest, ThrowsExceptionInSetUp) {
+  ADD_FAILURE() << "CxxExceptionInSetUpTest test body "
+                << "called unexpectedly.";
+}
+
+class CxxExceptionInTearDownTest : public Test {
+ public:
+  static void TearDownTestSuite() {
+    printf("%s",
+           "CxxExceptionInTearDownTest::TearDownTestSuite() "
+           "called as expected.\n");
+  }
+
+ protected:
+  ~CxxExceptionInTearDownTest() override {
+    printf("%s",
+           "CxxExceptionInTearDownTest destructor "
+           "called as expected.\n");
+  }
+
+  void TearDown() override {
+    throw std::runtime_error("Standard C++ exception");
+  }
+};
+
+TEST_F(CxxExceptionInTearDownTest, ThrowsExceptionInTearDown) {}
+
+class CxxExceptionInTestBodyTest : public Test {
+ public:
+  static void TearDownTestSuite() {
+    printf("%s",
+           "CxxExceptionInTestBodyTest::TearDownTestSuite() "
+           "called as expected.\n");
+  }
+
+ protected:
+  ~CxxExceptionInTestBodyTest() override {
+    printf("%s",
+           "CxxExceptionInTestBodyTest destructor "
+           "called as expected.\n");
+  }
+
+  void TearDown() override {
+    printf("%s",
+           "CxxExceptionInTestBodyTest::TearDown() "
+           "called as expected.\n");
+  }
+};
+
+TEST_F(CxxExceptionInTestBodyTest, ThrowsStdCxxException) {
+  throw std::runtime_error("Standard C++ exception");
+}
+
+TEST(CxxExceptionTest, ThrowsNonStdCxxException) {
+  throw "C-string";
+}
+
+// This terminate handler aborts the program using exit() rather than abort().
+// This avoids showing pop-ups on Windows systems and core dumps on Unix-like
+// ones.
+void TerminateHandler() {
+  fprintf(stderr, "%s\n", "Unhandled C++ exception terminating the program.");
+  fflush(nullptr);
+  exit(3);
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+int main(int argc, char** argv) {
+#if GTEST_HAS_EXCEPTIONS
+  std::set_terminate(&TerminateHandler);
+#endif
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/googletest-color-test.py b/3rdparty/gtest/test/googletest-color-test.py
new file mode 100644
index 0000000..f3b7c99
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-color-test.py
@@ -0,0 +1,127 @@
+#!/usr/bin/env python
+#
+# Copyright 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Verifies that Google Test correctly determines whether to use colors."""
+
+import os
+import gtest_test_utils
+
+IS_WINDOWS = os.name == 'nt'
+
+COLOR_ENV_VAR = 'GTEST_COLOR'
+COLOR_FLAG = 'gtest_color'
+COMMAND = gtest_test_utils.GetTestExecutablePath('googletest-color-test_')
+
+
+def SetEnvVar(env_var, value):
+  """Sets the env variable to 'value'; unsets it when 'value' is None."""
+
+  if value is not None:
+    os.environ[env_var] = value
+  elif env_var in os.environ:
+    del os.environ[env_var]
+
+
+def UsesColor(term, color_env_var, color_flag):
+  """Runs googletest-color-test_ and returns its exit code."""
+
+  SetEnvVar('TERM', term)
+  SetEnvVar(COLOR_ENV_VAR, color_env_var)
+
+  if color_flag is None:
+    args = []
+  else:
+    args = ['--%s=%s' % (COLOR_FLAG, color_flag)]
+  p = gtest_test_utils.Subprocess([COMMAND] + args)
+  return not p.exited or p.exit_code
+
+
+class GTestColorTest(gtest_test_utils.TestCase):
+  def testNoEnvVarNoFlag(self):
+    """Tests the case when there's neither GTEST_COLOR nor --gtest_color."""
+
+    if not IS_WINDOWS:
+      self.assert_(not UsesColor('dumb', None, None))
+      self.assert_(not UsesColor('emacs', None, None))
+      self.assert_(not UsesColor('xterm-mono', None, None))
+      self.assert_(not UsesColor('unknown', None, None))
+      self.assert_(not UsesColor(None, None, None))
+    self.assert_(UsesColor('linux', None, None))
+    self.assert_(UsesColor('cygwin', None, None))
+    self.assert_(UsesColor('xterm', None, None))
+    self.assert_(UsesColor('xterm-color', None, None))
+    self.assert_(UsesColor('xterm-256color', None, None))
+
+  def testFlagOnly(self):
+    """Tests the case when there's --gtest_color but not GTEST_COLOR."""
+
+    self.assert_(not UsesColor('dumb', None, 'no'))
+    self.assert_(not UsesColor('xterm-color', None, 'no'))
+    if not IS_WINDOWS:
+      self.assert_(not UsesColor('emacs', None, 'auto'))
+    self.assert_(UsesColor('xterm', None, 'auto'))
+    self.assert_(UsesColor('dumb', None, 'yes'))
+    self.assert_(UsesColor('xterm', None, 'yes'))
+
+  def testEnvVarOnly(self):
+    """Tests the case when there's GTEST_COLOR but not --gtest_color."""
+
+    self.assert_(not UsesColor('dumb', 'no', None))
+    self.assert_(not UsesColor('xterm-color', 'no', None))
+    if not IS_WINDOWS:
+      self.assert_(not UsesColor('dumb', 'auto', None))
+    self.assert_(UsesColor('xterm-color', 'auto', None))
+    self.assert_(UsesColor('dumb', 'yes', None))
+    self.assert_(UsesColor('xterm-color', 'yes', None))
+
+  def testEnvVarAndFlag(self):
+    """Tests the case when there are both GTEST_COLOR and --gtest_color."""
+
+    self.assert_(not UsesColor('xterm-color', 'no', 'no'))
+    self.assert_(UsesColor('dumb', 'no', 'yes'))
+    self.assert_(UsesColor('xterm-color', 'no', 'auto'))
+
+  def testAliasesOfYesAndNo(self):
+    """Tests using aliases in specifying --gtest_color."""
+
+    self.assert_(UsesColor('dumb', None, 'true'))
+    self.assert_(UsesColor('dumb', None, 'YES'))
+    self.assert_(UsesColor('dumb', None, 'T'))
+    self.assert_(UsesColor('dumb', None, '1'))
+
+    self.assert_(not UsesColor('xterm', None, 'f'))
+    self.assert_(not UsesColor('xterm', None, 'false'))
+    self.assert_(not UsesColor('xterm', None, '0'))
+    self.assert_(not UsesColor('xterm', None, 'unknown'))
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-color-test_.cc b/3rdparty/gtest/test/googletest-color-test_.cc
new file mode 100644
index 0000000..220a3a0
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-color-test_.cc
@@ -0,0 +1,62 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// A helper program for testing how Google Test determines whether to use
+// colors in the output.  It prints "YES" and returns 1 if Google Test
+// decides to use colors, and prints "NO" and returns 0 otherwise.
+
+#include <stdio.h>
+
+#include "gtest/gtest.h"
+#include "src/gtest-internal-inl.h"
+
+using testing::internal::ShouldUseColor;
+
+// The purpose of this is to ensure that the UnitTest singleton is
+// created before main() is entered, and thus that ShouldUseColor()
+// works the same way as in a real Google-Test-based test.  We don't actual
+// run the TEST itself.
+TEST(GTestColorTest, Dummy) {
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  if (ShouldUseColor(true)) {
+    // Google Test decides to use colors in the output (assuming it
+    // goes to a TTY).
+    printf("YES\n");
+    return 1;
+  } else {
+    // Google Test decides not to use colors in the output.
+    printf("NO\n");
+    return 0;
+  }
+}
diff --git a/3rdparty/gtest/test/googletest-death-test-test.cc b/3rdparty/gtest/test/googletest-death-test-test.cc
new file mode 100644
index 0000000..cba906c
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-death-test-test.cc
@@ -0,0 +1,1516 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests for death tests.
+
+#include "gtest/gtest-death-test.h"
+
+#include "gtest/gtest.h"
+#include "gtest/internal/gtest-filepath.h"
+
+using testing::internal::AlwaysFalse;
+using testing::internal::AlwaysTrue;
+
+#if GTEST_HAS_DEATH_TEST
+
+# if GTEST_OS_WINDOWS
+#  include <fcntl.h>           // For O_BINARY
+#  include <direct.h>          // For chdir().
+#  include <io.h>
+# else
+#  include <unistd.h>
+#  include <sys/wait.h>        // For waitpid.
+# endif  // GTEST_OS_WINDOWS
+
+# include <limits.h>
+# include <signal.h>
+# include <stdio.h>
+
+# if GTEST_OS_LINUX
+#  include <sys/time.h>
+# endif  // GTEST_OS_LINUX
+
+# include "gtest/gtest-spi.h"
+# include "src/gtest-internal-inl.h"
+
+namespace posix = ::testing::internal::posix;
+
+using testing::ContainsRegex;
+using testing::Matcher;
+using testing::Message;
+using testing::internal::DeathTest;
+using testing::internal::DeathTestFactory;
+using testing::internal::FilePath;
+using testing::internal::GetLastErrnoDescription;
+using testing::internal::GetUnitTestImpl;
+using testing::internal::InDeathTestChild;
+using testing::internal::ParseNaturalNumber;
+
+namespace testing {
+namespace internal {
+
+// A helper class whose objects replace the death test factory for a
+// single UnitTest object during their lifetimes.
+class ReplaceDeathTestFactory {
+ public:
+  explicit ReplaceDeathTestFactory(DeathTestFactory* new_factory)
+      : unit_test_impl_(GetUnitTestImpl()) {
+    old_factory_ = unit_test_impl_->death_test_factory_.release();
+    unit_test_impl_->death_test_factory_.reset(new_factory);
+  }
+
+  ~ReplaceDeathTestFactory() {
+    unit_test_impl_->death_test_factory_.release();
+    unit_test_impl_->death_test_factory_.reset(old_factory_);
+  }
+ private:
+  // Prevents copying ReplaceDeathTestFactory objects.
+  ReplaceDeathTestFactory(const ReplaceDeathTestFactory&);
+  void operator=(const ReplaceDeathTestFactory&);
+
+  UnitTestImpl* unit_test_impl_;
+  DeathTestFactory* old_factory_;
+};
+
+}  // namespace internal
+}  // namespace testing
+
+namespace {
+
+void DieWithMessage(const ::std::string& message) {
+  fprintf(stderr, "%s", message.c_str());
+  fflush(stderr);  // Make sure the text is printed before the process exits.
+
+  // We call _exit() instead of exit(), as the former is a direct
+  // system call and thus safer in the presence of threads.  exit()
+  // will invoke user-defined exit-hooks, which may do dangerous
+  // things that conflict with death tests.
+  //
+  // Some compilers can recognize that _exit() never returns and issue the
+  // 'unreachable code' warning for code following this function, unless
+  // fooled by a fake condition.
+  if (AlwaysTrue())
+    _exit(1);
+}
+
+void DieInside(const ::std::string& function) {
+  DieWithMessage("death inside " + function + "().");
+}
+
+// Tests that death tests work.
+
+class TestForDeathTest : public testing::Test {
+ protected:
+  TestForDeathTest() : original_dir_(FilePath::GetCurrentDir()) {}
+
+  ~TestForDeathTest() override { posix::ChDir(original_dir_.c_str()); }
+
+  // A static member function that's expected to die.
+  static void StaticMemberFunction() { DieInside("StaticMemberFunction"); }
+
+  // A method of the test fixture that may die.
+  void MemberFunction() {
+    if (should_die_)
+      DieInside("MemberFunction");
+  }
+
+  // True if and only if MemberFunction() should die.
+  bool should_die_;
+  const FilePath original_dir_;
+};
+
+// A class with a member function that may die.
+class MayDie {
+ public:
+  explicit MayDie(bool should_die) : should_die_(should_die) {}
+
+  // A member function that may die.
+  void MemberFunction() const {
+    if (should_die_)
+      DieInside("MayDie::MemberFunction");
+  }
+
+ private:
+  // True if and only if MemberFunction() should die.
+  bool should_die_;
+};
+
+// A global function that's expected to die.
+void GlobalFunction() { DieInside("GlobalFunction"); }
+
+// A non-void function that's expected to die.
+int NonVoidFunction() {
+  DieInside("NonVoidFunction");
+  return 1;
+}
+
+// A unary function that may die.
+void DieIf(bool should_die) {
+  if (should_die)
+    DieInside("DieIf");
+}
+
+// A binary function that may die.
+bool DieIfLessThan(int x, int y) {
+  if (x < y) {
+    DieInside("DieIfLessThan");
+  }
+  return true;
+}
+
+// Tests that ASSERT_DEATH can be used outside a TEST, TEST_F, or test fixture.
+void DeathTestSubroutine() {
+  EXPECT_DEATH(GlobalFunction(), "death.*GlobalFunction");
+  ASSERT_DEATH(GlobalFunction(), "death.*GlobalFunction");
+}
+
+// Death in dbg, not opt.
+int DieInDebugElse12(int* sideeffect) {
+  if (sideeffect) *sideeffect = 12;
+
+# ifndef NDEBUG
+
+  DieInside("DieInDebugElse12");
+
+# endif  // NDEBUG
+
+  return 12;
+}
+
+# if GTEST_OS_WINDOWS
+
+// Death in dbg due to Windows CRT assertion failure, not opt.
+int DieInCRTDebugElse12(int* sideeffect) {
+  if (sideeffect) *sideeffect = 12;
+
+  // Create an invalid fd by closing a valid one
+  int fdpipe[2];
+  EXPECT_EQ(_pipe(fdpipe, 256, O_BINARY), 0);
+  EXPECT_EQ(_close(fdpipe[0]), 0);
+  EXPECT_EQ(_close(fdpipe[1]), 0);
+
+  // _dup() should crash in debug mode
+  EXPECT_EQ(_dup(fdpipe[0]), -1);
+
+  return 12;
+}
+
+#endif  // GTEST_OS_WINDOWS
+
+# if GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+// Tests the ExitedWithCode predicate.
+TEST(ExitStatusPredicateTest, ExitedWithCode) {
+  // On Windows, the process's exit code is the same as its exit status,
+  // so the predicate just compares the its input with its parameter.
+  EXPECT_TRUE(testing::ExitedWithCode(0)(0));
+  EXPECT_TRUE(testing::ExitedWithCode(1)(1));
+  EXPECT_TRUE(testing::ExitedWithCode(42)(42));
+  EXPECT_FALSE(testing::ExitedWithCode(0)(1));
+  EXPECT_FALSE(testing::ExitedWithCode(1)(0));
+}
+
+# else
+
+// Returns the exit status of a process that calls _exit(2) with a
+// given exit code.  This is a helper function for the
+// ExitStatusPredicateTest test suite.
+static int NormalExitStatus(int exit_code) {
+  pid_t child_pid = fork();
+  if (child_pid == 0) {
+    _exit(exit_code);
+  }
+  int status;
+  waitpid(child_pid, &status, 0);
+  return status;
+}
+
+// Returns the exit status of a process that raises a given signal.
+// If the signal does not cause the process to die, then it returns
+// instead the exit status of a process that exits normally with exit
+// code 1.  This is a helper function for the ExitStatusPredicateTest
+// test suite.
+static int KilledExitStatus(int signum) {
+  pid_t child_pid = fork();
+  if (child_pid == 0) {
+    raise(signum);
+    _exit(1);
+  }
+  int status;
+  waitpid(child_pid, &status, 0);
+  return status;
+}
+
+// Tests the ExitedWithCode predicate.
+TEST(ExitStatusPredicateTest, ExitedWithCode) {
+  const int status0  = NormalExitStatus(0);
+  const int status1  = NormalExitStatus(1);
+  const int status42 = NormalExitStatus(42);
+  const testing::ExitedWithCode pred0(0);
+  const testing::ExitedWithCode pred1(1);
+  const testing::ExitedWithCode pred42(42);
+  EXPECT_PRED1(pred0,  status0);
+  EXPECT_PRED1(pred1,  status1);
+  EXPECT_PRED1(pred42, status42);
+  EXPECT_FALSE(pred0(status1));
+  EXPECT_FALSE(pred42(status0));
+  EXPECT_FALSE(pred1(status42));
+}
+
+// Tests the KilledBySignal predicate.
+TEST(ExitStatusPredicateTest, KilledBySignal) {
+  const int status_segv = KilledExitStatus(SIGSEGV);
+  const int status_kill = KilledExitStatus(SIGKILL);
+  const testing::KilledBySignal pred_segv(SIGSEGV);
+  const testing::KilledBySignal pred_kill(SIGKILL);
+  EXPECT_PRED1(pred_segv, status_segv);
+  EXPECT_PRED1(pred_kill, status_kill);
+  EXPECT_FALSE(pred_segv(status_kill));
+  EXPECT_FALSE(pred_kill(status_segv));
+}
+
+# endif  // GTEST_OS_WINDOWS || GTEST_OS_FUCHSIA
+
+// Tests that the death test macros expand to code which may or may not
+// be followed by operator<<, and that in either case the complete text
+// comprises only a single C++ statement.
+TEST_F(TestForDeathTest, SingleStatement) {
+  if (AlwaysFalse())
+    // This would fail if executed; this is a compilation test only
+    ASSERT_DEATH(return, "");
+
+  if (AlwaysTrue())
+    EXPECT_DEATH(_exit(1), "");
+  else
+    // This empty "else" branch is meant to ensure that EXPECT_DEATH
+    // doesn't expand into an "if" statement without an "else"
+    ;
+
+  if (AlwaysFalse())
+    ASSERT_DEATH(return, "") << "did not die";
+
+  if (AlwaysFalse())
+    ;
+  else
+    EXPECT_DEATH(_exit(1), "") << 1 << 2 << 3;
+}
+
+# if GTEST_USES_PCRE
+
+void DieWithEmbeddedNul() {
+  fprintf(stderr, "Hello%cmy null world.\n", '\0');
+  fflush(stderr);
+  _exit(1);
+}
+
+// Tests that EXPECT_DEATH and ASSERT_DEATH work when the error
+// message has a NUL character in it.
+TEST_F(TestForDeathTest, EmbeddedNulInMessage) {
+  EXPECT_DEATH(DieWithEmbeddedNul(), "my null world");
+  ASSERT_DEATH(DieWithEmbeddedNul(), "my null world");
+}
+
+# endif  // GTEST_USES_PCRE
+
+// Tests that death test macros expand to code which interacts well with switch
+// statements.
+TEST_F(TestForDeathTest, SwitchStatement) {
+  // Microsoft compiler usually complains about switch statements without
+  // case labels. We suppress that warning for this test.
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4065)
+
+  switch (0)
+    default:
+      ASSERT_DEATH(_exit(1), "") << "exit in default switch handler";
+
+  switch (0)
+    case 0:
+      EXPECT_DEATH(_exit(1), "") << "exit in switch case";
+
+  GTEST_DISABLE_MSC_WARNINGS_POP_()
+}
+
+// Tests that a static member function can be used in a "fast" style
+// death test.
+TEST_F(TestForDeathTest, StaticMemberFunctionFastStyle) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  ASSERT_DEATH(StaticMemberFunction(), "death.*StaticMember");
+}
+
+// Tests that a method of the test fixture can be used in a "fast"
+// style death test.
+TEST_F(TestForDeathTest, MemberFunctionFastStyle) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  should_die_ = true;
+  EXPECT_DEATH(MemberFunction(), "inside.*MemberFunction");
+}
+
+void ChangeToRootDir() { posix::ChDir(GTEST_PATH_SEP_); }
+
+// Tests that death tests work even if the current directory has been
+// changed.
+TEST_F(TestForDeathTest, FastDeathTestInChangedDir) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+
+  ChangeToRootDir();
+  EXPECT_EXIT(_exit(1), testing::ExitedWithCode(1), "");
+
+  ChangeToRootDir();
+  ASSERT_DEATH(_exit(1), "");
+}
+
+# if GTEST_OS_LINUX
+void SigprofAction(int, siginfo_t*, void*) { /* no op */ }
+
+// Sets SIGPROF action and ITIMER_PROF timer (interval: 1ms).
+void SetSigprofActionAndTimer() {
+  struct itimerval timer;
+  timer.it_interval.tv_sec = 0;
+  timer.it_interval.tv_usec = 1;
+  timer.it_value = timer.it_interval;
+  ASSERT_EQ(0, setitimer(ITIMER_PROF, &timer, nullptr));
+  struct sigaction signal_action;
+  memset(&signal_action, 0, sizeof(signal_action));
+  sigemptyset(&signal_action.sa_mask);
+  signal_action.sa_sigaction = SigprofAction;
+  signal_action.sa_flags = SA_RESTART | SA_SIGINFO;
+  ASSERT_EQ(0, sigaction(SIGPROF, &signal_action, nullptr));
+}
+
+// Disables ITIMER_PROF timer and ignores SIGPROF signal.
+void DisableSigprofActionAndTimer(struct sigaction* old_signal_action) {
+  struct itimerval timer;
+  timer.it_interval.tv_sec = 0;
+  timer.it_interval.tv_usec = 0;
+  timer.it_value = timer.it_interval;
+  ASSERT_EQ(0, setitimer(ITIMER_PROF, &timer, nullptr));
+  struct sigaction signal_action;
+  memset(&signal_action, 0, sizeof(signal_action));
+  sigemptyset(&signal_action.sa_mask);
+  signal_action.sa_handler = SIG_IGN;
+  ASSERT_EQ(0, sigaction(SIGPROF, &signal_action, old_signal_action));
+}
+
+// Tests that death tests work when SIGPROF handler and timer are set.
+TEST_F(TestForDeathTest, FastSigprofActionSet) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  SetSigprofActionAndTimer();
+  EXPECT_DEATH(_exit(1), "");
+  struct sigaction old_signal_action;
+  DisableSigprofActionAndTimer(&old_signal_action);
+  EXPECT_TRUE(old_signal_action.sa_sigaction == SigprofAction);
+}
+
+TEST_F(TestForDeathTest, ThreadSafeSigprofActionSet) {
+  testing::GTEST_FLAG(death_test_style) = "threadsafe";
+  SetSigprofActionAndTimer();
+  EXPECT_DEATH(_exit(1), "");
+  struct sigaction old_signal_action;
+  DisableSigprofActionAndTimer(&old_signal_action);
+  EXPECT_TRUE(old_signal_action.sa_sigaction == SigprofAction);
+}
+# endif  // GTEST_OS_LINUX
+
+// Repeats a representative sample of death tests in the "threadsafe" style:
+
+TEST_F(TestForDeathTest, StaticMemberFunctionThreadsafeStyle) {
+  testing::GTEST_FLAG(death_test_style) = "threadsafe";
+  ASSERT_DEATH(StaticMemberFunction(), "death.*StaticMember");
+}
+
+TEST_F(TestForDeathTest, MemberFunctionThreadsafeStyle) {
+  testing::GTEST_FLAG(death_test_style) = "threadsafe";
+  should_die_ = true;
+  EXPECT_DEATH(MemberFunction(), "inside.*MemberFunction");
+}
+
+TEST_F(TestForDeathTest, ThreadsafeDeathTestInLoop) {
+  testing::GTEST_FLAG(death_test_style) = "threadsafe";
+
+  for (int i = 0; i < 3; ++i)
+    EXPECT_EXIT(_exit(i), testing::ExitedWithCode(i), "") << ": i = " << i;
+}
+
+TEST_F(TestForDeathTest, ThreadsafeDeathTestInChangedDir) {
+  testing::GTEST_FLAG(death_test_style) = "threadsafe";
+
+  ChangeToRootDir();
+  EXPECT_EXIT(_exit(1), testing::ExitedWithCode(1), "");
+
+  ChangeToRootDir();
+  ASSERT_DEATH(_exit(1), "");
+}
+
+TEST_F(TestForDeathTest, MixedStyles) {
+  testing::GTEST_FLAG(death_test_style) = "threadsafe";
+  EXPECT_DEATH(_exit(1), "");
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  EXPECT_DEATH(_exit(1), "");
+}
+
+# if GTEST_HAS_CLONE && GTEST_HAS_PTHREAD
+
+bool pthread_flag;
+
+void SetPthreadFlag() {
+  pthread_flag = true;
+}
+
+TEST_F(TestForDeathTest, DoesNotExecuteAtforkHooks) {
+  if (!testing::GTEST_FLAG(death_test_use_fork)) {
+    testing::GTEST_FLAG(death_test_style) = "threadsafe";
+    pthread_flag = false;
+    ASSERT_EQ(0, pthread_atfork(&SetPthreadFlag, nullptr, nullptr));
+    ASSERT_DEATH(_exit(1), "");
+    ASSERT_FALSE(pthread_flag);
+  }
+}
+
+# endif  // GTEST_HAS_CLONE && GTEST_HAS_PTHREAD
+
+// Tests that a method of another class can be used in a death test.
+TEST_F(TestForDeathTest, MethodOfAnotherClass) {
+  const MayDie x(true);
+  ASSERT_DEATH(x.MemberFunction(), "MayDie\\:\\:MemberFunction");
+}
+
+// Tests that a global function can be used in a death test.
+TEST_F(TestForDeathTest, GlobalFunction) {
+  EXPECT_DEATH(GlobalFunction(), "GlobalFunction");
+}
+
+// Tests that any value convertible to an RE works as a second
+// argument to EXPECT_DEATH.
+TEST_F(TestForDeathTest, AcceptsAnythingConvertibleToRE) {
+  static const char regex_c_str[] = "GlobalFunction";
+  EXPECT_DEATH(GlobalFunction(), regex_c_str);
+
+  const testing::internal::RE regex(regex_c_str);
+  EXPECT_DEATH(GlobalFunction(), regex);
+
+# if !GTEST_USES_PCRE
+
+  const ::std::string regex_std_str(regex_c_str);
+  EXPECT_DEATH(GlobalFunction(), regex_std_str);
+
+  // This one is tricky; a temporary pointer into another temporary.  Reference
+  // lifetime extension of the pointer is not sufficient.
+  EXPECT_DEATH(GlobalFunction(), ::std::string(regex_c_str).c_str());
+
+# endif  // !GTEST_USES_PCRE
+}
+
+// Tests that a non-void function can be used in a death test.
+TEST_F(TestForDeathTest, NonVoidFunction) {
+  ASSERT_DEATH(NonVoidFunction(), "NonVoidFunction");
+}
+
+// Tests that functions that take parameter(s) can be used in a death test.
+TEST_F(TestForDeathTest, FunctionWithParameter) {
+  EXPECT_DEATH(DieIf(true), "DieIf\\(\\)");
+  EXPECT_DEATH(DieIfLessThan(2, 3), "DieIfLessThan");
+}
+
+// Tests that ASSERT_DEATH can be used outside a TEST, TEST_F, or test fixture.
+TEST_F(TestForDeathTest, OutsideFixture) {
+  DeathTestSubroutine();
+}
+
+// Tests that death tests can be done inside a loop.
+TEST_F(TestForDeathTest, InsideLoop) {
+  for (int i = 0; i < 5; i++) {
+    EXPECT_DEATH(DieIfLessThan(-1, i), "DieIfLessThan") << "where i == " << i;
+  }
+}
+
+// Tests that a compound statement can be used in a death test.
+TEST_F(TestForDeathTest, CompoundStatement) {
+  EXPECT_DEATH({  // NOLINT
+    const int x = 2;
+    const int y = x + 1;
+    DieIfLessThan(x, y);
+  },
+  "DieIfLessThan");
+}
+
+// Tests that code that doesn't die causes a death test to fail.
+TEST_F(TestForDeathTest, DoesNotDie) {
+  EXPECT_NONFATAL_FAILURE(EXPECT_DEATH(DieIf(false), "DieIf"),
+                          "failed to die");
+}
+
+// Tests that a death test fails when the error message isn't expected.
+TEST_F(TestForDeathTest, ErrorMessageMismatch) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_DEATH(DieIf(true), "DieIfLessThan") << "End of death test message.";
+  }, "died but not with expected error");
+}
+
+// On exit, *aborted will be true if and only if the EXPECT_DEATH()
+// statement aborted the function.
+void ExpectDeathTestHelper(bool* aborted) {
+  *aborted = true;
+  EXPECT_DEATH(DieIf(false), "DieIf");  // This assertion should fail.
+  *aborted = false;
+}
+
+// Tests that EXPECT_DEATH doesn't abort the test on failure.
+TEST_F(TestForDeathTest, EXPECT_DEATH) {
+  bool aborted = true;
+  EXPECT_NONFATAL_FAILURE(ExpectDeathTestHelper(&aborted),
+                          "failed to die");
+  EXPECT_FALSE(aborted);
+}
+
+// Tests that ASSERT_DEATH does abort the test on failure.
+TEST_F(TestForDeathTest, ASSERT_DEATH) {
+  static bool aborted;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    aborted = true;
+    ASSERT_DEATH(DieIf(false), "DieIf");  // This assertion should fail.
+    aborted = false;
+  }, "failed to die");
+  EXPECT_TRUE(aborted);
+}
+
+// Tests that EXPECT_DEATH evaluates the arguments exactly once.
+TEST_F(TestForDeathTest, SingleEvaluation) {
+  int x = 3;
+  EXPECT_DEATH(DieIf((++x) == 4), "DieIf");
+
+  const char* regex = "DieIf";
+  const char* regex_save = regex;
+  EXPECT_DEATH(DieIfLessThan(3, 4), regex++);
+  EXPECT_EQ(regex_save + 1, regex);
+}
+
+// Tests that run-away death tests are reported as failures.
+TEST_F(TestForDeathTest, RunawayIsFailure) {
+  EXPECT_NONFATAL_FAILURE(EXPECT_DEATH(static_cast<void>(0), "Foo"),
+                          "failed to die.");
+}
+
+// Tests that death tests report executing 'return' in the statement as
+// failure.
+TEST_F(TestForDeathTest, ReturnIsFailure) {
+  EXPECT_FATAL_FAILURE(ASSERT_DEATH(return, "Bar"),
+                       "illegal return in test statement.");
+}
+
+// Tests that EXPECT_DEBUG_DEATH works as expected, that is, you can stream a
+// message to it, and in debug mode it:
+// 1. Asserts on death.
+// 2. Has no side effect.
+//
+// And in opt mode, it:
+// 1.  Has side effects but does not assert.
+TEST_F(TestForDeathTest, TestExpectDebugDeath) {
+  int sideeffect = 0;
+
+  // Put the regex in a local variable to make sure we don't get an "unused"
+  // warning in opt mode.
+  const char* regex = "death.*DieInDebugElse12";
+
+  EXPECT_DEBUG_DEATH(DieInDebugElse12(&sideeffect), regex)
+      << "Must accept a streamed message";
+
+# ifdef NDEBUG
+
+  // Checks that the assignment occurs in opt mode (sideeffect).
+  EXPECT_EQ(12, sideeffect);
+
+# else
+
+  // Checks that the assignment does not occur in dbg mode (no sideeffect).
+  EXPECT_EQ(0, sideeffect);
+
+# endif
+}
+
+# if GTEST_OS_WINDOWS
+
+// Tests that EXPECT_DEBUG_DEATH works as expected when in debug mode
+// the Windows CRT crashes the process with an assertion failure.
+// 1. Asserts on death.
+// 2. Has no side effect (doesn't pop up a window or wait for user input).
+//
+// And in opt mode, it:
+// 1.  Has side effects but does not assert.
+TEST_F(TestForDeathTest, CRTDebugDeath) {
+  int sideeffect = 0;
+
+  // Put the regex in a local variable to make sure we don't get an "unused"
+  // warning in opt mode.
+  const char* regex = "dup.* : Assertion failed";
+
+  EXPECT_DEBUG_DEATH(DieInCRTDebugElse12(&sideeffect), regex)
+      << "Must accept a streamed message";
+
+# ifdef NDEBUG
+
+  // Checks that the assignment occurs in opt mode (sideeffect).
+  EXPECT_EQ(12, sideeffect);
+
+# else
+
+  // Checks that the assignment does not occur in dbg mode (no sideeffect).
+  EXPECT_EQ(0, sideeffect);
+
+# endif
+}
+
+# endif  // GTEST_OS_WINDOWS
+
+// Tests that ASSERT_DEBUG_DEATH works as expected, that is, you can stream a
+// message to it, and in debug mode it:
+// 1. Asserts on death.
+// 2. Has no side effect.
+//
+// And in opt mode, it:
+// 1.  Has side effects but does not assert.
+TEST_F(TestForDeathTest, TestAssertDebugDeath) {
+  int sideeffect = 0;
+
+  ASSERT_DEBUG_DEATH(DieInDebugElse12(&sideeffect), "death.*DieInDebugElse12")
+      << "Must accept a streamed message";
+
+# ifdef NDEBUG
+
+  // Checks that the assignment occurs in opt mode (sideeffect).
+  EXPECT_EQ(12, sideeffect);
+
+# else
+
+  // Checks that the assignment does not occur in dbg mode (no sideeffect).
+  EXPECT_EQ(0, sideeffect);
+
+# endif
+}
+
+# ifndef NDEBUG
+
+void ExpectDebugDeathHelper(bool* aborted) {
+  *aborted = true;
+  EXPECT_DEBUG_DEATH(return, "") << "This is expected to fail.";
+  *aborted = false;
+}
+
+#  if GTEST_OS_WINDOWS
+TEST(PopUpDeathTest, DoesNotShowPopUpOnAbort) {
+  printf("This test should be considered failing if it shows "
+         "any pop-up dialogs.\n");
+  fflush(stdout);
+
+  EXPECT_DEATH({
+    testing::GTEST_FLAG(catch_exceptions) = false;
+    abort();
+  }, "");
+}
+#  endif  // GTEST_OS_WINDOWS
+
+// Tests that EXPECT_DEBUG_DEATH in debug mode does not abort
+// the function.
+TEST_F(TestForDeathTest, ExpectDebugDeathDoesNotAbort) {
+  bool aborted = true;
+  EXPECT_NONFATAL_FAILURE(ExpectDebugDeathHelper(&aborted), "");
+  EXPECT_FALSE(aborted);
+}
+
+void AssertDebugDeathHelper(bool* aborted) {
+  *aborted = true;
+  GTEST_LOG_(INFO) << "Before ASSERT_DEBUG_DEATH";
+  ASSERT_DEBUG_DEATH(GTEST_LOG_(INFO) << "In ASSERT_DEBUG_DEATH"; return, "")
+      << "This is expected to fail.";
+  GTEST_LOG_(INFO) << "After ASSERT_DEBUG_DEATH";
+  *aborted = false;
+}
+
+// Tests that ASSERT_DEBUG_DEATH in debug mode aborts the function on
+// failure.
+TEST_F(TestForDeathTest, AssertDebugDeathAborts) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+TEST_F(TestForDeathTest, AssertDebugDeathAborts2) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+TEST_F(TestForDeathTest, AssertDebugDeathAborts3) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+TEST_F(TestForDeathTest, AssertDebugDeathAborts4) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+TEST_F(TestForDeathTest, AssertDebugDeathAborts5) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+TEST_F(TestForDeathTest, AssertDebugDeathAborts6) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+TEST_F(TestForDeathTest, AssertDebugDeathAborts7) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+TEST_F(TestForDeathTest, AssertDebugDeathAborts8) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+TEST_F(TestForDeathTest, AssertDebugDeathAborts9) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+TEST_F(TestForDeathTest, AssertDebugDeathAborts10) {
+  static bool aborted;
+  aborted = false;
+  EXPECT_FATAL_FAILURE(AssertDebugDeathHelper(&aborted), "");
+  EXPECT_TRUE(aborted);
+}
+
+# endif  // _NDEBUG
+
+// Tests the *_EXIT family of macros, using a variety of predicates.
+static void TestExitMacros() {
+  EXPECT_EXIT(_exit(1),  testing::ExitedWithCode(1),  "");
+  ASSERT_EXIT(_exit(42), testing::ExitedWithCode(42), "");
+
+# if GTEST_OS_WINDOWS
+
+  // Of all signals effects on the process exit code, only those of SIGABRT
+  // are documented on Windows.
+  // See https://msdn.microsoft.com/en-us/query-bi/m/dwwzkt4c.
+  EXPECT_EXIT(raise(SIGABRT), testing::ExitedWithCode(3), "") << "b_ar";
+
+# elif !GTEST_OS_FUCHSIA
+
+  // Fuchsia has no unix signals.
+  EXPECT_EXIT(raise(SIGKILL), testing::KilledBySignal(SIGKILL), "") << "foo";
+  ASSERT_EXIT(raise(SIGUSR2), testing::KilledBySignal(SIGUSR2), "") << "bar";
+
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_EXIT(_exit(0), testing::KilledBySignal(SIGSEGV), "")
+      << "This failure is expected, too.";
+  }, "This failure is expected, too.");
+
+# endif  // GTEST_OS_WINDOWS
+
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_EXIT(raise(SIGSEGV), testing::ExitedWithCode(0), "")
+      << "This failure is expected.";
+  }, "This failure is expected.");
+}
+
+TEST_F(TestForDeathTest, ExitMacros) {
+  TestExitMacros();
+}
+
+TEST_F(TestForDeathTest, ExitMacrosUsingFork) {
+  testing::GTEST_FLAG(death_test_use_fork) = true;
+  TestExitMacros();
+}
+
+TEST_F(TestForDeathTest, InvalidStyle) {
+  testing::GTEST_FLAG(death_test_style) = "rococo";
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_DEATH(_exit(0), "") << "This failure is expected.";
+  }, "This failure is expected.");
+}
+
+TEST_F(TestForDeathTest, DeathTestFailedOutput) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_DEATH(DieWithMessage("death\n"),
+                   "expected message"),
+      "Actual msg:\n"
+      "[  DEATH   ] death\n");
+}
+
+TEST_F(TestForDeathTest, DeathTestUnexpectedReturnOutput) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_DEATH({
+          fprintf(stderr, "returning\n");
+          fflush(stderr);
+          return;
+        }, ""),
+      "    Result: illegal return in test statement.\n"
+      " Error msg:\n"
+      "[  DEATH   ] returning\n");
+}
+
+TEST_F(TestForDeathTest, DeathTestBadExitCodeOutput) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_EXIT(DieWithMessage("exiting with rc 1\n"),
+                  testing::ExitedWithCode(3),
+                  "expected message"),
+      "    Result: died but not with expected exit code:\n"
+      "            Exited with exit status 1\n"
+      "Actual msg:\n"
+      "[  DEATH   ] exiting with rc 1\n");
+}
+
+TEST_F(TestForDeathTest, DeathTestMultiLineMatchFail) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_DEATH(DieWithMessage("line 1\nline 2\nline 3\n"),
+                   "line 1\nxyz\nline 3\n"),
+      "Actual msg:\n"
+      "[  DEATH   ] line 1\n"
+      "[  DEATH   ] line 2\n"
+      "[  DEATH   ] line 3\n");
+}
+
+TEST_F(TestForDeathTest, DeathTestMultiLineMatchPass) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  EXPECT_DEATH(DieWithMessage("line 1\nline 2\nline 3\n"),
+               "line 1\nline 2\nline 3\n");
+}
+
+// A DeathTestFactory that returns MockDeathTests.
+class MockDeathTestFactory : public DeathTestFactory {
+ public:
+  MockDeathTestFactory();
+  bool Create(const char* statement,
+              testing::Matcher<const std::string&> matcher, const char* file,
+              int line, DeathTest** test) override;
+
+  // Sets the parameters for subsequent calls to Create.
+  void SetParameters(bool create, DeathTest::TestRole role,
+                     int status, bool passed);
+
+  // Accessors.
+  int AssumeRoleCalls() const { return assume_role_calls_; }
+  int WaitCalls() const { return wait_calls_; }
+  size_t PassedCalls() const { return passed_args_.size(); }
+  bool PassedArgument(int n) const {
+    return passed_args_[static_cast<size_t>(n)];
+  }
+  size_t AbortCalls() const { return abort_args_.size(); }
+  DeathTest::AbortReason AbortArgument(int n) const {
+    return abort_args_[static_cast<size_t>(n)];
+  }
+  bool TestDeleted() const { return test_deleted_; }
+
+ private:
+  friend class MockDeathTest;
+  // If true, Create will return a MockDeathTest; otherwise it returns
+  // NULL.
+  bool create_;
+  // The value a MockDeathTest will return from its AssumeRole method.
+  DeathTest::TestRole role_;
+  // The value a MockDeathTest will return from its Wait method.
+  int status_;
+  // The value a MockDeathTest will return from its Passed method.
+  bool passed_;
+
+  // Number of times AssumeRole was called.
+  int assume_role_calls_;
+  // Number of times Wait was called.
+  int wait_calls_;
+  // The arguments to the calls to Passed since the last call to
+  // SetParameters.
+  std::vector<bool> passed_args_;
+  // The arguments to the calls to Abort since the last call to
+  // SetParameters.
+  std::vector<DeathTest::AbortReason> abort_args_;
+  // True if the last MockDeathTest returned by Create has been
+  // deleted.
+  bool test_deleted_;
+};
+
+
+// A DeathTest implementation useful in testing.  It returns values set
+// at its creation from its various inherited DeathTest methods, and
+// reports calls to those methods to its parent MockDeathTestFactory
+// object.
+class MockDeathTest : public DeathTest {
+ public:
+  MockDeathTest(MockDeathTestFactory *parent,
+                TestRole role, int status, bool passed) :
+      parent_(parent), role_(role), status_(status), passed_(passed) {
+  }
+  ~MockDeathTest() override { parent_->test_deleted_ = true; }
+  TestRole AssumeRole() override {
+    ++parent_->assume_role_calls_;
+    return role_;
+  }
+  int Wait() override {
+    ++parent_->wait_calls_;
+    return status_;
+  }
+  bool Passed(bool exit_status_ok) override {
+    parent_->passed_args_.push_back(exit_status_ok);
+    return passed_;
+  }
+  void Abort(AbortReason reason) override {
+    parent_->abort_args_.push_back(reason);
+  }
+
+ private:
+  MockDeathTestFactory* const parent_;
+  const TestRole role_;
+  const int status_;
+  const bool passed_;
+};
+
+
+// MockDeathTestFactory constructor.
+MockDeathTestFactory::MockDeathTestFactory()
+    : create_(true),
+      role_(DeathTest::OVERSEE_TEST),
+      status_(0),
+      passed_(true),
+      assume_role_calls_(0),
+      wait_calls_(0),
+      passed_args_(),
+      abort_args_() {
+}
+
+
+// Sets the parameters for subsequent calls to Create.
+void MockDeathTestFactory::SetParameters(bool create,
+                                         DeathTest::TestRole role,
+                                         int status, bool passed) {
+  create_ = create;
+  role_ = role;
+  status_ = status;
+  passed_ = passed;
+
+  assume_role_calls_ = 0;
+  wait_calls_ = 0;
+  passed_args_.clear();
+  abort_args_.clear();
+}
+
+
+// Sets test to NULL (if create_ is false) or to the address of a new
+// MockDeathTest object with parameters taken from the last call
+// to SetParameters (if create_ is true).  Always returns true.
+bool MockDeathTestFactory::Create(
+    const char* /*statement*/, testing::Matcher<const std::string&> /*matcher*/,
+    const char* /*file*/, int /*line*/, DeathTest** test) {
+  test_deleted_ = false;
+  if (create_) {
+    *test = new MockDeathTest(this, role_, status_, passed_);
+  } else {
+    *test = nullptr;
+  }
+  return true;
+}
+
+// A test fixture for testing the logic of the GTEST_DEATH_TEST_ macro.
+// It installs a MockDeathTestFactory that is used for the duration
+// of the test case.
+class MacroLogicDeathTest : public testing::Test {
+ protected:
+  static testing::internal::ReplaceDeathTestFactory* replacer_;
+  static MockDeathTestFactory* factory_;
+
+  static void SetUpTestSuite() {
+    factory_ = new MockDeathTestFactory;
+    replacer_ = new testing::internal::ReplaceDeathTestFactory(factory_);
+  }
+
+  static void TearDownTestSuite() {
+    delete replacer_;
+    replacer_ = nullptr;
+    delete factory_;
+    factory_ = nullptr;
+  }
+
+  // Runs a death test that breaks the rules by returning.  Such a death
+  // test cannot be run directly from a test routine that uses a
+  // MockDeathTest, or the remainder of the routine will not be executed.
+  static void RunReturningDeathTest(bool* flag) {
+    ASSERT_DEATH({  // NOLINT
+      *flag = true;
+      return;
+    }, "");
+  }
+};
+
+testing::internal::ReplaceDeathTestFactory* MacroLogicDeathTest::replacer_ =
+    nullptr;
+MockDeathTestFactory* MacroLogicDeathTest::factory_ = nullptr;
+
+// Test that nothing happens when the factory doesn't return a DeathTest:
+TEST_F(MacroLogicDeathTest, NothingHappens) {
+  bool flag = false;
+  factory_->SetParameters(false, DeathTest::OVERSEE_TEST, 0, true);
+  EXPECT_DEATH(flag = true, "");
+  EXPECT_FALSE(flag);
+  EXPECT_EQ(0, factory_->AssumeRoleCalls());
+  EXPECT_EQ(0, factory_->WaitCalls());
+  EXPECT_EQ(0U, factory_->PassedCalls());
+  EXPECT_EQ(0U, factory_->AbortCalls());
+  EXPECT_FALSE(factory_->TestDeleted());
+}
+
+// Test that the parent process doesn't run the death test code,
+// and that the Passed method returns false when the (simulated)
+// child process exits with status 0:
+TEST_F(MacroLogicDeathTest, ChildExitsSuccessfully) {
+  bool flag = false;
+  factory_->SetParameters(true, DeathTest::OVERSEE_TEST, 0, true);
+  EXPECT_DEATH(flag = true, "");
+  EXPECT_FALSE(flag);
+  EXPECT_EQ(1, factory_->AssumeRoleCalls());
+  EXPECT_EQ(1, factory_->WaitCalls());
+  ASSERT_EQ(1U, factory_->PassedCalls());
+  EXPECT_FALSE(factory_->PassedArgument(0));
+  EXPECT_EQ(0U, factory_->AbortCalls());
+  EXPECT_TRUE(factory_->TestDeleted());
+}
+
+// Tests that the Passed method was given the argument "true" when
+// the (simulated) child process exits with status 1:
+TEST_F(MacroLogicDeathTest, ChildExitsUnsuccessfully) {
+  bool flag = false;
+  factory_->SetParameters(true, DeathTest::OVERSEE_TEST, 1, true);
+  EXPECT_DEATH(flag = true, "");
+  EXPECT_FALSE(flag);
+  EXPECT_EQ(1, factory_->AssumeRoleCalls());
+  EXPECT_EQ(1, factory_->WaitCalls());
+  ASSERT_EQ(1U, factory_->PassedCalls());
+  EXPECT_TRUE(factory_->PassedArgument(0));
+  EXPECT_EQ(0U, factory_->AbortCalls());
+  EXPECT_TRUE(factory_->TestDeleted());
+}
+
+// Tests that the (simulated) child process executes the death test
+// code, and is aborted with the correct AbortReason if it
+// executes a return statement.
+TEST_F(MacroLogicDeathTest, ChildPerformsReturn) {
+  bool flag = false;
+  factory_->SetParameters(true, DeathTest::EXECUTE_TEST, 0, true);
+  RunReturningDeathTest(&flag);
+  EXPECT_TRUE(flag);
+  EXPECT_EQ(1, factory_->AssumeRoleCalls());
+  EXPECT_EQ(0, factory_->WaitCalls());
+  EXPECT_EQ(0U, factory_->PassedCalls());
+  EXPECT_EQ(1U, factory_->AbortCalls());
+  EXPECT_EQ(DeathTest::TEST_ENCOUNTERED_RETURN_STATEMENT,
+            factory_->AbortArgument(0));
+  EXPECT_TRUE(factory_->TestDeleted());
+}
+
+// Tests that the (simulated) child process is aborted with the
+// correct AbortReason if it does not die.
+TEST_F(MacroLogicDeathTest, ChildDoesNotDie) {
+  bool flag = false;
+  factory_->SetParameters(true, DeathTest::EXECUTE_TEST, 0, true);
+  EXPECT_DEATH(flag = true, "");
+  EXPECT_TRUE(flag);
+  EXPECT_EQ(1, factory_->AssumeRoleCalls());
+  EXPECT_EQ(0, factory_->WaitCalls());
+  EXPECT_EQ(0U, factory_->PassedCalls());
+  // This time there are two calls to Abort: one since the test didn't
+  // die, and another from the ReturnSentinel when it's destroyed.  The
+  // sentinel normally isn't destroyed if a test doesn't die, since
+  // _exit(2) is called in that case by ForkingDeathTest, but not by
+  // our MockDeathTest.
+  ASSERT_EQ(2U, factory_->AbortCalls());
+  EXPECT_EQ(DeathTest::TEST_DID_NOT_DIE,
+            factory_->AbortArgument(0));
+  EXPECT_EQ(DeathTest::TEST_ENCOUNTERED_RETURN_STATEMENT,
+            factory_->AbortArgument(1));
+  EXPECT_TRUE(factory_->TestDeleted());
+}
+
+// Tests that a successful death test does not register a successful
+// test part.
+TEST(SuccessRegistrationDeathTest, NoSuccessPart) {
+  EXPECT_DEATH(_exit(1), "");
+  EXPECT_EQ(0, GetUnitTestImpl()->current_test_result()->total_part_count());
+}
+
+TEST(StreamingAssertionsDeathTest, DeathTest) {
+  EXPECT_DEATH(_exit(1), "") << "unexpected failure";
+  ASSERT_DEATH(_exit(1), "") << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_DEATH(_exit(0), "") << "expected failure";
+  }, "expected failure");
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_DEATH(_exit(0), "") << "expected failure";
+  }, "expected failure");
+}
+
+// Tests that GetLastErrnoDescription returns an empty string when the
+// last error is 0 and non-empty string when it is non-zero.
+TEST(GetLastErrnoDescription, GetLastErrnoDescriptionWorks) {
+  errno = ENOENT;
+  EXPECT_STRNE("", GetLastErrnoDescription().c_str());
+  errno = 0;
+  EXPECT_STREQ("", GetLastErrnoDescription().c_str());
+}
+
+# if GTEST_OS_WINDOWS
+TEST(AutoHandleTest, AutoHandleWorks) {
+  HANDLE handle = ::CreateEvent(NULL, FALSE, FALSE, NULL);
+  ASSERT_NE(INVALID_HANDLE_VALUE, handle);
+
+  // Tests that the AutoHandle is correctly initialized with a handle.
+  testing::internal::AutoHandle auto_handle(handle);
+  EXPECT_EQ(handle, auto_handle.Get());
+
+  // Tests that Reset assigns INVALID_HANDLE_VALUE.
+  // Note that this cannot verify whether the original handle is closed.
+  auto_handle.Reset();
+  EXPECT_EQ(INVALID_HANDLE_VALUE, auto_handle.Get());
+
+  // Tests that Reset assigns the new handle.
+  // Note that this cannot verify whether the original handle is closed.
+  handle = ::CreateEvent(NULL, FALSE, FALSE, NULL);
+  ASSERT_NE(INVALID_HANDLE_VALUE, handle);
+  auto_handle.Reset(handle);
+  EXPECT_EQ(handle, auto_handle.Get());
+
+  // Tests that AutoHandle contains INVALID_HANDLE_VALUE by default.
+  testing::internal::AutoHandle auto_handle2;
+  EXPECT_EQ(INVALID_HANDLE_VALUE, auto_handle2.Get());
+}
+# endif  // GTEST_OS_WINDOWS
+
+# if GTEST_OS_WINDOWS
+typedef unsigned __int64 BiggestParsable;
+typedef signed __int64 BiggestSignedParsable;
+# else
+typedef unsigned long long BiggestParsable;
+typedef signed long long BiggestSignedParsable;
+# endif  // GTEST_OS_WINDOWS
+
+// We cannot use std::numeric_limits<T>::max() as it clashes with the
+// max() macro defined by <windows.h>.
+const BiggestParsable kBiggestParsableMax = ULLONG_MAX;
+const BiggestSignedParsable kBiggestSignedParsableMax = LLONG_MAX;
+
+TEST(ParseNaturalNumberTest, RejectsInvalidFormat) {
+  BiggestParsable result = 0;
+
+  // Rejects non-numbers.
+  EXPECT_FALSE(ParseNaturalNumber("non-number string", &result));
+
+  // Rejects numbers with whitespace prefix.
+  EXPECT_FALSE(ParseNaturalNumber(" 123", &result));
+
+  // Rejects negative numbers.
+  EXPECT_FALSE(ParseNaturalNumber("-123", &result));
+
+  // Rejects numbers starting with a plus sign.
+  EXPECT_FALSE(ParseNaturalNumber("+123", &result));
+  errno = 0;
+}
+
+TEST(ParseNaturalNumberTest, RejectsOverflownNumbers) {
+  BiggestParsable result = 0;
+
+  EXPECT_FALSE(ParseNaturalNumber("99999999999999999999999", &result));
+
+  signed char char_result = 0;
+  EXPECT_FALSE(ParseNaturalNumber("200", &char_result));
+  errno = 0;
+}
+
+TEST(ParseNaturalNumberTest, AcceptsValidNumbers) {
+  BiggestParsable result = 0;
+
+  result = 0;
+  ASSERT_TRUE(ParseNaturalNumber("123", &result));
+  EXPECT_EQ(123U, result);
+
+  // Check 0 as an edge case.
+  result = 1;
+  ASSERT_TRUE(ParseNaturalNumber("0", &result));
+  EXPECT_EQ(0U, result);
+
+  result = 1;
+  ASSERT_TRUE(ParseNaturalNumber("00000", &result));
+  EXPECT_EQ(0U, result);
+}
+
+TEST(ParseNaturalNumberTest, AcceptsTypeLimits) {
+  Message msg;
+  msg << kBiggestParsableMax;
+
+  BiggestParsable result = 0;
+  EXPECT_TRUE(ParseNaturalNumber(msg.GetString(), &result));
+  EXPECT_EQ(kBiggestParsableMax, result);
+
+  Message msg2;
+  msg2 << kBiggestSignedParsableMax;
+
+  BiggestSignedParsable signed_result = 0;
+  EXPECT_TRUE(ParseNaturalNumber(msg2.GetString(), &signed_result));
+  EXPECT_EQ(kBiggestSignedParsableMax, signed_result);
+
+  Message msg3;
+  msg3 << INT_MAX;
+
+  int int_result = 0;
+  EXPECT_TRUE(ParseNaturalNumber(msg3.GetString(), &int_result));
+  EXPECT_EQ(INT_MAX, int_result);
+
+  Message msg4;
+  msg4 << UINT_MAX;
+
+  unsigned int uint_result = 0;
+  EXPECT_TRUE(ParseNaturalNumber(msg4.GetString(), &uint_result));
+  EXPECT_EQ(UINT_MAX, uint_result);
+}
+
+TEST(ParseNaturalNumberTest, WorksForShorterIntegers) {
+  short short_result = 0;
+  ASSERT_TRUE(ParseNaturalNumber("123", &short_result));
+  EXPECT_EQ(123, short_result);
+
+  signed char char_result = 0;
+  ASSERT_TRUE(ParseNaturalNumber("123", &char_result));
+  EXPECT_EQ(123, char_result);
+}
+
+# if GTEST_OS_WINDOWS
+TEST(EnvironmentTest, HandleFitsIntoSizeT) {
+  ASSERT_TRUE(sizeof(HANDLE) <= sizeof(size_t));
+}
+# endif  // GTEST_OS_WINDOWS
+
+// Tests that EXPECT_DEATH_IF_SUPPORTED/ASSERT_DEATH_IF_SUPPORTED trigger
+// failures when death tests are available on the system.
+TEST(ConditionalDeathMacrosDeathTest, ExpectsDeathWhenDeathTestsAvailable) {
+  EXPECT_DEATH_IF_SUPPORTED(DieInside("CondDeathTestExpectMacro"),
+                            "death inside CondDeathTestExpectMacro");
+  ASSERT_DEATH_IF_SUPPORTED(DieInside("CondDeathTestAssertMacro"),
+                            "death inside CondDeathTestAssertMacro");
+
+  // Empty statement will not crash, which must trigger a failure.
+  EXPECT_NONFATAL_FAILURE(EXPECT_DEATH_IF_SUPPORTED(;, ""), "");
+  EXPECT_FATAL_FAILURE(ASSERT_DEATH_IF_SUPPORTED(;, ""), "");
+}
+
+TEST(InDeathTestChildDeathTest, ReportsDeathTestCorrectlyInFastStyle) {
+  testing::GTEST_FLAG(death_test_style) = "fast";
+  EXPECT_FALSE(InDeathTestChild());
+  EXPECT_DEATH({
+    fprintf(stderr, InDeathTestChild() ? "Inside" : "Outside");
+    fflush(stderr);
+    _exit(1);
+  }, "Inside");
+}
+
+TEST(InDeathTestChildDeathTest, ReportsDeathTestCorrectlyInThreadSafeStyle) {
+  testing::GTEST_FLAG(death_test_style) = "threadsafe";
+  EXPECT_FALSE(InDeathTestChild());
+  EXPECT_DEATH({
+    fprintf(stderr, InDeathTestChild() ? "Inside" : "Outside");
+    fflush(stderr);
+    _exit(1);
+  }, "Inside");
+}
+
+void DieWithMessage(const char* message) {
+  fputs(message, stderr);
+  fflush(stderr);  // Make sure the text is printed before the process exits.
+  _exit(1);
+}
+
+TEST(MatcherDeathTest, DoesNotBreakBareRegexMatching) {
+  // googletest tests this, of course; here we ensure that including googlemock
+  // has not broken it.
+  EXPECT_DEATH(DieWithMessage("O, I die, Horatio."), "I d[aeiou]e");
+}
+
+TEST(MatcherDeathTest, MonomorphicMatcherMatches) {
+  EXPECT_DEATH(DieWithMessage("Behind O, I am slain!"),
+               Matcher<const std::string&>(ContainsRegex("I am slain")));
+}
+
+TEST(MatcherDeathTest, MonomorphicMatcherDoesNotMatch) {
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_DEATH(
+          DieWithMessage("Behind O, I am slain!"),
+          Matcher<const std::string&>(ContainsRegex("Ow, I am slain"))),
+      "Expected: contains regular expression \"Ow, I am slain\"");
+}
+
+TEST(MatcherDeathTest, PolymorphicMatcherMatches) {
+  EXPECT_DEATH(DieWithMessage("The rest is silence."),
+               ContainsRegex("rest is silence"));
+}
+
+TEST(MatcherDeathTest, PolymorphicMatcherDoesNotMatch) {
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_DEATH(DieWithMessage("The rest is silence."),
+                   ContainsRegex("rest is science")),
+      "Expected: contains regular expression \"rest is science\"");
+}
+
+}  // namespace
+
+#else  // !GTEST_HAS_DEATH_TEST follows
+
+namespace {
+
+using testing::internal::CaptureStderr;
+using testing::internal::GetCapturedStderr;
+
+// Tests that EXPECT_DEATH_IF_SUPPORTED/ASSERT_DEATH_IF_SUPPORTED are still
+// defined but do not trigger failures when death tests are not available on
+// the system.
+TEST(ConditionalDeathMacrosTest, WarnsWhenDeathTestsNotAvailable) {
+  // Empty statement will not crash, but that should not trigger a failure
+  // when death tests are not supported.
+  CaptureStderr();
+  EXPECT_DEATH_IF_SUPPORTED(;, "");
+  std::string output = GetCapturedStderr();
+  ASSERT_TRUE(NULL != strstr(output.c_str(),
+                             "Death tests are not supported on this platform"));
+  ASSERT_TRUE(NULL != strstr(output.c_str(), ";"));
+
+  // The streamed message should not be printed as there is no test failure.
+  CaptureStderr();
+  EXPECT_DEATH_IF_SUPPORTED(;, "") << "streamed message";
+  output = GetCapturedStderr();
+  ASSERT_TRUE(NULL == strstr(output.c_str(), "streamed message"));
+
+  CaptureStderr();
+  ASSERT_DEATH_IF_SUPPORTED(;, "");  // NOLINT
+  output = GetCapturedStderr();
+  ASSERT_TRUE(NULL != strstr(output.c_str(),
+                             "Death tests are not supported on this platform"));
+  ASSERT_TRUE(NULL != strstr(output.c_str(), ";"));
+
+  CaptureStderr();
+  ASSERT_DEATH_IF_SUPPORTED(;, "") << "streamed message";  // NOLINT
+  output = GetCapturedStderr();
+  ASSERT_TRUE(NULL == strstr(output.c_str(), "streamed message"));
+}
+
+void FuncWithAssert(int* n) {
+  ASSERT_DEATH_IF_SUPPORTED(return;, "");
+  (*n)++;
+}
+
+// Tests that ASSERT_DEATH_IF_SUPPORTED does not return from the current
+// function (as ASSERT_DEATH does) if death tests are not supported.
+TEST(ConditionalDeathMacrosTest, AssertDeatDoesNotReturnhIfUnsupported) {
+  int n = 0;
+  FuncWithAssert(&n);
+  EXPECT_EQ(1, n);
+}
+
+}  // namespace
+
+#endif  // !GTEST_HAS_DEATH_TEST
+
+namespace {
+
+// Tests that the death test macros expand to code which may or may not
+// be followed by operator<<, and that in either case the complete text
+// comprises only a single C++ statement.
+//
+// The syntax should work whether death tests are available or not.
+TEST(ConditionalDeathMacrosSyntaxDeathTest, SingleStatement) {
+  if (AlwaysFalse())
+    // This would fail if executed; this is a compilation test only
+    ASSERT_DEATH_IF_SUPPORTED(return, "");
+
+  if (AlwaysTrue())
+    EXPECT_DEATH_IF_SUPPORTED(_exit(1), "");
+  else
+    // This empty "else" branch is meant to ensure that EXPECT_DEATH
+    // doesn't expand into an "if" statement without an "else"
+    ;  // NOLINT
+
+  if (AlwaysFalse())
+    ASSERT_DEATH_IF_SUPPORTED(return, "") << "did not die";
+
+  if (AlwaysFalse())
+    ;  // NOLINT
+  else
+    EXPECT_DEATH_IF_SUPPORTED(_exit(1), "") << 1 << 2 << 3;
+}
+
+// Tests that conditional death test macros expand to code which interacts
+// well with switch statements.
+TEST(ConditionalDeathMacrosSyntaxDeathTest, SwitchStatement) {
+  // Microsoft compiler usually complains about switch statements without
+  // case labels. We suppress that warning for this test.
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4065)
+
+  switch (0)
+    default:
+      ASSERT_DEATH_IF_SUPPORTED(_exit(1), "")
+          << "exit in default switch handler";
+
+  switch (0)
+    case 0:
+      EXPECT_DEATH_IF_SUPPORTED(_exit(1), "") << "exit in switch case";
+
+  GTEST_DISABLE_MSC_WARNINGS_POP_()
+}
+
+// Tests that a test case whose name ends with "DeathTest" works fine
+// on Windows.
+TEST(NotADeathTest, Test) {
+  SUCCEED();
+}
+
+}  // namespace
diff --git a/3rdparty/gtest/test/googletest-death-test_ex_test.cc b/3rdparty/gtest/test/googletest-death-test_ex_test.cc
new file mode 100644
index 0000000..7ea5b94
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-death-test_ex_test.cc
@@ -0,0 +1,92 @@
+// Copyright 2010, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests that verify interaction of exceptions and death tests.
+
+#include "gtest/gtest-death-test.h"
+#include "gtest/gtest.h"
+
+#if GTEST_HAS_DEATH_TEST
+
+# if GTEST_HAS_SEH
+#  include <windows.h>          // For RaiseException().
+# endif
+
+# include "gtest/gtest-spi.h"
+
+# if GTEST_HAS_EXCEPTIONS
+
+#  include <exception>  // For std::exception.
+
+// Tests that death tests report thrown exceptions as failures and that the
+// exceptions do not escape death test macros.
+TEST(CxxExceptionDeathTest, ExceptionIsFailure) {
+  try {
+    EXPECT_NONFATAL_FAILURE(EXPECT_DEATH(throw 1, ""), "threw an exception");
+  } catch (...) {  // NOLINT
+    FAIL() << "An exception escaped a death test macro invocation "
+           << "with catch_exceptions "
+           << (testing::GTEST_FLAG(catch_exceptions) ? "enabled" : "disabled");
+  }
+}
+
+class TestException : public std::exception {
+ public:
+  const char* what() const throw() override { return "exceptional message"; }
+};
+
+TEST(CxxExceptionDeathTest, PrintsMessageForStdExceptions) {
+  // Verifies that the exception message is quoted in the failure text.
+  EXPECT_NONFATAL_FAILURE(EXPECT_DEATH(throw TestException(), ""),
+                          "exceptional message");
+  // Verifies that the location is mentioned in the failure text.
+  EXPECT_NONFATAL_FAILURE(EXPECT_DEATH(throw TestException(), ""),
+                          __FILE__);
+}
+# endif  // GTEST_HAS_EXCEPTIONS
+
+# if GTEST_HAS_SEH
+// Tests that enabling interception of SEH exceptions with the
+// catch_exceptions flag does not interfere with SEH exceptions being
+// treated as death by death tests.
+TEST(SehExceptionDeasTest, CatchExceptionsDoesNotInterfere) {
+  EXPECT_DEATH(RaiseException(42, 0x0, 0, NULL), "")
+      << "with catch_exceptions "
+      << (testing::GTEST_FLAG(catch_exceptions) ? "enabled" : "disabled");
+}
+# endif
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  testing::GTEST_FLAG(catch_exceptions) = GTEST_ENABLE_CATCH_EXCEPTIONS_ != 0;
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/googletest-env-var-test.py b/3rdparty/gtest/test/googletest-env-var-test.py
new file mode 100644
index 0000000..2f0e406
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-env-var-test.py
@@ -0,0 +1,117 @@
+#!/usr/bin/env python
+#
+# Copyright 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Verifies that Google Test correctly parses environment variables."""
+
+import os
+import gtest_test_utils
+
+
+IS_WINDOWS = os.name == 'nt'
+IS_LINUX = os.name == 'posix' and os.uname()[0] == 'Linux'
+
+COMMAND = gtest_test_utils.GetTestExecutablePath('googletest-env-var-test_')
+
+environ = os.environ.copy()
+
+
+def AssertEq(expected, actual):
+  if expected != actual:
+    print('Expected: %s' % (expected,))
+    print('  Actual: %s' % (actual,))
+    raise AssertionError
+
+
+def SetEnvVar(env_var, value):
+  """Sets the env variable to 'value'; unsets it when 'value' is None."""
+
+  if value is not None:
+    environ[env_var] = value
+  elif env_var in environ:
+    del environ[env_var]
+
+
+def GetFlag(flag):
+  """Runs googletest-env-var-test_ and returns its output."""
+
+  args = [COMMAND]
+  if flag is not None:
+    args += [flag]
+  return gtest_test_utils.Subprocess(args, env=environ).output
+
+
+def TestFlag(flag, test_val, default_val):
+  """Verifies that the given flag is affected by the corresponding env var."""
+
+  env_var = 'GTEST_' + flag.upper()
+  SetEnvVar(env_var, test_val)
+  AssertEq(test_val, GetFlag(flag))
+  SetEnvVar(env_var, None)
+  AssertEq(default_val, GetFlag(flag))
+
+
+class GTestEnvVarTest(gtest_test_utils.TestCase):
+
+  def testEnvVarAffectsFlag(self):
+    """Tests that environment variable should affect the corresponding flag."""
+
+    TestFlag('break_on_failure', '1', '0')
+    TestFlag('color', 'yes', 'auto')
+    TestFlag('filter', 'FooTest.Bar', '*')
+    SetEnvVar('XML_OUTPUT_FILE', None)  # For 'output' test
+    TestFlag('output', 'xml:tmp/foo.xml', '')
+    TestFlag('print_time', '0', '1')
+    TestFlag('repeat', '999', '1')
+    TestFlag('throw_on_failure', '1', '0')
+    TestFlag('death_test_style', 'threadsafe', 'fast')
+    TestFlag('catch_exceptions', '0', '1')
+
+    if IS_LINUX:
+      TestFlag('death_test_use_fork', '1', '0')
+      TestFlag('stack_trace_depth', '0', '100')
+
+
+  def testXmlOutputFile(self):
+    """Tests that $XML_OUTPUT_FILE affects the output flag."""
+
+    SetEnvVar('GTEST_OUTPUT', None)
+    SetEnvVar('XML_OUTPUT_FILE', 'tmp/bar.xml')
+    AssertEq('xml:tmp/bar.xml', GetFlag('output'))
+
+  def testXmlOutputFileOverride(self):
+    """Tests that $XML_OUTPUT_FILE is overridden by $GTEST_OUTPUT."""
+
+    SetEnvVar('GTEST_OUTPUT', 'xml:tmp/foo.xml')
+    SetEnvVar('XML_OUTPUT_FILE', 'tmp/bar.xml')
+    AssertEq('xml:tmp/foo.xml', GetFlag('output'))
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-env-var-test_.cc b/3rdparty/gtest/test/googletest-env-var-test_.cc
new file mode 100644
index 0000000..fd2aa82
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-env-var-test_.cc
@@ -0,0 +1,122 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// A helper program for testing that Google Test parses the environment
+// variables correctly.
+
+#include <iostream>
+
+#include "gtest/gtest.h"
+#include "src/gtest-internal-inl.h"
+
+using ::std::cout;
+
+namespace testing {
+
+// The purpose of this is to make the test more realistic by ensuring
+// that the UnitTest singleton is created before main() is entered.
+// We don't actual run the TEST itself.
+TEST(GTestEnvVarTest, Dummy) {
+}
+
+void PrintFlag(const char* flag) {
+  if (strcmp(flag, "break_on_failure") == 0) {
+    cout << GTEST_FLAG(break_on_failure);
+    return;
+  }
+
+  if (strcmp(flag, "catch_exceptions") == 0) {
+    cout << GTEST_FLAG(catch_exceptions);
+    return;
+  }
+
+  if (strcmp(flag, "color") == 0) {
+    cout << GTEST_FLAG(color);
+    return;
+  }
+
+  if (strcmp(flag, "death_test_style") == 0) {
+    cout << GTEST_FLAG(death_test_style);
+    return;
+  }
+
+  if (strcmp(flag, "death_test_use_fork") == 0) {
+    cout << GTEST_FLAG(death_test_use_fork);
+    return;
+  }
+
+  if (strcmp(flag, "filter") == 0) {
+    cout << GTEST_FLAG(filter);
+    return;
+  }
+
+  if (strcmp(flag, "output") == 0) {
+    cout << GTEST_FLAG(output);
+    return;
+  }
+
+  if (strcmp(flag, "print_time") == 0) {
+    cout << GTEST_FLAG(print_time);
+    return;
+  }
+
+  if (strcmp(flag, "repeat") == 0) {
+    cout << GTEST_FLAG(repeat);
+    return;
+  }
+
+  if (strcmp(flag, "stack_trace_depth") == 0) {
+    cout << GTEST_FLAG(stack_trace_depth);
+    return;
+  }
+
+  if (strcmp(flag, "throw_on_failure") == 0) {
+    cout << GTEST_FLAG(throw_on_failure);
+    return;
+  }
+
+  cout << "Invalid flag name " << flag
+       << ".  Valid names are break_on_failure, color, filter, etc.\n";
+  exit(1);
+}
+
+}  // namespace testing
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  if (argc != 2) {
+    cout << "Usage: googletest-env-var-test_ NAME_OF_FLAG\n";
+    return 1;
+  }
+
+  testing::PrintFlag(argv[1]);
+  return 0;
+}
diff --git a/3rdparty/gtest/test/googletest-filepath-test.cc b/3rdparty/gtest/test/googletest-filepath-test.cc
new file mode 100644
index 0000000..aafad36
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-filepath-test.cc
@@ -0,0 +1,649 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Google Test filepath utilities
+//
+// This file tests classes and functions used internally by
+// Google Test.  They are subject to change without notice.
+//
+// This file is #included from gtest-internal.h.
+// Do not #include this file anywhere else!
+
+#include "gtest/internal/gtest-filepath.h"
+#include "gtest/gtest.h"
+#include "src/gtest-internal-inl.h"
+
+#if GTEST_OS_WINDOWS_MOBILE
+# include <windows.h>  // NOLINT
+#elif GTEST_OS_WINDOWS
+# include <direct.h>  // NOLINT
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+namespace testing {
+namespace internal {
+namespace {
+
+#if GTEST_OS_WINDOWS_MOBILE
+
+// Windows CE doesn't have the remove C function.
+int remove(const char* path) {
+  LPCWSTR wpath = String::AnsiToUtf16(path);
+  int ret = DeleteFile(wpath) ? 0 : -1;
+  delete [] wpath;
+  return ret;
+}
+// Windows CE doesn't have the _rmdir C function.
+int _rmdir(const char* path) {
+  FilePath filepath(path);
+  LPCWSTR wpath = String::AnsiToUtf16(
+      filepath.RemoveTrailingPathSeparator().c_str());
+  int ret = RemoveDirectory(wpath) ? 0 : -1;
+  delete [] wpath;
+  return ret;
+}
+
+#else
+
+TEST(GetCurrentDirTest, ReturnsCurrentDir) {
+  const FilePath original_dir = FilePath::GetCurrentDir();
+  EXPECT_FALSE(original_dir.IsEmpty());
+
+  posix::ChDir(GTEST_PATH_SEP_);
+  const FilePath cwd = FilePath::GetCurrentDir();
+  posix::ChDir(original_dir.c_str());
+
+# if GTEST_OS_WINDOWS || GTEST_OS_OS2
+
+  // Skips the ":".
+  const char* const cwd_without_drive = strchr(cwd.c_str(), ':');
+  ASSERT_TRUE(cwd_without_drive != NULL);
+  EXPECT_STREQ(GTEST_PATH_SEP_, cwd_without_drive + 1);
+
+# else
+
+  EXPECT_EQ(GTEST_PATH_SEP_, cwd.string());
+
+# endif
+}
+
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+TEST(IsEmptyTest, ReturnsTrueForEmptyPath) {
+  EXPECT_TRUE(FilePath("").IsEmpty());
+}
+
+TEST(IsEmptyTest, ReturnsFalseForNonEmptyPath) {
+  EXPECT_FALSE(FilePath("a").IsEmpty());
+  EXPECT_FALSE(FilePath(".").IsEmpty());
+  EXPECT_FALSE(FilePath("a/b").IsEmpty());
+  EXPECT_FALSE(FilePath("a\\b\\").IsEmpty());
+}
+
+// RemoveDirectoryName "" -> ""
+TEST(RemoveDirectoryNameTest, WhenEmptyName) {
+  EXPECT_EQ("", FilePath("").RemoveDirectoryName().string());
+}
+
+// RemoveDirectoryName "afile" -> "afile"
+TEST(RemoveDirectoryNameTest, ButNoDirectory) {
+  EXPECT_EQ("afile",
+      FilePath("afile").RemoveDirectoryName().string());
+}
+
+// RemoveDirectoryName "/afile" -> "afile"
+TEST(RemoveDirectoryNameTest, RootFileShouldGiveFileName) {
+  EXPECT_EQ("afile",
+      FilePath(GTEST_PATH_SEP_ "afile").RemoveDirectoryName().string());
+}
+
+// RemoveDirectoryName "adir/" -> ""
+TEST(RemoveDirectoryNameTest, WhereThereIsNoFileName) {
+  EXPECT_EQ("",
+      FilePath("adir" GTEST_PATH_SEP_).RemoveDirectoryName().string());
+}
+
+// RemoveDirectoryName "adir/afile" -> "afile"
+TEST(RemoveDirectoryNameTest, ShouldGiveFileName) {
+  EXPECT_EQ("afile",
+      FilePath("adir" GTEST_PATH_SEP_ "afile").RemoveDirectoryName().string());
+}
+
+// RemoveDirectoryName "adir/subdir/afile" -> "afile"
+TEST(RemoveDirectoryNameTest, ShouldAlsoGiveFileName) {
+  EXPECT_EQ("afile",
+      FilePath("adir" GTEST_PATH_SEP_ "subdir" GTEST_PATH_SEP_ "afile")
+      .RemoveDirectoryName().string());
+}
+
+#if GTEST_HAS_ALT_PATH_SEP_
+
+// Tests that RemoveDirectoryName() works with the alternate separator
+// on Windows.
+
+// RemoveDirectoryName("/afile") -> "afile"
+TEST(RemoveDirectoryNameTest, RootFileShouldGiveFileNameForAlternateSeparator) {
+  EXPECT_EQ("afile", FilePath("/afile").RemoveDirectoryName().string());
+}
+
+// RemoveDirectoryName("adir/") -> ""
+TEST(RemoveDirectoryNameTest, WhereThereIsNoFileNameForAlternateSeparator) {
+  EXPECT_EQ("", FilePath("adir/").RemoveDirectoryName().string());
+}
+
+// RemoveDirectoryName("adir/afile") -> "afile"
+TEST(RemoveDirectoryNameTest, ShouldGiveFileNameForAlternateSeparator) {
+  EXPECT_EQ("afile", FilePath("adir/afile").RemoveDirectoryName().string());
+}
+
+// RemoveDirectoryName("adir/subdir/afile") -> "afile"
+TEST(RemoveDirectoryNameTest, ShouldAlsoGiveFileNameForAlternateSeparator) {
+  EXPECT_EQ("afile",
+            FilePath("adir/subdir/afile").RemoveDirectoryName().string());
+}
+
+#endif
+
+// RemoveFileName "" -> "./"
+TEST(RemoveFileNameTest, EmptyName) {
+#if GTEST_OS_WINDOWS_MOBILE
+  // On Windows CE, we use the root as the current directory.
+  EXPECT_EQ(GTEST_PATH_SEP_, FilePath("").RemoveFileName().string());
+#else
+  EXPECT_EQ("." GTEST_PATH_SEP_, FilePath("").RemoveFileName().string());
+#endif
+}
+
+// RemoveFileName "adir/" -> "adir/"
+TEST(RemoveFileNameTest, ButNoFile) {
+  EXPECT_EQ("adir" GTEST_PATH_SEP_,
+      FilePath("adir" GTEST_PATH_SEP_).RemoveFileName().string());
+}
+
+// RemoveFileName "adir/afile" -> "adir/"
+TEST(RemoveFileNameTest, GivesDirName) {
+  EXPECT_EQ("adir" GTEST_PATH_SEP_,
+            FilePath("adir" GTEST_PATH_SEP_ "afile").RemoveFileName().string());
+}
+
+// RemoveFileName "adir/subdir/afile" -> "adir/subdir/"
+TEST(RemoveFileNameTest, GivesDirAndSubDirName) {
+  EXPECT_EQ("adir" GTEST_PATH_SEP_ "subdir" GTEST_PATH_SEP_,
+      FilePath("adir" GTEST_PATH_SEP_ "subdir" GTEST_PATH_SEP_ "afile")
+      .RemoveFileName().string());
+}
+
+// RemoveFileName "/afile" -> "/"
+TEST(RemoveFileNameTest, GivesRootDir) {
+  EXPECT_EQ(GTEST_PATH_SEP_,
+      FilePath(GTEST_PATH_SEP_ "afile").RemoveFileName().string());
+}
+
+#if GTEST_HAS_ALT_PATH_SEP_
+
+// Tests that RemoveFileName() works with the alternate separator on
+// Windows.
+
+// RemoveFileName("adir/") -> "adir/"
+TEST(RemoveFileNameTest, ButNoFileForAlternateSeparator) {
+  EXPECT_EQ("adir" GTEST_PATH_SEP_,
+            FilePath("adir/").RemoveFileName().string());
+}
+
+// RemoveFileName("adir/afile") -> "adir/"
+TEST(RemoveFileNameTest, GivesDirNameForAlternateSeparator) {
+  EXPECT_EQ("adir" GTEST_PATH_SEP_,
+            FilePath("adir/afile").RemoveFileName().string());
+}
+
+// RemoveFileName("adir/subdir/afile") -> "adir/subdir/"
+TEST(RemoveFileNameTest, GivesDirAndSubDirNameForAlternateSeparator) {
+  EXPECT_EQ("adir" GTEST_PATH_SEP_ "subdir" GTEST_PATH_SEP_,
+            FilePath("adir/subdir/afile").RemoveFileName().string());
+}
+
+// RemoveFileName("/afile") -> "\"
+TEST(RemoveFileNameTest, GivesRootDirForAlternateSeparator) {
+  EXPECT_EQ(GTEST_PATH_SEP_, FilePath("/afile").RemoveFileName().string());
+}
+
+#endif
+
+TEST(MakeFileNameTest, GenerateWhenNumberIsZero) {
+  FilePath actual = FilePath::MakeFileName(FilePath("foo"), FilePath("bar"),
+      0, "xml");
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar.xml", actual.string());
+}
+
+TEST(MakeFileNameTest, GenerateFileNameNumberGtZero) {
+  FilePath actual = FilePath::MakeFileName(FilePath("foo"), FilePath("bar"),
+      12, "xml");
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar_12.xml", actual.string());
+}
+
+TEST(MakeFileNameTest, GenerateFileNameWithSlashNumberIsZero) {
+  FilePath actual = FilePath::MakeFileName(FilePath("foo" GTEST_PATH_SEP_),
+      FilePath("bar"), 0, "xml");
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar.xml", actual.string());
+}
+
+TEST(MakeFileNameTest, GenerateFileNameWithSlashNumberGtZero) {
+  FilePath actual = FilePath::MakeFileName(FilePath("foo" GTEST_PATH_SEP_),
+      FilePath("bar"), 12, "xml");
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar_12.xml", actual.string());
+}
+
+TEST(MakeFileNameTest, GenerateWhenNumberIsZeroAndDirIsEmpty) {
+  FilePath actual = FilePath::MakeFileName(FilePath(""), FilePath("bar"),
+      0, "xml");
+  EXPECT_EQ("bar.xml", actual.string());
+}
+
+TEST(MakeFileNameTest, GenerateWhenNumberIsNotZeroAndDirIsEmpty) {
+  FilePath actual = FilePath::MakeFileName(FilePath(""), FilePath("bar"),
+      14, "xml");
+  EXPECT_EQ("bar_14.xml", actual.string());
+}
+
+TEST(ConcatPathsTest, WorksWhenDirDoesNotEndWithPathSep) {
+  FilePath actual = FilePath::ConcatPaths(FilePath("foo"),
+                                          FilePath("bar.xml"));
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar.xml", actual.string());
+}
+
+TEST(ConcatPathsTest, WorksWhenPath1EndsWithPathSep) {
+  FilePath actual = FilePath::ConcatPaths(FilePath("foo" GTEST_PATH_SEP_),
+                                          FilePath("bar.xml"));
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar.xml", actual.string());
+}
+
+TEST(ConcatPathsTest, Path1BeingEmpty) {
+  FilePath actual = FilePath::ConcatPaths(FilePath(""),
+                                          FilePath("bar.xml"));
+  EXPECT_EQ("bar.xml", actual.string());
+}
+
+TEST(ConcatPathsTest, Path2BeingEmpty) {
+  FilePath actual = FilePath::ConcatPaths(FilePath("foo"), FilePath(""));
+  EXPECT_EQ("foo" GTEST_PATH_SEP_, actual.string());
+}
+
+TEST(ConcatPathsTest, BothPathBeingEmpty) {
+  FilePath actual = FilePath::ConcatPaths(FilePath(""),
+                                          FilePath(""));
+  EXPECT_EQ("", actual.string());
+}
+
+TEST(ConcatPathsTest, Path1ContainsPathSep) {
+  FilePath actual = FilePath::ConcatPaths(FilePath("foo" GTEST_PATH_SEP_ "bar"),
+                                          FilePath("foobar.xml"));
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar" GTEST_PATH_SEP_ "foobar.xml",
+            actual.string());
+}
+
+TEST(ConcatPathsTest, Path2ContainsPathSep) {
+  FilePath actual = FilePath::ConcatPaths(
+      FilePath("foo" GTEST_PATH_SEP_),
+      FilePath("bar" GTEST_PATH_SEP_ "bar.xml"));
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar" GTEST_PATH_SEP_ "bar.xml",
+            actual.string());
+}
+
+TEST(ConcatPathsTest, Path2EndsWithPathSep) {
+  FilePath actual = FilePath::ConcatPaths(FilePath("foo"),
+                                          FilePath("bar" GTEST_PATH_SEP_));
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar" GTEST_PATH_SEP_, actual.string());
+}
+
+// RemoveTrailingPathSeparator "" -> ""
+TEST(RemoveTrailingPathSeparatorTest, EmptyString) {
+  EXPECT_EQ("", FilePath("").RemoveTrailingPathSeparator().string());
+}
+
+// RemoveTrailingPathSeparator "foo" -> "foo"
+TEST(RemoveTrailingPathSeparatorTest, FileNoSlashString) {
+  EXPECT_EQ("foo", FilePath("foo").RemoveTrailingPathSeparator().string());
+}
+
+// RemoveTrailingPathSeparator "foo/" -> "foo"
+TEST(RemoveTrailingPathSeparatorTest, ShouldRemoveTrailingSeparator) {
+  EXPECT_EQ("foo",
+      FilePath("foo" GTEST_PATH_SEP_).RemoveTrailingPathSeparator().string());
+#if GTEST_HAS_ALT_PATH_SEP_
+  EXPECT_EQ("foo", FilePath("foo/").RemoveTrailingPathSeparator().string());
+#endif
+}
+
+// RemoveTrailingPathSeparator "foo/bar/" -> "foo/bar/"
+TEST(RemoveTrailingPathSeparatorTest, ShouldRemoveLastSeparator) {
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar",
+            FilePath("foo" GTEST_PATH_SEP_ "bar" GTEST_PATH_SEP_)
+                .RemoveTrailingPathSeparator().string());
+}
+
+// RemoveTrailingPathSeparator "foo/bar" -> "foo/bar"
+TEST(RemoveTrailingPathSeparatorTest, ShouldReturnUnmodified) {
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar",
+            FilePath("foo" GTEST_PATH_SEP_ "bar")
+                .RemoveTrailingPathSeparator().string());
+}
+
+TEST(DirectoryTest, RootDirectoryExists) {
+#if GTEST_OS_WINDOWS  // We are on Windows.
+  char current_drive[_MAX_PATH];  // NOLINT
+  current_drive[0] = static_cast<char>(_getdrive() + 'A' - 1);
+  current_drive[1] = ':';
+  current_drive[2] = '\\';
+  current_drive[3] = '\0';
+  EXPECT_TRUE(FilePath(current_drive).DirectoryExists());
+#else
+  EXPECT_TRUE(FilePath("/").DirectoryExists());
+#endif  // GTEST_OS_WINDOWS
+}
+
+#if GTEST_OS_WINDOWS
+TEST(DirectoryTest, RootOfWrongDriveDoesNotExists) {
+  const int saved_drive_ = _getdrive();
+  // Find a drive that doesn't exist. Start with 'Z' to avoid common ones.
+  for (char drive = 'Z'; drive >= 'A'; drive--)
+    if (_chdrive(drive - 'A' + 1) == -1) {
+      char non_drive[_MAX_PATH];  // NOLINT
+      non_drive[0] = drive;
+      non_drive[1] = ':';
+      non_drive[2] = '\\';
+      non_drive[3] = '\0';
+      EXPECT_FALSE(FilePath(non_drive).DirectoryExists());
+      break;
+    }
+  _chdrive(saved_drive_);
+}
+#endif  // GTEST_OS_WINDOWS
+
+#if !GTEST_OS_WINDOWS_MOBILE
+// Windows CE _does_ consider an empty directory to exist.
+TEST(DirectoryTest, EmptyPathDirectoryDoesNotExist) {
+  EXPECT_FALSE(FilePath("").DirectoryExists());
+}
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+TEST(DirectoryTest, CurrentDirectoryExists) {
+#if GTEST_OS_WINDOWS  // We are on Windows.
+# ifndef _WIN32_CE  // Windows CE doesn't have a current directory.
+
+  EXPECT_TRUE(FilePath(".").DirectoryExists());
+  EXPECT_TRUE(FilePath(".\\").DirectoryExists());
+
+# endif  // _WIN32_CE
+#else
+  EXPECT_TRUE(FilePath(".").DirectoryExists());
+  EXPECT_TRUE(FilePath("./").DirectoryExists());
+#endif  // GTEST_OS_WINDOWS
+}
+
+// "foo/bar" == foo//bar" == "foo///bar"
+TEST(NormalizeTest, MultipleConsecutiveSepaparatorsInMidstring) {
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar",
+            FilePath("foo" GTEST_PATH_SEP_ "bar").string());
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar",
+            FilePath("foo" GTEST_PATH_SEP_ GTEST_PATH_SEP_ "bar").string());
+  EXPECT_EQ("foo" GTEST_PATH_SEP_ "bar",
+            FilePath("foo" GTEST_PATH_SEP_ GTEST_PATH_SEP_
+                     GTEST_PATH_SEP_ "bar").string());
+}
+
+// "/bar" == //bar" == "///bar"
+TEST(NormalizeTest, MultipleConsecutiveSepaparatorsAtStringStart) {
+  EXPECT_EQ(GTEST_PATH_SEP_ "bar",
+    FilePath(GTEST_PATH_SEP_ "bar").string());
+  EXPECT_EQ(GTEST_PATH_SEP_ "bar",
+    FilePath(GTEST_PATH_SEP_ GTEST_PATH_SEP_ "bar").string());
+  EXPECT_EQ(GTEST_PATH_SEP_ "bar",
+    FilePath(GTEST_PATH_SEP_ GTEST_PATH_SEP_ GTEST_PATH_SEP_ "bar").string());
+}
+
+// "foo/" == foo//" == "foo///"
+TEST(NormalizeTest, MultipleConsecutiveSepaparatorsAtStringEnd) {
+  EXPECT_EQ("foo" GTEST_PATH_SEP_,
+    FilePath("foo" GTEST_PATH_SEP_).string());
+  EXPECT_EQ("foo" GTEST_PATH_SEP_,
+    FilePath("foo" GTEST_PATH_SEP_ GTEST_PATH_SEP_).string());
+  EXPECT_EQ("foo" GTEST_PATH_SEP_,
+    FilePath("foo" GTEST_PATH_SEP_ GTEST_PATH_SEP_ GTEST_PATH_SEP_).string());
+}
+
+#if GTEST_HAS_ALT_PATH_SEP_
+
+// Tests that separators at the end of the string are normalized
+// regardless of their combination (e.g. "foo\" =="foo/\" ==
+// "foo\\/").
+TEST(NormalizeTest, MixAlternateSeparatorAtStringEnd) {
+  EXPECT_EQ("foo" GTEST_PATH_SEP_,
+            FilePath("foo/").string());
+  EXPECT_EQ("foo" GTEST_PATH_SEP_,
+            FilePath("foo" GTEST_PATH_SEP_ "/").string());
+  EXPECT_EQ("foo" GTEST_PATH_SEP_,
+            FilePath("foo//" GTEST_PATH_SEP_).string());
+}
+
+#endif
+
+TEST(AssignmentOperatorTest, DefaultAssignedToNonDefault) {
+  FilePath default_path;
+  FilePath non_default_path("path");
+  non_default_path = default_path;
+  EXPECT_EQ("", non_default_path.string());
+  EXPECT_EQ("", default_path.string());  // RHS var is unchanged.
+}
+
+TEST(AssignmentOperatorTest, NonDefaultAssignedToDefault) {
+  FilePath non_default_path("path");
+  FilePath default_path;
+  default_path = non_default_path;
+  EXPECT_EQ("path", default_path.string());
+  EXPECT_EQ("path", non_default_path.string());  // RHS var is unchanged.
+}
+
+TEST(AssignmentOperatorTest, ConstAssignedToNonConst) {
+  const FilePath const_default_path("const_path");
+  FilePath non_default_path("path");
+  non_default_path = const_default_path;
+  EXPECT_EQ("const_path", non_default_path.string());
+}
+
+class DirectoryCreationTest : public Test {
+ protected:
+  void SetUp() override {
+    testdata_path_.Set(FilePath(
+        TempDir() + GetCurrentExecutableName().string() +
+        "_directory_creation" GTEST_PATH_SEP_ "test" GTEST_PATH_SEP_));
+    testdata_file_.Set(testdata_path_.RemoveTrailingPathSeparator());
+
+    unique_file0_.Set(FilePath::MakeFileName(testdata_path_, FilePath("unique"),
+        0, "txt"));
+    unique_file1_.Set(FilePath::MakeFileName(testdata_path_, FilePath("unique"),
+        1, "txt"));
+
+    remove(testdata_file_.c_str());
+    remove(unique_file0_.c_str());
+    remove(unique_file1_.c_str());
+    posix::RmDir(testdata_path_.c_str());
+  }
+
+  void TearDown() override {
+    remove(testdata_file_.c_str());
+    remove(unique_file0_.c_str());
+    remove(unique_file1_.c_str());
+    posix::RmDir(testdata_path_.c_str());
+  }
+
+  void CreateTextFile(const char* filename) {
+    FILE* f = posix::FOpen(filename, "w");
+    fprintf(f, "text\n");
+    fclose(f);
+  }
+
+  // Strings representing a directory and a file, with identical paths
+  // except for the trailing separator character that distinquishes
+  // a directory named 'test' from a file named 'test'. Example names:
+  FilePath testdata_path_;  // "/tmp/directory_creation/test/"
+  FilePath testdata_file_;  // "/tmp/directory_creation/test"
+  FilePath unique_file0_;  // "/tmp/directory_creation/test/unique.txt"
+  FilePath unique_file1_;  // "/tmp/directory_creation/test/unique_1.txt"
+};
+
+TEST_F(DirectoryCreationTest, CreateDirectoriesRecursively) {
+  EXPECT_FALSE(testdata_path_.DirectoryExists()) << testdata_path_.string();
+  EXPECT_TRUE(testdata_path_.CreateDirectoriesRecursively());
+  EXPECT_TRUE(testdata_path_.DirectoryExists());
+}
+
+TEST_F(DirectoryCreationTest, CreateDirectoriesForAlreadyExistingPath) {
+  EXPECT_FALSE(testdata_path_.DirectoryExists()) << testdata_path_.string();
+  EXPECT_TRUE(testdata_path_.CreateDirectoriesRecursively());
+  // Call 'create' again... should still succeed.
+  EXPECT_TRUE(testdata_path_.CreateDirectoriesRecursively());
+}
+
+TEST_F(DirectoryCreationTest, CreateDirectoriesAndUniqueFilename) {
+  FilePath file_path(FilePath::GenerateUniqueFileName(testdata_path_,
+      FilePath("unique"), "txt"));
+  EXPECT_EQ(unique_file0_.string(), file_path.string());
+  EXPECT_FALSE(file_path.FileOrDirectoryExists());  // file not there
+
+  testdata_path_.CreateDirectoriesRecursively();
+  EXPECT_FALSE(file_path.FileOrDirectoryExists());  // file still not there
+  CreateTextFile(file_path.c_str());
+  EXPECT_TRUE(file_path.FileOrDirectoryExists());
+
+  FilePath file_path2(FilePath::GenerateUniqueFileName(testdata_path_,
+      FilePath("unique"), "txt"));
+  EXPECT_EQ(unique_file1_.string(), file_path2.string());
+  EXPECT_FALSE(file_path2.FileOrDirectoryExists());  // file not there
+  CreateTextFile(file_path2.c_str());
+  EXPECT_TRUE(file_path2.FileOrDirectoryExists());
+}
+
+TEST_F(DirectoryCreationTest, CreateDirectoriesFail) {
+  // force a failure by putting a file where we will try to create a directory.
+  CreateTextFile(testdata_file_.c_str());
+  EXPECT_TRUE(testdata_file_.FileOrDirectoryExists());
+  EXPECT_FALSE(testdata_file_.DirectoryExists());
+  EXPECT_FALSE(testdata_file_.CreateDirectoriesRecursively());
+}
+
+TEST(NoDirectoryCreationTest, CreateNoDirectoriesForDefaultXmlFile) {
+  const FilePath test_detail_xml("test_detail.xml");
+  EXPECT_FALSE(test_detail_xml.CreateDirectoriesRecursively());
+}
+
+TEST(FilePathTest, DefaultConstructor) {
+  FilePath fp;
+  EXPECT_EQ("", fp.string());
+}
+
+TEST(FilePathTest, CharAndCopyConstructors) {
+  const FilePath fp("spicy");
+  EXPECT_EQ("spicy", fp.string());
+
+  const FilePath fp_copy(fp);
+  EXPECT_EQ("spicy", fp_copy.string());
+}
+
+TEST(FilePathTest, StringConstructor) {
+  const FilePath fp(std::string("cider"));
+  EXPECT_EQ("cider", fp.string());
+}
+
+TEST(FilePathTest, Set) {
+  const FilePath apple("apple");
+  FilePath mac("mac");
+  mac.Set(apple);  // Implement Set() since overloading operator= is forbidden.
+  EXPECT_EQ("apple", mac.string());
+  EXPECT_EQ("apple", apple.string());
+}
+
+TEST(FilePathTest, ToString) {
+  const FilePath file("drink");
+  EXPECT_EQ("drink", file.string());
+}
+
+TEST(FilePathTest, RemoveExtension) {
+  EXPECT_EQ("app", FilePath("app.cc").RemoveExtension("cc").string());
+  EXPECT_EQ("app", FilePath("app.exe").RemoveExtension("exe").string());
+  EXPECT_EQ("APP", FilePath("APP.EXE").RemoveExtension("exe").string());
+}
+
+TEST(FilePathTest, RemoveExtensionWhenThereIsNoExtension) {
+  EXPECT_EQ("app", FilePath("app").RemoveExtension("exe").string());
+}
+
+TEST(FilePathTest, IsDirectory) {
+  EXPECT_FALSE(FilePath("cola").IsDirectory());
+  EXPECT_TRUE(FilePath("koala" GTEST_PATH_SEP_).IsDirectory());
+#if GTEST_HAS_ALT_PATH_SEP_
+  EXPECT_TRUE(FilePath("koala/").IsDirectory());
+#endif
+}
+
+TEST(FilePathTest, IsAbsolutePath) {
+  EXPECT_FALSE(FilePath("is" GTEST_PATH_SEP_ "relative").IsAbsolutePath());
+  EXPECT_FALSE(FilePath("").IsAbsolutePath());
+#if GTEST_OS_WINDOWS
+  EXPECT_TRUE(FilePath("c:\\" GTEST_PATH_SEP_ "is_not"
+                       GTEST_PATH_SEP_ "relative").IsAbsolutePath());
+  EXPECT_FALSE(FilePath("c:foo" GTEST_PATH_SEP_ "bar").IsAbsolutePath());
+  EXPECT_TRUE(FilePath("c:/" GTEST_PATH_SEP_ "is_not"
+                       GTEST_PATH_SEP_ "relative").IsAbsolutePath());
+#else
+  EXPECT_TRUE(FilePath(GTEST_PATH_SEP_ "is_not" GTEST_PATH_SEP_ "relative")
+              .IsAbsolutePath());
+#endif  // GTEST_OS_WINDOWS
+}
+
+TEST(FilePathTest, IsRootDirectory) {
+#if GTEST_OS_WINDOWS
+  EXPECT_TRUE(FilePath("a:\\").IsRootDirectory());
+  EXPECT_TRUE(FilePath("Z:/").IsRootDirectory());
+  EXPECT_TRUE(FilePath("e://").IsRootDirectory());
+  EXPECT_FALSE(FilePath("").IsRootDirectory());
+  EXPECT_FALSE(FilePath("b:").IsRootDirectory());
+  EXPECT_FALSE(FilePath("b:a").IsRootDirectory());
+  EXPECT_FALSE(FilePath("8:/").IsRootDirectory());
+  EXPECT_FALSE(FilePath("c|/").IsRootDirectory());
+#else
+  EXPECT_TRUE(FilePath("/").IsRootDirectory());
+  EXPECT_TRUE(FilePath("//").IsRootDirectory());
+  EXPECT_FALSE(FilePath("").IsRootDirectory());
+  EXPECT_FALSE(FilePath("\\").IsRootDirectory());
+  EXPECT_FALSE(FilePath("/x").IsRootDirectory());
+#endif
+}
+
+}  // namespace
+}  // namespace internal
+}  // namespace testing
diff --git a/3rdparty/gtest/test/googletest-filter-unittest.py b/3rdparty/gtest/test/googletest-filter-unittest.py
new file mode 100644
index 0000000..6b32f2d
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-filter-unittest.py
@@ -0,0 +1,639 @@
+#!/usr/bin/env python
+#
+# Copyright 2005 Google Inc. All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test for Google Test test filters.
+
+A user can specify which test(s) in a Google Test program to run via either
+the GTEST_FILTER environment variable or the --gtest_filter flag.
+This script tests such functionality by invoking
+googletest-filter-unittest_ (a program written with Google Test) with different
+environments and command line flags.
+
+Note that test sharding may also influence which tests are filtered. Therefore,
+we test that here also.
+"""
+
+import os
+import re
+try:
+  from sets import Set as set  # For Python 2.3 compatibility
+except ImportError:
+  pass
+import sys
+import gtest_test_utils
+
+# Constants.
+
+# Checks if this platform can pass empty environment variables to child
+# processes.  We set an env variable to an empty string and invoke a python
+# script in a subprocess to print whether the variable is STILL in
+# os.environ.  We then use 'eval' to parse the child's output so that an
+# exception is thrown if the input is anything other than 'True' nor 'False'.
+CAN_PASS_EMPTY_ENV = False
+if sys.executable:
+  os.environ['EMPTY_VAR'] = ''
+  child = gtest_test_utils.Subprocess(
+      [sys.executable, '-c', 'import os; print(\'EMPTY_VAR\' in os.environ)'])
+  CAN_PASS_EMPTY_ENV = eval(child.output)
+
+
+# Check if this platform can unset environment variables in child processes.
+# We set an env variable to a non-empty string, unset it, and invoke
+# a python script in a subprocess to print whether the variable
+# is NO LONGER in os.environ.
+# We use 'eval' to parse the child's output so that an exception
+# is thrown if the input is neither 'True' nor 'False'.
+CAN_UNSET_ENV = False
+if sys.executable:
+  os.environ['UNSET_VAR'] = 'X'
+  del os.environ['UNSET_VAR']
+  child = gtest_test_utils.Subprocess(
+      [sys.executable, '-c', 'import os; print(\'UNSET_VAR\' not in os.environ)'
+      ])
+  CAN_UNSET_ENV = eval(child.output)
+
+
+# Checks if we should test with an empty filter. This doesn't
+# make sense on platforms that cannot pass empty env variables (Win32)
+# and on platforms that cannot unset variables (since we cannot tell
+# the difference between "" and NULL -- Borland and Solaris < 5.10)
+CAN_TEST_EMPTY_FILTER = (CAN_PASS_EMPTY_ENV and CAN_UNSET_ENV)
+
+
+# The environment variable for specifying the test filters.
+FILTER_ENV_VAR = 'GTEST_FILTER'
+
+# The environment variables for test sharding.
+TOTAL_SHARDS_ENV_VAR = 'GTEST_TOTAL_SHARDS'
+SHARD_INDEX_ENV_VAR = 'GTEST_SHARD_INDEX'
+SHARD_STATUS_FILE_ENV_VAR = 'GTEST_SHARD_STATUS_FILE'
+
+# The command line flag for specifying the test filters.
+FILTER_FLAG = 'gtest_filter'
+
+# The command line flag for including disabled tests.
+ALSO_RUN_DISABLED_TESTS_FLAG = 'gtest_also_run_disabled_tests'
+
+# Command to run the googletest-filter-unittest_ program.
+COMMAND = gtest_test_utils.GetTestExecutablePath('googletest-filter-unittest_')
+
+# Regex for determining whether parameterized tests are enabled in the binary.
+PARAM_TEST_REGEX = re.compile(r'/ParamTest')
+
+# Regex for parsing test case names from Google Test's output.
+TEST_CASE_REGEX = re.compile(r'^\[\-+\] \d+ tests? from (\w+(/\w+)?)')
+
+# Regex for parsing test names from Google Test's output.
+TEST_REGEX = re.compile(r'^\[\s*RUN\s*\].*\.(\w+(/\w+)?)')
+
+# The command line flag to tell Google Test to output the list of tests it
+# will run.
+LIST_TESTS_FLAG = '--gtest_list_tests'
+
+# Indicates whether Google Test supports death tests.
+SUPPORTS_DEATH_TESTS = 'HasDeathTest' in gtest_test_utils.Subprocess(
+    [COMMAND, LIST_TESTS_FLAG]).output
+
+# Full names of all tests in googletest-filter-unittests_.
+PARAM_TESTS = [
+    'SeqP/ParamTest.TestX/0',
+    'SeqP/ParamTest.TestX/1',
+    'SeqP/ParamTest.TestY/0',
+    'SeqP/ParamTest.TestY/1',
+    'SeqQ/ParamTest.TestX/0',
+    'SeqQ/ParamTest.TestX/1',
+    'SeqQ/ParamTest.TestY/0',
+    'SeqQ/ParamTest.TestY/1',
+    ]
+
+DISABLED_TESTS = [
+    'BarTest.DISABLED_TestFour',
+    'BarTest.DISABLED_TestFive',
+    'BazTest.DISABLED_TestC',
+    'DISABLED_FoobarTest.Test1',
+    'DISABLED_FoobarTest.DISABLED_Test2',
+    'DISABLED_FoobarbazTest.TestA',
+    ]
+
+if SUPPORTS_DEATH_TESTS:
+  DEATH_TESTS = [
+    'HasDeathTest.Test1',
+    'HasDeathTest.Test2',
+    ]
+else:
+  DEATH_TESTS = []
+
+# All the non-disabled tests.
+ACTIVE_TESTS = [
+    'FooTest.Abc',
+    'FooTest.Xyz',
+
+    'BarTest.TestOne',
+    'BarTest.TestTwo',
+    'BarTest.TestThree',
+
+    'BazTest.TestOne',
+    'BazTest.TestA',
+    'BazTest.TestB',
+    ] + DEATH_TESTS + PARAM_TESTS
+
+param_tests_present = None
+
+# Utilities.
+
+environ = os.environ.copy()
+
+
+def SetEnvVar(env_var, value):
+  """Sets the env variable to 'value'; unsets it when 'value' is None."""
+
+  if value is not None:
+    environ[env_var] = value
+  elif env_var in environ:
+    del environ[env_var]
+
+
+def RunAndReturnOutput(args = None):
+  """Runs the test program and returns its output."""
+
+  return gtest_test_utils.Subprocess([COMMAND] + (args or []),
+                                     env=environ).output
+
+
+def RunAndExtractTestList(args = None):
+  """Runs the test program and returns its exit code and a list of tests run."""
+
+  p = gtest_test_utils.Subprocess([COMMAND] + (args or []), env=environ)
+  tests_run = []
+  test_case = ''
+  test = ''
+  for line in p.output.split('\n'):
+    match = TEST_CASE_REGEX.match(line)
+    if match is not None:
+      test_case = match.group(1)
+    else:
+      match = TEST_REGEX.match(line)
+      if match is not None:
+        test = match.group(1)
+        tests_run.append(test_case + '.' + test)
+  return (tests_run, p.exit_code)
+
+
+def InvokeWithModifiedEnv(extra_env, function, *args, **kwargs):
+  """Runs the given function and arguments in a modified environment."""
+  try:
+    original_env = environ.copy()
+    environ.update(extra_env)
+    return function(*args, **kwargs)
+  finally:
+    environ.clear()
+    environ.update(original_env)
+
+
+def RunWithSharding(total_shards, shard_index, command):
+  """Runs a test program shard and returns exit code and a list of tests run."""
+
+  extra_env = {SHARD_INDEX_ENV_VAR: str(shard_index),
+               TOTAL_SHARDS_ENV_VAR: str(total_shards)}
+  return InvokeWithModifiedEnv(extra_env, RunAndExtractTestList, command)
+
+# The unit test.
+
+
+class GTestFilterUnitTest(gtest_test_utils.TestCase):
+  """Tests the env variable or the command line flag to filter tests."""
+
+  # Utilities.
+
+  def AssertSetEqual(self, lhs, rhs):
+    """Asserts that two sets are equal."""
+
+    for elem in lhs:
+      self.assert_(elem in rhs, '%s in %s' % (elem, rhs))
+
+    for elem in rhs:
+      self.assert_(elem in lhs, '%s in %s' % (elem, lhs))
+
+  def AssertPartitionIsValid(self, set_var, list_of_sets):
+    """Asserts that list_of_sets is a valid partition of set_var."""
+
+    full_partition = []
+    for slice_var in list_of_sets:
+      full_partition.extend(slice_var)
+    self.assertEqual(len(set_var), len(full_partition))
+    self.assertEqual(set(set_var), set(full_partition))
+
+  def AdjustForParameterizedTests(self, tests_to_run):
+    """Adjust tests_to_run in case value parameterized tests are disabled."""
+
+    global param_tests_present
+    if not param_tests_present:
+      return list(set(tests_to_run) - set(PARAM_TESTS))
+    else:
+      return tests_to_run
+
+  def RunAndVerify(self, gtest_filter, tests_to_run):
+    """Checks that the binary runs correct set of tests for a given filter."""
+
+    tests_to_run = self.AdjustForParameterizedTests(tests_to_run)
+
+    # First, tests using the environment variable.
+
+    # Windows removes empty variables from the environment when passing it
+    # to a new process.  This means it is impossible to pass an empty filter
+    # into a process using the environment variable.  However, we can still
+    # test the case when the variable is not supplied (i.e., gtest_filter is
+    # None).
+    # pylint: disable-msg=C6403
+    if CAN_TEST_EMPTY_FILTER or gtest_filter != '':
+      SetEnvVar(FILTER_ENV_VAR, gtest_filter)
+      tests_run = RunAndExtractTestList()[0]
+      SetEnvVar(FILTER_ENV_VAR, None)
+      self.AssertSetEqual(tests_run, tests_to_run)
+    # pylint: enable-msg=C6403
+
+    # Next, tests using the command line flag.
+
+    if gtest_filter is None:
+      args = []
+    else:
+      args = ['--%s=%s' % (FILTER_FLAG, gtest_filter)]
+
+    tests_run = RunAndExtractTestList(args)[0]
+    self.AssertSetEqual(tests_run, tests_to_run)
+
+  def RunAndVerifyWithSharding(self, gtest_filter, total_shards, tests_to_run,
+                               args=None, check_exit_0=False):
+    """Checks that binary runs correct tests for the given filter and shard.
+
+    Runs all shards of googletest-filter-unittest_ with the given filter, and
+    verifies that the right set of tests were run. The union of tests run
+    on each shard should be identical to tests_to_run, without duplicates.
+    If check_exit_0, .
+
+    Args:
+      gtest_filter: A filter to apply to the tests.
+      total_shards: A total number of shards to split test run into.
+      tests_to_run: A set of tests expected to run.
+      args   :      Arguments to pass to the to the test binary.
+      check_exit_0: When set to a true value, make sure that all shards
+                    return 0.
+    """
+
+    tests_to_run = self.AdjustForParameterizedTests(tests_to_run)
+
+    # Windows removes empty variables from the environment when passing it
+    # to a new process.  This means it is impossible to pass an empty filter
+    # into a process using the environment variable.  However, we can still
+    # test the case when the variable is not supplied (i.e., gtest_filter is
+    # None).
+    # pylint: disable-msg=C6403
+    if CAN_TEST_EMPTY_FILTER or gtest_filter != '':
+      SetEnvVar(FILTER_ENV_VAR, gtest_filter)
+      partition = []
+      for i in range(0, total_shards):
+        (tests_run, exit_code) = RunWithSharding(total_shards, i, args)
+        if check_exit_0:
+          self.assertEqual(0, exit_code)
+        partition.append(tests_run)
+
+      self.AssertPartitionIsValid(tests_to_run, partition)
+      SetEnvVar(FILTER_ENV_VAR, None)
+    # pylint: enable-msg=C6403
+
+  def RunAndVerifyAllowingDisabled(self, gtest_filter, tests_to_run):
+    """Checks that the binary runs correct set of tests for the given filter.
+
+    Runs googletest-filter-unittest_ with the given filter, and enables
+    disabled tests. Verifies that the right set of tests were run.
+
+    Args:
+      gtest_filter: A filter to apply to the tests.
+      tests_to_run: A set of tests expected to run.
+    """
+
+    tests_to_run = self.AdjustForParameterizedTests(tests_to_run)
+
+    # Construct the command line.
+    args = ['--%s' % ALSO_RUN_DISABLED_TESTS_FLAG]
+    if gtest_filter is not None:
+      args.append('--%s=%s' % (FILTER_FLAG, gtest_filter))
+
+    tests_run = RunAndExtractTestList(args)[0]
+    self.AssertSetEqual(tests_run, tests_to_run)
+
+  def setUp(self):
+    """Sets up test case.
+
+    Determines whether value-parameterized tests are enabled in the binary and
+    sets the flags accordingly.
+    """
+
+    global param_tests_present
+    if param_tests_present is None:
+      param_tests_present = PARAM_TEST_REGEX.search(
+          RunAndReturnOutput()) is not None
+
+  def testDefaultBehavior(self):
+    """Tests the behavior of not specifying the filter."""
+
+    self.RunAndVerify(None, ACTIVE_TESTS)
+
+  def testDefaultBehaviorWithShards(self):
+    """Tests the behavior without the filter, with sharding enabled."""
+
+    self.RunAndVerifyWithSharding(None, 1, ACTIVE_TESTS)
+    self.RunAndVerifyWithSharding(None, 2, ACTIVE_TESTS)
+    self.RunAndVerifyWithSharding(None, len(ACTIVE_TESTS) - 1, ACTIVE_TESTS)
+    self.RunAndVerifyWithSharding(None, len(ACTIVE_TESTS), ACTIVE_TESTS)
+    self.RunAndVerifyWithSharding(None, len(ACTIVE_TESTS) + 1, ACTIVE_TESTS)
+
+  def testEmptyFilter(self):
+    """Tests an empty filter."""
+
+    self.RunAndVerify('', [])
+    self.RunAndVerifyWithSharding('', 1, [])
+    self.RunAndVerifyWithSharding('', 2, [])
+
+  def testBadFilter(self):
+    """Tests a filter that matches nothing."""
+
+    self.RunAndVerify('BadFilter', [])
+    self.RunAndVerifyAllowingDisabled('BadFilter', [])
+
+  def testFullName(self):
+    """Tests filtering by full name."""
+
+    self.RunAndVerify('FooTest.Xyz', ['FooTest.Xyz'])
+    self.RunAndVerifyAllowingDisabled('FooTest.Xyz', ['FooTest.Xyz'])
+    self.RunAndVerifyWithSharding('FooTest.Xyz', 5, ['FooTest.Xyz'])
+
+  def testUniversalFilters(self):
+    """Tests filters that match everything."""
+
+    self.RunAndVerify('*', ACTIVE_TESTS)
+    self.RunAndVerify('*.*', ACTIVE_TESTS)
+    self.RunAndVerifyWithSharding('*.*', len(ACTIVE_TESTS) - 3, ACTIVE_TESTS)
+    self.RunAndVerifyAllowingDisabled('*', ACTIVE_TESTS + DISABLED_TESTS)
+    self.RunAndVerifyAllowingDisabled('*.*', ACTIVE_TESTS + DISABLED_TESTS)
+
+  def testFilterByTestCase(self):
+    """Tests filtering by test case name."""
+
+    self.RunAndVerify('FooTest.*', ['FooTest.Abc', 'FooTest.Xyz'])
+
+    BAZ_TESTS = ['BazTest.TestOne', 'BazTest.TestA', 'BazTest.TestB']
+    self.RunAndVerify('BazTest.*', BAZ_TESTS)
+    self.RunAndVerifyAllowingDisabled('BazTest.*',
+                                      BAZ_TESTS + ['BazTest.DISABLED_TestC'])
+
+  def testFilterByTest(self):
+    """Tests filtering by test name."""
+
+    self.RunAndVerify('*.TestOne', ['BarTest.TestOne', 'BazTest.TestOne'])
+
+  def testFilterDisabledTests(self):
+    """Select only the disabled tests to run."""
+
+    self.RunAndVerify('DISABLED_FoobarTest.Test1', [])
+    self.RunAndVerifyAllowingDisabled('DISABLED_FoobarTest.Test1',
+                                      ['DISABLED_FoobarTest.Test1'])
+
+    self.RunAndVerify('*DISABLED_*', [])
+    self.RunAndVerifyAllowingDisabled('*DISABLED_*', DISABLED_TESTS)
+
+    self.RunAndVerify('*.DISABLED_*', [])
+    self.RunAndVerifyAllowingDisabled('*.DISABLED_*', [
+        'BarTest.DISABLED_TestFour',
+        'BarTest.DISABLED_TestFive',
+        'BazTest.DISABLED_TestC',
+        'DISABLED_FoobarTest.DISABLED_Test2',
+        ])
+
+    self.RunAndVerify('DISABLED_*', [])
+    self.RunAndVerifyAllowingDisabled('DISABLED_*', [
+        'DISABLED_FoobarTest.Test1',
+        'DISABLED_FoobarTest.DISABLED_Test2',
+        'DISABLED_FoobarbazTest.TestA',
+        ])
+
+  def testWildcardInTestCaseName(self):
+    """Tests using wildcard in the test case name."""
+
+    self.RunAndVerify('*a*.*', [
+        'BarTest.TestOne',
+        'BarTest.TestTwo',
+        'BarTest.TestThree',
+
+        'BazTest.TestOne',
+        'BazTest.TestA',
+        'BazTest.TestB', ] + DEATH_TESTS + PARAM_TESTS)
+
+  def testWildcardInTestName(self):
+    """Tests using wildcard in the test name."""
+
+    self.RunAndVerify('*.*A*', ['FooTest.Abc', 'BazTest.TestA'])
+
+  def testFilterWithoutDot(self):
+    """Tests a filter that has no '.' in it."""
+
+    self.RunAndVerify('*z*', [
+        'FooTest.Xyz',
+
+        'BazTest.TestOne',
+        'BazTest.TestA',
+        'BazTest.TestB',
+        ])
+
+  def testTwoPatterns(self):
+    """Tests filters that consist of two patterns."""
+
+    self.RunAndVerify('Foo*.*:*A*', [
+        'FooTest.Abc',
+        'FooTest.Xyz',
+
+        'BazTest.TestA',
+        ])
+
+    # An empty pattern + a non-empty one
+    self.RunAndVerify(':*A*', ['FooTest.Abc', 'BazTest.TestA'])
+
+  def testThreePatterns(self):
+    """Tests filters that consist of three patterns."""
+
+    self.RunAndVerify('*oo*:*A*:*One', [
+        'FooTest.Abc',
+        'FooTest.Xyz',
+
+        'BarTest.TestOne',
+
+        'BazTest.TestOne',
+        'BazTest.TestA',
+        ])
+
+    # The 2nd pattern is empty.
+    self.RunAndVerify('*oo*::*One', [
+        'FooTest.Abc',
+        'FooTest.Xyz',
+
+        'BarTest.TestOne',
+
+        'BazTest.TestOne',
+        ])
+
+    # The last 2 patterns are empty.
+    self.RunAndVerify('*oo*::', [
+        'FooTest.Abc',
+        'FooTest.Xyz',
+        ])
+
+  def testNegativeFilters(self):
+    self.RunAndVerify('*-BazTest.TestOne', [
+        'FooTest.Abc',
+        'FooTest.Xyz',
+
+        'BarTest.TestOne',
+        'BarTest.TestTwo',
+        'BarTest.TestThree',
+
+        'BazTest.TestA',
+        'BazTest.TestB',
+        ] + DEATH_TESTS + PARAM_TESTS)
+
+    self.RunAndVerify('*-FooTest.Abc:BazTest.*', [
+        'FooTest.Xyz',
+
+        'BarTest.TestOne',
+        'BarTest.TestTwo',
+        'BarTest.TestThree',
+        ] + DEATH_TESTS + PARAM_TESTS)
+
+    self.RunAndVerify('BarTest.*-BarTest.TestOne', [
+        'BarTest.TestTwo',
+        'BarTest.TestThree',
+        ])
+
+    # Tests without leading '*'.
+    self.RunAndVerify('-FooTest.Abc:FooTest.Xyz:BazTest.*', [
+        'BarTest.TestOne',
+        'BarTest.TestTwo',
+        'BarTest.TestThree',
+        ] + DEATH_TESTS + PARAM_TESTS)
+
+    # Value parameterized tests.
+    self.RunAndVerify('*/*', PARAM_TESTS)
+
+    # Value parameterized tests filtering by the sequence name.
+    self.RunAndVerify('SeqP/*', [
+        'SeqP/ParamTest.TestX/0',
+        'SeqP/ParamTest.TestX/1',
+        'SeqP/ParamTest.TestY/0',
+        'SeqP/ParamTest.TestY/1',
+        ])
+
+    # Value parameterized tests filtering by the test name.
+    self.RunAndVerify('*/0', [
+        'SeqP/ParamTest.TestX/0',
+        'SeqP/ParamTest.TestY/0',
+        'SeqQ/ParamTest.TestX/0',
+        'SeqQ/ParamTest.TestY/0',
+        ])
+
+  def testFlagOverridesEnvVar(self):
+    """Tests that the filter flag overrides the filtering env. variable."""
+
+    SetEnvVar(FILTER_ENV_VAR, 'Foo*')
+    args = ['--%s=%s' % (FILTER_FLAG, '*One')]
+    tests_run = RunAndExtractTestList(args)[0]
+    SetEnvVar(FILTER_ENV_VAR, None)
+
+    self.AssertSetEqual(tests_run, ['BarTest.TestOne', 'BazTest.TestOne'])
+
+  def testShardStatusFileIsCreated(self):
+    """Tests that the shard file is created if specified in the environment."""
+
+    shard_status_file = os.path.join(gtest_test_utils.GetTempDir(),
+                                     'shard_status_file')
+    self.assert_(not os.path.exists(shard_status_file))
+
+    extra_env = {SHARD_STATUS_FILE_ENV_VAR: shard_status_file}
+    try:
+      InvokeWithModifiedEnv(extra_env, RunAndReturnOutput)
+    finally:
+      self.assert_(os.path.exists(shard_status_file))
+      os.remove(shard_status_file)
+
+  def testShardStatusFileIsCreatedWithListTests(self):
+    """Tests that the shard file is created with the "list_tests" flag."""
+
+    shard_status_file = os.path.join(gtest_test_utils.GetTempDir(),
+                                     'shard_status_file2')
+    self.assert_(not os.path.exists(shard_status_file))
+
+    extra_env = {SHARD_STATUS_FILE_ENV_VAR: shard_status_file}
+    try:
+      output = InvokeWithModifiedEnv(extra_env,
+                                     RunAndReturnOutput,
+                                     [LIST_TESTS_FLAG])
+    finally:
+      # This assertion ensures that Google Test enumerated the tests as
+      # opposed to running them.
+      self.assert_('[==========]' not in output,
+                   'Unexpected output during test enumeration.\n'
+                   'Please ensure that LIST_TESTS_FLAG is assigned the\n'
+                   'correct flag value for listing Google Test tests.')
+
+      self.assert_(os.path.exists(shard_status_file))
+      os.remove(shard_status_file)
+
+  if SUPPORTS_DEATH_TESTS:
+    def testShardingWorksWithDeathTests(self):
+      """Tests integration with death tests and sharding."""
+
+      gtest_filter = 'HasDeathTest.*:SeqP/*'
+      expected_tests = [
+          'HasDeathTest.Test1',
+          'HasDeathTest.Test2',
+
+          'SeqP/ParamTest.TestX/0',
+          'SeqP/ParamTest.TestX/1',
+          'SeqP/ParamTest.TestY/0',
+          'SeqP/ParamTest.TestY/1',
+          ]
+
+      for flag in ['--gtest_death_test_style=threadsafe',
+                   '--gtest_death_test_style=fast']:
+        self.RunAndVerifyWithSharding(gtest_filter, 3, expected_tests,
+                                      check_exit_0=True, args=[flag])
+        self.RunAndVerifyWithSharding(gtest_filter, 5, expected_tests,
+                                      check_exit_0=True, args=[flag])
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-filter-unittest_.cc b/3rdparty/gtest/test/googletest-filter-unittest_.cc
new file mode 100644
index 0000000..d30ec9c
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-filter-unittest_.cc
@@ -0,0 +1,137 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Unit test for Google Test test filters.
+//
+// A user can specify which test(s) in a Google Test program to run via
+// either the GTEST_FILTER environment variable or the --gtest_filter
+// flag.  This is used for testing such functionality.
+//
+// The program will be invoked from a Python unit test.  Don't run it
+// directly.
+
+#include "gtest/gtest.h"
+
+namespace {
+
+// Test case FooTest.
+
+class FooTest : public testing::Test {
+};
+
+TEST_F(FooTest, Abc) {
+}
+
+TEST_F(FooTest, Xyz) {
+  FAIL() << "Expected failure.";
+}
+
+// Test case BarTest.
+
+TEST(BarTest, TestOne) {
+}
+
+TEST(BarTest, TestTwo) {
+}
+
+TEST(BarTest, TestThree) {
+}
+
+TEST(BarTest, DISABLED_TestFour) {
+  FAIL() << "Expected failure.";
+}
+
+TEST(BarTest, DISABLED_TestFive) {
+  FAIL() << "Expected failure.";
+}
+
+// Test case BazTest.
+
+TEST(BazTest, TestOne) {
+  FAIL() << "Expected failure.";
+}
+
+TEST(BazTest, TestA) {
+}
+
+TEST(BazTest, TestB) {
+}
+
+TEST(BazTest, DISABLED_TestC) {
+  FAIL() << "Expected failure.";
+}
+
+// Test case HasDeathTest
+
+TEST(HasDeathTest, Test1) {
+  EXPECT_DEATH_IF_SUPPORTED(exit(1), ".*");
+}
+
+// We need at least two death tests to make sure that the all death tests
+// aren't on the first shard.
+TEST(HasDeathTest, Test2) {
+  EXPECT_DEATH_IF_SUPPORTED(exit(1), ".*");
+}
+
+// Test case FoobarTest
+
+TEST(DISABLED_FoobarTest, Test1) {
+  FAIL() << "Expected failure.";
+}
+
+TEST(DISABLED_FoobarTest, DISABLED_Test2) {
+  FAIL() << "Expected failure.";
+}
+
+// Test case FoobarbazTest
+
+TEST(DISABLED_FoobarbazTest, TestA) {
+  FAIL() << "Expected failure.";
+}
+
+class ParamTest : public testing::TestWithParam<int> {
+};
+
+TEST_P(ParamTest, TestX) {
+}
+
+TEST_P(ParamTest, TestY) {
+}
+
+INSTANTIATE_TEST_SUITE_P(SeqP, ParamTest, testing::Values(1, 2));
+INSTANTIATE_TEST_SUITE_P(SeqQ, ParamTest, testing::Values(5, 6));
+
+}  // namespace
+
+int main(int argc, char **argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/googletest-json-outfiles-test.py b/3rdparty/gtest/test/googletest-json-outfiles-test.py
new file mode 100644
index 0000000..8ef47b8
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-json-outfiles-test.py
@@ -0,0 +1,191 @@
+#!/usr/bin/env python
+# Copyright 2018, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test for the gtest_json_output module."""
+
+import json
+import os
+import gtest_json_test_utils
+import gtest_test_utils
+
+GTEST_OUTPUT_SUBDIR = 'json_outfiles'
+GTEST_OUTPUT_1_TEST = 'gtest_xml_outfile1_test_'
+GTEST_OUTPUT_2_TEST = 'gtest_xml_outfile2_test_'
+
+EXPECTED_1 = {
+    u'tests':
+        1,
+    u'failures':
+        0,
+    u'disabled':
+        0,
+    u'errors':
+        0,
+    u'time':
+        u'*',
+    u'timestamp':
+        u'*',
+    u'name':
+        u'AllTests',
+    u'testsuites': [{
+        u'name':
+            u'PropertyOne',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'TestSomeProperties',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'PropertyOne',
+            u'SetUpProp': u'1',
+            u'TestSomeProperty': u'1',
+            u'TearDownProp': u'1',
+        }],
+    }],
+}
+
+EXPECTED_2 = {
+    u'tests':
+        1,
+    u'failures':
+        0,
+    u'disabled':
+        0,
+    u'errors':
+        0,
+    u'time':
+        u'*',
+    u'timestamp':
+        u'*',
+    u'name':
+        u'AllTests',
+    u'testsuites': [{
+        u'name':
+            u'PropertyTwo',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'TestSomeProperties',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'timestamp': u'*',
+            u'time': u'*',
+            u'classname': u'PropertyTwo',
+            u'SetUpProp': u'2',
+            u'TestSomeProperty': u'2',
+            u'TearDownProp': u'2',
+        }],
+    }],
+}
+
+
+class GTestJsonOutFilesTest(gtest_test_utils.TestCase):
+  """Unit test for Google Test's JSON output functionality."""
+
+  def setUp(self):
+    # We want the trailing '/' that the last "" provides in os.path.join, for
+    # telling Google Test to create an output directory instead of a single file
+    # for xml output.
+    self.output_dir_ = os.path.join(gtest_test_utils.GetTempDir(),
+                                    GTEST_OUTPUT_SUBDIR, '')
+    self.DeleteFilesAndDir()
+
+  def tearDown(self):
+    self.DeleteFilesAndDir()
+
+  def DeleteFilesAndDir(self):
+    try:
+      os.remove(os.path.join(self.output_dir_, GTEST_OUTPUT_1_TEST + '.json'))
+    except os.error:
+      pass
+    try:
+      os.remove(os.path.join(self.output_dir_, GTEST_OUTPUT_2_TEST + '.json'))
+    except os.error:
+      pass
+    try:
+      os.rmdir(self.output_dir_)
+    except os.error:
+      pass
+
+  def testOutfile1(self):
+    self._TestOutFile(GTEST_OUTPUT_1_TEST, EXPECTED_1)
+
+  def testOutfile2(self):
+    self._TestOutFile(GTEST_OUTPUT_2_TEST, EXPECTED_2)
+
+  def _TestOutFile(self, test_name, expected):
+    gtest_prog_path = gtest_test_utils.GetTestExecutablePath(test_name)
+    command = [gtest_prog_path, '--gtest_output=json:%s' % self.output_dir_]
+    p = gtest_test_utils.Subprocess(command,
+                                    working_dir=gtest_test_utils.GetTempDir())
+    self.assert_(p.exited)
+    self.assertEquals(0, p.exit_code)
+
+    output_file_name1 = test_name + '.json'
+    output_file1 = os.path.join(self.output_dir_, output_file_name1)
+    output_file_name2 = 'lt-' + output_file_name1
+    output_file2 = os.path.join(self.output_dir_, output_file_name2)
+    self.assert_(os.path.isfile(output_file1) or os.path.isfile(output_file2),
+                 output_file1)
+
+    if os.path.isfile(output_file1):
+      with open(output_file1) as f:
+        actual = json.load(f)
+    else:
+      with open(output_file2) as f:
+        actual = json.load(f)
+    self.assertEqual(expected, gtest_json_test_utils.normalize(actual))
+
+
+if __name__ == '__main__':
+  os.environ['GTEST_STACK_TRACE_DEPTH'] = '0'
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-json-output-unittest.py b/3rdparty/gtest/test/googletest-json-output-unittest.py
new file mode 100644
index 0000000..15861f7
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-json-output-unittest.py
@@ -0,0 +1,778 @@
+#!/usr/bin/env python
+# Copyright 2018, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test for the gtest_json_output module."""
+
+import datetime
+import errno
+import json
+import os
+import re
+import sys
+
+import gtest_json_test_utils
+import gtest_test_utils
+
+GTEST_FILTER_FLAG = '--gtest_filter'
+GTEST_LIST_TESTS_FLAG = '--gtest_list_tests'
+GTEST_OUTPUT_FLAG = '--gtest_output'
+GTEST_DEFAULT_OUTPUT_FILE = 'test_detail.json'
+GTEST_PROGRAM_NAME = 'gtest_xml_output_unittest_'
+
+# The flag indicating stacktraces are not supported
+NO_STACKTRACE_SUPPORT_FLAG = '--no_stacktrace_support'
+
+SUPPORTS_STACK_TRACES = NO_STACKTRACE_SUPPORT_FLAG not in sys.argv
+
+if SUPPORTS_STACK_TRACES:
+  STACK_TRACE_TEMPLATE = '\nStack trace:\n*'
+else:
+  STACK_TRACE_TEMPLATE = ''
+
+EXPECTED_NON_EMPTY = {
+    u'tests':
+        24,
+    u'failures':
+        4,
+    u'disabled':
+        2,
+    u'errors':
+        0,
+    u'timestamp':
+        u'*',
+    u'time':
+        u'*',
+    u'ad_hoc_property':
+        u'42',
+    u'name':
+        u'AllTests',
+    u'testsuites': [{
+        u'name':
+            u'SuccessfulTest',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'Succeeds',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'SuccessfulTest'
+        }]
+    }, {
+        u'name':
+            u'FailedTest',
+        u'tests':
+            1,
+        u'failures':
+            1,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name':
+                u'Fails',
+            u'status':
+                u'RUN',
+            u'result':
+                u'COMPLETED',
+            u'time':
+                u'*',
+            u'timestamp':
+                u'*',
+            u'classname':
+                u'FailedTest',
+            u'failures': [{
+                u'failure': u'gtest_xml_output_unittest_.cc:*\n'
+                            u'Expected equality of these values:\n'
+                            u'  1\n  2' + STACK_TRACE_TEMPLATE,
+                u'type': u''
+            }]
+        }]
+    }, {
+        u'name':
+            u'DisabledTest',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            1,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'DISABLED_test_not_run',
+            u'status': u'NOTRUN',
+            u'result': u'SUPPRESSED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'DisabledTest'
+        }]
+    }, {
+        u'name':
+            u'SkippedTest',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'Skipped',
+            u'status': u'RUN',
+            u'result': u'SKIPPED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'SkippedTest'
+        }]
+    }, {
+        u'name':
+            u'MixedResultTest',
+        u'tests':
+            3,
+        u'failures':
+            1,
+        u'disabled':
+            1,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'Succeeds',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'MixedResultTest'
+        }, {
+            u'name':
+                u'Fails',
+            u'status':
+                u'RUN',
+            u'result':
+                u'COMPLETED',
+            u'time':
+                u'*',
+            u'timestamp':
+                u'*',
+            u'classname':
+                u'MixedResultTest',
+            u'failures': [{
+                u'failure': u'gtest_xml_output_unittest_.cc:*\n'
+                            u'Expected equality of these values:\n'
+                            u'  1\n  2' + STACK_TRACE_TEMPLATE,
+                u'type': u''
+            }, {
+                u'failure': u'gtest_xml_output_unittest_.cc:*\n'
+                            u'Expected equality of these values:\n'
+                            u'  2\n  3' + STACK_TRACE_TEMPLATE,
+                u'type': u''
+            }]
+        }, {
+            u'name': u'DISABLED_test',
+            u'status': u'NOTRUN',
+            u'result': u'SUPPRESSED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'MixedResultTest'
+        }]
+    }, {
+        u'name':
+            u'XmlQuotingTest',
+        u'tests':
+            1,
+        u'failures':
+            1,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name':
+                u'OutputsCData',
+            u'status':
+                u'RUN',
+            u'result':
+                u'COMPLETED',
+            u'time':
+                u'*',
+            u'timestamp':
+                u'*',
+            u'classname':
+                u'XmlQuotingTest',
+            u'failures': [{
+                u'failure': u'gtest_xml_output_unittest_.cc:*\n'
+                            u'Failed\nXML output: <?xml encoding="utf-8">'
+                            u'<top><![CDATA[cdata text]]></top>' +
+                            STACK_TRACE_TEMPLATE,
+                u'type': u''
+            }]
+        }]
+    }, {
+        u'name':
+            u'InvalidCharactersTest',
+        u'tests':
+            1,
+        u'failures':
+            1,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name':
+                u'InvalidCharactersInMessage',
+            u'status':
+                u'RUN',
+            u'result':
+                u'COMPLETED',
+            u'time':
+                u'*',
+            u'timestamp':
+                u'*',
+            u'classname':
+                u'InvalidCharactersTest',
+            u'failures': [{
+                u'failure': u'gtest_xml_output_unittest_.cc:*\n'
+                            u'Failed\nInvalid characters in brackets'
+                            u' [\x01\x02]' + STACK_TRACE_TEMPLATE,
+                u'type': u''
+            }]
+        }]
+    }, {
+        u'name':
+            u'PropertyRecordingTest',
+        u'tests':
+            4,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'SetUpTestSuite':
+            u'yes',
+        u'TearDownTestSuite':
+            u'aye',
+        u'testsuite': [{
+            u'name': u'OneProperty',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'PropertyRecordingTest',
+            u'key_1': u'1'
+        }, {
+            u'name': u'IntValuedProperty',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'PropertyRecordingTest',
+            u'key_int': u'1'
+        }, {
+            u'name': u'ThreeProperties',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'PropertyRecordingTest',
+            u'key_1': u'1',
+            u'key_2': u'2',
+            u'key_3': u'3'
+        }, {
+            u'name': u'TwoValuesForOneKeyUsesLastValue',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'PropertyRecordingTest',
+            u'key_1': u'2'
+        }]
+    }, {
+        u'name':
+            u'NoFixtureTest',
+        u'tests':
+            3,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'RecordProperty',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'NoFixtureTest',
+            u'key': u'1'
+        }, {
+            u'name': u'ExternalUtilityThatCallsRecordIntValuedProperty',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'NoFixtureTest',
+            u'key_for_utility_int': u'1'
+        }, {
+            u'name': u'ExternalUtilityThatCallsRecordStringValuedProperty',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'NoFixtureTest',
+            u'key_for_utility_string': u'1'
+        }]
+    }, {
+        u'name':
+            u'TypedTest/0',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'HasTypeParamAttribute',
+            u'type_param': u'int',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'TypedTest/0'
+        }]
+    }, {
+        u'name':
+            u'TypedTest/1',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'HasTypeParamAttribute',
+            u'type_param': u'long',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'TypedTest/1'
+        }]
+    }, {
+        u'name':
+            u'Single/TypeParameterizedTestSuite/0',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'HasTypeParamAttribute',
+            u'type_param': u'int',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'Single/TypeParameterizedTestSuite/0'
+        }]
+    }, {
+        u'name':
+            u'Single/TypeParameterizedTestSuite/1',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'HasTypeParamAttribute',
+            u'type_param': u'long',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'Single/TypeParameterizedTestSuite/1'
+        }]
+    }, {
+        u'name':
+            u'Single/ValueParamTest',
+        u'tests':
+            4,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'HasValueParamAttribute/0',
+            u'value_param': u'33',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'Single/ValueParamTest'
+        }, {
+            u'name': u'HasValueParamAttribute/1',
+            u'value_param': u'42',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'Single/ValueParamTest'
+        }, {
+            u'name': u'AnotherTestThatHasValueParamAttribute/0',
+            u'value_param': u'33',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'Single/ValueParamTest'
+        }, {
+            u'name': u'AnotherTestThatHasValueParamAttribute/1',
+            u'value_param': u'42',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'Single/ValueParamTest'
+        }]
+    }]
+}
+
+EXPECTED_FILTERED = {
+    u'tests':
+        1,
+    u'failures':
+        0,
+    u'disabled':
+        0,
+    u'errors':
+        0,
+    u'time':
+        u'*',
+    u'timestamp':
+        u'*',
+    u'name':
+        u'AllTests',
+    u'ad_hoc_property':
+        u'42',
+    u'testsuites': [{
+        u'name':
+            u'SuccessfulTest',
+        u'tests':
+            1,
+        u'failures':
+            0,
+        u'disabled':
+            0,
+        u'errors':
+            0,
+        u'time':
+            u'*',
+        u'timestamp':
+            u'*',
+        u'testsuite': [{
+            u'name': u'Succeeds',
+            u'status': u'RUN',
+            u'result': u'COMPLETED',
+            u'time': u'*',
+            u'timestamp': u'*',
+            u'classname': u'SuccessfulTest',
+        }]
+    }],
+}
+
+EXPECTED_EMPTY = {
+    u'tests': 0,
+    u'failures': 0,
+    u'disabled': 0,
+    u'errors': 0,
+    u'time': u'*',
+    u'timestamp': u'*',
+    u'name': u'AllTests',
+    u'testsuites': [],
+}
+
+GTEST_PROGRAM_PATH = gtest_test_utils.GetTestExecutablePath(GTEST_PROGRAM_NAME)
+
+SUPPORTS_TYPED_TESTS = 'TypedTest' in gtest_test_utils.Subprocess(
+    [GTEST_PROGRAM_PATH, GTEST_LIST_TESTS_FLAG], capture_stderr=False).output
+
+
+class GTestJsonOutputUnitTest(gtest_test_utils.TestCase):
+  """Unit test for Google Test's JSON output functionality.
+  """
+
+  # This test currently breaks on platforms that do not support typed and
+  # type-parameterized tests, so we don't run it under them.
+  if SUPPORTS_TYPED_TESTS:
+
+    def testNonEmptyJsonOutput(self):
+      """Verifies JSON output for a Google Test binary with non-empty output.
+
+      Runs a test program that generates a non-empty JSON output, and
+      tests that the JSON output is expected.
+      """
+      self._TestJsonOutput(GTEST_PROGRAM_NAME, EXPECTED_NON_EMPTY, 1)
+
+  def testEmptyJsonOutput(self):
+    """Verifies JSON output for a Google Test binary without actual tests.
+
+    Runs a test program that generates an empty JSON output, and
+    tests that the JSON output is expected.
+    """
+
+    self._TestJsonOutput('gtest_no_test_unittest', EXPECTED_EMPTY, 0)
+
+  def testTimestampValue(self):
+    """Checks whether the timestamp attribute in the JSON output is valid.
+
+    Runs a test program that generates an empty JSON output, and checks if
+    the timestamp attribute in the testsuites tag is valid.
+    """
+    actual = self._GetJsonOutput('gtest_no_test_unittest', [], 0)
+    date_time_str = actual['timestamp']
+    # datetime.strptime() is only available in Python 2.5+ so we have to
+    # parse the expected datetime manually.
+    match = re.match(r'(\d+)-(\d\d)-(\d\d)T(\d\d):(\d\d):(\d\d)', date_time_str)
+    self.assertTrue(
+        re.match,
+        'JSON datettime string %s has incorrect format' % date_time_str)
+    date_time_from_json = datetime.datetime(
+        year=int(match.group(1)), month=int(match.group(2)),
+        day=int(match.group(3)), hour=int(match.group(4)),
+        minute=int(match.group(5)), second=int(match.group(6)))
+
+    time_delta = abs(datetime.datetime.now() - date_time_from_json)
+    # timestamp value should be near the current local time
+    self.assertTrue(time_delta < datetime.timedelta(seconds=600),
+                    'time_delta is %s' % time_delta)
+
+  def testDefaultOutputFile(self):
+    """Verifies the default output file name.
+
+    Confirms that Google Test produces an JSON output file with the expected
+    default name if no name is explicitly specified.
+    """
+    output_file = os.path.join(gtest_test_utils.GetTempDir(),
+                               GTEST_DEFAULT_OUTPUT_FILE)
+    gtest_prog_path = gtest_test_utils.GetTestExecutablePath(
+        'gtest_no_test_unittest')
+    try:
+      os.remove(output_file)
+    except OSError:
+      e = sys.exc_info()[1]
+      if e.errno != errno.ENOENT:
+        raise
+
+    p = gtest_test_utils.Subprocess(
+        [gtest_prog_path, '%s=json' % GTEST_OUTPUT_FLAG],
+        working_dir=gtest_test_utils.GetTempDir())
+    self.assert_(p.exited)
+    self.assertEquals(0, p.exit_code)
+    self.assert_(os.path.isfile(output_file))
+
+  def testSuppressedJsonOutput(self):
+    """Verifies that no JSON output is generated.
+
+    Tests that no JSON file is generated if the default JSON listener is
+    shut down before RUN_ALL_TESTS is invoked.
+    """
+
+    json_path = os.path.join(gtest_test_utils.GetTempDir(),
+                             GTEST_PROGRAM_NAME + 'out.json')
+    if os.path.isfile(json_path):
+      os.remove(json_path)
+
+    command = [GTEST_PROGRAM_PATH,
+               '%s=json:%s' % (GTEST_OUTPUT_FLAG, json_path),
+               '--shut_down_xml']
+    p = gtest_test_utils.Subprocess(command)
+    if p.terminated_by_signal:
+      # p.signal is available only if p.terminated_by_signal is True.
+      self.assertFalse(
+          p.terminated_by_signal,
+          '%s was killed by signal %d' % (GTEST_PROGRAM_NAME, p.signal))
+    else:
+      self.assert_(p.exited)
+      self.assertEquals(1, p.exit_code,
+                        "'%s' exited with code %s, which doesn't match "
+                        'the expected exit code %s.'
+                        % (command, p.exit_code, 1))
+
+    self.assert_(not os.path.isfile(json_path))
+
+  def testFilteredTestJsonOutput(self):
+    """Verifies JSON output when a filter is applied.
+
+    Runs a test program that executes only some tests and verifies that
+    non-selected tests do not show up in the JSON output.
+    """
+
+    self._TestJsonOutput(GTEST_PROGRAM_NAME, EXPECTED_FILTERED, 0,
+                         extra_args=['%s=SuccessfulTest.*' % GTEST_FILTER_FLAG])
+
+  def _GetJsonOutput(self, gtest_prog_name, extra_args, expected_exit_code):
+    """Returns the JSON output generated by running the program gtest_prog_name.
+
+    Furthermore, the program's exit code must be expected_exit_code.
+
+    Args:
+      gtest_prog_name: Google Test binary name.
+      extra_args: extra arguments to binary invocation.
+      expected_exit_code: program's exit code.
+    """
+    json_path = os.path.join(gtest_test_utils.GetTempDir(),
+                             gtest_prog_name + 'out.json')
+    gtest_prog_path = gtest_test_utils.GetTestExecutablePath(gtest_prog_name)
+
+    command = (
+        [gtest_prog_path, '%s=json:%s' % (GTEST_OUTPUT_FLAG, json_path)] +
+        extra_args
+    )
+    p = gtest_test_utils.Subprocess(command)
+    if p.terminated_by_signal:
+      self.assert_(False,
+                   '%s was killed by signal %d' % (gtest_prog_name, p.signal))
+    else:
+      self.assert_(p.exited)
+      self.assertEquals(expected_exit_code, p.exit_code,
+                        "'%s' exited with code %s, which doesn't match "
+                        'the expected exit code %s.'
+                        % (command, p.exit_code, expected_exit_code))
+    with open(json_path) as f:
+      actual = json.load(f)
+    return actual
+
+  def _TestJsonOutput(self, gtest_prog_name, expected,
+                      expected_exit_code, extra_args=None):
+    """Checks the JSON output generated by the Google Test binary.
+
+    Asserts that the JSON document generated by running the program
+    gtest_prog_name matches expected_json, a string containing another
+    JSON document.  Furthermore, the program's exit code must be
+    expected_exit_code.
+
+    Args:
+      gtest_prog_name: Google Test binary name.
+      expected: expected output.
+      expected_exit_code: program's exit code.
+      extra_args: extra arguments to binary invocation.
+    """
+
+    actual = self._GetJsonOutput(gtest_prog_name, extra_args or [],
+                                 expected_exit_code)
+    self.assertEqual(expected, gtest_json_test_utils.normalize(actual))
+
+
+if __name__ == '__main__':
+  if NO_STACKTRACE_SUPPORT_FLAG in sys.argv:
+    # unittest.main() can't handle unknown flags
+    sys.argv.remove(NO_STACKTRACE_SUPPORT_FLAG)
+
+  os.environ['GTEST_STACK_TRACE_DEPTH'] = '1'
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-list-tests-unittest.py b/3rdparty/gtest/test/googletest-list-tests-unittest.py
new file mode 100644
index 0000000..81423a3
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-list-tests-unittest.py
@@ -0,0 +1,205 @@
+#!/usr/bin/env python
+#
+# Copyright 2006, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test for Google Test's --gtest_list_tests flag.
+
+A user can ask Google Test to list all tests by specifying the
+--gtest_list_tests flag.  This script tests such functionality
+by invoking googletest-list-tests-unittest_ (a program written with
+Google Test) the command line flags.
+"""
+
+import re
+import gtest_test_utils
+
+# Constants.
+
+# The command line flag for enabling/disabling listing all tests.
+LIST_TESTS_FLAG = 'gtest_list_tests'
+
+# Path to the googletest-list-tests-unittest_ program.
+EXE_PATH = gtest_test_utils.GetTestExecutablePath('googletest-list-tests-unittest_')
+
+# The expected output when running googletest-list-tests-unittest_ with
+# --gtest_list_tests
+EXPECTED_OUTPUT_NO_FILTER_RE = re.compile(r"""FooDeathTest\.
+  Test1
+Foo\.
+  Bar1
+  Bar2
+  DISABLED_Bar3
+Abc\.
+  Xyz
+  Def
+FooBar\.
+  Baz
+FooTest\.
+  Test1
+  DISABLED_Test2
+  Test3
+TypedTest/0\.  # TypeParam = (VeryLo{245}|class VeryLo{239})\.\.\.
+  TestA
+  TestB
+TypedTest/1\.  # TypeParam = int\s*\*( __ptr64)?
+  TestA
+  TestB
+TypedTest/2\.  # TypeParam = .*MyArray<bool,\s*42>
+  TestA
+  TestB
+My/TypeParamTest/0\.  # TypeParam = (VeryLo{245}|class VeryLo{239})\.\.\.
+  TestA
+  TestB
+My/TypeParamTest/1\.  # TypeParam = int\s*\*( __ptr64)?
+  TestA
+  TestB
+My/TypeParamTest/2\.  # TypeParam = .*MyArray<bool,\s*42>
+  TestA
+  TestB
+MyInstantiation/ValueParamTest\.
+  TestA/0  # GetParam\(\) = one line
+  TestA/1  # GetParam\(\) = two\\nlines
+  TestA/2  # GetParam\(\) = a very\\nlo{241}\.\.\.
+  TestB/0  # GetParam\(\) = one line
+  TestB/1  # GetParam\(\) = two\\nlines
+  TestB/2  # GetParam\(\) = a very\\nlo{241}\.\.\.
+""")
+
+# The expected output when running googletest-list-tests-unittest_ with
+# --gtest_list_tests and --gtest_filter=Foo*.
+EXPECTED_OUTPUT_FILTER_FOO_RE = re.compile(r"""FooDeathTest\.
+  Test1
+Foo\.
+  Bar1
+  Bar2
+  DISABLED_Bar3
+FooBar\.
+  Baz
+FooTest\.
+  Test1
+  DISABLED_Test2
+  Test3
+""")
+
+# Utilities.
+
+
+def Run(args):
+  """Runs googletest-list-tests-unittest_ and returns the list of tests printed."""
+
+  return gtest_test_utils.Subprocess([EXE_PATH] + args,
+                                     capture_stderr=False).output
+
+
+# The unit test.
+
+
+class GTestListTestsUnitTest(gtest_test_utils.TestCase):
+  """Tests using the --gtest_list_tests flag to list all tests."""
+
+  def RunAndVerify(self, flag_value, expected_output_re, other_flag):
+    """Runs googletest-list-tests-unittest_ and verifies that it prints
+    the correct tests.
+
+    Args:
+      flag_value:         value of the --gtest_list_tests flag;
+                          None if the flag should not be present.
+      expected_output_re: regular expression that matches the expected
+                          output after running command;
+      other_flag:         a different flag to be passed to command
+                          along with gtest_list_tests;
+                          None if the flag should not be present.
+    """
+
+    if flag_value is None:
+      flag = ''
+      flag_expression = 'not set'
+    elif flag_value == '0':
+      flag = '--%s=0' % LIST_TESTS_FLAG
+      flag_expression = '0'
+    else:
+      flag = '--%s' % LIST_TESTS_FLAG
+      flag_expression = '1'
+
+    args = [flag]
+
+    if other_flag is not None:
+      args += [other_flag]
+
+    output = Run(args)
+
+    if expected_output_re:
+      self.assert_(
+          expected_output_re.match(output),
+          ('when %s is %s, the output of "%s" is "%s",\n'
+           'which does not match regex "%s"' %
+           (LIST_TESTS_FLAG, flag_expression, ' '.join(args), output,
+            expected_output_re.pattern)))
+    else:
+      self.assert_(
+          not EXPECTED_OUTPUT_NO_FILTER_RE.match(output),
+          ('when %s is %s, the output of "%s" is "%s"'%
+           (LIST_TESTS_FLAG, flag_expression, ' '.join(args), output)))
+
+  def testDefaultBehavior(self):
+    """Tests the behavior of the default mode."""
+
+    self.RunAndVerify(flag_value=None,
+                      expected_output_re=None,
+                      other_flag=None)
+
+  def testFlag(self):
+    """Tests using the --gtest_list_tests flag."""
+
+    self.RunAndVerify(flag_value='0',
+                      expected_output_re=None,
+                      other_flag=None)
+    self.RunAndVerify(flag_value='1',
+                      expected_output_re=EXPECTED_OUTPUT_NO_FILTER_RE,
+                      other_flag=None)
+
+  def testOverrideNonFilterFlags(self):
+    """Tests that --gtest_list_tests overrides the non-filter flags."""
+
+    self.RunAndVerify(flag_value='1',
+                      expected_output_re=EXPECTED_OUTPUT_NO_FILTER_RE,
+                      other_flag='--gtest_break_on_failure')
+
+  def testWithFilterFlags(self):
+    """Tests that --gtest_list_tests takes into account the
+    --gtest_filter flag."""
+
+    self.RunAndVerify(flag_value='1',
+                      expected_output_re=EXPECTED_OUTPUT_FILTER_FOO_RE,
+                      other_flag='--gtest_filter=Foo*')
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-list-tests-unittest_.cc b/3rdparty/gtest/test/googletest-list-tests-unittest_.cc
new file mode 100644
index 0000000..493c6f0
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-list-tests-unittest_.cc
@@ -0,0 +1,156 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Unit test for Google Test's --gtest_list_tests flag.
+//
+// A user can ask Google Test to list all tests that will run
+// so that when using a filter, a user will know what
+// tests to look for. The tests will not be run after listing.
+//
+// This program will be invoked from a Python unit test.
+// Don't run it directly.
+
+#include "gtest/gtest.h"
+
+// Several different test cases and tests that will be listed.
+TEST(Foo, Bar1) {
+}
+
+TEST(Foo, Bar2) {
+}
+
+TEST(Foo, DISABLED_Bar3) {
+}
+
+TEST(Abc, Xyz) {
+}
+
+TEST(Abc, Def) {
+}
+
+TEST(FooBar, Baz) {
+}
+
+class FooTest : public testing::Test {
+};
+
+TEST_F(FooTest, Test1) {
+}
+
+TEST_F(FooTest, DISABLED_Test2) {
+}
+
+TEST_F(FooTest, Test3) {
+}
+
+TEST(FooDeathTest, Test1) {
+}
+
+// A group of value-parameterized tests.
+
+class MyType {
+ public:
+  explicit MyType(const std::string& a_value) : value_(a_value) {}
+
+  const std::string& value() const { return value_; }
+
+ private:
+  std::string value_;
+};
+
+// Teaches Google Test how to print a MyType.
+void PrintTo(const MyType& x, std::ostream* os) {
+  *os << x.value();
+}
+
+class ValueParamTest : public testing::TestWithParam<MyType> {
+};
+
+TEST_P(ValueParamTest, TestA) {
+}
+
+TEST_P(ValueParamTest, TestB) {
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    MyInstantiation, ValueParamTest,
+    testing::Values(MyType("one line"),
+                    MyType("two\nlines"),
+                    MyType("a very\nloooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong line")));  // NOLINT
+
+// A group of typed tests.
+
+// A deliberately long type name for testing the line-truncating
+// behavior when printing a type parameter.
+class VeryLoooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooogName {  // NOLINT
+};
+
+template <typename T>
+class TypedTest : public testing::Test {
+};
+
+template <typename T, int kSize>
+class MyArray {
+};
+
+typedef testing::Types<VeryLoooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooogName,  // NOLINT
+                       int*, MyArray<bool, 42> > MyTypes;
+
+TYPED_TEST_SUITE(TypedTest, MyTypes);
+
+TYPED_TEST(TypedTest, TestA) {
+}
+
+TYPED_TEST(TypedTest, TestB) {
+}
+
+// A group of type-parameterized tests.
+
+template <typename T>
+class TypeParamTest : public testing::Test {
+};
+
+TYPED_TEST_SUITE_P(TypeParamTest);
+
+TYPED_TEST_P(TypeParamTest, TestA) {
+}
+
+TYPED_TEST_P(TypeParamTest, TestB) {
+}
+
+REGISTER_TYPED_TEST_SUITE_P(TypeParamTest, TestA, TestB);
+
+INSTANTIATE_TYPED_TEST_SUITE_P(My, TypeParamTest, MyTypes);
+
+int main(int argc, char **argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/googletest-listener-test.cc b/3rdparty/gtest/test/googletest-listener-test.cc
new file mode 100644
index 0000000..10457af
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-listener-test.cc
@@ -0,0 +1,518 @@
+// Copyright 2009 Google Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This file verifies Google Test event listeners receive events at the
+// right times.
+
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "gtest/internal/custom/gtest.h"
+
+using ::testing::AddGlobalTestEnvironment;
+using ::testing::Environment;
+using ::testing::InitGoogleTest;
+using ::testing::Test;
+using ::testing::TestSuite;
+using ::testing::TestEventListener;
+using ::testing::TestInfo;
+using ::testing::TestPartResult;
+using ::testing::UnitTest;
+
+// Used by tests to register their events.
+std::vector<std::string>* g_events = nullptr;
+
+namespace testing {
+namespace internal {
+
+class EventRecordingListener : public TestEventListener {
+ public:
+  explicit EventRecordingListener(const char* name) : name_(name) {}
+
+ protected:
+  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnTestProgramStart"));
+  }
+
+  void OnTestIterationStart(const UnitTest& /*unit_test*/,
+                            int iteration) override {
+    Message message;
+    message << GetFullMethodName("OnTestIterationStart")
+            << "(" << iteration << ")";
+    g_events->push_back(message.GetString());
+  }
+
+  void OnEnvironmentsSetUpStart(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnEnvironmentsSetUpStart"));
+  }
+
+  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnEnvironmentsSetUpEnd"));
+  }
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseStart(const TestCase& /*test_case*/) override {
+    g_events->push_back(GetFullMethodName("OnTestCaseStart"));
+  }
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  void OnTestStart(const TestInfo& /*test_info*/) override {
+    g_events->push_back(GetFullMethodName("OnTestStart"));
+  }
+
+  void OnTestPartResult(const TestPartResult& /*test_part_result*/) override {
+    g_events->push_back(GetFullMethodName("OnTestPartResult"));
+  }
+
+  void OnTestEnd(const TestInfo& /*test_info*/) override {
+    g_events->push_back(GetFullMethodName("OnTestEnd"));
+  }
+
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+  void OnTestCaseEnd(const TestCase& /*test_case*/) override {
+    g_events->push_back(GetFullMethodName("OnTestCaseEnd"));
+  }
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  void OnEnvironmentsTearDownStart(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnEnvironmentsTearDownStart"));
+  }
+
+  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnEnvironmentsTearDownEnd"));
+  }
+
+  void OnTestIterationEnd(const UnitTest& /*unit_test*/,
+                          int iteration) override {
+    Message message;
+    message << GetFullMethodName("OnTestIterationEnd")
+            << "("  << iteration << ")";
+    g_events->push_back(message.GetString());
+  }
+
+  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnTestProgramEnd"));
+  }
+
+ private:
+  std::string GetFullMethodName(const char* name) {
+    return name_ + "." + name;
+  }
+
+  std::string name_;
+};
+
+// This listener is using OnTestSuiteStart, OnTestSuiteEnd API
+class EventRecordingListener2 : public TestEventListener {
+ public:
+  explicit EventRecordingListener2(const char* name) : name_(name) {}
+
+ protected:
+  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnTestProgramStart"));
+  }
+
+  void OnTestIterationStart(const UnitTest& /*unit_test*/,
+                            int iteration) override {
+    Message message;
+    message << GetFullMethodName("OnTestIterationStart") << "(" << iteration
+            << ")";
+    g_events->push_back(message.GetString());
+  }
+
+  void OnEnvironmentsSetUpStart(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnEnvironmentsSetUpStart"));
+  }
+
+  void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnEnvironmentsSetUpEnd"));
+  }
+
+  void OnTestSuiteStart(const TestSuite& /*test_suite*/) override {
+    g_events->push_back(GetFullMethodName("OnTestSuiteStart"));
+  }
+
+  void OnTestStart(const TestInfo& /*test_info*/) override {
+    g_events->push_back(GetFullMethodName("OnTestStart"));
+  }
+
+  void OnTestPartResult(const TestPartResult& /*test_part_result*/) override {
+    g_events->push_back(GetFullMethodName("OnTestPartResult"));
+  }
+
+  void OnTestEnd(const TestInfo& /*test_info*/) override {
+    g_events->push_back(GetFullMethodName("OnTestEnd"));
+  }
+
+  void OnTestSuiteEnd(const TestSuite& /*test_suite*/) override {
+    g_events->push_back(GetFullMethodName("OnTestSuiteEnd"));
+  }
+
+  void OnEnvironmentsTearDownStart(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnEnvironmentsTearDownStart"));
+  }
+
+  void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnEnvironmentsTearDownEnd"));
+  }
+
+  void OnTestIterationEnd(const UnitTest& /*unit_test*/,
+                          int iteration) override {
+    Message message;
+    message << GetFullMethodName("OnTestIterationEnd") << "(" << iteration
+            << ")";
+    g_events->push_back(message.GetString());
+  }
+
+  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {
+    g_events->push_back(GetFullMethodName("OnTestProgramEnd"));
+  }
+
+ private:
+  std::string GetFullMethodName(const char* name) { return name_ + "." + name; }
+
+  std::string name_;
+};
+
+class EnvironmentInvocationCatcher : public Environment {
+ protected:
+  void SetUp() override { g_events->push_back("Environment::SetUp"); }
+
+  void TearDown() override { g_events->push_back("Environment::TearDown"); }
+};
+
+class ListenerTest : public Test {
+ protected:
+  static void SetUpTestSuite() {
+    g_events->push_back("ListenerTest::SetUpTestSuite");
+  }
+
+  static void TearDownTestSuite() {
+    g_events->push_back("ListenerTest::TearDownTestSuite");
+  }
+
+  void SetUp() override { g_events->push_back("ListenerTest::SetUp"); }
+
+  void TearDown() override { g_events->push_back("ListenerTest::TearDown"); }
+};
+
+TEST_F(ListenerTest, DoesFoo) {
+  // Test execution order within a test case is not guaranteed so we are not
+  // recording the test name.
+  g_events->push_back("ListenerTest::* Test Body");
+  SUCCEED();  // Triggers OnTestPartResult.
+}
+
+TEST_F(ListenerTest, DoesBar) {
+  g_events->push_back("ListenerTest::* Test Body");
+  SUCCEED();  // Triggers OnTestPartResult.
+}
+
+}  // namespace internal
+
+}  // namespace testing
+
+using ::testing::internal::EnvironmentInvocationCatcher;
+using ::testing::internal::EventRecordingListener;
+using ::testing::internal::EventRecordingListener2;
+
+void VerifyResults(const std::vector<std::string>& data,
+                   const char* const* expected_data,
+                   size_t expected_data_size) {
+  const size_t actual_size = data.size();
+  // If the following assertion fails, a new entry will be appended to
+  // data.  Hence we save data.size() first.
+  EXPECT_EQ(expected_data_size, actual_size);
+
+  // Compares the common prefix.
+  const size_t shorter_size = expected_data_size <= actual_size ?
+      expected_data_size : actual_size;
+  size_t i = 0;
+  for (; i < shorter_size; ++i) {
+    ASSERT_STREQ(expected_data[i], data[i].c_str())
+        << "at position " << i;
+  }
+
+  // Prints extra elements in the actual data.
+  for (; i < actual_size; ++i) {
+    printf("  Actual event #%lu: %s\n",
+        static_cast<unsigned long>(i), data[i].c_str());
+  }
+}
+
+int main(int argc, char **argv) {
+  std::vector<std::string> events;
+  g_events = &events;
+  InitGoogleTest(&argc, argv);
+
+  UnitTest::GetInstance()->listeners().Append(
+      new EventRecordingListener("1st"));
+  UnitTest::GetInstance()->listeners().Append(
+      new EventRecordingListener("2nd"));
+  UnitTest::GetInstance()->listeners().Append(
+      new EventRecordingListener2("3rd"));
+
+  AddGlobalTestEnvironment(new EnvironmentInvocationCatcher);
+
+  GTEST_CHECK_(events.size() == 0)
+      << "AddGlobalTestEnvironment should not generate any events itself.";
+
+  ::testing::GTEST_FLAG(repeat) = 2;
+  int ret_val = RUN_ALL_TESTS();
+
+#ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  // The deprecated OnTestSuiteStart/OnTestCaseStart events are included
+  const char* const expected_events[] = {"1st.OnTestProgramStart",
+                                         "2nd.OnTestProgramStart",
+                                         "3rd.OnTestProgramStart",
+                                         "1st.OnTestIterationStart(0)",
+                                         "2nd.OnTestIterationStart(0)",
+                                         "3rd.OnTestIterationStart(0)",
+                                         "1st.OnEnvironmentsSetUpStart",
+                                         "2nd.OnEnvironmentsSetUpStart",
+                                         "3rd.OnEnvironmentsSetUpStart",
+                                         "Environment::SetUp",
+                                         "3rd.OnEnvironmentsSetUpEnd",
+                                         "2nd.OnEnvironmentsSetUpEnd",
+                                         "1st.OnEnvironmentsSetUpEnd",
+                                         "3rd.OnTestSuiteStart",
+                                         "1st.OnTestCaseStart",
+                                         "2nd.OnTestCaseStart",
+                                         "ListenerTest::SetUpTestSuite",
+                                         "1st.OnTestStart",
+                                         "2nd.OnTestStart",
+                                         "3rd.OnTestStart",
+                                         "ListenerTest::SetUp",
+                                         "ListenerTest::* Test Body",
+                                         "1st.OnTestPartResult",
+                                         "2nd.OnTestPartResult",
+                                         "3rd.OnTestPartResult",
+                                         "ListenerTest::TearDown",
+                                         "3rd.OnTestEnd",
+                                         "2nd.OnTestEnd",
+                                         "1st.OnTestEnd",
+                                         "1st.OnTestStart",
+                                         "2nd.OnTestStart",
+                                         "3rd.OnTestStart",
+                                         "ListenerTest::SetUp",
+                                         "ListenerTest::* Test Body",
+                                         "1st.OnTestPartResult",
+                                         "2nd.OnTestPartResult",
+                                         "3rd.OnTestPartResult",
+                                         "ListenerTest::TearDown",
+                                         "3rd.OnTestEnd",
+                                         "2nd.OnTestEnd",
+                                         "1st.OnTestEnd",
+                                         "ListenerTest::TearDownTestSuite",
+                                         "3rd.OnTestSuiteEnd",
+                                         "2nd.OnTestCaseEnd",
+                                         "1st.OnTestCaseEnd",
+                                         "1st.OnEnvironmentsTearDownStart",
+                                         "2nd.OnEnvironmentsTearDownStart",
+                                         "3rd.OnEnvironmentsTearDownStart",
+                                         "Environment::TearDown",
+                                         "3rd.OnEnvironmentsTearDownEnd",
+                                         "2nd.OnEnvironmentsTearDownEnd",
+                                         "1st.OnEnvironmentsTearDownEnd",
+                                         "3rd.OnTestIterationEnd(0)",
+                                         "2nd.OnTestIterationEnd(0)",
+                                         "1st.OnTestIterationEnd(0)",
+                                         "1st.OnTestIterationStart(1)",
+                                         "2nd.OnTestIterationStart(1)",
+                                         "3rd.OnTestIterationStart(1)",
+                                         "1st.OnEnvironmentsSetUpStart",
+                                         "2nd.OnEnvironmentsSetUpStart",
+                                         "3rd.OnEnvironmentsSetUpStart",
+                                         "Environment::SetUp",
+                                         "3rd.OnEnvironmentsSetUpEnd",
+                                         "2nd.OnEnvironmentsSetUpEnd",
+                                         "1st.OnEnvironmentsSetUpEnd",
+                                         "3rd.OnTestSuiteStart",
+                                         "1st.OnTestCaseStart",
+                                         "2nd.OnTestCaseStart",
+                                         "ListenerTest::SetUpTestSuite",
+                                         "1st.OnTestStart",
+                                         "2nd.OnTestStart",
+                                         "3rd.OnTestStart",
+                                         "ListenerTest::SetUp",
+                                         "ListenerTest::* Test Body",
+                                         "1st.OnTestPartResult",
+                                         "2nd.OnTestPartResult",
+                                         "3rd.OnTestPartResult",
+                                         "ListenerTest::TearDown",
+                                         "3rd.OnTestEnd",
+                                         "2nd.OnTestEnd",
+                                         "1st.OnTestEnd",
+                                         "1st.OnTestStart",
+                                         "2nd.OnTestStart",
+                                         "3rd.OnTestStart",
+                                         "ListenerTest::SetUp",
+                                         "ListenerTest::* Test Body",
+                                         "1st.OnTestPartResult",
+                                         "2nd.OnTestPartResult",
+                                         "3rd.OnTestPartResult",
+                                         "ListenerTest::TearDown",
+                                         "3rd.OnTestEnd",
+                                         "2nd.OnTestEnd",
+                                         "1st.OnTestEnd",
+                                         "ListenerTest::TearDownTestSuite",
+                                         "3rd.OnTestSuiteEnd",
+                                         "2nd.OnTestCaseEnd",
+                                         "1st.OnTestCaseEnd",
+                                         "1st.OnEnvironmentsTearDownStart",
+                                         "2nd.OnEnvironmentsTearDownStart",
+                                         "3rd.OnEnvironmentsTearDownStart",
+                                         "Environment::TearDown",
+                                         "3rd.OnEnvironmentsTearDownEnd",
+                                         "2nd.OnEnvironmentsTearDownEnd",
+                                         "1st.OnEnvironmentsTearDownEnd",
+                                         "3rd.OnTestIterationEnd(1)",
+                                         "2nd.OnTestIterationEnd(1)",
+                                         "1st.OnTestIterationEnd(1)",
+                                         "3rd.OnTestProgramEnd",
+                                         "2nd.OnTestProgramEnd",
+                                         "1st.OnTestProgramEnd"};
+#else
+  const char* const expected_events[] = {"1st.OnTestProgramStart",
+                                         "2nd.OnTestProgramStart",
+                                         "3rd.OnTestProgramStart",
+                                         "1st.OnTestIterationStart(0)",
+                                         "2nd.OnTestIterationStart(0)",
+                                         "3rd.OnTestIterationStart(0)",
+                                         "1st.OnEnvironmentsSetUpStart",
+                                         "2nd.OnEnvironmentsSetUpStart",
+                                         "3rd.OnEnvironmentsSetUpStart",
+                                         "Environment::SetUp",
+                                         "3rd.OnEnvironmentsSetUpEnd",
+                                         "2nd.OnEnvironmentsSetUpEnd",
+                                         "1st.OnEnvironmentsSetUpEnd",
+                                         "3rd.OnTestSuiteStart",
+                                         "ListenerTest::SetUpTestSuite",
+                                         "1st.OnTestStart",
+                                         "2nd.OnTestStart",
+                                         "3rd.OnTestStart",
+                                         "ListenerTest::SetUp",
+                                         "ListenerTest::* Test Body",
+                                         "1st.OnTestPartResult",
+                                         "2nd.OnTestPartResult",
+                                         "3rd.OnTestPartResult",
+                                         "ListenerTest::TearDown",
+                                         "3rd.OnTestEnd",
+                                         "2nd.OnTestEnd",
+                                         "1st.OnTestEnd",
+                                         "1st.OnTestStart",
+                                         "2nd.OnTestStart",
+                                         "3rd.OnTestStart",
+                                         "ListenerTest::SetUp",
+                                         "ListenerTest::* Test Body",
+                                         "1st.OnTestPartResult",
+                                         "2nd.OnTestPartResult",
+                                         "3rd.OnTestPartResult",
+                                         "ListenerTest::TearDown",
+                                         "3rd.OnTestEnd",
+                                         "2nd.OnTestEnd",
+                                         "1st.OnTestEnd",
+                                         "ListenerTest::TearDownTestSuite",
+                                         "3rd.OnTestSuiteEnd",
+                                         "1st.OnEnvironmentsTearDownStart",
+                                         "2nd.OnEnvironmentsTearDownStart",
+                                         "3rd.OnEnvironmentsTearDownStart",
+                                         "Environment::TearDown",
+                                         "3rd.OnEnvironmentsTearDownEnd",
+                                         "2nd.OnEnvironmentsTearDownEnd",
+                                         "1st.OnEnvironmentsTearDownEnd",
+                                         "3rd.OnTestIterationEnd(0)",
+                                         "2nd.OnTestIterationEnd(0)",
+                                         "1st.OnTestIterationEnd(0)",
+                                         "1st.OnTestIterationStart(1)",
+                                         "2nd.OnTestIterationStart(1)",
+                                         "3rd.OnTestIterationStart(1)",
+                                         "1st.OnEnvironmentsSetUpStart",
+                                         "2nd.OnEnvironmentsSetUpStart",
+                                         "3rd.OnEnvironmentsSetUpStart",
+                                         "Environment::SetUp",
+                                         "3rd.OnEnvironmentsSetUpEnd",
+                                         "2nd.OnEnvironmentsSetUpEnd",
+                                         "1st.OnEnvironmentsSetUpEnd",
+                                         "3rd.OnTestSuiteStart",
+                                         "ListenerTest::SetUpTestSuite",
+                                         "1st.OnTestStart",
+                                         "2nd.OnTestStart",
+                                         "3rd.OnTestStart",
+                                         "ListenerTest::SetUp",
+                                         "ListenerTest::* Test Body",
+                                         "1st.OnTestPartResult",
+                                         "2nd.OnTestPartResult",
+                                         "3rd.OnTestPartResult",
+                                         "ListenerTest::TearDown",
+                                         "3rd.OnTestEnd",
+                                         "2nd.OnTestEnd",
+                                         "1st.OnTestEnd",
+                                         "1st.OnTestStart",
+                                         "2nd.OnTestStart",
+                                         "3rd.OnTestStart",
+                                         "ListenerTest::SetUp",
+                                         "ListenerTest::* Test Body",
+                                         "1st.OnTestPartResult",
+                                         "2nd.OnTestPartResult",
+                                         "3rd.OnTestPartResult",
+                                         "ListenerTest::TearDown",
+                                         "3rd.OnTestEnd",
+                                         "2nd.OnTestEnd",
+                                         "1st.OnTestEnd",
+                                         "ListenerTest::TearDownTestSuite",
+                                         "3rd.OnTestSuiteEnd",
+                                         "1st.OnEnvironmentsTearDownStart",
+                                         "2nd.OnEnvironmentsTearDownStart",
+                                         "3rd.OnEnvironmentsTearDownStart",
+                                         "Environment::TearDown",
+                                         "3rd.OnEnvironmentsTearDownEnd",
+                                         "2nd.OnEnvironmentsTearDownEnd",
+                                         "1st.OnEnvironmentsTearDownEnd",
+                                         "3rd.OnTestIterationEnd(1)",
+                                         "2nd.OnTestIterationEnd(1)",
+                                         "1st.OnTestIterationEnd(1)",
+                                         "3rd.OnTestProgramEnd",
+                                         "2nd.OnTestProgramEnd",
+                                         "1st.OnTestProgramEnd"};
+#endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
+
+  VerifyResults(events,
+                expected_events,
+                sizeof(expected_events)/sizeof(expected_events[0]));
+
+  // We need to check manually for ad hoc test failures that happen after
+  // RUN_ALL_TESTS finishes.
+  if (UnitTest::GetInstance()->Failed())
+    ret_val = 1;
+
+  return ret_val;
+}
diff --git a/3rdparty/gtest/test/googletest-message-test.cc b/3rdparty/gtest/test/googletest-message-test.cc
new file mode 100644
index 0000000..962d519
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-message-test.cc
@@ -0,0 +1,158 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests for the Message class.
+
+#include "gtest/gtest-message.h"
+
+#include "gtest/gtest.h"
+
+namespace {
+
+using ::testing::Message;
+
+// Tests the testing::Message class
+
+// Tests the default constructor.
+TEST(MessageTest, DefaultConstructor) {
+  const Message msg;
+  EXPECT_EQ("", msg.GetString());
+}
+
+// Tests the copy constructor.
+TEST(MessageTest, CopyConstructor) {
+  const Message msg1("Hello");
+  const Message msg2(msg1);
+  EXPECT_EQ("Hello", msg2.GetString());
+}
+
+// Tests constructing a Message from a C-string.
+TEST(MessageTest, ConstructsFromCString) {
+  Message msg("Hello");
+  EXPECT_EQ("Hello", msg.GetString());
+}
+
+// Tests streaming a float.
+TEST(MessageTest, StreamsFloat) {
+  const std::string s = (Message() << 1.23456F << " " << 2.34567F).GetString();
+  // Both numbers should be printed with enough precision.
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, "1.234560", s.c_str());
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, " 2.345669", s.c_str());
+}
+
+// Tests streaming a double.
+TEST(MessageTest, StreamsDouble) {
+  const std::string s = (Message() << 1260570880.4555497 << " "
+                                  << 1260572265.1954534).GetString();
+  // Both numbers should be printed with enough precision.
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, "1260570880.45", s.c_str());
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, " 1260572265.19", s.c_str());
+}
+
+// Tests streaming a non-char pointer.
+TEST(MessageTest, StreamsPointer) {
+  int n = 0;
+  int* p = &n;
+  EXPECT_NE("(null)", (Message() << p).GetString());
+}
+
+// Tests streaming a NULL non-char pointer.
+TEST(MessageTest, StreamsNullPointer) {
+  int* p = nullptr;
+  EXPECT_EQ("(null)", (Message() << p).GetString());
+}
+
+// Tests streaming a C string.
+TEST(MessageTest, StreamsCString) {
+  EXPECT_EQ("Foo", (Message() << "Foo").GetString());
+}
+
+// Tests streaming a NULL C string.
+TEST(MessageTest, StreamsNullCString) {
+  char* p = nullptr;
+  EXPECT_EQ("(null)", (Message() << p).GetString());
+}
+
+// Tests streaming std::string.
+TEST(MessageTest, StreamsString) {
+  const ::std::string str("Hello");
+  EXPECT_EQ("Hello", (Message() << str).GetString());
+}
+
+// Tests that we can output strings containing embedded NULs.
+TEST(MessageTest, StreamsStringWithEmbeddedNUL) {
+  const char char_array_with_nul[] =
+      "Here's a NUL\0 and some more string";
+  const ::std::string string_with_nul(char_array_with_nul,
+                                      sizeof(char_array_with_nul) - 1);
+  EXPECT_EQ("Here's a NUL\\0 and some more string",
+            (Message() << string_with_nul).GetString());
+}
+
+// Tests streaming a NUL char.
+TEST(MessageTest, StreamsNULChar) {
+  EXPECT_EQ("\\0", (Message() << '\0').GetString());
+}
+
+// Tests streaming int.
+TEST(MessageTest, StreamsInt) {
+  EXPECT_EQ("123", (Message() << 123).GetString());
+}
+
+// Tests that basic IO manipulators (endl, ends, and flush) can be
+// streamed to Message.
+TEST(MessageTest, StreamsBasicIoManip) {
+  EXPECT_EQ("Line 1.\nA NUL char \\0 in line 2.",
+               (Message() << "Line 1." << std::endl
+                         << "A NUL char " << std::ends << std::flush
+                         << " in line 2.").GetString());
+}
+
+// Tests Message::GetString()
+TEST(MessageTest, GetString) {
+  Message msg;
+  msg << 1 << " lamb";
+  EXPECT_EQ("1 lamb", msg.GetString());
+}
+
+// Tests streaming a Message object to an ostream.
+TEST(MessageTest, StreamsToOStream) {
+  Message msg("Hello");
+  ::std::stringstream ss;
+  ss << msg;
+  EXPECT_EQ("Hello", testing::internal::StringStreamToString(&ss));
+}
+
+// Tests that a Message object doesn't take up too much stack space.
+TEST(MessageTest, DoesNotTakeUpMuchStackSpace) {
+  EXPECT_LE(sizeof(Message), 16U);
+}
+
+}  // namespace
diff --git a/3rdparty/gtest/test/googletest-options-test.cc b/3rdparty/gtest/test/googletest-options-test.cc
new file mode 100644
index 0000000..f07b316
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-options-test.cc
@@ -0,0 +1,216 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Google Test UnitTestOptions tests
+//
+// This file tests classes and functions used internally by
+// Google Test.  They are subject to change without notice.
+//
+// This file is #included from gtest.cc, to avoid changing build or
+// make-files on Windows and other platforms. Do not #include this file
+// anywhere else!
+
+#include "gtest/gtest.h"
+
+#if GTEST_OS_WINDOWS_MOBILE
+# include <windows.h>
+#elif GTEST_OS_WINDOWS
+# include <direct.h>
+#endif  // GTEST_OS_WINDOWS_MOBILE
+
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+namespace internal {
+namespace {
+
+// Turns the given relative path into an absolute path.
+FilePath GetAbsolutePathOf(const FilePath& relative_path) {
+  return FilePath::ConcatPaths(FilePath::GetCurrentDir(), relative_path);
+}
+
+// Testing UnitTestOptions::GetOutputFormat/GetOutputFile.
+
+TEST(XmlOutputTest, GetOutputFormatDefault) {
+  GTEST_FLAG(output) = "";
+  EXPECT_STREQ("", UnitTestOptions::GetOutputFormat().c_str());
+}
+
+TEST(XmlOutputTest, GetOutputFormat) {
+  GTEST_FLAG(output) = "xml:filename";
+  EXPECT_STREQ("xml", UnitTestOptions::GetOutputFormat().c_str());
+}
+
+TEST(XmlOutputTest, GetOutputFileDefault) {
+  GTEST_FLAG(output) = "";
+  EXPECT_EQ(GetAbsolutePathOf(FilePath("test_detail.xml")).string(),
+            UnitTestOptions::GetAbsolutePathToOutputFile());
+}
+
+TEST(XmlOutputTest, GetOutputFileSingleFile) {
+  GTEST_FLAG(output) = "xml:filename.abc";
+  EXPECT_EQ(GetAbsolutePathOf(FilePath("filename.abc")).string(),
+            UnitTestOptions::GetAbsolutePathToOutputFile());
+}
+
+TEST(XmlOutputTest, GetOutputFileFromDirectoryPath) {
+  GTEST_FLAG(output) = "xml:path" GTEST_PATH_SEP_;
+  const std::string expected_output_file =
+      GetAbsolutePathOf(
+          FilePath(std::string("path") + GTEST_PATH_SEP_ +
+                   GetCurrentExecutableName().string() + ".xml")).string();
+  const std::string& output_file =
+      UnitTestOptions::GetAbsolutePathToOutputFile();
+#if GTEST_OS_WINDOWS
+  EXPECT_STRCASEEQ(expected_output_file.c_str(), output_file.c_str());
+#else
+  EXPECT_EQ(expected_output_file, output_file.c_str());
+#endif
+}
+
+TEST(OutputFileHelpersTest, GetCurrentExecutableName) {
+  const std::string exe_str = GetCurrentExecutableName().string();
+#if GTEST_OS_WINDOWS
+  const bool success =
+      _strcmpi("googletest-options-test", exe_str.c_str()) == 0 ||
+      _strcmpi("gtest-options-ex_test", exe_str.c_str()) == 0 ||
+      _strcmpi("gtest_all_test", exe_str.c_str()) == 0 ||
+      _strcmpi("gtest_dll_test", exe_str.c_str()) == 0;
+#elif GTEST_OS_OS2
+  const bool success =
+      strcasecmp("googletest-options-test", exe_str.c_str()) == 0 ||
+      strcasecmp("gtest-options-ex_test", exe_str.c_str()) == 0 ||
+      strcasecmp("gtest_all_test", exe_str.c_str()) == 0 ||
+      strcasecmp("gtest_dll_test", exe_str.c_str()) == 0;
+#elif GTEST_OS_FUCHSIA
+  const bool success = exe_str == "app";
+#else
+  const bool success =
+      exe_str == "googletest-options-test" ||
+      exe_str == "gtest_all_test" ||
+      exe_str == "lt-gtest_all_test" ||
+      exe_str == "gtest_dll_test";
+#endif  // GTEST_OS_WINDOWS
+  if (!success)
+    FAIL() << "GetCurrentExecutableName() returns " << exe_str;
+}
+
+#if !GTEST_OS_FUCHSIA
+
+class XmlOutputChangeDirTest : public Test {
+ protected:
+  void SetUp() override {
+    original_working_dir_ = FilePath::GetCurrentDir();
+    posix::ChDir("..");
+    // This will make the test fail if run from the root directory.
+    EXPECT_NE(original_working_dir_.string(),
+              FilePath::GetCurrentDir().string());
+  }
+
+  void TearDown() override {
+    posix::ChDir(original_working_dir_.string().c_str());
+  }
+
+  FilePath original_working_dir_;
+};
+
+TEST_F(XmlOutputChangeDirTest, PreserveOriginalWorkingDirWithDefault) {
+  GTEST_FLAG(output) = "";
+  EXPECT_EQ(FilePath::ConcatPaths(original_working_dir_,
+                                  FilePath("test_detail.xml")).string(),
+            UnitTestOptions::GetAbsolutePathToOutputFile());
+}
+
+TEST_F(XmlOutputChangeDirTest, PreserveOriginalWorkingDirWithDefaultXML) {
+  GTEST_FLAG(output) = "xml";
+  EXPECT_EQ(FilePath::ConcatPaths(original_working_dir_,
+                                  FilePath("test_detail.xml")).string(),
+            UnitTestOptions::GetAbsolutePathToOutputFile());
+}
+
+TEST_F(XmlOutputChangeDirTest, PreserveOriginalWorkingDirWithRelativeFile) {
+  GTEST_FLAG(output) = "xml:filename.abc";
+  EXPECT_EQ(FilePath::ConcatPaths(original_working_dir_,
+                                  FilePath("filename.abc")).string(),
+            UnitTestOptions::GetAbsolutePathToOutputFile());
+}
+
+TEST_F(XmlOutputChangeDirTest, PreserveOriginalWorkingDirWithRelativePath) {
+  GTEST_FLAG(output) = "xml:path" GTEST_PATH_SEP_;
+  const std::string expected_output_file =
+      FilePath::ConcatPaths(
+          original_working_dir_,
+          FilePath(std::string("path") + GTEST_PATH_SEP_ +
+                   GetCurrentExecutableName().string() + ".xml")).string();
+  const std::string& output_file =
+      UnitTestOptions::GetAbsolutePathToOutputFile();
+#if GTEST_OS_WINDOWS
+  EXPECT_STRCASEEQ(expected_output_file.c_str(), output_file.c_str());
+#else
+  EXPECT_EQ(expected_output_file, output_file.c_str());
+#endif
+}
+
+TEST_F(XmlOutputChangeDirTest, PreserveOriginalWorkingDirWithAbsoluteFile) {
+#if GTEST_OS_WINDOWS
+  GTEST_FLAG(output) = "xml:c:\\tmp\\filename.abc";
+  EXPECT_EQ(FilePath("c:\\tmp\\filename.abc").string(),
+            UnitTestOptions::GetAbsolutePathToOutputFile());
+#else
+  GTEST_FLAG(output) ="xml:/tmp/filename.abc";
+  EXPECT_EQ(FilePath("/tmp/filename.abc").string(),
+            UnitTestOptions::GetAbsolutePathToOutputFile());
+#endif
+}
+
+TEST_F(XmlOutputChangeDirTest, PreserveOriginalWorkingDirWithAbsolutePath) {
+#if GTEST_OS_WINDOWS
+  const std::string path = "c:\\tmp\\";
+#else
+  const std::string path = "/tmp/";
+#endif
+
+  GTEST_FLAG(output) = "xml:" + path;
+  const std::string expected_output_file =
+      path + GetCurrentExecutableName().string() + ".xml";
+  const std::string& output_file =
+      UnitTestOptions::GetAbsolutePathToOutputFile();
+
+#if GTEST_OS_WINDOWS
+  EXPECT_STRCASEEQ(expected_output_file.c_str(), output_file.c_str());
+#else
+  EXPECT_EQ(expected_output_file, output_file.c_str());
+#endif
+}
+
+#endif  // !GTEST_OS_FUCHSIA
+
+}  // namespace
+}  // namespace internal
+}  // namespace testing
diff --git a/3rdparty/gtest/test/googletest-output-test-golden-lin.txt b/3rdparty/gtest/test/googletest-output-test-golden-lin.txt
new file mode 100644
index 0000000..038de92
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-output-test-golden-lin.txt
@@ -0,0 +1,1140 @@
+The non-test part of the code is expected to have 2 failures.
+
+googletest-output-test_.cc:#: Failure
+Value of: false
+  Actual: false
+Expected: true
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  2
+  3
+Stack trace: (omitted)
+
+[==========] Running 85 tests from 40 test suites.
+[----------] Global test environment set-up.
+FooEnvironment::SetUp() called.
+BarEnvironment::SetUp() called.
+[----------] 1 test from ADeathTest
+[ RUN      ] ADeathTest.ShouldRunFirst
+[       OK ] ADeathTest.ShouldRunFirst
+[----------] 1 test from ATypedDeathTest/0, where TypeParam = int
+[ RUN      ] ATypedDeathTest/0.ShouldRunFirst
+[       OK ] ATypedDeathTest/0.ShouldRunFirst
+[----------] 1 test from ATypedDeathTest/1, where TypeParam = double
+[ RUN      ] ATypedDeathTest/1.ShouldRunFirst
+[       OK ] ATypedDeathTest/1.ShouldRunFirst
+[----------] 1 test from My/ATypeParamDeathTest/0, where TypeParam = int
+[ RUN      ] My/ATypeParamDeathTest/0.ShouldRunFirst
+[       OK ] My/ATypeParamDeathTest/0.ShouldRunFirst
+[----------] 1 test from My/ATypeParamDeathTest/1, where TypeParam = double
+[ RUN      ] My/ATypeParamDeathTest/1.ShouldRunFirst
+[       OK ] My/ATypeParamDeathTest/1.ShouldRunFirst
+[----------] 2 tests from PassingTest
+[ RUN      ] PassingTest.PassingTest1
+[       OK ] PassingTest.PassingTest1
+[ RUN      ] PassingTest.PassingTest2
+[       OK ] PassingTest.PassingTest2
+[----------] 2 tests from NonfatalFailureTest
+[ RUN      ] NonfatalFailureTest.EscapesStringOperands
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  kGoldenString
+    Which is: "\"Line"
+  actual
+    Which is: "actual \"string\""
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  golden
+    Which is: "\"Line"
+  actual
+    Which is: "actual \"string\""
+Stack trace: (omitted)
+
+[  FAILED  ] NonfatalFailureTest.EscapesStringOperands
+[ RUN      ] NonfatalFailureTest.DiffForLongStrings
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  golden_str
+    Which is: "\"Line\0 1\"\nLine 2"
+  "Line 2"
+With diff:
+@@ -1,2 @@
+-\"Line\0 1\"
+ Line 2
+
+Stack trace: (omitted)
+
+[  FAILED  ] NonfatalFailureTest.DiffForLongStrings
+[----------] 3 tests from FatalFailureTest
+[ RUN      ] FatalFailureTest.FatalFailureInSubroutine
+(expecting a failure that x should be 1)
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1
+  x
+    Which is: 2
+Stack trace: (omitted)
+
+[  FAILED  ] FatalFailureTest.FatalFailureInSubroutine
+[ RUN      ] FatalFailureTest.FatalFailureInNestedSubroutine
+(expecting a failure that x should be 1)
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1
+  x
+    Which is: 2
+Stack trace: (omitted)
+
+[  FAILED  ] FatalFailureTest.FatalFailureInNestedSubroutine
+[ RUN      ] FatalFailureTest.NonfatalFailureInSubroutine
+(expecting a failure on false)
+googletest-output-test_.cc:#: Failure
+Value of: false
+  Actual: false
+Expected: true
+Stack trace: (omitted)
+
+[  FAILED  ] FatalFailureTest.NonfatalFailureInSubroutine
+[----------] 1 test from LoggingTest
+[ RUN      ] LoggingTest.InterleavingLoggingAndAssertions
+(expecting 2 failures on (3) >= (a[i]))
+i == 0
+i == 1
+googletest-output-test_.cc:#: Failure
+Expected: (3) >= (a[i]), actual: 3 vs 9
+Stack trace: (omitted)
+
+i == 2
+i == 3
+googletest-output-test_.cc:#: Failure
+Expected: (3) >= (a[i]), actual: 3 vs 6
+Stack trace: (omitted)
+
+[  FAILED  ] LoggingTest.InterleavingLoggingAndAssertions
+[----------] 7 tests from SCOPED_TRACETest
+[ RUN      ] SCOPED_TRACETest.AcceptedValues
+googletest-output-test_.cc:#: Failure
+Failed
+Just checking that all these values work fine.
+Google Test trace:
+googletest-output-test_.cc:#: (null)
+googletest-output-test_.cc:#: 1337
+googletest-output-test_.cc:#: std::string
+googletest-output-test_.cc:#: literal string
+Stack trace: (omitted)
+
+[  FAILED  ] SCOPED_TRACETest.AcceptedValues
+[ RUN      ] SCOPED_TRACETest.ObeysScopes
+(expected to fail)
+googletest-output-test_.cc:#: Failure
+Failed
+This failure is expected, and shouldn't have a trace.
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+This failure is expected, and should have a trace.
+Google Test trace:
+googletest-output-test_.cc:#: Expected trace
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+This failure is expected, and shouldn't have a trace.
+Stack trace: (omitted)
+
+[  FAILED  ] SCOPED_TRACETest.ObeysScopes
+[ RUN      ] SCOPED_TRACETest.WorksInLoop
+(expected to fail)
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  2
+  n
+    Which is: 1
+Google Test trace:
+googletest-output-test_.cc:#: i = 1
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1
+  n
+    Which is: 2
+Google Test trace:
+googletest-output-test_.cc:#: i = 2
+Stack trace: (omitted)
+
+[  FAILED  ] SCOPED_TRACETest.WorksInLoop
+[ RUN      ] SCOPED_TRACETest.WorksInSubroutine
+(expected to fail)
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  2
+  n
+    Which is: 1
+Google Test trace:
+googletest-output-test_.cc:#: n = 1
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1
+  n
+    Which is: 2
+Google Test trace:
+googletest-output-test_.cc:#: n = 2
+Stack trace: (omitted)
+
+[  FAILED  ] SCOPED_TRACETest.WorksInSubroutine
+[ RUN      ] SCOPED_TRACETest.CanBeNested
+(expected to fail)
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1
+  n
+    Which is: 2
+Google Test trace:
+googletest-output-test_.cc:#: n = 2
+googletest-output-test_.cc:#: 
+Stack trace: (omitted)
+
+[  FAILED  ] SCOPED_TRACETest.CanBeNested
+[ RUN      ] SCOPED_TRACETest.CanBeRepeated
+(expected to fail)
+googletest-output-test_.cc:#: Failure
+Failed
+This failure is expected, and should contain trace point A.
+Google Test trace:
+googletest-output-test_.cc:#: A
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+This failure is expected, and should contain trace point A and B.
+Google Test trace:
+googletest-output-test_.cc:#: B
+googletest-output-test_.cc:#: A
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+This failure is expected, and should contain trace point A, B, and C.
+Google Test trace:
+googletest-output-test_.cc:#: C
+googletest-output-test_.cc:#: B
+googletest-output-test_.cc:#: A
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+This failure is expected, and should contain trace point A, B, and D.
+Google Test trace:
+googletest-output-test_.cc:#: D
+googletest-output-test_.cc:#: B
+googletest-output-test_.cc:#: A
+Stack trace: (omitted)
+
+[  FAILED  ] SCOPED_TRACETest.CanBeRepeated
+[ RUN      ] SCOPED_TRACETest.WorksConcurrently
+(expecting 6 failures)
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #1 (in thread B, only trace B alive).
+Google Test trace:
+googletest-output-test_.cc:#: Trace B
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #2 (in thread A, trace A & B both alive).
+Google Test trace:
+googletest-output-test_.cc:#: Trace A
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #3 (in thread B, trace A & B both alive).
+Google Test trace:
+googletest-output-test_.cc:#: Trace B
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #4 (in thread B, only trace A alive).
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #5 (in thread A, only trace A alive).
+Google Test trace:
+googletest-output-test_.cc:#: Trace A
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #6 (in thread A, no trace alive).
+Stack trace: (omitted)
+
+[  FAILED  ] SCOPED_TRACETest.WorksConcurrently
+[----------] 1 test from ScopedTraceTest
+[ RUN      ] ScopedTraceTest.WithExplicitFileAndLine
+googletest-output-test_.cc:#: Failure
+Failed
+Check that the trace is attached to a particular location.
+Google Test trace:
+explicit_file.cc:123: expected trace message
+Stack trace: (omitted)
+
+[  FAILED  ] ScopedTraceTest.WithExplicitFileAndLine
+[----------] 1 test from NonFatalFailureInFixtureConstructorTest
+[ RUN      ] NonFatalFailureInFixtureConstructorTest.FailureInConstructor
+(expecting 5 failures)
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #1, in the test fixture c'tor.
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #2, in SetUp().
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #3, in the test body.
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #4, in TearDown.
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #5, in the test fixture d'tor.
+Stack trace: (omitted)
+
+[  FAILED  ] NonFatalFailureInFixtureConstructorTest.FailureInConstructor
+[----------] 1 test from FatalFailureInFixtureConstructorTest
+[ RUN      ] FatalFailureInFixtureConstructorTest.FailureInConstructor
+(expecting 2 failures)
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #1, in the test fixture c'tor.
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #2, in the test fixture d'tor.
+Stack trace: (omitted)
+
+[  FAILED  ] FatalFailureInFixtureConstructorTest.FailureInConstructor
+[----------] 1 test from NonFatalFailureInSetUpTest
+[ RUN      ] NonFatalFailureInSetUpTest.FailureInSetUp
+(expecting 4 failures)
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #1, in SetUp().
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #2, in the test function.
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #3, in TearDown().
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #4, in the test fixture d'tor.
+Stack trace: (omitted)
+
+[  FAILED  ] NonFatalFailureInSetUpTest.FailureInSetUp
+[----------] 1 test from FatalFailureInSetUpTest
+[ RUN      ] FatalFailureInSetUpTest.FailureInSetUp
+(expecting 3 failures)
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #1, in SetUp().
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #2, in TearDown().
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected failure #3, in the test fixture d'tor.
+Stack trace: (omitted)
+
+[  FAILED  ] FatalFailureInSetUpTest.FailureInSetUp
+[----------] 1 test from AddFailureAtTest
+[ RUN      ] AddFailureAtTest.MessageContainsSpecifiedFileAndLineNumber
+foo.cc:42: Failure
+Failed
+Expected nonfatal failure in foo.cc
+Stack trace: (omitted)
+
+[  FAILED  ] AddFailureAtTest.MessageContainsSpecifiedFileAndLineNumber
+[----------] 1 test from GtestFailAtTest
+[ RUN      ] GtestFailAtTest.MessageContainsSpecifiedFileAndLineNumber
+foo.cc:42: Failure
+Failed
+Expected fatal failure in foo.cc
+Stack trace: (omitted)
+
+[  FAILED  ] GtestFailAtTest.MessageContainsSpecifiedFileAndLineNumber
+[----------] 4 tests from MixedUpTestSuiteTest
+[ RUN      ] MixedUpTestSuiteTest.FirstTestFromNamespaceFoo
+[       OK ] MixedUpTestSuiteTest.FirstTestFromNamespaceFoo
+[ RUN      ] MixedUpTestSuiteTest.SecondTestFromNamespaceFoo
+[       OK ] MixedUpTestSuiteTest.SecondTestFromNamespaceFoo
+[ RUN      ] MixedUpTestSuiteTest.ThisShouldFail
+gtest.cc:#: Failure
+Failed
+All tests in the same test suite must use the same test fixture
+class.  However, in test suite MixedUpTestSuiteTest,
+you defined test FirstTestFromNamespaceFoo and test ThisShouldFail
+using two different test fixture classes.  This can happen if
+the two classes are from different namespaces or translation
+units and have the same name.  You should probably rename one
+of the classes to put the tests into different test suites.
+Stack trace: (omitted)
+
+[  FAILED  ] MixedUpTestSuiteTest.ThisShouldFail
+[ RUN      ] MixedUpTestSuiteTest.ThisShouldFailToo
+gtest.cc:#: Failure
+Failed
+All tests in the same test suite must use the same test fixture
+class.  However, in test suite MixedUpTestSuiteTest,
+you defined test FirstTestFromNamespaceFoo and test ThisShouldFailToo
+using two different test fixture classes.  This can happen if
+the two classes are from different namespaces or translation
+units and have the same name.  You should probably rename one
+of the classes to put the tests into different test suites.
+Stack trace: (omitted)
+
+[  FAILED  ] MixedUpTestSuiteTest.ThisShouldFailToo
+[----------] 2 tests from MixedUpTestSuiteWithSameTestNameTest
+[ RUN      ] MixedUpTestSuiteWithSameTestNameTest.TheSecondTestWithThisNameShouldFail
+[       OK ] MixedUpTestSuiteWithSameTestNameTest.TheSecondTestWithThisNameShouldFail
+[ RUN      ] MixedUpTestSuiteWithSameTestNameTest.TheSecondTestWithThisNameShouldFail
+gtest.cc:#: Failure
+Failed
+All tests in the same test suite must use the same test fixture
+class.  However, in test suite MixedUpTestSuiteWithSameTestNameTest,
+you defined test TheSecondTestWithThisNameShouldFail and test TheSecondTestWithThisNameShouldFail
+using two different test fixture classes.  This can happen if
+the two classes are from different namespaces or translation
+units and have the same name.  You should probably rename one
+of the classes to put the tests into different test suites.
+Stack trace: (omitted)
+
+[  FAILED  ] MixedUpTestSuiteWithSameTestNameTest.TheSecondTestWithThisNameShouldFail
+[----------] 2 tests from TEST_F_before_TEST_in_same_test_case
+[ RUN      ] TEST_F_before_TEST_in_same_test_case.DefinedUsingTEST_F
+[       OK ] TEST_F_before_TEST_in_same_test_case.DefinedUsingTEST_F
+[ RUN      ] TEST_F_before_TEST_in_same_test_case.DefinedUsingTESTAndShouldFail
+gtest.cc:#: Failure
+Failed
+All tests in the same test suite must use the same test fixture
+class, so mixing TEST_F and TEST in the same test suite is
+illegal.  In test suite TEST_F_before_TEST_in_same_test_case,
+test DefinedUsingTEST_F is defined using TEST_F but
+test DefinedUsingTESTAndShouldFail is defined using TEST.  You probably
+want to change the TEST to TEST_F or move it to another test
+case.
+Stack trace: (omitted)
+
+[  FAILED  ] TEST_F_before_TEST_in_same_test_case.DefinedUsingTESTAndShouldFail
+[----------] 2 tests from TEST_before_TEST_F_in_same_test_case
+[ RUN      ] TEST_before_TEST_F_in_same_test_case.DefinedUsingTEST
+[       OK ] TEST_before_TEST_F_in_same_test_case.DefinedUsingTEST
+[ RUN      ] TEST_before_TEST_F_in_same_test_case.DefinedUsingTEST_FAndShouldFail
+gtest.cc:#: Failure
+Failed
+All tests in the same test suite must use the same test fixture
+class, so mixing TEST_F and TEST in the same test suite is
+illegal.  In test suite TEST_before_TEST_F_in_same_test_case,
+test DefinedUsingTEST_FAndShouldFail is defined using TEST_F but
+test DefinedUsingTEST is defined using TEST.  You probably
+want to change the TEST to TEST_F or move it to another test
+case.
+Stack trace: (omitted)
+
+[  FAILED  ] TEST_before_TEST_F_in_same_test_case.DefinedUsingTEST_FAndShouldFail
+[----------] 8 tests from ExpectNonfatalFailureTest
+[ RUN      ] ExpectNonfatalFailureTest.CanReferenceGlobalVariables
+[       OK ] ExpectNonfatalFailureTest.CanReferenceGlobalVariables
+[ RUN      ] ExpectNonfatalFailureTest.CanReferenceLocalVariables
+[       OK ] ExpectNonfatalFailureTest.CanReferenceLocalVariables
+[ RUN      ] ExpectNonfatalFailureTest.SucceedsWhenThereIsOneNonfatalFailure
+[       OK ] ExpectNonfatalFailureTest.SucceedsWhenThereIsOneNonfatalFailure
+[ RUN      ] ExpectNonfatalFailureTest.FailsWhenThereIsNoNonfatalFailure
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual: 0 failures
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenThereIsNoNonfatalFailure
+[ RUN      ] ExpectNonfatalFailureTest.FailsWhenThereAreTwoNonfatalFailures
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual: 2 failures
+googletest-output-test_.cc:#: Non-fatal failure:
+Failed
+Expected non-fatal failure 1.
+Stack trace: (omitted)
+
+
+googletest-output-test_.cc:#: Non-fatal failure:
+Failed
+Expected non-fatal failure 2.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenThereAreTwoNonfatalFailures
+[ RUN      ] ExpectNonfatalFailureTest.FailsWhenThereIsOneFatalFailure
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual:
+googletest-output-test_.cc:#: Fatal failure:
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenThereIsOneFatalFailure
+[ RUN      ] ExpectNonfatalFailureTest.FailsWhenStatementReturns
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual: 0 failures
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenStatementReturns
+[ RUN      ] ExpectNonfatalFailureTest.FailsWhenStatementThrows
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual: 0 failures
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenStatementThrows
+[----------] 8 tests from ExpectFatalFailureTest
+[ RUN      ] ExpectFatalFailureTest.CanReferenceGlobalVariables
+[       OK ] ExpectFatalFailureTest.CanReferenceGlobalVariables
+[ RUN      ] ExpectFatalFailureTest.CanReferenceLocalStaticVariables
+[       OK ] ExpectFatalFailureTest.CanReferenceLocalStaticVariables
+[ RUN      ] ExpectFatalFailureTest.SucceedsWhenThereIsOneFatalFailure
+[       OK ] ExpectFatalFailureTest.SucceedsWhenThereIsOneFatalFailure
+[ RUN      ] ExpectFatalFailureTest.FailsWhenThereIsNoFatalFailure
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual: 0 failures
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenThereIsNoFatalFailure
+[ RUN      ] ExpectFatalFailureTest.FailsWhenThereAreTwoFatalFailures
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual: 2 failures
+googletest-output-test_.cc:#: Fatal failure:
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+
+googletest-output-test_.cc:#: Fatal failure:
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenThereAreTwoFatalFailures
+[ RUN      ] ExpectFatalFailureTest.FailsWhenThereIsOneNonfatalFailure
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual:
+googletest-output-test_.cc:#: Non-fatal failure:
+Failed
+Expected non-fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenThereIsOneNonfatalFailure
+[ RUN      ] ExpectFatalFailureTest.FailsWhenStatementReturns
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual: 0 failures
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenStatementReturns
+[ RUN      ] ExpectFatalFailureTest.FailsWhenStatementThrows
+(expecting a failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual: 0 failures
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenStatementThrows
+[----------] 2 tests from TypedTest/0, where TypeParam = int
+[ RUN      ] TypedTest/0.Success
+[       OK ] TypedTest/0.Success
+[ RUN      ] TypedTest/0.Failure
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1
+  TypeParam()
+    Which is: 0
+Expected failure
+Stack trace: (omitted)
+
+[  FAILED  ] TypedTest/0.Failure, where TypeParam = int
+[----------] 2 tests from TypedTestWithNames/char0, where TypeParam = char
+[ RUN      ] TypedTestWithNames/char0.Success
+[       OK ] TypedTestWithNames/char0.Success
+[ RUN      ] TypedTestWithNames/char0.Failure
+googletest-output-test_.cc:#: Failure
+Failed
+Stack trace: (omitted)
+
+[  FAILED  ] TypedTestWithNames/char0.Failure, where TypeParam = char
+[----------] 2 tests from TypedTestWithNames/int1, where TypeParam = int
+[ RUN      ] TypedTestWithNames/int1.Success
+[       OK ] TypedTestWithNames/int1.Success
+[ RUN      ] TypedTestWithNames/int1.Failure
+googletest-output-test_.cc:#: Failure
+Failed
+Stack trace: (omitted)
+
+[  FAILED  ] TypedTestWithNames/int1.Failure, where TypeParam = int
+[----------] 2 tests from Unsigned/TypedTestP/0, where TypeParam = unsigned char
+[ RUN      ] Unsigned/TypedTestP/0.Success
+[       OK ] Unsigned/TypedTestP/0.Success
+[ RUN      ] Unsigned/TypedTestP/0.Failure
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1U
+    Which is: 1
+  TypeParam()
+    Which is: '\0'
+Expected failure
+Stack trace: (omitted)
+
+[  FAILED  ] Unsigned/TypedTestP/0.Failure, where TypeParam = unsigned char
+[----------] 2 tests from Unsigned/TypedTestP/1, where TypeParam = unsigned int
+[ RUN      ] Unsigned/TypedTestP/1.Success
+[       OK ] Unsigned/TypedTestP/1.Success
+[ RUN      ] Unsigned/TypedTestP/1.Failure
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1U
+    Which is: 1
+  TypeParam()
+    Which is: 0
+Expected failure
+Stack trace: (omitted)
+
+[  FAILED  ] Unsigned/TypedTestP/1.Failure, where TypeParam = unsigned int
+[----------] 2 tests from UnsignedCustomName/TypedTestP/unsignedChar0, where TypeParam = unsigned char
+[ RUN      ] UnsignedCustomName/TypedTestP/unsignedChar0.Success
+[       OK ] UnsignedCustomName/TypedTestP/unsignedChar0.Success
+[ RUN      ] UnsignedCustomName/TypedTestP/unsignedChar0.Failure
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1U
+    Which is: 1
+  TypeParam()
+    Which is: '\0'
+Expected failure
+Stack trace: (omitted)
+
+[  FAILED  ] UnsignedCustomName/TypedTestP/unsignedChar0.Failure, where TypeParam = unsigned char
+[----------] 2 tests from UnsignedCustomName/TypedTestP/unsignedInt1, where TypeParam = unsigned int
+[ RUN      ] UnsignedCustomName/TypedTestP/unsignedInt1.Success
+[       OK ] UnsignedCustomName/TypedTestP/unsignedInt1.Success
+[ RUN      ] UnsignedCustomName/TypedTestP/unsignedInt1.Failure
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1U
+    Which is: 1
+  TypeParam()
+    Which is: 0
+Expected failure
+Stack trace: (omitted)
+
+[  FAILED  ] UnsignedCustomName/TypedTestP/unsignedInt1.Failure, where TypeParam = unsigned int
+[----------] 4 tests from ExpectFailureTest
+[ RUN      ] ExpectFailureTest.ExpectFatalFailure
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual:
+googletest-output-test_.cc:#: Success:
+Succeeded
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual:
+googletest-output-test_.cc:#: Non-fatal failure:
+Failed
+Expected non-fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure containing "Some other fatal failure expected."
+  Actual:
+googletest-output-test_.cc:#: Fatal failure:
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFailureTest.ExpectFatalFailure
+[ RUN      ] ExpectFailureTest.ExpectNonFatalFailure
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual:
+googletest-output-test_.cc:#: Success:
+Succeeded
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual:
+googletest-output-test_.cc:#: Fatal failure:
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure containing "Some other non-fatal failure."
+  Actual:
+googletest-output-test_.cc:#: Non-fatal failure:
+Failed
+Expected non-fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFailureTest.ExpectNonFatalFailure
+[ RUN      ] ExpectFailureTest.ExpectFatalFailureOnAllThreads
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual:
+googletest-output-test_.cc:#: Success:
+Succeeded
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual:
+googletest-output-test_.cc:#: Non-fatal failure:
+Failed
+Expected non-fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 fatal failure containing "Some other fatal failure expected."
+  Actual:
+googletest-output-test_.cc:#: Fatal failure:
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFailureTest.ExpectFatalFailureOnAllThreads
+[ RUN      ] ExpectFailureTest.ExpectNonFatalFailureOnAllThreads
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual:
+googletest-output-test_.cc:#: Success:
+Succeeded
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual:
+googletest-output-test_.cc:#: Fatal failure:
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+(expecting 1 failure)
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure containing "Some other non-fatal failure."
+  Actual:
+googletest-output-test_.cc:#: Non-fatal failure:
+Failed
+Expected non-fatal failure.
+Stack trace: (omitted)
+
+
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFailureTest.ExpectNonFatalFailureOnAllThreads
+[----------] 2 tests from ExpectFailureWithThreadsTest
+[ RUN      ] ExpectFailureWithThreadsTest.ExpectFatalFailure
+(expecting 2 failures)
+googletest-output-test_.cc:#: Failure
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+gtest.cc:#: Failure
+Expected: 1 fatal failure
+  Actual: 0 failures
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFailureWithThreadsTest.ExpectFatalFailure
+[ RUN      ] ExpectFailureWithThreadsTest.ExpectNonFatalFailure
+(expecting 2 failures)
+googletest-output-test_.cc:#: Failure
+Failed
+Expected non-fatal failure.
+Stack trace: (omitted)
+
+gtest.cc:#: Failure
+Expected: 1 non-fatal failure
+  Actual: 0 failures
+Stack trace: (omitted)
+
+[  FAILED  ] ExpectFailureWithThreadsTest.ExpectNonFatalFailure
+[----------] 1 test from ScopedFakeTestPartResultReporterTest
+[ RUN      ] ScopedFakeTestPartResultReporterTest.InterceptOnlyCurrentThread
+(expecting 2 failures)
+googletest-output-test_.cc:#: Failure
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+googletest-output-test_.cc:#: Failure
+Failed
+Expected non-fatal failure.
+Stack trace: (omitted)
+
+[  FAILED  ] ScopedFakeTestPartResultReporterTest.InterceptOnlyCurrentThread
+[----------] 2 tests from DynamicFixture
+DynamicFixture::SetUpTestSuite
+[ RUN      ] DynamicFixture.DynamicTestPass
+DynamicFixture()
+DynamicFixture::SetUp
+DynamicFixture::TearDown
+~DynamicFixture()
+[       OK ] DynamicFixture.DynamicTestPass
+[ RUN      ] DynamicFixture.DynamicTestFail
+DynamicFixture()
+DynamicFixture::SetUp
+googletest-output-test_.cc:#: Failure
+Value of: Pass
+  Actual: false
+Expected: true
+Stack trace: (omitted)
+
+DynamicFixture::TearDown
+~DynamicFixture()
+[  FAILED  ] DynamicFixture.DynamicTestFail
+DynamicFixture::TearDownTestSuite
+[----------] 1 test from DynamicFixtureAnotherName
+DynamicFixture::SetUpTestSuite
+[ RUN      ] DynamicFixtureAnotherName.DynamicTestPass
+DynamicFixture()
+DynamicFixture::SetUp
+DynamicFixture::TearDown
+~DynamicFixture()
+[       OK ] DynamicFixtureAnotherName.DynamicTestPass
+DynamicFixture::TearDownTestSuite
+[----------] 2 tests from BadDynamicFixture1
+DynamicFixture::SetUpTestSuite
+[ RUN      ] BadDynamicFixture1.FixtureBase
+DynamicFixture()
+DynamicFixture::SetUp
+DynamicFixture::TearDown
+~DynamicFixture()
+[       OK ] BadDynamicFixture1.FixtureBase
+[ RUN      ] BadDynamicFixture1.TestBase
+DynamicFixture()
+gtest.cc:#: Failure
+Failed
+All tests in the same test suite must use the same test fixture
+class, so mixing TEST_F and TEST in the same test suite is
+illegal.  In test suite BadDynamicFixture1,
+test FixtureBase is defined using TEST_F but
+test TestBase is defined using TEST.  You probably
+want to change the TEST to TEST_F or move it to another test
+case.
+Stack trace: (omitted)
+
+~DynamicFixture()
+[  FAILED  ] BadDynamicFixture1.TestBase
+DynamicFixture::TearDownTestSuite
+[----------] 2 tests from BadDynamicFixture2
+DynamicFixture::SetUpTestSuite
+[ RUN      ] BadDynamicFixture2.FixtureBase
+DynamicFixture()
+DynamicFixture::SetUp
+DynamicFixture::TearDown
+~DynamicFixture()
+[       OK ] BadDynamicFixture2.FixtureBase
+[ RUN      ] BadDynamicFixture2.Derived
+DynamicFixture()
+gtest.cc:#: Failure
+Failed
+All tests in the same test suite must use the same test fixture
+class.  However, in test suite BadDynamicFixture2,
+you defined test FixtureBase and test Derived
+using two different test fixture classes.  This can happen if
+the two classes are from different namespaces or translation
+units and have the same name.  You should probably rename one
+of the classes to put the tests into different test suites.
+Stack trace: (omitted)
+
+~DynamicFixture()
+[  FAILED  ] BadDynamicFixture2.Derived
+DynamicFixture::TearDownTestSuite
+[----------] 1 test from PrintingFailingParams/FailingParamTest
+[ RUN      ] PrintingFailingParams/FailingParamTest.Fails/0
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1
+  GetParam()
+    Which is: 2
+Stack trace: (omitted)
+
+[  FAILED  ] PrintingFailingParams/FailingParamTest.Fails/0, where GetParam() = 2
+[----------] 1 test from EmptyBasenameParamInst
+[ RUN      ] EmptyBasenameParamInst.Passes/0
+[       OK ] EmptyBasenameParamInst.Passes/0
+[----------] 2 tests from PrintingStrings/ParamTest
+[ RUN      ] PrintingStrings/ParamTest.Success/a
+[       OK ] PrintingStrings/ParamTest.Success/a
+[ RUN      ] PrintingStrings/ParamTest.Failure/a
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  "b"
+  GetParam()
+    Which is: "a"
+Expected failure
+Stack trace: (omitted)
+
+[  FAILED  ] PrintingStrings/ParamTest.Failure/a, where GetParam() = "a"
+[----------] Global test environment tear-down
+BarEnvironment::TearDown() called.
+googletest-output-test_.cc:#: Failure
+Failed
+Expected non-fatal failure.
+Stack trace: (omitted)
+
+FooEnvironment::TearDown() called.
+googletest-output-test_.cc:#: Failure
+Failed
+Expected fatal failure.
+Stack trace: (omitted)
+
+[==========] 85 tests from 40 test suites ran.
+[  PASSED  ] 31 tests.
+[  FAILED  ] 54 tests, listed below:
+[  FAILED  ] NonfatalFailureTest.EscapesStringOperands
+[  FAILED  ] NonfatalFailureTest.DiffForLongStrings
+[  FAILED  ] FatalFailureTest.FatalFailureInSubroutine
+[  FAILED  ] FatalFailureTest.FatalFailureInNestedSubroutine
+[  FAILED  ] FatalFailureTest.NonfatalFailureInSubroutine
+[  FAILED  ] LoggingTest.InterleavingLoggingAndAssertions
+[  FAILED  ] SCOPED_TRACETest.AcceptedValues
+[  FAILED  ] SCOPED_TRACETest.ObeysScopes
+[  FAILED  ] SCOPED_TRACETest.WorksInLoop
+[  FAILED  ] SCOPED_TRACETest.WorksInSubroutine
+[  FAILED  ] SCOPED_TRACETest.CanBeNested
+[  FAILED  ] SCOPED_TRACETest.CanBeRepeated
+[  FAILED  ] SCOPED_TRACETest.WorksConcurrently
+[  FAILED  ] ScopedTraceTest.WithExplicitFileAndLine
+[  FAILED  ] NonFatalFailureInFixtureConstructorTest.FailureInConstructor
+[  FAILED  ] FatalFailureInFixtureConstructorTest.FailureInConstructor
+[  FAILED  ] NonFatalFailureInSetUpTest.FailureInSetUp
+[  FAILED  ] FatalFailureInSetUpTest.FailureInSetUp
+[  FAILED  ] AddFailureAtTest.MessageContainsSpecifiedFileAndLineNumber
+[  FAILED  ] GtestFailAtTest.MessageContainsSpecifiedFileAndLineNumber
+[  FAILED  ] MixedUpTestSuiteTest.ThisShouldFail
+[  FAILED  ] MixedUpTestSuiteTest.ThisShouldFailToo
+[  FAILED  ] MixedUpTestSuiteWithSameTestNameTest.TheSecondTestWithThisNameShouldFail
+[  FAILED  ] TEST_F_before_TEST_in_same_test_case.DefinedUsingTESTAndShouldFail
+[  FAILED  ] TEST_before_TEST_F_in_same_test_case.DefinedUsingTEST_FAndShouldFail
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenThereIsNoNonfatalFailure
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenThereAreTwoNonfatalFailures
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenThereIsOneFatalFailure
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenStatementReturns
+[  FAILED  ] ExpectNonfatalFailureTest.FailsWhenStatementThrows
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenThereIsNoFatalFailure
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenThereAreTwoFatalFailures
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenThereIsOneNonfatalFailure
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenStatementReturns
+[  FAILED  ] ExpectFatalFailureTest.FailsWhenStatementThrows
+[  FAILED  ] TypedTest/0.Failure, where TypeParam = int
+[  FAILED  ] TypedTestWithNames/char0.Failure, where TypeParam = char
+[  FAILED  ] TypedTestWithNames/int1.Failure, where TypeParam = int
+[  FAILED  ] Unsigned/TypedTestP/0.Failure, where TypeParam = unsigned char
+[  FAILED  ] Unsigned/TypedTestP/1.Failure, where TypeParam = unsigned int
+[  FAILED  ] UnsignedCustomName/TypedTestP/unsignedChar0.Failure, where TypeParam = unsigned char
+[  FAILED  ] UnsignedCustomName/TypedTestP/unsignedInt1.Failure, where TypeParam = unsigned int
+[  FAILED  ] ExpectFailureTest.ExpectFatalFailure
+[  FAILED  ] ExpectFailureTest.ExpectNonFatalFailure
+[  FAILED  ] ExpectFailureTest.ExpectFatalFailureOnAllThreads
+[  FAILED  ] ExpectFailureTest.ExpectNonFatalFailureOnAllThreads
+[  FAILED  ] ExpectFailureWithThreadsTest.ExpectFatalFailure
+[  FAILED  ] ExpectFailureWithThreadsTest.ExpectNonFatalFailure
+[  FAILED  ] ScopedFakeTestPartResultReporterTest.InterceptOnlyCurrentThread
+[  FAILED  ] DynamicFixture.DynamicTestFail
+[  FAILED  ] BadDynamicFixture1.TestBase
+[  FAILED  ] BadDynamicFixture2.Derived
+[  FAILED  ] PrintingFailingParams/FailingParamTest.Fails/0, where GetParam() = 2
+[  FAILED  ] PrintingStrings/ParamTest.Failure/a, where GetParam() = "a"
+
+54 FAILED TESTS
+  YOU HAVE 1 DISABLED TEST
+
+Note: Google Test filter = FatalFailureTest.*:LoggingTest.*
+[==========] Running 4 tests from 2 test suites.
+[----------] Global test environment set-up.
+[----------] 3 tests from FatalFailureTest
+[ RUN      ] FatalFailureTest.FatalFailureInSubroutine
+(expecting a failure that x should be 1)
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1
+  x
+    Which is: 2
+Stack trace: (omitted)
+
+[  FAILED  ] FatalFailureTest.FatalFailureInSubroutine (? ms)
+[ RUN      ] FatalFailureTest.FatalFailureInNestedSubroutine
+(expecting a failure that x should be 1)
+googletest-output-test_.cc:#: Failure
+Expected equality of these values:
+  1
+  x
+    Which is: 2
+Stack trace: (omitted)
+
+[  FAILED  ] FatalFailureTest.FatalFailureInNestedSubroutine (? ms)
+[ RUN      ] FatalFailureTest.NonfatalFailureInSubroutine
+(expecting a failure on false)
+googletest-output-test_.cc:#: Failure
+Value of: false
+  Actual: false
+Expected: true
+Stack trace: (omitted)
+
+[  FAILED  ] FatalFailureTest.NonfatalFailureInSubroutine (? ms)
+[----------] 3 tests from FatalFailureTest (? ms total)
+
+[----------] 1 test from LoggingTest
+[ RUN      ] LoggingTest.InterleavingLoggingAndAssertions
+(expecting 2 failures on (3) >= (a[i]))
+i == 0
+i == 1
+googletest-output-test_.cc:#: Failure
+Expected: (3) >= (a[i]), actual: 3 vs 9
+Stack trace: (omitted)
+
+i == 2
+i == 3
+googletest-output-test_.cc:#: Failure
+Expected: (3) >= (a[i]), actual: 3 vs 6
+Stack trace: (omitted)
+
+[  FAILED  ] LoggingTest.InterleavingLoggingAndAssertions (? ms)
+[----------] 1 test from LoggingTest (? ms total)
+
+[----------] Global test environment tear-down
+[==========] 4 tests from 2 test suites ran. (? ms total)
+[  PASSED  ] 0 tests.
+[  FAILED  ] 4 tests, listed below:
+[  FAILED  ] FatalFailureTest.FatalFailureInSubroutine
+[  FAILED  ] FatalFailureTest.FatalFailureInNestedSubroutine
+[  FAILED  ] FatalFailureTest.NonfatalFailureInSubroutine
+[  FAILED  ] LoggingTest.InterleavingLoggingAndAssertions
+
+ 4 FAILED TESTS
+Note: Google Test filter = *DISABLED_*
+[==========] Running 1 test from 1 test suite.
+[----------] Global test environment set-up.
+[----------] 1 test from DisabledTestsWarningTest
+[ RUN      ] DisabledTestsWarningTest.DISABLED_AlsoRunDisabledTestsFlagSuppressesWarning
+[       OK ] DisabledTestsWarningTest.DISABLED_AlsoRunDisabledTestsFlagSuppressesWarning
+[----------] Global test environment tear-down
+[==========] 1 test from 1 test suite ran.
+[  PASSED  ] 1 test.
+Note: Google Test filter = PassingTest.*
+Note: This is test shard 2 of 2.
+[==========] Running 1 test from 1 test suite.
+[----------] Global test environment set-up.
+[----------] 1 test from PassingTest
+[ RUN      ] PassingTest.PassingTest2
+[       OK ] PassingTest.PassingTest2
+[----------] Global test environment tear-down
+[==========] 1 test from 1 test suite ran.
+[  PASSED  ] 1 test.
diff --git a/3rdparty/gtest/test/googletest-output-test.py b/3rdparty/gtest/test/googletest-output-test.py
new file mode 100644
index 0000000..c727f17
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-output-test.py
@@ -0,0 +1,346 @@
+#!/usr/bin/env python
+#
+# Copyright 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Tests the text output of Google C++ Testing and Mocking Framework.
+
+To update the golden file:
+googletest_output_test.py --build_dir=BUILD/DIR --gengolden
+where BUILD/DIR contains the built googletest-output-test_ file.
+googletest_output_test.py --gengolden
+googletest_output_test.py
+"""
+
+import difflib
+import os
+import re
+import sys
+import gtest_test_utils
+
+
+# The flag for generating the golden file
+GENGOLDEN_FLAG = '--gengolden'
+CATCH_EXCEPTIONS_ENV_VAR_NAME = 'GTEST_CATCH_EXCEPTIONS'
+
+# The flag indicating stacktraces are not supported
+NO_STACKTRACE_SUPPORT_FLAG = '--no_stacktrace_support'
+
+IS_LINUX = os.name == 'posix' and os.uname()[0] == 'Linux'
+IS_WINDOWS = os.name == 'nt'
+
+GOLDEN_NAME = 'googletest-output-test-golden-lin.txt'
+
+PROGRAM_PATH = gtest_test_utils.GetTestExecutablePath('googletest-output-test_')
+
+# At least one command we exercise must not have the
+# 'internal_skip_environment_and_ad_hoc_tests' argument.
+COMMAND_LIST_TESTS = ({}, [PROGRAM_PATH, '--gtest_list_tests'])
+COMMAND_WITH_COLOR = ({}, [PROGRAM_PATH, '--gtest_color=yes'])
+COMMAND_WITH_TIME = ({}, [PROGRAM_PATH,
+                          '--gtest_print_time',
+                          'internal_skip_environment_and_ad_hoc_tests',
+                          '--gtest_filter=FatalFailureTest.*:LoggingTest.*'])
+COMMAND_WITH_DISABLED = (
+    {}, [PROGRAM_PATH,
+         '--gtest_also_run_disabled_tests',
+         'internal_skip_environment_and_ad_hoc_tests',
+         '--gtest_filter=*DISABLED_*'])
+COMMAND_WITH_SHARDING = (
+    {'GTEST_SHARD_INDEX': '1', 'GTEST_TOTAL_SHARDS': '2'},
+    [PROGRAM_PATH,
+     'internal_skip_environment_and_ad_hoc_tests',
+     '--gtest_filter=PassingTest.*'])
+
+GOLDEN_PATH = os.path.join(gtest_test_utils.GetSourceDir(), GOLDEN_NAME)
+
+
+def ToUnixLineEnding(s):
+  """Changes all Windows/Mac line endings in s to UNIX line endings."""
+
+  return s.replace('\r\n', '\n').replace('\r', '\n')
+
+
+def RemoveLocations(test_output):
+  """Removes all file location info from a Google Test program's output.
+
+  Args:
+       test_output:  the output of a Google Test program.
+
+  Returns:
+       output with all file location info (in the form of
+       'DIRECTORY/FILE_NAME:LINE_NUMBER: 'or
+       'DIRECTORY\\FILE_NAME(LINE_NUMBER): ') replaced by
+       'FILE_NAME:#: '.
+  """
+
+  return re.sub(r'.*[/\\]((googletest-output-test_|gtest).cc)(\:\d+|\(\d+\))\: ',
+                r'\1:#: ', test_output)
+
+
+def RemoveStackTraceDetails(output):
+  """Removes all stack traces from a Google Test program's output."""
+
+  # *? means "find the shortest string that matches".
+  return re.sub(r'Stack trace:(.|\n)*?\n\n',
+                'Stack trace: (omitted)\n\n', output)
+
+
+def RemoveStackTraces(output):
+  """Removes all traces of stack traces from a Google Test program's output."""
+
+  # *? means "find the shortest string that matches".
+  return re.sub(r'Stack trace:(.|\n)*?\n\n', '', output)
+
+
+def RemoveTime(output):
+  """Removes all time information from a Google Test program's output."""
+
+  return re.sub(r'\(\d+ ms', '(? ms', output)
+
+
+def RemoveTypeInfoDetails(test_output):
+  """Removes compiler-specific type info from Google Test program's output.
+
+  Args:
+       test_output:  the output of a Google Test program.
+
+  Returns:
+       output with type information normalized to canonical form.
+  """
+
+  # some compilers output the name of type 'unsigned int' as 'unsigned'
+  return re.sub(r'unsigned int', 'unsigned', test_output)
+
+
+def NormalizeToCurrentPlatform(test_output):
+  """Normalizes platform specific output details for easier comparison."""
+
+  if IS_WINDOWS:
+    # Removes the color information that is not present on Windows.
+    test_output = re.sub('\x1b\\[(0;3\d)?m', '', test_output)
+    # Changes failure message headers into the Windows format.
+    test_output = re.sub(r': Failure\n', r': error: ', test_output)
+    # Changes file(line_number) to file:line_number.
+    test_output = re.sub(r'((\w|\.)+)\((\d+)\):', r'\1:\3:', test_output)
+
+  return test_output
+
+
+def RemoveTestCounts(output):
+  """Removes test counts from a Google Test program's output."""
+
+  output = re.sub(r'\d+ tests?, listed below',
+                  '? tests, listed below', output)
+  output = re.sub(r'\d+ FAILED TESTS',
+                  '? FAILED TESTS', output)
+  output = re.sub(r'\d+ tests? from \d+ test cases?',
+                  '? tests from ? test cases', output)
+  output = re.sub(r'\d+ tests? from ([a-zA-Z_])',
+                  r'? tests from \1', output)
+  return re.sub(r'\d+ tests?\.', '? tests.', output)
+
+
+def RemoveMatchingTests(test_output, pattern):
+  """Removes output of specified tests from a Google Test program's output.
+
+  This function strips not only the beginning and the end of a test but also
+  all output in between.
+
+  Args:
+    test_output:       A string containing the test output.
+    pattern:           A regex string that matches names of test cases or
+                       tests to remove.
+
+  Returns:
+    Contents of test_output with tests whose names match pattern removed.
+  """
+
+  test_output = re.sub(
+      r'.*\[ RUN      \] .*%s(.|\n)*?\[(  FAILED  |       OK )\] .*%s.*\n' % (
+          pattern, pattern),
+      '',
+      test_output)
+  return re.sub(r'.*%s.*\n' % pattern, '', test_output)
+
+
+def NormalizeOutput(output):
+  """Normalizes output (the output of googletest-output-test_.exe)."""
+
+  output = ToUnixLineEnding(output)
+  output = RemoveLocations(output)
+  output = RemoveStackTraceDetails(output)
+  output = RemoveTime(output)
+  return output
+
+
+def GetShellCommandOutput(env_cmd):
+  """Runs a command in a sub-process, and returns its output in a string.
+
+  Args:
+    env_cmd: The shell command. A 2-tuple where element 0 is a dict of extra
+             environment variables to set, and element 1 is a string with
+             the command and any flags.
+
+  Returns:
+    A string with the command's combined standard and diagnostic output.
+  """
+
+  # Spawns cmd in a sub-process, and gets its standard I/O file objects.
+  # Set and save the environment properly.
+  environ = os.environ.copy()
+  environ.update(env_cmd[0])
+  p = gtest_test_utils.Subprocess(env_cmd[1], env=environ)
+
+  return p.output
+
+
+def GetCommandOutput(env_cmd):
+  """Runs a command and returns its output with all file location
+  info stripped off.
+
+  Args:
+    env_cmd:  The shell command. A 2-tuple where element 0 is a dict of extra
+              environment variables to set, and element 1 is a string with
+              the command and any flags.
+  """
+
+  # Disables exception pop-ups on Windows.
+  environ, cmdline = env_cmd
+  environ = dict(environ)  # Ensures we are modifying a copy.
+  environ[CATCH_EXCEPTIONS_ENV_VAR_NAME] = '1'
+  return NormalizeOutput(GetShellCommandOutput((environ, cmdline)))
+
+
+def GetOutputOfAllCommands():
+  """Returns concatenated output from several representative commands."""
+
+  return (GetCommandOutput(COMMAND_WITH_COLOR) +
+          GetCommandOutput(COMMAND_WITH_TIME) +
+          GetCommandOutput(COMMAND_WITH_DISABLED) +
+          GetCommandOutput(COMMAND_WITH_SHARDING))
+
+
+test_list = GetShellCommandOutput(COMMAND_LIST_TESTS)
+SUPPORTS_DEATH_TESTS = 'DeathTest' in test_list
+SUPPORTS_TYPED_TESTS = 'TypedTest' in test_list
+SUPPORTS_THREADS = 'ExpectFailureWithThreadsTest' in test_list
+SUPPORTS_STACK_TRACES = NO_STACKTRACE_SUPPORT_FLAG not in sys.argv
+
+CAN_GENERATE_GOLDEN_FILE = (SUPPORTS_DEATH_TESTS and
+                            SUPPORTS_TYPED_TESTS and
+                            SUPPORTS_THREADS and
+                            SUPPORTS_STACK_TRACES)
+
+class GTestOutputTest(gtest_test_utils.TestCase):
+  def RemoveUnsupportedTests(self, test_output):
+    if not SUPPORTS_DEATH_TESTS:
+      test_output = RemoveMatchingTests(test_output, 'DeathTest')
+    if not SUPPORTS_TYPED_TESTS:
+      test_output = RemoveMatchingTests(test_output, 'TypedTest')
+      test_output = RemoveMatchingTests(test_output, 'TypedDeathTest')
+      test_output = RemoveMatchingTests(test_output, 'TypeParamDeathTest')
+    if not SUPPORTS_THREADS:
+      test_output = RemoveMatchingTests(test_output,
+                                        'ExpectFailureWithThreadsTest')
+      test_output = RemoveMatchingTests(test_output,
+                                        'ScopedFakeTestPartResultReporterTest')
+      test_output = RemoveMatchingTests(test_output,
+                                        'WorksConcurrently')
+    if not SUPPORTS_STACK_TRACES:
+      test_output = RemoveStackTraces(test_output)
+
+    return test_output
+
+  def testOutput(self):
+    output = GetOutputOfAllCommands()
+
+    golden_file = open(GOLDEN_PATH, 'rb')
+    # A mis-configured source control system can cause \r appear in EOL
+    # sequences when we read the golden file irrespective of an operating
+    # system used. Therefore, we need to strip those \r's from newlines
+    # unconditionally.
+    golden = ToUnixLineEnding(golden_file.read().decode())
+    golden_file.close()
+
+    # We want the test to pass regardless of certain features being
+    # supported or not.
+
+    # We still have to remove type name specifics in all cases.
+    normalized_actual = RemoveTypeInfoDetails(output)
+    normalized_golden = RemoveTypeInfoDetails(golden)
+
+    if CAN_GENERATE_GOLDEN_FILE:
+      self.assertEqual(normalized_golden, normalized_actual,
+                       '\n'.join(difflib.unified_diff(
+                           normalized_golden.split('\n'),
+                           normalized_actual.split('\n'),
+                           'golden', 'actual')))
+    else:
+      normalized_actual = NormalizeToCurrentPlatform(
+          RemoveTestCounts(normalized_actual))
+      normalized_golden = NormalizeToCurrentPlatform(
+          RemoveTestCounts(self.RemoveUnsupportedTests(normalized_golden)))
+
+      # This code is very handy when debugging golden file differences:
+      if os.getenv('DEBUG_GTEST_OUTPUT_TEST'):
+        open(os.path.join(
+            gtest_test_utils.GetSourceDir(),
+            '_googletest-output-test_normalized_actual.txt'), 'wb').write(
+                normalized_actual)
+        open(os.path.join(
+            gtest_test_utils.GetSourceDir(),
+            '_googletest-output-test_normalized_golden.txt'), 'wb').write(
+                normalized_golden)
+
+      self.assertEqual(normalized_golden, normalized_actual)
+
+
+if __name__ == '__main__':
+  if NO_STACKTRACE_SUPPORT_FLAG in sys.argv:
+    # unittest.main() can't handle unknown flags
+    sys.argv.remove(NO_STACKTRACE_SUPPORT_FLAG)
+
+  if GENGOLDEN_FLAG in sys.argv:
+    if CAN_GENERATE_GOLDEN_FILE:
+      output = GetOutputOfAllCommands()
+      golden_file = open(GOLDEN_PATH, 'wb')
+      golden_file.write(output)
+      golden_file.close()
+    else:
+      message = (
+          """Unable to write a golden file when compiled in an environment
+that does not support all the required features (death tests,
+typed tests, stack traces, and multiple threads).
+Please build this test and generate the golden file using Blaze on Linux.""")
+
+      sys.stderr.write(message)
+      sys.exit(1)
+  else:
+    gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-output-test_.cc b/3rdparty/gtest/test/googletest-output-test_.cc
new file mode 100644
index 0000000..4f716d8
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-output-test_.cc
@@ -0,0 +1,1157 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// The purpose of this file is to generate Google Test output under
+// various conditions.  The output will then be verified by
+// googletest-output-test.py to ensure that Google Test generates the
+// desired messages.  Therefore, most tests in this file are MEANT TO
+// FAIL.
+
+#include "gtest/gtest-spi.h"
+#include "gtest/gtest.h"
+#include "src/gtest-internal-inl.h"
+
+#include <stdlib.h>
+
+#if _MSC_VER
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4127 /* conditional expression is constant */)
+#endif  //  _MSC_VER
+
+#if GTEST_IS_THREADSAFE
+using testing::ScopedFakeTestPartResultReporter;
+using testing::TestPartResultArray;
+
+using testing::internal::Notification;
+using testing::internal::ThreadWithParam;
+#endif
+
+namespace posix = ::testing::internal::posix;
+
+// Tests catching fatal failures.
+
+// A subroutine used by the following test.
+void TestEq1(int x) {
+  ASSERT_EQ(1, x);
+}
+
+// This function calls a test subroutine, catches the fatal failure it
+// generates, and then returns early.
+void TryTestSubroutine() {
+  // Calls a subrountine that yields a fatal failure.
+  TestEq1(2);
+
+  // Catches the fatal failure and aborts the test.
+  //
+  // The testing::Test:: prefix is necessary when calling
+  // HasFatalFailure() outside of a TEST, TEST_F, or test fixture.
+  if (testing::Test::HasFatalFailure()) return;
+
+  // If we get here, something is wrong.
+  FAIL() << "This should never be reached.";
+}
+
+TEST(PassingTest, PassingTest1) {
+}
+
+TEST(PassingTest, PassingTest2) {
+}
+
+// Tests that parameters of failing parameterized tests are printed in the
+// failing test summary.
+class FailingParamTest : public testing::TestWithParam<int> {};
+
+TEST_P(FailingParamTest, Fails) {
+  EXPECT_EQ(1, GetParam());
+}
+
+// This generates a test which will fail. Google Test is expected to print
+// its parameter when it outputs the list of all failed tests.
+INSTANTIATE_TEST_SUITE_P(PrintingFailingParams,
+                         FailingParamTest,
+                         testing::Values(2));
+
+// Tests that an empty value for the test suite basename yields just
+// the test name without any prior /
+class EmptyBasenameParamInst : public testing::TestWithParam<int> {};
+
+TEST_P(EmptyBasenameParamInst, Passes) { EXPECT_EQ(1, GetParam()); }
+
+INSTANTIATE_TEST_SUITE_P(, EmptyBasenameParamInst, testing::Values(1));
+
+static const char kGoldenString[] = "\"Line\0 1\"\nLine 2";
+
+TEST(NonfatalFailureTest, EscapesStringOperands) {
+  std::string actual = "actual \"string\"";
+  EXPECT_EQ(kGoldenString, actual);
+
+  const char* golden = kGoldenString;
+  EXPECT_EQ(golden, actual);
+}
+
+TEST(NonfatalFailureTest, DiffForLongStrings) {
+  std::string golden_str(kGoldenString, sizeof(kGoldenString) - 1);
+  EXPECT_EQ(golden_str, "Line 2");
+}
+
+// Tests catching a fatal failure in a subroutine.
+TEST(FatalFailureTest, FatalFailureInSubroutine) {
+  printf("(expecting a failure that x should be 1)\n");
+
+  TryTestSubroutine();
+}
+
+// Tests catching a fatal failure in a nested subroutine.
+TEST(FatalFailureTest, FatalFailureInNestedSubroutine) {
+  printf("(expecting a failure that x should be 1)\n");
+
+  // Calls a subrountine that yields a fatal failure.
+  TryTestSubroutine();
+
+  // Catches the fatal failure and aborts the test.
+  //
+  // When calling HasFatalFailure() inside a TEST, TEST_F, or test
+  // fixture, the testing::Test:: prefix is not needed.
+  if (HasFatalFailure()) return;
+
+  // If we get here, something is wrong.
+  FAIL() << "This should never be reached.";
+}
+
+// Tests HasFatalFailure() after a failed EXPECT check.
+TEST(FatalFailureTest, NonfatalFailureInSubroutine) {
+  printf("(expecting a failure on false)\n");
+  EXPECT_TRUE(false);  // Generates a nonfatal failure
+  ASSERT_FALSE(HasFatalFailure());  // This should succeed.
+}
+
+// Tests interleaving user logging and Google Test assertions.
+TEST(LoggingTest, InterleavingLoggingAndAssertions) {
+  static const int a[4] = {
+    3, 9, 2, 6
+  };
+
+  printf("(expecting 2 failures on (3) >= (a[i]))\n");
+  for (int i = 0; i < static_cast<int>(sizeof(a)/sizeof(*a)); i++) {
+    printf("i == %d\n", i);
+    EXPECT_GE(3, a[i]);
+  }
+}
+
+// Tests the SCOPED_TRACE macro.
+
+// A helper function for testing SCOPED_TRACE.
+void SubWithoutTrace(int n) {
+  EXPECT_EQ(1, n);
+  ASSERT_EQ(2, n);
+}
+
+// Another helper function for testing SCOPED_TRACE.
+void SubWithTrace(int n) {
+  SCOPED_TRACE(testing::Message() << "n = " << n);
+
+  SubWithoutTrace(n);
+}
+
+TEST(SCOPED_TRACETest, AcceptedValues) {
+  SCOPED_TRACE("literal string");
+  SCOPED_TRACE(std::string("std::string"));
+  SCOPED_TRACE(1337);  // streamable type
+  const char* null_value = nullptr;
+  SCOPED_TRACE(null_value);
+
+  ADD_FAILURE() << "Just checking that all these values work fine.";
+}
+
+// Tests that SCOPED_TRACE() obeys lexical scopes.
+TEST(SCOPED_TRACETest, ObeysScopes) {
+  printf("(expected to fail)\n");
+
+  // There should be no trace before SCOPED_TRACE() is invoked.
+  ADD_FAILURE() << "This failure is expected, and shouldn't have a trace.";
+
+  {
+    SCOPED_TRACE("Expected trace");
+    // After SCOPED_TRACE(), a failure in the current scope should contain
+    // the trace.
+    ADD_FAILURE() << "This failure is expected, and should have a trace.";
+  }
+
+  // Once the control leaves the scope of the SCOPED_TRACE(), there
+  // should be no trace again.
+  ADD_FAILURE() << "This failure is expected, and shouldn't have a trace.";
+}
+
+// Tests that SCOPED_TRACE works inside a loop.
+TEST(SCOPED_TRACETest, WorksInLoop) {
+  printf("(expected to fail)\n");
+
+  for (int i = 1; i <= 2; i++) {
+    SCOPED_TRACE(testing::Message() << "i = " << i);
+
+    SubWithoutTrace(i);
+  }
+}
+
+// Tests that SCOPED_TRACE works in a subroutine.
+TEST(SCOPED_TRACETest, WorksInSubroutine) {
+  printf("(expected to fail)\n");
+
+  SubWithTrace(1);
+  SubWithTrace(2);
+}
+
+// Tests that SCOPED_TRACE can be nested.
+TEST(SCOPED_TRACETest, CanBeNested) {
+  printf("(expected to fail)\n");
+
+  SCOPED_TRACE("");  // A trace without a message.
+
+  SubWithTrace(2);
+}
+
+// Tests that multiple SCOPED_TRACEs can be used in the same scope.
+TEST(SCOPED_TRACETest, CanBeRepeated) {
+  printf("(expected to fail)\n");
+
+  SCOPED_TRACE("A");
+  ADD_FAILURE()
+      << "This failure is expected, and should contain trace point A.";
+
+  SCOPED_TRACE("B");
+  ADD_FAILURE()
+      << "This failure is expected, and should contain trace point A and B.";
+
+  {
+    SCOPED_TRACE("C");
+    ADD_FAILURE() << "This failure is expected, and should "
+                  << "contain trace point A, B, and C.";
+  }
+
+  SCOPED_TRACE("D");
+  ADD_FAILURE() << "This failure is expected, and should "
+                << "contain trace point A, B, and D.";
+}
+
+#if GTEST_IS_THREADSAFE
+// Tests that SCOPED_TRACE()s can be used concurrently from multiple
+// threads.  Namely, an assertion should be affected by
+// SCOPED_TRACE()s in its own thread only.
+
+// Here's the sequence of actions that happen in the test:
+//
+//   Thread A (main)                | Thread B (spawned)
+//   ===============================|================================
+//   spawns thread B                |
+//   -------------------------------+--------------------------------
+//   waits for n1                   | SCOPED_TRACE("Trace B");
+//                                  | generates failure #1
+//                                  | notifies n1
+//   -------------------------------+--------------------------------
+//   SCOPED_TRACE("Trace A");       | waits for n2
+//   generates failure #2           |
+//   notifies n2                    |
+//   -------------------------------|--------------------------------
+//   waits for n3                   | generates failure #3
+//                                  | trace B dies
+//                                  | generates failure #4
+//                                  | notifies n3
+//   -------------------------------|--------------------------------
+//   generates failure #5           | finishes
+//   trace A dies                   |
+//   generates failure #6           |
+//   -------------------------------|--------------------------------
+//   waits for thread B to finish   |
+
+struct CheckPoints {
+  Notification n1;
+  Notification n2;
+  Notification n3;
+};
+
+static void ThreadWithScopedTrace(CheckPoints* check_points) {
+  {
+    SCOPED_TRACE("Trace B");
+    ADD_FAILURE()
+        << "Expected failure #1 (in thread B, only trace B alive).";
+    check_points->n1.Notify();
+    check_points->n2.WaitForNotification();
+
+    ADD_FAILURE()
+        << "Expected failure #3 (in thread B, trace A & B both alive).";
+  }  // Trace B dies here.
+  ADD_FAILURE()
+      << "Expected failure #4 (in thread B, only trace A alive).";
+  check_points->n3.Notify();
+}
+
+TEST(SCOPED_TRACETest, WorksConcurrently) {
+  printf("(expecting 6 failures)\n");
+
+  CheckPoints check_points;
+  ThreadWithParam<CheckPoints*> thread(&ThreadWithScopedTrace, &check_points,
+                                       nullptr);
+  check_points.n1.WaitForNotification();
+
+  {
+    SCOPED_TRACE("Trace A");
+    ADD_FAILURE()
+        << "Expected failure #2 (in thread A, trace A & B both alive).";
+    check_points.n2.Notify();
+    check_points.n3.WaitForNotification();
+
+    ADD_FAILURE()
+        << "Expected failure #5 (in thread A, only trace A alive).";
+  }  // Trace A dies here.
+  ADD_FAILURE()
+      << "Expected failure #6 (in thread A, no trace alive).";
+  thread.Join();
+}
+#endif  // GTEST_IS_THREADSAFE
+
+// Tests basic functionality of the ScopedTrace utility (most of its features
+// are already tested in SCOPED_TRACETest).
+TEST(ScopedTraceTest, WithExplicitFileAndLine) {
+  testing::ScopedTrace trace("explicit_file.cc", 123, "expected trace message");
+  ADD_FAILURE() << "Check that the trace is attached to a particular location.";
+}
+
+TEST(DisabledTestsWarningTest,
+     DISABLED_AlsoRunDisabledTestsFlagSuppressesWarning) {
+  // This test body is intentionally empty.  Its sole purpose is for
+  // verifying that the --gtest_also_run_disabled_tests flag
+  // suppresses the "YOU HAVE 12 DISABLED TESTS" warning at the end of
+  // the test output.
+}
+
+// Tests using assertions outside of TEST and TEST_F.
+//
+// This function creates two failures intentionally.
+void AdHocTest() {
+  printf("The non-test part of the code is expected to have 2 failures.\n\n");
+  EXPECT_TRUE(false);
+  EXPECT_EQ(2, 3);
+}
+
+// Runs all TESTs, all TEST_Fs, and the ad hoc test.
+int RunAllTests() {
+  AdHocTest();
+  return RUN_ALL_TESTS();
+}
+
+// Tests non-fatal failures in the fixture constructor.
+class NonFatalFailureInFixtureConstructorTest : public testing::Test {
+ protected:
+  NonFatalFailureInFixtureConstructorTest() {
+    printf("(expecting 5 failures)\n");
+    ADD_FAILURE() << "Expected failure #1, in the test fixture c'tor.";
+  }
+
+  ~NonFatalFailureInFixtureConstructorTest() override {
+    ADD_FAILURE() << "Expected failure #5, in the test fixture d'tor.";
+  }
+
+  void SetUp() override { ADD_FAILURE() << "Expected failure #2, in SetUp()."; }
+
+  void TearDown() override {
+    ADD_FAILURE() << "Expected failure #4, in TearDown.";
+  }
+};
+
+TEST_F(NonFatalFailureInFixtureConstructorTest, FailureInConstructor) {
+  ADD_FAILURE() << "Expected failure #3, in the test body.";
+}
+
+// Tests fatal failures in the fixture constructor.
+class FatalFailureInFixtureConstructorTest : public testing::Test {
+ protected:
+  FatalFailureInFixtureConstructorTest() {
+    printf("(expecting 2 failures)\n");
+    Init();
+  }
+
+  ~FatalFailureInFixtureConstructorTest() override {
+    ADD_FAILURE() << "Expected failure #2, in the test fixture d'tor.";
+  }
+
+  void SetUp() override {
+    ADD_FAILURE() << "UNEXPECTED failure in SetUp().  "
+                  << "We should never get here, as the test fixture c'tor "
+                  << "had a fatal failure.";
+  }
+
+  void TearDown() override {
+    ADD_FAILURE() << "UNEXPECTED failure in TearDown().  "
+                  << "We should never get here, as the test fixture c'tor "
+                  << "had a fatal failure.";
+  }
+
+ private:
+  void Init() {
+    FAIL() << "Expected failure #1, in the test fixture c'tor.";
+  }
+};
+
+TEST_F(FatalFailureInFixtureConstructorTest, FailureInConstructor) {
+  ADD_FAILURE() << "UNEXPECTED failure in the test body.  "
+                << "We should never get here, as the test fixture c'tor "
+                << "had a fatal failure.";
+}
+
+// Tests non-fatal failures in SetUp().
+class NonFatalFailureInSetUpTest : public testing::Test {
+ protected:
+  ~NonFatalFailureInSetUpTest() override { Deinit(); }
+
+  void SetUp() override {
+    printf("(expecting 4 failures)\n");
+    ADD_FAILURE() << "Expected failure #1, in SetUp().";
+  }
+
+  void TearDown() override { FAIL() << "Expected failure #3, in TearDown()."; }
+
+ private:
+  void Deinit() {
+    FAIL() << "Expected failure #4, in the test fixture d'tor.";
+  }
+};
+
+TEST_F(NonFatalFailureInSetUpTest, FailureInSetUp) {
+  FAIL() << "Expected failure #2, in the test function.";
+}
+
+// Tests fatal failures in SetUp().
+class FatalFailureInSetUpTest : public testing::Test {
+ protected:
+  ~FatalFailureInSetUpTest() override { Deinit(); }
+
+  void SetUp() override {
+    printf("(expecting 3 failures)\n");
+    FAIL() << "Expected failure #1, in SetUp().";
+  }
+
+  void TearDown() override { FAIL() << "Expected failure #2, in TearDown()."; }
+
+ private:
+  void Deinit() {
+    FAIL() << "Expected failure #3, in the test fixture d'tor.";
+  }
+};
+
+TEST_F(FatalFailureInSetUpTest, FailureInSetUp) {
+  FAIL() << "UNEXPECTED failure in the test function.  "
+         << "We should never get here, as SetUp() failed.";
+}
+
+TEST(AddFailureAtTest, MessageContainsSpecifiedFileAndLineNumber) {
+  ADD_FAILURE_AT("foo.cc", 42) << "Expected nonfatal failure in foo.cc";
+}
+
+TEST(GtestFailAtTest, MessageContainsSpecifiedFileAndLineNumber) {
+  GTEST_FAIL_AT("foo.cc", 42) << "Expected fatal failure in foo.cc";
+}
+
+#if GTEST_IS_THREADSAFE
+
+// A unary function that may die.
+void DieIf(bool should_die) {
+  GTEST_CHECK_(!should_die) << " - death inside DieIf().";
+}
+
+// Tests running death tests in a multi-threaded context.
+
+// Used for coordination between the main and the spawn thread.
+struct SpawnThreadNotifications {
+  SpawnThreadNotifications() {}
+
+  Notification spawn_thread_started;
+  Notification spawn_thread_ok_to_terminate;
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(SpawnThreadNotifications);
+};
+
+// The function to be executed in the thread spawn by the
+// MultipleThreads test (below).
+static void ThreadRoutine(SpawnThreadNotifications* notifications) {
+  // Signals the main thread that this thread has started.
+  notifications->spawn_thread_started.Notify();
+
+  // Waits for permission to finish from the main thread.
+  notifications->spawn_thread_ok_to_terminate.WaitForNotification();
+}
+
+// This is a death-test test, but it's not named with a DeathTest
+// suffix.  It starts threads which might interfere with later
+// death tests, so it must run after all other death tests.
+class DeathTestAndMultiThreadsTest : public testing::Test {
+ protected:
+  // Starts a thread and waits for it to begin.
+  void SetUp() override {
+    thread_.reset(new ThreadWithParam<SpawnThreadNotifications*>(
+        &ThreadRoutine, &notifications_, nullptr));
+    notifications_.spawn_thread_started.WaitForNotification();
+  }
+  // Tells the thread to finish, and reaps it.
+  // Depending on the version of the thread library in use,
+  // a manager thread might still be left running that will interfere
+  // with later death tests.  This is unfortunate, but this class
+  // cleans up after itself as best it can.
+  void TearDown() override {
+    notifications_.spawn_thread_ok_to_terminate.Notify();
+  }
+
+ private:
+  SpawnThreadNotifications notifications_;
+  std::unique_ptr<ThreadWithParam<SpawnThreadNotifications*> > thread_;
+};
+
+#endif  // GTEST_IS_THREADSAFE
+
+// The MixedUpTestSuiteTest test case verifies that Google Test will fail a
+// test if it uses a different fixture class than what other tests in
+// the same test case use.  It deliberately contains two fixture
+// classes with the same name but defined in different namespaces.
+
+// The MixedUpTestSuiteWithSameTestNameTest test case verifies that
+// when the user defines two tests with the same test case name AND
+// same test name (but in different namespaces), the second test will
+// fail.
+
+namespace foo {
+
+class MixedUpTestSuiteTest : public testing::Test {
+};
+
+TEST_F(MixedUpTestSuiteTest, FirstTestFromNamespaceFoo) {}
+TEST_F(MixedUpTestSuiteTest, SecondTestFromNamespaceFoo) {}
+
+class MixedUpTestSuiteWithSameTestNameTest : public testing::Test {
+};
+
+TEST_F(MixedUpTestSuiteWithSameTestNameTest,
+       TheSecondTestWithThisNameShouldFail) {}
+
+}  // namespace foo
+
+namespace bar {
+
+class MixedUpTestSuiteTest : public testing::Test {
+};
+
+// The following two tests are expected to fail.  We rely on the
+// golden file to check that Google Test generates the right error message.
+TEST_F(MixedUpTestSuiteTest, ThisShouldFail) {}
+TEST_F(MixedUpTestSuiteTest, ThisShouldFailToo) {}
+
+class MixedUpTestSuiteWithSameTestNameTest : public testing::Test {
+};
+
+// Expected to fail.  We rely on the golden file to check that Google Test
+// generates the right error message.
+TEST_F(MixedUpTestSuiteWithSameTestNameTest,
+       TheSecondTestWithThisNameShouldFail) {}
+
+}  // namespace bar
+
+// The following two test cases verify that Google Test catches the user
+// error of mixing TEST and TEST_F in the same test case.  The first
+// test case checks the scenario where TEST_F appears before TEST, and
+// the second one checks where TEST appears before TEST_F.
+
+class TEST_F_before_TEST_in_same_test_case : public testing::Test {
+};
+
+TEST_F(TEST_F_before_TEST_in_same_test_case, DefinedUsingTEST_F) {}
+
+// Expected to fail.  We rely on the golden file to check that Google Test
+// generates the right error message.
+TEST(TEST_F_before_TEST_in_same_test_case, DefinedUsingTESTAndShouldFail) {}
+
+class TEST_before_TEST_F_in_same_test_case : public testing::Test {
+};
+
+TEST(TEST_before_TEST_F_in_same_test_case, DefinedUsingTEST) {}
+
+// Expected to fail.  We rely on the golden file to check that Google Test
+// generates the right error message.
+TEST_F(TEST_before_TEST_F_in_same_test_case, DefinedUsingTEST_FAndShouldFail) {
+}
+
+// Used for testing EXPECT_NONFATAL_FAILURE() and EXPECT_FATAL_FAILURE().
+int global_integer = 0;
+
+// Tests that EXPECT_NONFATAL_FAILURE() can reference global variables.
+TEST(ExpectNonfatalFailureTest, CanReferenceGlobalVariables) {
+  global_integer = 0;
+  EXPECT_NONFATAL_FAILURE({
+    EXPECT_EQ(1, global_integer) << "Expected non-fatal failure.";
+  }, "Expected non-fatal failure.");
+}
+
+// Tests that EXPECT_NONFATAL_FAILURE() can reference local variables
+// (static or not).
+TEST(ExpectNonfatalFailureTest, CanReferenceLocalVariables) {
+  int m = 0;
+  static int n;
+  n = 1;
+  EXPECT_NONFATAL_FAILURE({
+    EXPECT_EQ(m, n) << "Expected non-fatal failure.";
+  }, "Expected non-fatal failure.");
+}
+
+// Tests that EXPECT_NONFATAL_FAILURE() succeeds when there is exactly
+// one non-fatal failure and no fatal failure.
+TEST(ExpectNonfatalFailureTest, SucceedsWhenThereIsOneNonfatalFailure) {
+  EXPECT_NONFATAL_FAILURE({
+    ADD_FAILURE() << "Expected non-fatal failure.";
+  }, "Expected non-fatal failure.");
+}
+
+// Tests that EXPECT_NONFATAL_FAILURE() fails when there is no
+// non-fatal failure.
+TEST(ExpectNonfatalFailureTest, FailsWhenThereIsNoNonfatalFailure) {
+  printf("(expecting a failure)\n");
+  EXPECT_NONFATAL_FAILURE({
+  }, "");
+}
+
+// Tests that EXPECT_NONFATAL_FAILURE() fails when there are two
+// non-fatal failures.
+TEST(ExpectNonfatalFailureTest, FailsWhenThereAreTwoNonfatalFailures) {
+  printf("(expecting a failure)\n");
+  EXPECT_NONFATAL_FAILURE({
+    ADD_FAILURE() << "Expected non-fatal failure 1.";
+    ADD_FAILURE() << "Expected non-fatal failure 2.";
+  }, "");
+}
+
+// Tests that EXPECT_NONFATAL_FAILURE() fails when there is one fatal
+// failure.
+TEST(ExpectNonfatalFailureTest, FailsWhenThereIsOneFatalFailure) {
+  printf("(expecting a failure)\n");
+  EXPECT_NONFATAL_FAILURE({
+    FAIL() << "Expected fatal failure.";
+  }, "");
+}
+
+// Tests that EXPECT_NONFATAL_FAILURE() fails when the statement being
+// tested returns.
+TEST(ExpectNonfatalFailureTest, FailsWhenStatementReturns) {
+  printf("(expecting a failure)\n");
+  EXPECT_NONFATAL_FAILURE({
+    return;
+  }, "");
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+// Tests that EXPECT_NONFATAL_FAILURE() fails when the statement being
+// tested throws.
+TEST(ExpectNonfatalFailureTest, FailsWhenStatementThrows) {
+  printf("(expecting a failure)\n");
+  try {
+    EXPECT_NONFATAL_FAILURE({
+      throw 0;
+    }, "");
+  } catch(int) {  // NOLINT
+  }
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// Tests that EXPECT_FATAL_FAILURE() can reference global variables.
+TEST(ExpectFatalFailureTest, CanReferenceGlobalVariables) {
+  global_integer = 0;
+  EXPECT_FATAL_FAILURE({
+    ASSERT_EQ(1, global_integer) << "Expected fatal failure.";
+  }, "Expected fatal failure.");
+}
+
+// Tests that EXPECT_FATAL_FAILURE() can reference local static
+// variables.
+TEST(ExpectFatalFailureTest, CanReferenceLocalStaticVariables) {
+  static int n;
+  n = 1;
+  EXPECT_FATAL_FAILURE({
+    ASSERT_EQ(0, n) << "Expected fatal failure.";
+  }, "Expected fatal failure.");
+}
+
+// Tests that EXPECT_FATAL_FAILURE() succeeds when there is exactly
+// one fatal failure and no non-fatal failure.
+TEST(ExpectFatalFailureTest, SucceedsWhenThereIsOneFatalFailure) {
+  EXPECT_FATAL_FAILURE({
+    FAIL() << "Expected fatal failure.";
+  }, "Expected fatal failure.");
+}
+
+// Tests that EXPECT_FATAL_FAILURE() fails when there is no fatal
+// failure.
+TEST(ExpectFatalFailureTest, FailsWhenThereIsNoFatalFailure) {
+  printf("(expecting a failure)\n");
+  EXPECT_FATAL_FAILURE({
+  }, "");
+}
+
+// A helper for generating a fatal failure.
+void FatalFailure() {
+  FAIL() << "Expected fatal failure.";
+}
+
+// Tests that EXPECT_FATAL_FAILURE() fails when there are two
+// fatal failures.
+TEST(ExpectFatalFailureTest, FailsWhenThereAreTwoFatalFailures) {
+  printf("(expecting a failure)\n");
+  EXPECT_FATAL_FAILURE({
+    FatalFailure();
+    FatalFailure();
+  }, "");
+}
+
+// Tests that EXPECT_FATAL_FAILURE() fails when there is one non-fatal
+// failure.
+TEST(ExpectFatalFailureTest, FailsWhenThereIsOneNonfatalFailure) {
+  printf("(expecting a failure)\n");
+  EXPECT_FATAL_FAILURE({
+    ADD_FAILURE() << "Expected non-fatal failure.";
+  }, "");
+}
+
+// Tests that EXPECT_FATAL_FAILURE() fails when the statement being
+// tested returns.
+TEST(ExpectFatalFailureTest, FailsWhenStatementReturns) {
+  printf("(expecting a failure)\n");
+  EXPECT_FATAL_FAILURE({
+    return;
+  }, "");
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+// Tests that EXPECT_FATAL_FAILURE() fails when the statement being
+// tested throws.
+TEST(ExpectFatalFailureTest, FailsWhenStatementThrows) {
+  printf("(expecting a failure)\n");
+  try {
+    EXPECT_FATAL_FAILURE({
+      throw 0;
+    }, "");
+  } catch(int) {  // NOLINT
+  }
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// This #ifdef block tests the output of value-parameterized tests.
+
+std::string ParamNameFunc(const testing::TestParamInfo<std::string>& info) {
+  return info.param;
+}
+
+class ParamTest : public testing::TestWithParam<std::string> {
+};
+
+TEST_P(ParamTest, Success) {
+  EXPECT_EQ("a", GetParam());
+}
+
+TEST_P(ParamTest, Failure) {
+  EXPECT_EQ("b", GetParam()) << "Expected failure";
+}
+
+INSTANTIATE_TEST_SUITE_P(PrintingStrings,
+                         ParamTest,
+                         testing::Values(std::string("a")),
+                         ParamNameFunc);
+
+// This #ifdef block tests the output of typed tests.
+#if GTEST_HAS_TYPED_TEST
+
+template <typename T>
+class TypedTest : public testing::Test {
+};
+
+TYPED_TEST_SUITE(TypedTest, testing::Types<int>);
+
+TYPED_TEST(TypedTest, Success) {
+  EXPECT_EQ(0, TypeParam());
+}
+
+TYPED_TEST(TypedTest, Failure) {
+  EXPECT_EQ(1, TypeParam()) << "Expected failure";
+}
+
+typedef testing::Types<char, int> TypesForTestWithNames;
+
+template <typename T>
+class TypedTestWithNames : public testing::Test {};
+
+class TypedTestNames {
+ public:
+  template <typename T>
+  static std::string GetName(int i) {
+    if (std::is_same<T, char>::value)
+      return std::string("char") + ::testing::PrintToString(i);
+    if (std::is_same<T, int>::value)
+      return std::string("int") + ::testing::PrintToString(i);
+  }
+};
+
+TYPED_TEST_SUITE(TypedTestWithNames, TypesForTestWithNames, TypedTestNames);
+
+TYPED_TEST(TypedTestWithNames, Success) {}
+
+TYPED_TEST(TypedTestWithNames, Failure) { FAIL(); }
+
+#endif  // GTEST_HAS_TYPED_TEST
+
+// This #ifdef block tests the output of type-parameterized tests.
+#if GTEST_HAS_TYPED_TEST_P
+
+template <typename T>
+class TypedTestP : public testing::Test {
+};
+
+TYPED_TEST_SUITE_P(TypedTestP);
+
+TYPED_TEST_P(TypedTestP, Success) {
+  EXPECT_EQ(0U, TypeParam());
+}
+
+TYPED_TEST_P(TypedTestP, Failure) {
+  EXPECT_EQ(1U, TypeParam()) << "Expected failure";
+}
+
+REGISTER_TYPED_TEST_SUITE_P(TypedTestP, Success, Failure);
+
+typedef testing::Types<unsigned char, unsigned int> UnsignedTypes;
+INSTANTIATE_TYPED_TEST_SUITE_P(Unsigned, TypedTestP, UnsignedTypes);
+
+class TypedTestPNames {
+ public:
+  template <typename T>
+  static std::string GetName(int i) {
+    if (std::is_same<T, unsigned char>::value) {
+      return std::string("unsignedChar") + ::testing::PrintToString(i);
+    }
+    if (std::is_same<T, unsigned int>::value) {
+      return std::string("unsignedInt") + ::testing::PrintToString(i);
+    }
+  }
+};
+
+INSTANTIATE_TYPED_TEST_SUITE_P(UnsignedCustomName, TypedTestP, UnsignedTypes,
+                              TypedTestPNames);
+
+#endif  // GTEST_HAS_TYPED_TEST_P
+
+#if GTEST_HAS_DEATH_TEST
+
+// We rely on the golden file to verify that tests whose test case
+// name ends with DeathTest are run first.
+
+TEST(ADeathTest, ShouldRunFirst) {
+}
+
+# if GTEST_HAS_TYPED_TEST
+
+// We rely on the golden file to verify that typed tests whose test
+// case name ends with DeathTest are run first.
+
+template <typename T>
+class ATypedDeathTest : public testing::Test {
+};
+
+typedef testing::Types<int, double> NumericTypes;
+TYPED_TEST_SUITE(ATypedDeathTest, NumericTypes);
+
+TYPED_TEST(ATypedDeathTest, ShouldRunFirst) {
+}
+
+# endif  // GTEST_HAS_TYPED_TEST
+
+# if GTEST_HAS_TYPED_TEST_P
+
+
+// We rely on the golden file to verify that type-parameterized tests
+// whose test case name ends with DeathTest are run first.
+
+template <typename T>
+class ATypeParamDeathTest : public testing::Test {
+};
+
+TYPED_TEST_SUITE_P(ATypeParamDeathTest);
+
+TYPED_TEST_P(ATypeParamDeathTest, ShouldRunFirst) {
+}
+
+REGISTER_TYPED_TEST_SUITE_P(ATypeParamDeathTest, ShouldRunFirst);
+
+INSTANTIATE_TYPED_TEST_SUITE_P(My, ATypeParamDeathTest, NumericTypes);
+
+# endif  // GTEST_HAS_TYPED_TEST_P
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+// Tests various failure conditions of
+// EXPECT_{,NON}FATAL_FAILURE{,_ON_ALL_THREADS}.
+class ExpectFailureTest : public testing::Test {
+ public:  // Must be public and not protected due to a bug in g++ 3.4.2.
+  enum FailureMode {
+    FATAL_FAILURE,
+    NONFATAL_FAILURE
+  };
+  static void AddFailure(FailureMode failure) {
+    if (failure == FATAL_FAILURE) {
+      FAIL() << "Expected fatal failure.";
+    } else {
+      ADD_FAILURE() << "Expected non-fatal failure.";
+    }
+  }
+};
+
+TEST_F(ExpectFailureTest, ExpectFatalFailure) {
+  // Expected fatal failure, but succeeds.
+  printf("(expecting 1 failure)\n");
+  EXPECT_FATAL_FAILURE(SUCCEED(), "Expected fatal failure.");
+  // Expected fatal failure, but got a non-fatal failure.
+  printf("(expecting 1 failure)\n");
+  EXPECT_FATAL_FAILURE(AddFailure(NONFATAL_FAILURE), "Expected non-fatal "
+                       "failure.");
+  // Wrong message.
+  printf("(expecting 1 failure)\n");
+  EXPECT_FATAL_FAILURE(AddFailure(FATAL_FAILURE), "Some other fatal failure "
+                       "expected.");
+}
+
+TEST_F(ExpectFailureTest, ExpectNonFatalFailure) {
+  // Expected non-fatal failure, but succeeds.
+  printf("(expecting 1 failure)\n");
+  EXPECT_NONFATAL_FAILURE(SUCCEED(), "Expected non-fatal failure.");
+  // Expected non-fatal failure, but got a fatal failure.
+  printf("(expecting 1 failure)\n");
+  EXPECT_NONFATAL_FAILURE(AddFailure(FATAL_FAILURE), "Expected fatal failure.");
+  // Wrong message.
+  printf("(expecting 1 failure)\n");
+  EXPECT_NONFATAL_FAILURE(AddFailure(NONFATAL_FAILURE), "Some other non-fatal "
+                          "failure.");
+}
+
+#if GTEST_IS_THREADSAFE
+
+class ExpectFailureWithThreadsTest : public ExpectFailureTest {
+ protected:
+  static void AddFailureInOtherThread(FailureMode failure) {
+    ThreadWithParam<FailureMode> thread(&AddFailure, failure, nullptr);
+    thread.Join();
+  }
+};
+
+TEST_F(ExpectFailureWithThreadsTest, ExpectFatalFailure) {
+  // We only intercept the current thread.
+  printf("(expecting 2 failures)\n");
+  EXPECT_FATAL_FAILURE(AddFailureInOtherThread(FATAL_FAILURE),
+                       "Expected fatal failure.");
+}
+
+TEST_F(ExpectFailureWithThreadsTest, ExpectNonFatalFailure) {
+  // We only intercept the current thread.
+  printf("(expecting 2 failures)\n");
+  EXPECT_NONFATAL_FAILURE(AddFailureInOtherThread(NONFATAL_FAILURE),
+                          "Expected non-fatal failure.");
+}
+
+typedef ExpectFailureWithThreadsTest ScopedFakeTestPartResultReporterTest;
+
+// Tests that the ScopedFakeTestPartResultReporter only catches failures from
+// the current thread if it is instantiated with INTERCEPT_ONLY_CURRENT_THREAD.
+TEST_F(ScopedFakeTestPartResultReporterTest, InterceptOnlyCurrentThread) {
+  printf("(expecting 2 failures)\n");
+  TestPartResultArray results;
+  {
+    ScopedFakeTestPartResultReporter reporter(
+        ScopedFakeTestPartResultReporter::INTERCEPT_ONLY_CURRENT_THREAD,
+        &results);
+    AddFailureInOtherThread(FATAL_FAILURE);
+    AddFailureInOtherThread(NONFATAL_FAILURE);
+  }
+  // The two failures should not have been intercepted.
+  EXPECT_EQ(0, results.size()) << "This shouldn't fail.";
+}
+
+#endif  // GTEST_IS_THREADSAFE
+
+TEST_F(ExpectFailureTest, ExpectFatalFailureOnAllThreads) {
+  // Expected fatal failure, but succeeds.
+  printf("(expecting 1 failure)\n");
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(SUCCEED(), "Expected fatal failure.");
+  // Expected fatal failure, but got a non-fatal failure.
+  printf("(expecting 1 failure)\n");
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(AddFailure(NONFATAL_FAILURE),
+                                      "Expected non-fatal failure.");
+  // Wrong message.
+  printf("(expecting 1 failure)\n");
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(AddFailure(FATAL_FAILURE),
+                                      "Some other fatal failure expected.");
+}
+
+TEST_F(ExpectFailureTest, ExpectNonFatalFailureOnAllThreads) {
+  // Expected non-fatal failure, but succeeds.
+  printf("(expecting 1 failure)\n");
+  EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(SUCCEED(), "Expected non-fatal "
+                                         "failure.");
+  // Expected non-fatal failure, but got a fatal failure.
+  printf("(expecting 1 failure)\n");
+  EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(AddFailure(FATAL_FAILURE),
+                                         "Expected fatal failure.");
+  // Wrong message.
+  printf("(expecting 1 failure)\n");
+  EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(AddFailure(NONFATAL_FAILURE),
+                                         "Some other non-fatal failure.");
+}
+
+class DynamicFixture : public testing::Test {
+ protected:
+  DynamicFixture() { printf("DynamicFixture()\n"); }
+  ~DynamicFixture() override { printf("~DynamicFixture()\n"); }
+  void SetUp() override { printf("DynamicFixture::SetUp\n"); }
+  void TearDown() override { printf("DynamicFixture::TearDown\n"); }
+
+  static void SetUpTestSuite() { printf("DynamicFixture::SetUpTestSuite\n"); }
+  static void TearDownTestSuite() {
+    printf("DynamicFixture::TearDownTestSuite\n");
+  }
+};
+
+template <bool Pass>
+class DynamicTest : public DynamicFixture {
+ public:
+  void TestBody() override { EXPECT_TRUE(Pass); }
+};
+
+auto dynamic_test = (
+    // Register two tests with the same fixture correctly.
+    testing::RegisterTest(
+        "DynamicFixture", "DynamicTestPass", nullptr, nullptr, __FILE__,
+        __LINE__, []() -> DynamicFixture* { return new DynamicTest<true>; }),
+    testing::RegisterTest(
+        "DynamicFixture", "DynamicTestFail", nullptr, nullptr, __FILE__,
+        __LINE__, []() -> DynamicFixture* { return new DynamicTest<false>; }),
+
+    // Register the same fixture with another name. That's fine.
+    testing::RegisterTest(
+        "DynamicFixtureAnotherName", "DynamicTestPass", nullptr, nullptr,
+        __FILE__, __LINE__,
+        []() -> DynamicFixture* { return new DynamicTest<true>; }),
+
+    // Register two tests with the same fixture incorrectly.
+    testing::RegisterTest(
+        "BadDynamicFixture1", "FixtureBase", nullptr, nullptr, __FILE__,
+        __LINE__, []() -> DynamicFixture* { return new DynamicTest<true>; }),
+    testing::RegisterTest(
+        "BadDynamicFixture1", "TestBase", nullptr, nullptr, __FILE__, __LINE__,
+        []() -> testing::Test* { return new DynamicTest<true>; }),
+
+    // Register two tests with the same fixture incorrectly by ommiting the
+    // return type.
+    testing::RegisterTest(
+        "BadDynamicFixture2", "FixtureBase", nullptr, nullptr, __FILE__,
+        __LINE__, []() -> DynamicFixture* { return new DynamicTest<true>; }),
+    testing::RegisterTest("BadDynamicFixture2", "Derived", nullptr, nullptr,
+                          __FILE__, __LINE__,
+                          []() { return new DynamicTest<true>; }));
+
+// Two test environments for testing testing::AddGlobalTestEnvironment().
+
+class FooEnvironment : public testing::Environment {
+ public:
+  void SetUp() override { printf("%s", "FooEnvironment::SetUp() called.\n"); }
+
+  void TearDown() override {
+    printf("%s", "FooEnvironment::TearDown() called.\n");
+    FAIL() << "Expected fatal failure.";
+  }
+};
+
+class BarEnvironment : public testing::Environment {
+ public:
+  void SetUp() override { printf("%s", "BarEnvironment::SetUp() called.\n"); }
+
+  void TearDown() override {
+    printf("%s", "BarEnvironment::TearDown() called.\n");
+    ADD_FAILURE() << "Expected non-fatal failure.";
+  }
+};
+
+// The main function.
+//
+// The idea is to use Google Test to run all the tests we have defined (some
+// of them are intended to fail), and then compare the test results
+// with the "golden" file.
+int main(int argc, char **argv) {
+  testing::GTEST_FLAG(print_time) = false;
+
+  // We just run the tests, knowing some of them are intended to fail.
+  // We will use a separate Python script to compare the output of
+  // this program with the golden file.
+
+  // It's hard to test InitGoogleTest() directly, as it has many
+  // global side effects.  The following line serves as a sanity test
+  // for it.
+  testing::InitGoogleTest(&argc, argv);
+  bool internal_skip_environment_and_ad_hoc_tests =
+      std::count(argv, argv + argc,
+                 std::string("internal_skip_environment_and_ad_hoc_tests")) > 0;
+
+#if GTEST_HAS_DEATH_TEST
+  if (testing::internal::GTEST_FLAG(internal_run_death_test) != "") {
+    // Skip the usual output capturing if we're running as the child
+    // process of an threadsafe-style death test.
+# if GTEST_OS_WINDOWS
+    posix::FReopen("nul:", "w", stdout);
+# else
+    posix::FReopen("/dev/null", "w", stdout);
+# endif  // GTEST_OS_WINDOWS
+    return RUN_ALL_TESTS();
+  }
+#endif  // GTEST_HAS_DEATH_TEST
+
+  if (internal_skip_environment_and_ad_hoc_tests)
+    return RUN_ALL_TESTS();
+
+  // Registers two global test environments.
+  // The golden file verifies that they are set up in the order they
+  // are registered, and torn down in the reverse order.
+  testing::AddGlobalTestEnvironment(new FooEnvironment);
+  testing::AddGlobalTestEnvironment(new BarEnvironment);
+#if _MSC_VER
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4127
+#endif  //  _MSC_VER
+  return RunAllTests();
+}
diff --git a/3rdparty/gtest/test/googletest-param-test-invalid-name1-test.py b/3rdparty/gtest/test/googletest-param-test-invalid-name1-test.py
new file mode 100644
index 0000000..2a08477
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-param-test-invalid-name1-test.py
@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+#
+# Copyright 2015 Google Inc. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Verifies that Google Test warns the user when not initialized properly."""
+
+import gtest_test_utils
+
+binary_name = 'googletest-param-test-invalid-name1-test_'
+COMMAND = gtest_test_utils.GetTestExecutablePath(binary_name)
+
+
+def Assert(condition):
+  if not condition:
+    raise AssertionError
+
+
+def TestExitCodeAndOutput(command):
+  """Runs the given command and verifies its exit code and output."""
+
+  err = ('Parameterized test name \'"InvalidWithQuotes"\' is invalid')
+
+  p = gtest_test_utils.Subprocess(command)
+  Assert(p.terminated_by_signal)
+
+  # Verify the output message contains appropriate output
+  Assert(err in p.output)
+
+
+class GTestParamTestInvalidName1Test(gtest_test_utils.TestCase):
+
+  def testExitCodeAndOutput(self):
+    TestExitCodeAndOutput(COMMAND)
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-param-test-invalid-name1-test_.cc b/3rdparty/gtest/test/googletest-param-test-invalid-name1-test_.cc
new file mode 100644
index 0000000..955d699
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-param-test-invalid-name1-test_.cc
@@ -0,0 +1,50 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include "gtest/gtest.h"
+
+namespace {
+class DummyTest : public ::testing::TestWithParam<const char *> {};
+
+TEST_P(DummyTest, Dummy) {
+}
+
+INSTANTIATE_TEST_SUITE_P(InvalidTestName,
+                         DummyTest,
+                         ::testing::Values("InvalidWithQuotes"),
+                         ::testing::PrintToStringParamName());
+
+}  // namespace
+
+int main(int argc, char *argv[]) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+
diff --git a/3rdparty/gtest/test/googletest-param-test-invalid-name2-test.py b/3rdparty/gtest/test/googletest-param-test-invalid-name2-test.py
new file mode 100644
index 0000000..ab838f4
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-param-test-invalid-name2-test.py
@@ -0,0 +1,62 @@
+#!/usr/bin/env python
+#
+# Copyright 2015 Google Inc. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Verifies that Google Test warns the user when not initialized properly."""
+
+import gtest_test_utils
+
+binary_name = 'googletest-param-test-invalid-name2-test_'
+COMMAND = gtest_test_utils.GetTestExecutablePath(binary_name)
+
+
+def Assert(condition):
+  if not condition:
+    raise AssertionError
+
+
+def TestExitCodeAndOutput(command):
+  """Runs the given command and verifies its exit code and output."""
+
+  err = ('Duplicate parameterized test name \'a\'')
+
+  p = gtest_test_utils.Subprocess(command)
+  Assert(p.terminated_by_signal)
+
+  # Check for appropriate output
+  Assert(err in p.output)
+
+
+class GTestParamTestInvalidName2Test(gtest_test_utils.TestCase):
+
+  def testExitCodeAndOutput(self):
+    TestExitCodeAndOutput(COMMAND)
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-param-test-invalid-name2-test_.cc b/3rdparty/gtest/test/googletest-param-test-invalid-name2-test_.cc
new file mode 100644
index 0000000..76371df
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-param-test-invalid-name2-test_.cc
@@ -0,0 +1,55 @@
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include "gtest/gtest.h"
+
+namespace {
+class DummyTest : public ::testing::TestWithParam<const char *> {};
+
+std::string StringParamTestSuffix(
+    const testing::TestParamInfo<const char*>& info) {
+  return std::string(info.param);
+}
+
+TEST_P(DummyTest, Dummy) {
+}
+
+INSTANTIATE_TEST_SUITE_P(DuplicateTestNames,
+                         DummyTest,
+                         ::testing::Values("a", "b", "a", "c"),
+                         StringParamTestSuffix);
+}  // namespace
+
+int main(int argc, char *argv[]) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+
+
diff --git a/3rdparty/gtest/test/googletest-param-test-test.cc b/3rdparty/gtest/test/googletest-param-test-test.cc
new file mode 100644
index 0000000..6c187df
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-param-test-test.cc
@@ -0,0 +1,1055 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests for Google Test itself. This file verifies that the parameter
+// generators objects produce correct parameter sequences and that
+// Google Test runtime instantiates correct tests from those sequences.
+
+#include "gtest/gtest.h"
+
+# include <algorithm>
+# include <iostream>
+# include <list>
+# include <sstream>
+# include <string>
+# include <vector>
+
+# include "src/gtest-internal-inl.h"  // for UnitTestOptions
+# include "test/googletest-param-test-test.h"
+
+using ::std::vector;
+using ::std::sort;
+
+using ::testing::AddGlobalTestEnvironment;
+using ::testing::Bool;
+using ::testing::Combine;
+using ::testing::Message;
+using ::testing::Range;
+using ::testing::TestWithParam;
+using ::testing::Values;
+using ::testing::ValuesIn;
+
+using ::testing::internal::ParamGenerator;
+using ::testing::internal::UnitTestOptions;
+
+// Prints a value to a string.
+//
+// FIXME: remove PrintValue() when we move matchers and
+// EXPECT_THAT() from Google Mock to Google Test.  At that time, we
+// can write EXPECT_THAT(x, Eq(y)) to compare two tuples x and y, as
+// EXPECT_THAT() and the matchers know how to print tuples.
+template <typename T>
+::std::string PrintValue(const T& value) {
+  return testing::PrintToString(value);
+}
+
+// Verifies that a sequence generated by the generator and accessed
+// via the iterator object matches the expected one using Google Test
+// assertions.
+template <typename T, size_t N>
+void VerifyGenerator(const ParamGenerator<T>& generator,
+                     const T (&expected_values)[N]) {
+  typename ParamGenerator<T>::iterator it = generator.begin();
+  for (size_t i = 0; i < N; ++i) {
+    ASSERT_FALSE(it == generator.end())
+        << "At element " << i << " when accessing via an iterator "
+        << "created with the copy constructor.\n";
+    // We cannot use EXPECT_EQ() here as the values may be tuples,
+    // which don't support <<.
+    EXPECT_TRUE(expected_values[i] == *it)
+        << "where i is " << i
+        << ", expected_values[i] is " << PrintValue(expected_values[i])
+        << ", *it is " << PrintValue(*it)
+        << ", and 'it' is an iterator created with the copy constructor.\n";
+    ++it;
+  }
+  EXPECT_TRUE(it == generator.end())
+        << "At the presumed end of sequence when accessing via an iterator "
+        << "created with the copy constructor.\n";
+
+  // Test the iterator assignment. The following lines verify that
+  // the sequence accessed via an iterator initialized via the
+  // assignment operator (as opposed to a copy constructor) matches
+  // just the same.
+  it = generator.begin();
+  for (size_t i = 0; i < N; ++i) {
+    ASSERT_FALSE(it == generator.end())
+        << "At element " << i << " when accessing via an iterator "
+        << "created with the assignment operator.\n";
+    EXPECT_TRUE(expected_values[i] == *it)
+        << "where i is " << i
+        << ", expected_values[i] is " << PrintValue(expected_values[i])
+        << ", *it is " << PrintValue(*it)
+        << ", and 'it' is an iterator created with the copy constructor.\n";
+    ++it;
+  }
+  EXPECT_TRUE(it == generator.end())
+        << "At the presumed end of sequence when accessing via an iterator "
+        << "created with the assignment operator.\n";
+}
+
+template <typename T>
+void VerifyGeneratorIsEmpty(const ParamGenerator<T>& generator) {
+  typename ParamGenerator<T>::iterator it = generator.begin();
+  EXPECT_TRUE(it == generator.end());
+
+  it = generator.begin();
+  EXPECT_TRUE(it == generator.end());
+}
+
+// Generator tests. They test that each of the provided generator functions
+// generates an expected sequence of values. The general test pattern
+// instantiates a generator using one of the generator functions,
+// checks the sequence produced by the generator using its iterator API,
+// and then resets the iterator back to the beginning of the sequence
+// and checks the sequence again.
+
+// Tests that iterators produced by generator functions conform to the
+// ForwardIterator concept.
+TEST(IteratorTest, ParamIteratorConformsToForwardIteratorConcept) {
+  const ParamGenerator<int> gen = Range(0, 10);
+  ParamGenerator<int>::iterator it = gen.begin();
+
+  // Verifies that iterator initialization works as expected.
+  ParamGenerator<int>::iterator it2 = it;
+  EXPECT_TRUE(*it == *it2) << "Initialized iterators must point to the "
+                           << "element same as its source points to";
+
+  // Verifies that iterator assignment works as expected.
+  ++it;
+  EXPECT_FALSE(*it == *it2);
+  it2 = it;
+  EXPECT_TRUE(*it == *it2) << "Assigned iterators must point to the "
+                           << "element same as its source points to";
+
+  // Verifies that prefix operator++() returns *this.
+  EXPECT_EQ(&it, &(++it)) << "Result of the prefix operator++ must be "
+                          << "refer to the original object";
+
+  // Verifies that the result of the postfix operator++ points to the value
+  // pointed to by the original iterator.
+  int original_value = *it;  // Have to compute it outside of macro call to be
+                             // unaffected by the parameter evaluation order.
+  EXPECT_EQ(original_value, *(it++));
+
+  // Verifies that prefix and postfix operator++() advance an iterator
+  // all the same.
+  it2 = it;
+  ++it;
+  ++it2;
+  EXPECT_TRUE(*it == *it2);
+}
+
+// Tests that Range() generates the expected sequence.
+TEST(RangeTest, IntRangeWithDefaultStep) {
+  const ParamGenerator<int> gen = Range(0, 3);
+  const int expected_values[] = {0, 1, 2};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Edge case. Tests that Range() generates the single element sequence
+// as expected when provided with range limits that are equal.
+TEST(RangeTest, IntRangeSingleValue) {
+  const ParamGenerator<int> gen = Range(0, 1);
+  const int expected_values[] = {0};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Edge case. Tests that Range() with generates empty sequence when
+// supplied with an empty range.
+TEST(RangeTest, IntRangeEmpty) {
+  const ParamGenerator<int> gen = Range(0, 0);
+  VerifyGeneratorIsEmpty(gen);
+}
+
+// Tests that Range() with custom step (greater then one) generates
+// the expected sequence.
+TEST(RangeTest, IntRangeWithCustomStep) {
+  const ParamGenerator<int> gen = Range(0, 9, 3);
+  const int expected_values[] = {0, 3, 6};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Tests that Range() with custom step (greater then one) generates
+// the expected sequence when the last element does not fall on the
+// upper range limit. Sequences generated by Range() must not have
+// elements beyond the range limits.
+TEST(RangeTest, IntRangeWithCustomStepOverUpperBound) {
+  const ParamGenerator<int> gen = Range(0, 4, 3);
+  const int expected_values[] = {0, 3};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Verifies that Range works with user-defined types that define
+// copy constructor, operator=(), operator+(), and operator<().
+class DogAdder {
+ public:
+  explicit DogAdder(const char* a_value) : value_(a_value) {}
+  DogAdder(const DogAdder& other) : value_(other.value_.c_str()) {}
+
+  DogAdder operator=(const DogAdder& other) {
+    if (this != &other)
+      value_ = other.value_;
+    return *this;
+  }
+  DogAdder operator+(const DogAdder& other) const {
+    Message msg;
+    msg << value_.c_str() << other.value_.c_str();
+    return DogAdder(msg.GetString().c_str());
+  }
+  bool operator<(const DogAdder& other) const {
+    return value_ < other.value_;
+  }
+  const std::string& value() const { return value_; }
+
+ private:
+  std::string value_;
+};
+
+TEST(RangeTest, WorksWithACustomType) {
+  const ParamGenerator<DogAdder> gen =
+      Range(DogAdder("cat"), DogAdder("catdogdog"), DogAdder("dog"));
+  ParamGenerator<DogAdder>::iterator it = gen.begin();
+
+  ASSERT_FALSE(it == gen.end());
+  EXPECT_STREQ("cat", it->value().c_str());
+
+  ASSERT_FALSE(++it == gen.end());
+  EXPECT_STREQ("catdog", it->value().c_str());
+
+  EXPECT_TRUE(++it == gen.end());
+}
+
+class IntWrapper {
+ public:
+  explicit IntWrapper(int a_value) : value_(a_value) {}
+  IntWrapper(const IntWrapper& other) : value_(other.value_) {}
+
+  IntWrapper operator=(const IntWrapper& other) {
+    value_ = other.value_;
+    return *this;
+  }
+  // operator+() adds a different type.
+  IntWrapper operator+(int other) const { return IntWrapper(value_ + other); }
+  bool operator<(const IntWrapper& other) const {
+    return value_ < other.value_;
+  }
+  int value() const { return value_; }
+
+ private:
+  int value_;
+};
+
+TEST(RangeTest, WorksWithACustomTypeWithDifferentIncrementType) {
+  const ParamGenerator<IntWrapper> gen = Range(IntWrapper(0), IntWrapper(2));
+  ParamGenerator<IntWrapper>::iterator it = gen.begin();
+
+  ASSERT_FALSE(it == gen.end());
+  EXPECT_EQ(0, it->value());
+
+  ASSERT_FALSE(++it == gen.end());
+  EXPECT_EQ(1, it->value());
+
+  EXPECT_TRUE(++it == gen.end());
+}
+
+// Tests that ValuesIn() with an array parameter generates
+// the expected sequence.
+TEST(ValuesInTest, ValuesInArray) {
+  int array[] = {3, 5, 8};
+  const ParamGenerator<int> gen = ValuesIn(array);
+  VerifyGenerator(gen, array);
+}
+
+// Tests that ValuesIn() with a const array parameter generates
+// the expected sequence.
+TEST(ValuesInTest, ValuesInConstArray) {
+  const int array[] = {3, 5, 8};
+  const ParamGenerator<int> gen = ValuesIn(array);
+  VerifyGenerator(gen, array);
+}
+
+// Edge case. Tests that ValuesIn() with an array parameter containing a
+// single element generates the single element sequence.
+TEST(ValuesInTest, ValuesInSingleElementArray) {
+  int array[] = {42};
+  const ParamGenerator<int> gen = ValuesIn(array);
+  VerifyGenerator(gen, array);
+}
+
+// Tests that ValuesIn() generates the expected sequence for an STL
+// container (vector).
+TEST(ValuesInTest, ValuesInVector) {
+  typedef ::std::vector<int> ContainerType;
+  ContainerType values;
+  values.push_back(3);
+  values.push_back(5);
+  values.push_back(8);
+  const ParamGenerator<int> gen = ValuesIn(values);
+
+  const int expected_values[] = {3, 5, 8};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Tests that ValuesIn() generates the expected sequence.
+TEST(ValuesInTest, ValuesInIteratorRange) {
+  typedef ::std::vector<int> ContainerType;
+  ContainerType values;
+  values.push_back(3);
+  values.push_back(5);
+  values.push_back(8);
+  const ParamGenerator<int> gen = ValuesIn(values.begin(), values.end());
+
+  const int expected_values[] = {3, 5, 8};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Edge case. Tests that ValuesIn() provided with an iterator range specifying a
+// single value generates a single-element sequence.
+TEST(ValuesInTest, ValuesInSingleElementIteratorRange) {
+  typedef ::std::vector<int> ContainerType;
+  ContainerType values;
+  values.push_back(42);
+  const ParamGenerator<int> gen = ValuesIn(values.begin(), values.end());
+
+  const int expected_values[] = {42};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Edge case. Tests that ValuesIn() provided with an empty iterator range
+// generates an empty sequence.
+TEST(ValuesInTest, ValuesInEmptyIteratorRange) {
+  typedef ::std::vector<int> ContainerType;
+  ContainerType values;
+  const ParamGenerator<int> gen = ValuesIn(values.begin(), values.end());
+
+  VerifyGeneratorIsEmpty(gen);
+}
+
+// Tests that the Values() generates the expected sequence.
+TEST(ValuesTest, ValuesWorks) {
+  const ParamGenerator<int> gen = Values(3, 5, 8);
+
+  const int expected_values[] = {3, 5, 8};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Tests that Values() generates the expected sequences from elements of
+// different types convertible to ParamGenerator's parameter type.
+TEST(ValuesTest, ValuesWorksForValuesOfCompatibleTypes) {
+  const ParamGenerator<double> gen = Values(3, 5.0f, 8.0);
+
+  const double expected_values[] = {3.0, 5.0, 8.0};
+  VerifyGenerator(gen, expected_values);
+}
+
+TEST(ValuesTest, ValuesWorksForMaxLengthList) {
+  const ParamGenerator<int> gen = Values(
+      10, 20, 30, 40, 50, 60, 70, 80, 90, 100,
+      110, 120, 130, 140, 150, 160, 170, 180, 190, 200,
+      210, 220, 230, 240, 250, 260, 270, 280, 290, 300,
+      310, 320, 330, 340, 350, 360, 370, 380, 390, 400,
+      410, 420, 430, 440, 450, 460, 470, 480, 490, 500);
+
+  const int expected_values[] = {
+      10, 20, 30, 40, 50, 60, 70, 80, 90, 100,
+      110, 120, 130, 140, 150, 160, 170, 180, 190, 200,
+      210, 220, 230, 240, 250, 260, 270, 280, 290, 300,
+      310, 320, 330, 340, 350, 360, 370, 380, 390, 400,
+      410, 420, 430, 440, 450, 460, 470, 480, 490, 500};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Edge case test. Tests that single-parameter Values() generates the sequence
+// with the single value.
+TEST(ValuesTest, ValuesWithSingleParameter) {
+  const ParamGenerator<int> gen = Values(42);
+
+  const int expected_values[] = {42};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Tests that Bool() generates sequence (false, true).
+TEST(BoolTest, BoolWorks) {
+  const ParamGenerator<bool> gen = Bool();
+
+  const bool expected_values[] = {false, true};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Tests that Combine() with two parameters generates the expected sequence.
+TEST(CombineTest, CombineWithTwoParameters) {
+  const char* foo = "foo";
+  const char* bar = "bar";
+  const ParamGenerator<std::tuple<const char*, int> > gen =
+      Combine(Values(foo, bar), Values(3, 4));
+
+  std::tuple<const char*, int> expected_values[] = {
+      std::make_tuple(foo, 3), std::make_tuple(foo, 4), std::make_tuple(bar, 3),
+      std::make_tuple(bar, 4)};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Tests that Combine() with three parameters generates the expected sequence.
+TEST(CombineTest, CombineWithThreeParameters) {
+  const ParamGenerator<std::tuple<int, int, int> > gen =
+      Combine(Values(0, 1), Values(3, 4), Values(5, 6));
+  std::tuple<int, int, int> expected_values[] = {
+      std::make_tuple(0, 3, 5), std::make_tuple(0, 3, 6),
+      std::make_tuple(0, 4, 5), std::make_tuple(0, 4, 6),
+      std::make_tuple(1, 3, 5), std::make_tuple(1, 3, 6),
+      std::make_tuple(1, 4, 5), std::make_tuple(1, 4, 6)};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Tests that the Combine() with the first parameter generating a single value
+// sequence generates a sequence with the number of elements equal to the
+// number of elements in the sequence generated by the second parameter.
+TEST(CombineTest, CombineWithFirstParameterSingleValue) {
+  const ParamGenerator<std::tuple<int, int> > gen =
+      Combine(Values(42), Values(0, 1));
+
+  std::tuple<int, int> expected_values[] = {std::make_tuple(42, 0),
+                                            std::make_tuple(42, 1)};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Tests that the Combine() with the second parameter generating a single value
+// sequence generates a sequence with the number of elements equal to the
+// number of elements in the sequence generated by the first parameter.
+TEST(CombineTest, CombineWithSecondParameterSingleValue) {
+  const ParamGenerator<std::tuple<int, int> > gen =
+      Combine(Values(0, 1), Values(42));
+
+  std::tuple<int, int> expected_values[] = {std::make_tuple(0, 42),
+                                            std::make_tuple(1, 42)};
+  VerifyGenerator(gen, expected_values);
+}
+
+// Tests that when the first parameter produces an empty sequence,
+// Combine() produces an empty sequence, too.
+TEST(CombineTest, CombineWithFirstParameterEmptyRange) {
+  const ParamGenerator<std::tuple<int, int> > gen =
+      Combine(Range(0, 0), Values(0, 1));
+  VerifyGeneratorIsEmpty(gen);
+}
+
+// Tests that when the second parameter produces an empty sequence,
+// Combine() produces an empty sequence, too.
+TEST(CombineTest, CombineWithSecondParameterEmptyRange) {
+  const ParamGenerator<std::tuple<int, int> > gen =
+      Combine(Values(0, 1), Range(1, 1));
+  VerifyGeneratorIsEmpty(gen);
+}
+
+// Edge case. Tests that combine works with the maximum number
+// of parameters supported by Google Test (currently 10).
+TEST(CombineTest, CombineWithMaxNumberOfParameters) {
+  const char* foo = "foo";
+  const char* bar = "bar";
+  const ParamGenerator<
+      std::tuple<const char*, int, int, int, int, int, int, int, int, int> >
+      gen =
+          Combine(Values(foo, bar), Values(1), Values(2), Values(3), Values(4),
+                  Values(5), Values(6), Values(7), Values(8), Values(9));
+
+  std::tuple<const char*, int, int, int, int, int, int, int, int, int>
+      expected_values[] = {std::make_tuple(foo, 1, 2, 3, 4, 5, 6, 7, 8, 9),
+                           std::make_tuple(bar, 1, 2, 3, 4, 5, 6, 7, 8, 9)};
+  VerifyGenerator(gen, expected_values);
+}
+
+class NonDefaultConstructAssignString {
+ public:
+  NonDefaultConstructAssignString(const std::string& s) : str_(s) {}
+
+  const std::string& str() const { return str_; }
+
+ private:
+  std::string str_;
+
+  // Not default constructible
+  NonDefaultConstructAssignString();
+  // Not assignable
+  void operator=(const NonDefaultConstructAssignString&);
+};
+
+TEST(CombineTest, NonDefaultConstructAssign) {
+  const ParamGenerator<std::tuple<int, NonDefaultConstructAssignString> > gen =
+      Combine(Values(0, 1), Values(NonDefaultConstructAssignString("A"),
+                                   NonDefaultConstructAssignString("B")));
+
+  ParamGenerator<std::tuple<int, NonDefaultConstructAssignString> >::iterator
+      it = gen.begin();
+
+  EXPECT_EQ(0, std::get<0>(*it));
+  EXPECT_EQ("A", std::get<1>(*it).str());
+  ++it;
+
+  EXPECT_EQ(0, std::get<0>(*it));
+  EXPECT_EQ("B", std::get<1>(*it).str());
+  ++it;
+
+  EXPECT_EQ(1, std::get<0>(*it));
+  EXPECT_EQ("A", std::get<1>(*it).str());
+  ++it;
+
+  EXPECT_EQ(1, std::get<0>(*it));
+  EXPECT_EQ("B", std::get<1>(*it).str());
+  ++it;
+
+  EXPECT_TRUE(it == gen.end());
+}
+
+
+// Tests that an generator produces correct sequence after being
+// assigned from another generator.
+TEST(ParamGeneratorTest, AssignmentWorks) {
+  ParamGenerator<int> gen = Values(1, 2);
+  const ParamGenerator<int> gen2 = Values(3, 4);
+  gen = gen2;
+
+  const int expected_values[] = {3, 4};
+  VerifyGenerator(gen, expected_values);
+}
+
+// This test verifies that the tests are expanded and run as specified:
+// one test per element from the sequence produced by the generator
+// specified in INSTANTIATE_TEST_SUITE_P. It also verifies that the test's
+// fixture constructor, SetUp(), and TearDown() have run and have been
+// supplied with the correct parameters.
+
+// The use of environment object allows detection of the case where no test
+// case functionality is run at all. In this case TearDownTestSuite will not
+// be able to detect missing tests, naturally.
+template <int kExpectedCalls>
+class TestGenerationEnvironment : public ::testing::Environment {
+ public:
+  static TestGenerationEnvironment* Instance() {
+    static TestGenerationEnvironment* instance = new TestGenerationEnvironment;
+    return instance;
+  }
+
+  void FixtureConstructorExecuted() { fixture_constructor_count_++; }
+  void SetUpExecuted() { set_up_count_++; }
+  void TearDownExecuted() { tear_down_count_++; }
+  void TestBodyExecuted() { test_body_count_++; }
+
+  void TearDown() override {
+    // If all MultipleTestGenerationTest tests have been de-selected
+    // by the filter flag, the following checks make no sense.
+    bool perform_check = false;
+
+    for (int i = 0; i < kExpectedCalls; ++i) {
+      Message msg;
+      msg << "TestsExpandedAndRun/" << i;
+      if (UnitTestOptions::FilterMatchesTest(
+             "TestExpansionModule/MultipleTestGenerationTest",
+              msg.GetString().c_str())) {
+        perform_check = true;
+      }
+    }
+    if (perform_check) {
+      EXPECT_EQ(kExpectedCalls, fixture_constructor_count_)
+          << "Fixture constructor of ParamTestGenerationTest test case "
+          << "has not been run as expected.";
+      EXPECT_EQ(kExpectedCalls, set_up_count_)
+          << "Fixture SetUp method of ParamTestGenerationTest test case "
+          << "has not been run as expected.";
+      EXPECT_EQ(kExpectedCalls, tear_down_count_)
+          << "Fixture TearDown method of ParamTestGenerationTest test case "
+          << "has not been run as expected.";
+      EXPECT_EQ(kExpectedCalls, test_body_count_)
+          << "Test in ParamTestGenerationTest test case "
+          << "has not been run as expected.";
+    }
+  }
+
+ private:
+  TestGenerationEnvironment() : fixture_constructor_count_(0), set_up_count_(0),
+                                tear_down_count_(0), test_body_count_(0) {}
+
+  int fixture_constructor_count_;
+  int set_up_count_;
+  int tear_down_count_;
+  int test_body_count_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestGenerationEnvironment);
+};
+
+const int test_generation_params[] = {36, 42, 72};
+
+class TestGenerationTest : public TestWithParam<int> {
+ public:
+  enum {
+    PARAMETER_COUNT =
+        sizeof(test_generation_params)/sizeof(test_generation_params[0])
+  };
+
+  typedef TestGenerationEnvironment<PARAMETER_COUNT> Environment;
+
+  TestGenerationTest() {
+    Environment::Instance()->FixtureConstructorExecuted();
+    current_parameter_ = GetParam();
+  }
+  void SetUp() override {
+    Environment::Instance()->SetUpExecuted();
+    EXPECT_EQ(current_parameter_, GetParam());
+  }
+  void TearDown() override {
+    Environment::Instance()->TearDownExecuted();
+    EXPECT_EQ(current_parameter_, GetParam());
+  }
+
+  static void SetUpTestSuite() {
+    bool all_tests_in_test_case_selected = true;
+
+    for (int i = 0; i < PARAMETER_COUNT; ++i) {
+      Message test_name;
+      test_name << "TestsExpandedAndRun/" << i;
+      if ( !UnitTestOptions::FilterMatchesTest(
+                "TestExpansionModule/MultipleTestGenerationTest",
+                test_name.GetString())) {
+        all_tests_in_test_case_selected = false;
+      }
+    }
+    EXPECT_TRUE(all_tests_in_test_case_selected)
+        << "When running the TestGenerationTest test case all of its tests\n"
+        << "must be selected by the filter flag for the test case to pass.\n"
+        << "If not all of them are enabled, we can't reliably conclude\n"
+        << "that the correct number of tests have been generated.";
+
+    collected_parameters_.clear();
+  }
+
+  static void TearDownTestSuite() {
+    vector<int> expected_values(test_generation_params,
+                                test_generation_params + PARAMETER_COUNT);
+    // Test execution order is not guaranteed by Google Test,
+    // so the order of values in collected_parameters_ can be
+    // different and we have to sort to compare.
+    sort(expected_values.begin(), expected_values.end());
+    sort(collected_parameters_.begin(), collected_parameters_.end());
+
+    EXPECT_TRUE(collected_parameters_ == expected_values);
+  }
+
+ protected:
+  int current_parameter_;
+  static vector<int> collected_parameters_;
+
+ private:
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestGenerationTest);
+};
+vector<int> TestGenerationTest::collected_parameters_;
+
+TEST_P(TestGenerationTest, TestsExpandedAndRun) {
+  Environment::Instance()->TestBodyExecuted();
+  EXPECT_EQ(current_parameter_, GetParam());
+  collected_parameters_.push_back(GetParam());
+}
+INSTANTIATE_TEST_SUITE_P(TestExpansionModule, TestGenerationTest,
+                         ValuesIn(test_generation_params));
+
+// This test verifies that the element sequence (third parameter of
+// INSTANTIATE_TEST_SUITE_P) is evaluated in InitGoogleTest() and neither at
+// the call site of INSTANTIATE_TEST_SUITE_P nor in RUN_ALL_TESTS().  For
+// that, we declare param_value_ to be a static member of
+// GeneratorEvaluationTest and initialize it to 0.  We set it to 1 in
+// main(), just before invocation of InitGoogleTest().  After calling
+// InitGoogleTest(), we set the value to 2.  If the sequence is evaluated
+// before or after InitGoogleTest, INSTANTIATE_TEST_SUITE_P will create a
+// test with parameter other than 1, and the test body will fail the
+// assertion.
+class GeneratorEvaluationTest : public TestWithParam<int> {
+ public:
+  static int param_value() { return param_value_; }
+  static void set_param_value(int param_value) { param_value_ = param_value; }
+
+ private:
+  static int param_value_;
+};
+int GeneratorEvaluationTest::param_value_ = 0;
+
+TEST_P(GeneratorEvaluationTest, GeneratorsEvaluatedInMain) {
+  EXPECT_EQ(1, GetParam());
+}
+INSTANTIATE_TEST_SUITE_P(GenEvalModule, GeneratorEvaluationTest,
+                         Values(GeneratorEvaluationTest::param_value()));
+
+// Tests that generators defined in a different translation unit are
+// functional. Generator extern_gen is defined in gtest-param-test_test2.cc.
+extern ParamGenerator<int> extern_gen;
+class ExternalGeneratorTest : public TestWithParam<int> {};
+TEST_P(ExternalGeneratorTest, ExternalGenerator) {
+  // Sequence produced by extern_gen contains only a single value
+  // which we verify here.
+  EXPECT_EQ(GetParam(), 33);
+}
+INSTANTIATE_TEST_SUITE_P(ExternalGeneratorModule, ExternalGeneratorTest,
+                         extern_gen);
+
+// Tests that a parameterized test case can be defined in one translation
+// unit and instantiated in another. This test will be instantiated in
+// gtest-param-test_test2.cc. ExternalInstantiationTest fixture class is
+// defined in gtest-param-test_test.h.
+TEST_P(ExternalInstantiationTest, IsMultipleOf33) {
+  EXPECT_EQ(0, GetParam() % 33);
+}
+
+// Tests that a parameterized test case can be instantiated with multiple
+// generators.
+class MultipleInstantiationTest : public TestWithParam<int> {};
+TEST_P(MultipleInstantiationTest, AllowsMultipleInstances) {
+}
+INSTANTIATE_TEST_SUITE_P(Sequence1, MultipleInstantiationTest, Values(1, 2));
+INSTANTIATE_TEST_SUITE_P(Sequence2, MultipleInstantiationTest, Range(3, 5));
+
+// Tests that a parameterized test case can be instantiated
+// in multiple translation units. This test will be instantiated
+// here and in gtest-param-test_test2.cc.
+// InstantiationInMultipleTranslationUnitsTest fixture class
+// is defined in gtest-param-test_test.h.
+TEST_P(InstantiationInMultipleTranslationUnitsTest, IsMultipleOf42) {
+  EXPECT_EQ(0, GetParam() % 42);
+}
+INSTANTIATE_TEST_SUITE_P(Sequence1, InstantiationInMultipleTranslationUnitsTest,
+                         Values(42, 42 * 2));
+
+// Tests that each iteration of parameterized test runs in a separate test
+// object.
+class SeparateInstanceTest : public TestWithParam<int> {
+ public:
+  SeparateInstanceTest() : count_(0) {}
+
+  static void TearDownTestSuite() {
+    EXPECT_GE(global_count_, 2)
+        << "If some (but not all) SeparateInstanceTest tests have been "
+        << "filtered out this test will fail. Make sure that all "
+        << "GeneratorEvaluationTest are selected or de-selected together "
+        << "by the test filter.";
+  }
+
+ protected:
+  int count_;
+  static int global_count_;
+};
+int SeparateInstanceTest::global_count_ = 0;
+
+TEST_P(SeparateInstanceTest, TestsRunInSeparateInstances) {
+  EXPECT_EQ(0, count_++);
+  global_count_++;
+}
+INSTANTIATE_TEST_SUITE_P(FourElemSequence, SeparateInstanceTest, Range(1, 4));
+
+// Tests that all instantiations of a test have named appropriately. Test
+// defined with TEST_P(TestSuiteName, TestName) and instantiated with
+// INSTANTIATE_TEST_SUITE_P(SequenceName, TestSuiteName, generator) must be
+// named SequenceName/TestSuiteName.TestName/i, where i is the 0-based index of
+// the sequence element used to instantiate the test.
+class NamingTest : public TestWithParam<int> {};
+
+TEST_P(NamingTest, TestsReportCorrectNamesAndParameters) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+
+  EXPECT_STREQ("ZeroToFiveSequence/NamingTest", test_info->test_suite_name());
+
+  Message index_stream;
+  index_stream << "TestsReportCorrectNamesAndParameters/" << GetParam();
+  EXPECT_STREQ(index_stream.GetString().c_str(), test_info->name());
+
+  EXPECT_EQ(::testing::PrintToString(GetParam()), test_info->value_param());
+}
+
+INSTANTIATE_TEST_SUITE_P(ZeroToFiveSequence, NamingTest, Range(0, 5));
+
+// Tests that macros in test names are expanded correctly.
+class MacroNamingTest : public TestWithParam<int> {};
+
+#define PREFIX_WITH_FOO(test_name) Foo##test_name
+#define PREFIX_WITH_MACRO(test_name) Macro##test_name
+
+TEST_P(PREFIX_WITH_MACRO(NamingTest), PREFIX_WITH_FOO(SomeTestName)) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+
+  EXPECT_STREQ("FortyTwo/MacroNamingTest", test_info->test_suite_name());
+  EXPECT_STREQ("FooSomeTestName", test_info->name());
+}
+
+INSTANTIATE_TEST_SUITE_P(FortyTwo, MacroNamingTest, Values(42));
+
+// Tests the same thing for non-parametrized tests.
+class MacroNamingTestNonParametrized : public ::testing::Test {};
+
+TEST_F(PREFIX_WITH_MACRO(NamingTestNonParametrized),
+       PREFIX_WITH_FOO(SomeTestName)) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+
+  EXPECT_STREQ("MacroNamingTestNonParametrized", test_info->test_suite_name());
+  EXPECT_STREQ("FooSomeTestName", test_info->name());
+}
+
+// Tests that user supplied custom parameter names are working correctly.
+// Runs the test with a builtin helper method which uses PrintToString,
+// as well as a custom function and custom functor to ensure all possible
+// uses work correctly.
+class CustomFunctorNamingTest : public TestWithParam<std::string> {};
+TEST_P(CustomFunctorNamingTest, CustomTestNames) {}
+
+struct CustomParamNameFunctor {
+  std::string operator()(const ::testing::TestParamInfo<std::string>& inf) {
+    return inf.param;
+  }
+};
+
+INSTANTIATE_TEST_SUITE_P(CustomParamNameFunctor, CustomFunctorNamingTest,
+                         Values(std::string("FunctorName")),
+                         CustomParamNameFunctor());
+
+INSTANTIATE_TEST_SUITE_P(AllAllowedCharacters, CustomFunctorNamingTest,
+                         Values("abcdefghijklmnopqrstuvwxyz",
+                                "ABCDEFGHIJKLMNOPQRSTUVWXYZ", "01234567890_"),
+                         CustomParamNameFunctor());
+
+inline std::string CustomParamNameFunction(
+    const ::testing::TestParamInfo<std::string>& inf) {
+  return inf.param;
+}
+
+class CustomFunctionNamingTest : public TestWithParam<std::string> {};
+TEST_P(CustomFunctionNamingTest, CustomTestNames) {}
+
+INSTANTIATE_TEST_SUITE_P(CustomParamNameFunction, CustomFunctionNamingTest,
+                         Values(std::string("FunctionName")),
+                         CustomParamNameFunction);
+
+INSTANTIATE_TEST_SUITE_P(CustomParamNameFunctionP, CustomFunctionNamingTest,
+                         Values(std::string("FunctionNameP")),
+                         &CustomParamNameFunction);
+
+// Test custom naming with a lambda
+
+class CustomLambdaNamingTest : public TestWithParam<std::string> {};
+TEST_P(CustomLambdaNamingTest, CustomTestNames) {}
+
+INSTANTIATE_TEST_SUITE_P(CustomParamNameLambda, CustomLambdaNamingTest,
+                         Values(std::string("LambdaName")),
+                         [](const ::testing::TestParamInfo<std::string>& inf) {
+                           return inf.param;
+                         });
+
+TEST(CustomNamingTest, CheckNameRegistry) {
+  ::testing::UnitTest* unit_test = ::testing::UnitTest::GetInstance();
+  std::set<std::string> test_names;
+  for (int suite_num = 0; suite_num < unit_test->total_test_suite_count();
+       ++suite_num) {
+    const ::testing::TestSuite* test_suite = unit_test->GetTestSuite(suite_num);
+    for (int test_num = 0; test_num < test_suite->total_test_count();
+         ++test_num) {
+      const ::testing::TestInfo* test_info = test_suite->GetTestInfo(test_num);
+      test_names.insert(std::string(test_info->name()));
+    }
+  }
+  EXPECT_EQ(1u, test_names.count("CustomTestNames/FunctorName"));
+  EXPECT_EQ(1u, test_names.count("CustomTestNames/FunctionName"));
+  EXPECT_EQ(1u, test_names.count("CustomTestNames/FunctionNameP"));
+  EXPECT_EQ(1u, test_names.count("CustomTestNames/LambdaName"));
+}
+
+// Test a numeric name to ensure PrintToStringParamName works correctly.
+
+class CustomIntegerNamingTest : public TestWithParam<int> {};
+
+TEST_P(CustomIntegerNamingTest, TestsReportCorrectNames) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+  Message test_name_stream;
+  test_name_stream << "TestsReportCorrectNames/" << GetParam();
+  EXPECT_STREQ(test_name_stream.GetString().c_str(), test_info->name());
+}
+
+INSTANTIATE_TEST_SUITE_P(PrintToString, CustomIntegerNamingTest, Range(0, 5),
+                         ::testing::PrintToStringParamName());
+
+// Test a custom struct with PrintToString.
+
+struct CustomStruct {
+  explicit CustomStruct(int value) : x(value) {}
+  int x;
+};
+
+std::ostream& operator<<(std::ostream& stream, const CustomStruct& val) {
+  stream << val.x;
+  return stream;
+}
+
+class CustomStructNamingTest : public TestWithParam<CustomStruct> {};
+
+TEST_P(CustomStructNamingTest, TestsReportCorrectNames) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+  Message test_name_stream;
+  test_name_stream << "TestsReportCorrectNames/" << GetParam();
+  EXPECT_STREQ(test_name_stream.GetString().c_str(), test_info->name());
+}
+
+INSTANTIATE_TEST_SUITE_P(PrintToString, CustomStructNamingTest,
+                         Values(CustomStruct(0), CustomStruct(1)),
+                         ::testing::PrintToStringParamName());
+
+// Test that using a stateful parameter naming function works as expected.
+
+struct StatefulNamingFunctor {
+  StatefulNamingFunctor() : sum(0) {}
+  std::string operator()(const ::testing::TestParamInfo<int>& info) {
+    int value = info.param + sum;
+    sum += info.param;
+    return ::testing::PrintToString(value);
+  }
+  int sum;
+};
+
+class StatefulNamingTest : public ::testing::TestWithParam<int> {
+ protected:
+  StatefulNamingTest() : sum_(0) {}
+  int sum_;
+};
+
+TEST_P(StatefulNamingTest, TestsReportCorrectNames) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+  sum_ += GetParam();
+  Message test_name_stream;
+  test_name_stream << "TestsReportCorrectNames/" << sum_;
+  EXPECT_STREQ(test_name_stream.GetString().c_str(), test_info->name());
+}
+
+INSTANTIATE_TEST_SUITE_P(StatefulNamingFunctor, StatefulNamingTest, Range(0, 5),
+                         StatefulNamingFunctor());
+
+// Class that cannot be streamed into an ostream.  It needs to be copyable
+// (and, in case of MSVC, also assignable) in order to be a test parameter
+// type.  Its default copy constructor and assignment operator do exactly
+// what we need.
+class Unstreamable {
+ public:
+  explicit Unstreamable(int value) : value_(value) {}
+  // -Wunused-private-field: dummy accessor for `value_`.
+  const int& dummy_value() const { return value_; }
+
+ private:
+  int value_;
+};
+
+class CommentTest : public TestWithParam<Unstreamable> {};
+
+TEST_P(CommentTest, TestsCorrectlyReportUnstreamableParams) {
+  const ::testing::TestInfo* const test_info =
+     ::testing::UnitTest::GetInstance()->current_test_info();
+
+  EXPECT_EQ(::testing::PrintToString(GetParam()), test_info->value_param());
+}
+
+INSTANTIATE_TEST_SUITE_P(InstantiationWithComments, CommentTest,
+                         Values(Unstreamable(1)));
+
+// Verify that we can create a hierarchy of test fixtures, where the base
+// class fixture is not parameterized and the derived class is. In this case
+// ParameterizedDerivedTest inherits from NonParameterizedBaseTest.  We
+// perform simple tests on both.
+class NonParameterizedBaseTest : public ::testing::Test {
+ public:
+  NonParameterizedBaseTest() : n_(17) { }
+ protected:
+  int n_;
+};
+
+class ParameterizedDerivedTest : public NonParameterizedBaseTest,
+                                 public ::testing::WithParamInterface<int> {
+ protected:
+  ParameterizedDerivedTest() : count_(0) { }
+  int count_;
+  static int global_count_;
+};
+
+int ParameterizedDerivedTest::global_count_ = 0;
+
+TEST_F(NonParameterizedBaseTest, FixtureIsInitialized) {
+  EXPECT_EQ(17, n_);
+}
+
+TEST_P(ParameterizedDerivedTest, SeesSequence) {
+  EXPECT_EQ(17, n_);
+  EXPECT_EQ(0, count_++);
+  EXPECT_EQ(GetParam(), global_count_++);
+}
+
+class ParameterizedDeathTest : public ::testing::TestWithParam<int> { };
+
+TEST_F(ParameterizedDeathTest, GetParamDiesFromTestF) {
+  EXPECT_DEATH_IF_SUPPORTED(GetParam(),
+                            ".* value-parameterized test .*");
+}
+
+INSTANTIATE_TEST_SUITE_P(RangeZeroToFive, ParameterizedDerivedTest,
+                         Range(0, 5));
+
+// Tests param generator working with Enums
+enum MyEnums {
+  ENUM1 = 1,
+  ENUM2 = 3,
+  ENUM3 = 8,
+};
+
+class MyEnumTest : public testing::TestWithParam<MyEnums> {};
+
+TEST_P(MyEnumTest, ChecksParamMoreThanZero) { EXPECT_GE(10, GetParam()); }
+INSTANTIATE_TEST_SUITE_P(MyEnumTests, MyEnumTest,
+                         ::testing::Values(ENUM1, ENUM2, 0));
+
+int main(int argc, char **argv) {
+  // Used in TestGenerationTest test suite.
+  AddGlobalTestEnvironment(TestGenerationTest::Environment::Instance());
+  // Used in GeneratorEvaluationTest test suite. Tests that the updated value
+  // will be picked up for instantiating tests in GeneratorEvaluationTest.
+  GeneratorEvaluationTest::set_param_value(1);
+
+  ::testing::InitGoogleTest(&argc, argv);
+
+  // Used in GeneratorEvaluationTest test suite. Tests that value updated
+  // here will NOT be used for instantiating tests in
+  // GeneratorEvaluationTest.
+  GeneratorEvaluationTest::set_param_value(2);
+
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/googletest-param-test-test.h b/3rdparty/gtest/test/googletest-param-test-test.h
new file mode 100644
index 0000000..6480570
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-param-test-test.h
@@ -0,0 +1,51 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This header file provides classes and functions used internally
+// for testing Google Test itself.
+
+#ifndef GTEST_TEST_GTEST_PARAM_TEST_TEST_H_
+#define GTEST_TEST_GTEST_PARAM_TEST_TEST_H_
+
+#include "gtest/gtest.h"
+
+// Test fixture for testing definition and instantiation of a test
+// in separate translation units.
+class ExternalInstantiationTest : public ::testing::TestWithParam<int> {
+};
+
+// Test fixture for testing instantiation of a test in multiple
+// translation units.
+class InstantiationInMultipleTranslationUnitsTest
+    : public ::testing::TestWithParam<int> {
+};
+
+#endif  // GTEST_TEST_GTEST_PARAM_TEST_TEST_H_
diff --git a/3rdparty/gtest/test/googletest-param-test2-test.cc b/3rdparty/gtest/test/googletest-param-test2-test.cc
new file mode 100644
index 0000000..2a29fb1
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-param-test2-test.cc
@@ -0,0 +1,61 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests for Google Test itself.  This verifies that the basic constructs of
+// Google Test work.
+
+#include "gtest/gtest.h"
+#include "test/googletest-param-test-test.h"
+
+using ::testing::Values;
+using ::testing::internal::ParamGenerator;
+
+// Tests that generators defined in a different translation unit
+// are functional. The test using extern_gen is defined
+// in googletest-param-test-test.cc.
+ParamGenerator<int> extern_gen = Values(33);
+
+// Tests that a parameterized test case can be defined in one translation unit
+// and instantiated in another. The test is defined in
+// googletest-param-test-test.cc and ExternalInstantiationTest fixture class is
+// defined in gtest-param-test_test.h.
+INSTANTIATE_TEST_SUITE_P(MultiplesOf33,
+                         ExternalInstantiationTest,
+                         Values(33, 66));
+
+// Tests that a parameterized test case can be instantiated
+// in multiple translation units. Another instantiation is defined
+// in googletest-param-test-test.cc and
+// InstantiationInMultipleTranslationUnitsTest fixture is defined in
+// gtest-param-test_test.h
+INSTANTIATE_TEST_SUITE_P(Sequence2,
+                         InstantiationInMultipleTranslationUnitsTest,
+                         Values(42*3, 42*4, 42*5));
+
diff --git a/3rdparty/gtest/test/googletest-port-test.cc b/3rdparty/gtest/test/googletest-port-test.cc
new file mode 100644
index 0000000..60d637c
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-port-test.cc
@@ -0,0 +1,1272 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// This file tests the internal cross-platform support utilities.
+#include <stdio.h>
+
+#include "gtest/internal/gtest-port.h"
+
+#if GTEST_OS_MAC
+# include <time.h>
+#endif  // GTEST_OS_MAC
+
+#include <list>
+#include <memory>
+#include <utility>  // For std::pair and std::make_pair.
+#include <vector>
+
+#include "gtest/gtest.h"
+#include "gtest/gtest-spi.h"
+#include "src/gtest-internal-inl.h"
+
+using std::make_pair;
+using std::pair;
+
+namespace testing {
+namespace internal {
+
+TEST(IsXDigitTest, WorksForNarrowAscii) {
+  EXPECT_TRUE(IsXDigit('0'));
+  EXPECT_TRUE(IsXDigit('9'));
+  EXPECT_TRUE(IsXDigit('A'));
+  EXPECT_TRUE(IsXDigit('F'));
+  EXPECT_TRUE(IsXDigit('a'));
+  EXPECT_TRUE(IsXDigit('f'));
+
+  EXPECT_FALSE(IsXDigit('-'));
+  EXPECT_FALSE(IsXDigit('g'));
+  EXPECT_FALSE(IsXDigit('G'));
+}
+
+TEST(IsXDigitTest, ReturnsFalseForNarrowNonAscii) {
+  EXPECT_FALSE(IsXDigit(static_cast<char>('\x80')));
+  EXPECT_FALSE(IsXDigit(static_cast<char>('0' | '\x80')));
+}
+
+TEST(IsXDigitTest, WorksForWideAscii) {
+  EXPECT_TRUE(IsXDigit(L'0'));
+  EXPECT_TRUE(IsXDigit(L'9'));
+  EXPECT_TRUE(IsXDigit(L'A'));
+  EXPECT_TRUE(IsXDigit(L'F'));
+  EXPECT_TRUE(IsXDigit(L'a'));
+  EXPECT_TRUE(IsXDigit(L'f'));
+
+  EXPECT_FALSE(IsXDigit(L'-'));
+  EXPECT_FALSE(IsXDigit(L'g'));
+  EXPECT_FALSE(IsXDigit(L'G'));
+}
+
+TEST(IsXDigitTest, ReturnsFalseForWideNonAscii) {
+  EXPECT_FALSE(IsXDigit(static_cast<wchar_t>(0x80)));
+  EXPECT_FALSE(IsXDigit(static_cast<wchar_t>(L'0' | 0x80)));
+  EXPECT_FALSE(IsXDigit(static_cast<wchar_t>(L'0' | 0x100)));
+}
+
+class Base {
+ public:
+  // Copy constructor and assignment operator do exactly what we need, so we
+  // use them.
+  Base() : member_(0) {}
+  explicit Base(int n) : member_(n) {}
+  virtual ~Base() {}
+  int member() { return member_; }
+
+ private:
+  int member_;
+};
+
+class Derived : public Base {
+ public:
+  explicit Derived(int n) : Base(n) {}
+};
+
+TEST(ImplicitCastTest, ConvertsPointers) {
+  Derived derived(0);
+  EXPECT_TRUE(&derived == ::testing::internal::ImplicitCast_<Base*>(&derived));
+}
+
+TEST(ImplicitCastTest, CanUseInheritance) {
+  Derived derived(1);
+  Base base = ::testing::internal::ImplicitCast_<Base>(derived);
+  EXPECT_EQ(derived.member(), base.member());
+}
+
+class Castable {
+ public:
+  explicit Castable(bool* converted) : converted_(converted) {}
+  operator Base() {
+    *converted_ = true;
+    return Base();
+  }
+
+ private:
+  bool* converted_;
+};
+
+TEST(ImplicitCastTest, CanUseNonConstCastOperator) {
+  bool converted = false;
+  Castable castable(&converted);
+  Base base = ::testing::internal::ImplicitCast_<Base>(castable);
+  EXPECT_TRUE(converted);
+}
+
+class ConstCastable {
+ public:
+  explicit ConstCastable(bool* converted) : converted_(converted) {}
+  operator Base() const {
+    *converted_ = true;
+    return Base();
+  }
+
+ private:
+  bool* converted_;
+};
+
+TEST(ImplicitCastTest, CanUseConstCastOperatorOnConstValues) {
+  bool converted = false;
+  const ConstCastable const_castable(&converted);
+  Base base = ::testing::internal::ImplicitCast_<Base>(const_castable);
+  EXPECT_TRUE(converted);
+}
+
+class ConstAndNonConstCastable {
+ public:
+  ConstAndNonConstCastable(bool* converted, bool* const_converted)
+      : converted_(converted), const_converted_(const_converted) {}
+  operator Base() {
+    *converted_ = true;
+    return Base();
+  }
+  operator Base() const {
+    *const_converted_ = true;
+    return Base();
+  }
+
+ private:
+  bool* converted_;
+  bool* const_converted_;
+};
+
+TEST(ImplicitCastTest, CanSelectBetweenConstAndNonConstCasrAppropriately) {
+  bool converted = false;
+  bool const_converted = false;
+  ConstAndNonConstCastable castable(&converted, &const_converted);
+  Base base = ::testing::internal::ImplicitCast_<Base>(castable);
+  EXPECT_TRUE(converted);
+  EXPECT_FALSE(const_converted);
+
+  converted = false;
+  const_converted = false;
+  const ConstAndNonConstCastable const_castable(&converted, &const_converted);
+  base = ::testing::internal::ImplicitCast_<Base>(const_castable);
+  EXPECT_FALSE(converted);
+  EXPECT_TRUE(const_converted);
+}
+
+class To {
+ public:
+  To(bool* converted) { *converted = true; }  // NOLINT
+};
+
+TEST(ImplicitCastTest, CanUseImplicitConstructor) {
+  bool converted = false;
+  To to = ::testing::internal::ImplicitCast_<To>(&converted);
+  (void)to;
+  EXPECT_TRUE(converted);
+}
+
+TEST(GtestCheckSyntaxTest, BehavesLikeASingleStatement) {
+  if (AlwaysFalse())
+    GTEST_CHECK_(false) << "This should never be executed; "
+                           "It's a compilation test only.";
+
+  if (AlwaysTrue())
+    GTEST_CHECK_(true);
+  else
+    ;  // NOLINT
+
+  if (AlwaysFalse())
+    ;  // NOLINT
+  else
+    GTEST_CHECK_(true) << "";
+}
+
+TEST(GtestCheckSyntaxTest, WorksWithSwitch) {
+  switch (0) {
+    case 1:
+      break;
+    default:
+      GTEST_CHECK_(true);
+  }
+
+  switch (0)
+    case 0:
+      GTEST_CHECK_(true) << "Check failed in switch case";
+}
+
+// Verifies behavior of FormatFileLocation.
+TEST(FormatFileLocationTest, FormatsFileLocation) {
+  EXPECT_PRED_FORMAT2(IsSubstring, "foo.cc", FormatFileLocation("foo.cc", 42));
+  EXPECT_PRED_FORMAT2(IsSubstring, "42", FormatFileLocation("foo.cc", 42));
+}
+
+TEST(FormatFileLocationTest, FormatsUnknownFile) {
+  EXPECT_PRED_FORMAT2(IsSubstring, "unknown file",
+                      FormatFileLocation(nullptr, 42));
+  EXPECT_PRED_FORMAT2(IsSubstring, "42", FormatFileLocation(nullptr, 42));
+}
+
+TEST(FormatFileLocationTest, FormatsUknownLine) {
+  EXPECT_EQ("foo.cc:", FormatFileLocation("foo.cc", -1));
+}
+
+TEST(FormatFileLocationTest, FormatsUknownFileAndLine) {
+  EXPECT_EQ("unknown file:", FormatFileLocation(nullptr, -1));
+}
+
+// Verifies behavior of FormatCompilerIndependentFileLocation.
+TEST(FormatCompilerIndependentFileLocationTest, FormatsFileLocation) {
+  EXPECT_EQ("foo.cc:42", FormatCompilerIndependentFileLocation("foo.cc", 42));
+}
+
+TEST(FormatCompilerIndependentFileLocationTest, FormatsUknownFile) {
+  EXPECT_EQ("unknown file:42",
+            FormatCompilerIndependentFileLocation(nullptr, 42));
+}
+
+TEST(FormatCompilerIndependentFileLocationTest, FormatsUknownLine) {
+  EXPECT_EQ("foo.cc", FormatCompilerIndependentFileLocation("foo.cc", -1));
+}
+
+TEST(FormatCompilerIndependentFileLocationTest, FormatsUknownFileAndLine) {
+  EXPECT_EQ("unknown file", FormatCompilerIndependentFileLocation(nullptr, -1));
+}
+
+#if GTEST_OS_LINUX || GTEST_OS_MAC || GTEST_OS_QNX || GTEST_OS_FUCHSIA || \
+    GTEST_OS_DRAGONFLY || GTEST_OS_FREEBSD || GTEST_OS_GNU_KFREEBSD || \
+    GTEST_OS_NETBSD || GTEST_OS_OPENBSD
+void* ThreadFunc(void* data) {
+  internal::Mutex* mutex = static_cast<internal::Mutex*>(data);
+  mutex->Lock();
+  mutex->Unlock();
+  return nullptr;
+}
+
+TEST(GetThreadCountTest, ReturnsCorrectValue) {
+  const size_t starting_count = GetThreadCount();
+  pthread_t       thread_id;
+
+  internal::Mutex mutex;
+  {
+    internal::MutexLock lock(&mutex);
+    pthread_attr_t  attr;
+    ASSERT_EQ(0, pthread_attr_init(&attr));
+    ASSERT_EQ(0, pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE));
+
+    const int status = pthread_create(&thread_id, &attr, &ThreadFunc, &mutex);
+    ASSERT_EQ(0, pthread_attr_destroy(&attr));
+    ASSERT_EQ(0, status);
+    EXPECT_EQ(starting_count + 1, GetThreadCount());
+  }
+
+  void* dummy;
+  ASSERT_EQ(0, pthread_join(thread_id, &dummy));
+
+  // The OS may not immediately report the updated thread count after
+  // joining a thread, causing flakiness in this test. To counter that, we
+  // wait for up to .5 seconds for the OS to report the correct value.
+  for (int i = 0; i < 5; ++i) {
+    if (GetThreadCount() == starting_count)
+      break;
+
+    SleepMilliseconds(100);
+  }
+
+  EXPECT_EQ(starting_count, GetThreadCount());
+}
+#else
+TEST(GetThreadCountTest, ReturnsZeroWhenUnableToCountThreads) {
+  EXPECT_EQ(0U, GetThreadCount());
+}
+#endif  // GTEST_OS_LINUX || GTEST_OS_MAC || GTEST_OS_QNX || GTEST_OS_FUCHSIA
+
+TEST(GtestCheckDeathTest, DiesWithCorrectOutputOnFailure) {
+  const bool a_false_condition = false;
+  const char regex[] =
+#ifdef _MSC_VER
+     "googletest-port-test\\.cc\\(\\d+\\):"
+#elif GTEST_USES_POSIX_RE
+     "googletest-port-test\\.cc:[0-9]+"
+#else
+     "googletest-port-test\\.cc:\\d+"
+#endif  // _MSC_VER
+     ".*a_false_condition.*Extra info.*";
+
+  EXPECT_DEATH_IF_SUPPORTED(GTEST_CHECK_(a_false_condition) << "Extra info",
+                            regex);
+}
+
+#if GTEST_HAS_DEATH_TEST
+
+TEST(GtestCheckDeathTest, LivesSilentlyOnSuccess) {
+  EXPECT_EXIT({
+      GTEST_CHECK_(true) << "Extra info";
+      ::std::cerr << "Success\n";
+      exit(0); },
+      ::testing::ExitedWithCode(0), "Success");
+}
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+// Verifies that Google Test choose regular expression engine appropriate to
+// the platform. The test will produce compiler errors in case of failure.
+// For simplicity, we only cover the most important platforms here.
+TEST(RegexEngineSelectionTest, SelectsCorrectRegexEngine) {
+#if !GTEST_USES_PCRE
+# if GTEST_HAS_POSIX_RE
+
+  EXPECT_TRUE(GTEST_USES_POSIX_RE);
+
+# else
+
+  EXPECT_TRUE(GTEST_USES_SIMPLE_RE);
+
+# endif
+#endif  // !GTEST_USES_PCRE
+}
+
+#if GTEST_USES_POSIX_RE
+
+# if GTEST_HAS_TYPED_TEST
+
+template <typename Str>
+class RETest : public ::testing::Test {};
+
+// Defines StringTypes as the list of all string types that class RE
+// supports.
+typedef testing::Types< ::std::string, const char*> StringTypes;
+
+TYPED_TEST_SUITE(RETest, StringTypes);
+
+// Tests RE's implicit constructors.
+TYPED_TEST(RETest, ImplicitConstructorWorks) {
+  const RE empty(TypeParam(""));
+  EXPECT_STREQ("", empty.pattern());
+
+  const RE simple(TypeParam("hello"));
+  EXPECT_STREQ("hello", simple.pattern());
+
+  const RE normal(TypeParam(".*(\\w+)"));
+  EXPECT_STREQ(".*(\\w+)", normal.pattern());
+}
+
+// Tests that RE's constructors reject invalid regular expressions.
+TYPED_TEST(RETest, RejectsInvalidRegex) {
+  EXPECT_NONFATAL_FAILURE({
+    const RE invalid(TypeParam("?"));
+  }, "\"?\" is not a valid POSIX Extended regular expression.");
+}
+
+// Tests RE::FullMatch().
+TYPED_TEST(RETest, FullMatchWorks) {
+  const RE empty(TypeParam(""));
+  EXPECT_TRUE(RE::FullMatch(TypeParam(""), empty));
+  EXPECT_FALSE(RE::FullMatch(TypeParam("a"), empty));
+
+  const RE re(TypeParam("a.*z"));
+  EXPECT_TRUE(RE::FullMatch(TypeParam("az"), re));
+  EXPECT_TRUE(RE::FullMatch(TypeParam("axyz"), re));
+  EXPECT_FALSE(RE::FullMatch(TypeParam("baz"), re));
+  EXPECT_FALSE(RE::FullMatch(TypeParam("azy"), re));
+}
+
+// Tests RE::PartialMatch().
+TYPED_TEST(RETest, PartialMatchWorks) {
+  const RE empty(TypeParam(""));
+  EXPECT_TRUE(RE::PartialMatch(TypeParam(""), empty));
+  EXPECT_TRUE(RE::PartialMatch(TypeParam("a"), empty));
+
+  const RE re(TypeParam("a.*z"));
+  EXPECT_TRUE(RE::PartialMatch(TypeParam("az"), re));
+  EXPECT_TRUE(RE::PartialMatch(TypeParam("axyz"), re));
+  EXPECT_TRUE(RE::PartialMatch(TypeParam("baz"), re));
+  EXPECT_TRUE(RE::PartialMatch(TypeParam("azy"), re));
+  EXPECT_FALSE(RE::PartialMatch(TypeParam("zza"), re));
+}
+
+# endif  // GTEST_HAS_TYPED_TEST
+
+#elif GTEST_USES_SIMPLE_RE
+
+TEST(IsInSetTest, NulCharIsNotInAnySet) {
+  EXPECT_FALSE(IsInSet('\0', ""));
+  EXPECT_FALSE(IsInSet('\0', "\0"));
+  EXPECT_FALSE(IsInSet('\0', "a"));
+}
+
+TEST(IsInSetTest, WorksForNonNulChars) {
+  EXPECT_FALSE(IsInSet('a', "Ab"));
+  EXPECT_FALSE(IsInSet('c', ""));
+
+  EXPECT_TRUE(IsInSet('b', "bcd"));
+  EXPECT_TRUE(IsInSet('b', "ab"));
+}
+
+TEST(IsAsciiDigitTest, IsFalseForNonDigit) {
+  EXPECT_FALSE(IsAsciiDigit('\0'));
+  EXPECT_FALSE(IsAsciiDigit(' '));
+  EXPECT_FALSE(IsAsciiDigit('+'));
+  EXPECT_FALSE(IsAsciiDigit('-'));
+  EXPECT_FALSE(IsAsciiDigit('.'));
+  EXPECT_FALSE(IsAsciiDigit('a'));
+}
+
+TEST(IsAsciiDigitTest, IsTrueForDigit) {
+  EXPECT_TRUE(IsAsciiDigit('0'));
+  EXPECT_TRUE(IsAsciiDigit('1'));
+  EXPECT_TRUE(IsAsciiDigit('5'));
+  EXPECT_TRUE(IsAsciiDigit('9'));
+}
+
+TEST(IsAsciiPunctTest, IsFalseForNonPunct) {
+  EXPECT_FALSE(IsAsciiPunct('\0'));
+  EXPECT_FALSE(IsAsciiPunct(' '));
+  EXPECT_FALSE(IsAsciiPunct('\n'));
+  EXPECT_FALSE(IsAsciiPunct('a'));
+  EXPECT_FALSE(IsAsciiPunct('0'));
+}
+
+TEST(IsAsciiPunctTest, IsTrueForPunct) {
+  for (const char* p = "^-!\"#$%&'()*+,./:;<=>?@[\\]_`{|}~"; *p; p++) {
+    EXPECT_PRED1(IsAsciiPunct, *p);
+  }
+}
+
+TEST(IsRepeatTest, IsFalseForNonRepeatChar) {
+  EXPECT_FALSE(IsRepeat('\0'));
+  EXPECT_FALSE(IsRepeat(' '));
+  EXPECT_FALSE(IsRepeat('a'));
+  EXPECT_FALSE(IsRepeat('1'));
+  EXPECT_FALSE(IsRepeat('-'));
+}
+
+TEST(IsRepeatTest, IsTrueForRepeatChar) {
+  EXPECT_TRUE(IsRepeat('?'));
+  EXPECT_TRUE(IsRepeat('*'));
+  EXPECT_TRUE(IsRepeat('+'));
+}
+
+TEST(IsAsciiWhiteSpaceTest, IsFalseForNonWhiteSpace) {
+  EXPECT_FALSE(IsAsciiWhiteSpace('\0'));
+  EXPECT_FALSE(IsAsciiWhiteSpace('a'));
+  EXPECT_FALSE(IsAsciiWhiteSpace('1'));
+  EXPECT_FALSE(IsAsciiWhiteSpace('+'));
+  EXPECT_FALSE(IsAsciiWhiteSpace('_'));
+}
+
+TEST(IsAsciiWhiteSpaceTest, IsTrueForWhiteSpace) {
+  EXPECT_TRUE(IsAsciiWhiteSpace(' '));
+  EXPECT_TRUE(IsAsciiWhiteSpace('\n'));
+  EXPECT_TRUE(IsAsciiWhiteSpace('\r'));
+  EXPECT_TRUE(IsAsciiWhiteSpace('\t'));
+  EXPECT_TRUE(IsAsciiWhiteSpace('\v'));
+  EXPECT_TRUE(IsAsciiWhiteSpace('\f'));
+}
+
+TEST(IsAsciiWordCharTest, IsFalseForNonWordChar) {
+  EXPECT_FALSE(IsAsciiWordChar('\0'));
+  EXPECT_FALSE(IsAsciiWordChar('+'));
+  EXPECT_FALSE(IsAsciiWordChar('.'));
+  EXPECT_FALSE(IsAsciiWordChar(' '));
+  EXPECT_FALSE(IsAsciiWordChar('\n'));
+}
+
+TEST(IsAsciiWordCharTest, IsTrueForLetter) {
+  EXPECT_TRUE(IsAsciiWordChar('a'));
+  EXPECT_TRUE(IsAsciiWordChar('b'));
+  EXPECT_TRUE(IsAsciiWordChar('A'));
+  EXPECT_TRUE(IsAsciiWordChar('Z'));
+}
+
+TEST(IsAsciiWordCharTest, IsTrueForDigit) {
+  EXPECT_TRUE(IsAsciiWordChar('0'));
+  EXPECT_TRUE(IsAsciiWordChar('1'));
+  EXPECT_TRUE(IsAsciiWordChar('7'));
+  EXPECT_TRUE(IsAsciiWordChar('9'));
+}
+
+TEST(IsAsciiWordCharTest, IsTrueForUnderscore) {
+  EXPECT_TRUE(IsAsciiWordChar('_'));
+}
+
+TEST(IsValidEscapeTest, IsFalseForNonPrintable) {
+  EXPECT_FALSE(IsValidEscape('\0'));
+  EXPECT_FALSE(IsValidEscape('\007'));
+}
+
+TEST(IsValidEscapeTest, IsFalseForDigit) {
+  EXPECT_FALSE(IsValidEscape('0'));
+  EXPECT_FALSE(IsValidEscape('9'));
+}
+
+TEST(IsValidEscapeTest, IsFalseForWhiteSpace) {
+  EXPECT_FALSE(IsValidEscape(' '));
+  EXPECT_FALSE(IsValidEscape('\n'));
+}
+
+TEST(IsValidEscapeTest, IsFalseForSomeLetter) {
+  EXPECT_FALSE(IsValidEscape('a'));
+  EXPECT_FALSE(IsValidEscape('Z'));
+}
+
+TEST(IsValidEscapeTest, IsTrueForPunct) {
+  EXPECT_TRUE(IsValidEscape('.'));
+  EXPECT_TRUE(IsValidEscape('-'));
+  EXPECT_TRUE(IsValidEscape('^'));
+  EXPECT_TRUE(IsValidEscape('$'));
+  EXPECT_TRUE(IsValidEscape('('));
+  EXPECT_TRUE(IsValidEscape(']'));
+  EXPECT_TRUE(IsValidEscape('{'));
+  EXPECT_TRUE(IsValidEscape('|'));
+}
+
+TEST(IsValidEscapeTest, IsTrueForSomeLetter) {
+  EXPECT_TRUE(IsValidEscape('d'));
+  EXPECT_TRUE(IsValidEscape('D'));
+  EXPECT_TRUE(IsValidEscape('s'));
+  EXPECT_TRUE(IsValidEscape('S'));
+  EXPECT_TRUE(IsValidEscape('w'));
+  EXPECT_TRUE(IsValidEscape('W'));
+}
+
+TEST(AtomMatchesCharTest, EscapedPunct) {
+  EXPECT_FALSE(AtomMatchesChar(true, '\\', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(true, '\\', ' '));
+  EXPECT_FALSE(AtomMatchesChar(true, '_', '.'));
+  EXPECT_FALSE(AtomMatchesChar(true, '.', 'a'));
+
+  EXPECT_TRUE(AtomMatchesChar(true, '\\', '\\'));
+  EXPECT_TRUE(AtomMatchesChar(true, '_', '_'));
+  EXPECT_TRUE(AtomMatchesChar(true, '+', '+'));
+  EXPECT_TRUE(AtomMatchesChar(true, '.', '.'));
+}
+
+TEST(AtomMatchesCharTest, Escaped_d) {
+  EXPECT_FALSE(AtomMatchesChar(true, 'd', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'd', 'a'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'd', '.'));
+
+  EXPECT_TRUE(AtomMatchesChar(true, 'd', '0'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'd', '9'));
+}
+
+TEST(AtomMatchesCharTest, Escaped_D) {
+  EXPECT_FALSE(AtomMatchesChar(true, 'D', '0'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'D', '9'));
+
+  EXPECT_TRUE(AtomMatchesChar(true, 'D', '\0'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'D', 'a'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'D', '-'));
+}
+
+TEST(AtomMatchesCharTest, Escaped_s) {
+  EXPECT_FALSE(AtomMatchesChar(true, 's', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(true, 's', 'a'));
+  EXPECT_FALSE(AtomMatchesChar(true, 's', '.'));
+  EXPECT_FALSE(AtomMatchesChar(true, 's', '9'));
+
+  EXPECT_TRUE(AtomMatchesChar(true, 's', ' '));
+  EXPECT_TRUE(AtomMatchesChar(true, 's', '\n'));
+  EXPECT_TRUE(AtomMatchesChar(true, 's', '\t'));
+}
+
+TEST(AtomMatchesCharTest, Escaped_S) {
+  EXPECT_FALSE(AtomMatchesChar(true, 'S', ' '));
+  EXPECT_FALSE(AtomMatchesChar(true, 'S', '\r'));
+
+  EXPECT_TRUE(AtomMatchesChar(true, 'S', '\0'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'S', 'a'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'S', '9'));
+}
+
+TEST(AtomMatchesCharTest, Escaped_w) {
+  EXPECT_FALSE(AtomMatchesChar(true, 'w', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'w', '+'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'w', ' '));
+  EXPECT_FALSE(AtomMatchesChar(true, 'w', '\n'));
+
+  EXPECT_TRUE(AtomMatchesChar(true, 'w', '0'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'w', 'b'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'w', 'C'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'w', '_'));
+}
+
+TEST(AtomMatchesCharTest, Escaped_W) {
+  EXPECT_FALSE(AtomMatchesChar(true, 'W', 'A'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'W', 'b'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'W', '9'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'W', '_'));
+
+  EXPECT_TRUE(AtomMatchesChar(true, 'W', '\0'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'W', '*'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'W', '\n'));
+}
+
+TEST(AtomMatchesCharTest, EscapedWhiteSpace) {
+  EXPECT_FALSE(AtomMatchesChar(true, 'f', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'f', '\n'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'n', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'n', '\r'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'r', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'r', 'a'));
+  EXPECT_FALSE(AtomMatchesChar(true, 't', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(true, 't', 't'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'v', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(true, 'v', '\f'));
+
+  EXPECT_TRUE(AtomMatchesChar(true, 'f', '\f'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'n', '\n'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'r', '\r'));
+  EXPECT_TRUE(AtomMatchesChar(true, 't', '\t'));
+  EXPECT_TRUE(AtomMatchesChar(true, 'v', '\v'));
+}
+
+TEST(AtomMatchesCharTest, UnescapedDot) {
+  EXPECT_FALSE(AtomMatchesChar(false, '.', '\n'));
+
+  EXPECT_TRUE(AtomMatchesChar(false, '.', '\0'));
+  EXPECT_TRUE(AtomMatchesChar(false, '.', '.'));
+  EXPECT_TRUE(AtomMatchesChar(false, '.', 'a'));
+  EXPECT_TRUE(AtomMatchesChar(false, '.', ' '));
+}
+
+TEST(AtomMatchesCharTest, UnescapedChar) {
+  EXPECT_FALSE(AtomMatchesChar(false, 'a', '\0'));
+  EXPECT_FALSE(AtomMatchesChar(false, 'a', 'b'));
+  EXPECT_FALSE(AtomMatchesChar(false, '$', 'a'));
+
+  EXPECT_TRUE(AtomMatchesChar(false, '$', '$'));
+  EXPECT_TRUE(AtomMatchesChar(false, '5', '5'));
+  EXPECT_TRUE(AtomMatchesChar(false, 'Z', 'Z'));
+}
+
+TEST(ValidateRegexTest, GeneratesFailureAndReturnsFalseForInvalid) {
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex(NULL)),
+                          "NULL is not a valid simple regular expression");
+  EXPECT_NONFATAL_FAILURE(
+      ASSERT_FALSE(ValidateRegex("a\\")),
+      "Syntax error at index 1 in simple regular expression \"a\\\": ");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("a\\")),
+                          "'\\' cannot appear at the end");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("\\n\\")),
+                          "'\\' cannot appear at the end");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("\\s\\hb")),
+                          "invalid escape sequence \"\\h\"");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("^^")),
+                          "'^' can only appear at the beginning");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex(".*^b")),
+                          "'^' can only appear at the beginning");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("$$")),
+                          "'$' can only appear at the end");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("^$a")),
+                          "'$' can only appear at the end");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("a(b")),
+                          "'(' is unsupported");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("ab)")),
+                          "')' is unsupported");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("[ab")),
+                          "'[' is unsupported");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("a{2")),
+                          "'{' is unsupported");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("?")),
+                          "'?' can only follow a repeatable token");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("^*")),
+                          "'*' can only follow a repeatable token");
+  EXPECT_NONFATAL_FAILURE(ASSERT_FALSE(ValidateRegex("5*+")),
+                          "'+' can only follow a repeatable token");
+}
+
+TEST(ValidateRegexTest, ReturnsTrueForValid) {
+  EXPECT_TRUE(ValidateRegex(""));
+  EXPECT_TRUE(ValidateRegex("a"));
+  EXPECT_TRUE(ValidateRegex(".*"));
+  EXPECT_TRUE(ValidateRegex("^a_+"));
+  EXPECT_TRUE(ValidateRegex("^a\\t\\&?"));
+  EXPECT_TRUE(ValidateRegex("09*$"));
+  EXPECT_TRUE(ValidateRegex("^Z$"));
+  EXPECT_TRUE(ValidateRegex("a\\^Z\\$\\(\\)\\|\\[\\]\\{\\}"));
+}
+
+TEST(MatchRepetitionAndRegexAtHeadTest, WorksForZeroOrOne) {
+  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, 'a', '?', "a", "ba"));
+  // Repeating more than once.
+  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, 'a', '?', "b", "aab"));
+
+  // Repeating zero times.
+  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, 'a', '?', "b", "ba"));
+  // Repeating once.
+  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, 'a', '?', "b", "ab"));
+  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, '#', '?', ".", "##"));
+}
+
+TEST(MatchRepetitionAndRegexAtHeadTest, WorksForZeroOrMany) {
+  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, '.', '*', "a$", "baab"));
+
+  // Repeating zero times.
+  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, '.', '*', "b", "bc"));
+  // Repeating once.
+  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, '.', '*', "b", "abc"));
+  // Repeating more than once.
+  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(true, 'w', '*', "-", "ab_1-g"));
+}
+
+TEST(MatchRepetitionAndRegexAtHeadTest, WorksForOneOrMany) {
+  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, '.', '+', "a$", "baab"));
+  // Repeating zero times.
+  EXPECT_FALSE(MatchRepetitionAndRegexAtHead(false, '.', '+', "b", "bc"));
+
+  // Repeating once.
+  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(false, '.', '+', "b", "abc"));
+  // Repeating more than once.
+  EXPECT_TRUE(MatchRepetitionAndRegexAtHead(true, 'w', '+', "-", "ab_1-g"));
+}
+
+TEST(MatchRegexAtHeadTest, ReturnsTrueForEmptyRegex) {
+  EXPECT_TRUE(MatchRegexAtHead("", ""));
+  EXPECT_TRUE(MatchRegexAtHead("", "ab"));
+}
+
+TEST(MatchRegexAtHeadTest, WorksWhenDollarIsInRegex) {
+  EXPECT_FALSE(MatchRegexAtHead("$", "a"));
+
+  EXPECT_TRUE(MatchRegexAtHead("$", ""));
+  EXPECT_TRUE(MatchRegexAtHead("a$", "a"));
+}
+
+TEST(MatchRegexAtHeadTest, WorksWhenRegexStartsWithEscapeSequence) {
+  EXPECT_FALSE(MatchRegexAtHead("\\w", "+"));
+  EXPECT_FALSE(MatchRegexAtHead("\\W", "ab"));
+
+  EXPECT_TRUE(MatchRegexAtHead("\\sa", "\nab"));
+  EXPECT_TRUE(MatchRegexAtHead("\\d", "1a"));
+}
+
+TEST(MatchRegexAtHeadTest, WorksWhenRegexStartsWithRepetition) {
+  EXPECT_FALSE(MatchRegexAtHead(".+a", "abc"));
+  EXPECT_FALSE(MatchRegexAtHead("a?b", "aab"));
+
+  EXPECT_TRUE(MatchRegexAtHead(".*a", "bc12-ab"));
+  EXPECT_TRUE(MatchRegexAtHead("a?b", "b"));
+  EXPECT_TRUE(MatchRegexAtHead("a?b", "ab"));
+}
+
+TEST(MatchRegexAtHeadTest,
+     WorksWhenRegexStartsWithRepetionOfEscapeSequence) {
+  EXPECT_FALSE(MatchRegexAtHead("\\.+a", "abc"));
+  EXPECT_FALSE(MatchRegexAtHead("\\s?b", "  b"));
+
+  EXPECT_TRUE(MatchRegexAtHead("\\(*a", "((((ab"));
+  EXPECT_TRUE(MatchRegexAtHead("\\^?b", "^b"));
+  EXPECT_TRUE(MatchRegexAtHead("\\\\?b", "b"));
+  EXPECT_TRUE(MatchRegexAtHead("\\\\?b", "\\b"));
+}
+
+TEST(MatchRegexAtHeadTest, MatchesSequentially) {
+  EXPECT_FALSE(MatchRegexAtHead("ab.*c", "acabc"));
+
+  EXPECT_TRUE(MatchRegexAtHead("ab.*c", "ab-fsc"));
+}
+
+TEST(MatchRegexAnywhereTest, ReturnsFalseWhenStringIsNull) {
+  EXPECT_FALSE(MatchRegexAnywhere("", NULL));
+}
+
+TEST(MatchRegexAnywhereTest, WorksWhenRegexStartsWithCaret) {
+  EXPECT_FALSE(MatchRegexAnywhere("^a", "ba"));
+  EXPECT_FALSE(MatchRegexAnywhere("^$", "a"));
+
+  EXPECT_TRUE(MatchRegexAnywhere("^a", "ab"));
+  EXPECT_TRUE(MatchRegexAnywhere("^", "ab"));
+  EXPECT_TRUE(MatchRegexAnywhere("^$", ""));
+}
+
+TEST(MatchRegexAnywhereTest, ReturnsFalseWhenNoMatch) {
+  EXPECT_FALSE(MatchRegexAnywhere("a", "bcde123"));
+  EXPECT_FALSE(MatchRegexAnywhere("a.+a", "--aa88888888"));
+}
+
+TEST(MatchRegexAnywhereTest, ReturnsTrueWhenMatchingPrefix) {
+  EXPECT_TRUE(MatchRegexAnywhere("\\w+", "ab1_ - 5"));
+  EXPECT_TRUE(MatchRegexAnywhere(".*=", "="));
+  EXPECT_TRUE(MatchRegexAnywhere("x.*ab?.*bc", "xaaabc"));
+}
+
+TEST(MatchRegexAnywhereTest, ReturnsTrueWhenMatchingNonPrefix) {
+  EXPECT_TRUE(MatchRegexAnywhere("\\w+", "$$$ ab1_ - 5"));
+  EXPECT_TRUE(MatchRegexAnywhere("\\.+=", "=  ...="));
+}
+
+// Tests RE's implicit constructors.
+TEST(RETest, ImplicitConstructorWorks) {
+  const RE empty("");
+  EXPECT_STREQ("", empty.pattern());
+
+  const RE simple("hello");
+  EXPECT_STREQ("hello", simple.pattern());
+}
+
+// Tests that RE's constructors reject invalid regular expressions.
+TEST(RETest, RejectsInvalidRegex) {
+  EXPECT_NONFATAL_FAILURE({
+    const RE normal(NULL);
+  }, "NULL is not a valid simple regular expression");
+
+  EXPECT_NONFATAL_FAILURE({
+    const RE normal(".*(\\w+");
+  }, "'(' is unsupported");
+
+  EXPECT_NONFATAL_FAILURE({
+    const RE invalid("^?");
+  }, "'?' can only follow a repeatable token");
+}
+
+// Tests RE::FullMatch().
+TEST(RETest, FullMatchWorks) {
+  const RE empty("");
+  EXPECT_TRUE(RE::FullMatch("", empty));
+  EXPECT_FALSE(RE::FullMatch("a", empty));
+
+  const RE re1("a");
+  EXPECT_TRUE(RE::FullMatch("a", re1));
+
+  const RE re("a.*z");
+  EXPECT_TRUE(RE::FullMatch("az", re));
+  EXPECT_TRUE(RE::FullMatch("axyz", re));
+  EXPECT_FALSE(RE::FullMatch("baz", re));
+  EXPECT_FALSE(RE::FullMatch("azy", re));
+}
+
+// Tests RE::PartialMatch().
+TEST(RETest, PartialMatchWorks) {
+  const RE empty("");
+  EXPECT_TRUE(RE::PartialMatch("", empty));
+  EXPECT_TRUE(RE::PartialMatch("a", empty));
+
+  const RE re("a.*z");
+  EXPECT_TRUE(RE::PartialMatch("az", re));
+  EXPECT_TRUE(RE::PartialMatch("axyz", re));
+  EXPECT_TRUE(RE::PartialMatch("baz", re));
+  EXPECT_TRUE(RE::PartialMatch("azy", re));
+  EXPECT_FALSE(RE::PartialMatch("zza", re));
+}
+
+#endif  // GTEST_USES_POSIX_RE
+
+#if !GTEST_OS_WINDOWS_MOBILE
+
+TEST(CaptureTest, CapturesStdout) {
+  CaptureStdout();
+  fprintf(stdout, "abc");
+  EXPECT_STREQ("abc", GetCapturedStdout().c_str());
+
+  CaptureStdout();
+  fprintf(stdout, "def%cghi", '\0');
+  EXPECT_EQ(::std::string("def\0ghi", 7), ::std::string(GetCapturedStdout()));
+}
+
+TEST(CaptureTest, CapturesStderr) {
+  CaptureStderr();
+  fprintf(stderr, "jkl");
+  EXPECT_STREQ("jkl", GetCapturedStderr().c_str());
+
+  CaptureStderr();
+  fprintf(stderr, "jkl%cmno", '\0');
+  EXPECT_EQ(::std::string("jkl\0mno", 7), ::std::string(GetCapturedStderr()));
+}
+
+// Tests that stdout and stderr capture don't interfere with each other.
+TEST(CaptureTest, CapturesStdoutAndStderr) {
+  CaptureStdout();
+  CaptureStderr();
+  fprintf(stdout, "pqr");
+  fprintf(stderr, "stu");
+  EXPECT_STREQ("pqr", GetCapturedStdout().c_str());
+  EXPECT_STREQ("stu", GetCapturedStderr().c_str());
+}
+
+TEST(CaptureDeathTest, CannotReenterStdoutCapture) {
+  CaptureStdout();
+  EXPECT_DEATH_IF_SUPPORTED(CaptureStdout(),
+                            "Only one stdout capturer can exist at a time");
+  GetCapturedStdout();
+
+  // We cannot test stderr capturing using death tests as they use it
+  // themselves.
+}
+
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+TEST(ThreadLocalTest, DefaultConstructorInitializesToDefaultValues) {
+  ThreadLocal<int> t1;
+  EXPECT_EQ(0, t1.get());
+
+  ThreadLocal<void*> t2;
+  EXPECT_TRUE(t2.get() == nullptr);
+}
+
+TEST(ThreadLocalTest, SingleParamConstructorInitializesToParam) {
+  ThreadLocal<int> t1(123);
+  EXPECT_EQ(123, t1.get());
+
+  int i = 0;
+  ThreadLocal<int*> t2(&i);
+  EXPECT_EQ(&i, t2.get());
+}
+
+class NoDefaultContructor {
+ public:
+  explicit NoDefaultContructor(const char*) {}
+  NoDefaultContructor(const NoDefaultContructor&) {}
+};
+
+TEST(ThreadLocalTest, ValueDefaultContructorIsNotRequiredForParamVersion) {
+  ThreadLocal<NoDefaultContructor> bar(NoDefaultContructor("foo"));
+  bar.pointer();
+}
+
+TEST(ThreadLocalTest, GetAndPointerReturnSameValue) {
+  ThreadLocal<std::string> thread_local_string;
+
+  EXPECT_EQ(thread_local_string.pointer(), &(thread_local_string.get()));
+
+  // Verifies the condition still holds after calling set.
+  thread_local_string.set("foo");
+  EXPECT_EQ(thread_local_string.pointer(), &(thread_local_string.get()));
+}
+
+TEST(ThreadLocalTest, PointerAndConstPointerReturnSameValue) {
+  ThreadLocal<std::string> thread_local_string;
+  const ThreadLocal<std::string>& const_thread_local_string =
+      thread_local_string;
+
+  EXPECT_EQ(thread_local_string.pointer(), const_thread_local_string.pointer());
+
+  thread_local_string.set("foo");
+  EXPECT_EQ(thread_local_string.pointer(), const_thread_local_string.pointer());
+}
+
+#if GTEST_IS_THREADSAFE
+
+void AddTwo(int* param) { *param += 2; }
+
+TEST(ThreadWithParamTest, ConstructorExecutesThreadFunc) {
+  int i = 40;
+  ThreadWithParam<int*> thread(&AddTwo, &i, nullptr);
+  thread.Join();
+  EXPECT_EQ(42, i);
+}
+
+TEST(MutexDeathTest, AssertHeldShouldAssertWhenNotLocked) {
+  // AssertHeld() is flaky only in the presence of multiple threads accessing
+  // the lock. In this case, the test is robust.
+  EXPECT_DEATH_IF_SUPPORTED({
+    Mutex m;
+    { MutexLock lock(&m); }
+    m.AssertHeld();
+  },
+  "thread .*hold");
+}
+
+TEST(MutexTest, AssertHeldShouldNotAssertWhenLocked) {
+  Mutex m;
+  MutexLock lock(&m);
+  m.AssertHeld();
+}
+
+class AtomicCounterWithMutex {
+ public:
+  explicit AtomicCounterWithMutex(Mutex* mutex) :
+    value_(0), mutex_(mutex), random_(42) {}
+
+  void Increment() {
+    MutexLock lock(mutex_);
+    int temp = value_;
+    {
+      // We need to put up a memory barrier to prevent reads and writes to
+      // value_ rearranged with the call to SleepMilliseconds when observed
+      // from other threads.
+#if GTEST_HAS_PTHREAD
+      // On POSIX, locking a mutex puts up a memory barrier.  We cannot use
+      // Mutex and MutexLock here or rely on their memory barrier
+      // functionality as we are testing them here.
+      pthread_mutex_t memory_barrier_mutex;
+      GTEST_CHECK_POSIX_SUCCESS_(
+          pthread_mutex_init(&memory_barrier_mutex, nullptr));
+      GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_lock(&memory_barrier_mutex));
+
+      SleepMilliseconds(static_cast<int>(random_.Generate(30)));
+
+      GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_unlock(&memory_barrier_mutex));
+      GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_destroy(&memory_barrier_mutex));
+#elif GTEST_OS_WINDOWS
+      // On Windows, performing an interlocked access puts up a memory barrier.
+      volatile LONG dummy = 0;
+      ::InterlockedIncrement(&dummy);
+      SleepMilliseconds(static_cast<int>(random_.Generate(30)));
+      ::InterlockedIncrement(&dummy);
+#else
+# error "Memory barrier not implemented on this platform."
+#endif  // GTEST_HAS_PTHREAD
+    }
+    value_ = temp + 1;
+  }
+  int value() const { return value_; }
+
+ private:
+  volatile int value_;
+  Mutex* const mutex_;  // Protects value_.
+  Random       random_;
+};
+
+void CountingThreadFunc(pair<AtomicCounterWithMutex*, int> param) {
+  for (int i = 0; i < param.second; ++i)
+      param.first->Increment();
+}
+
+// Tests that the mutex only lets one thread at a time to lock it.
+TEST(MutexTest, OnlyOneThreadCanLockAtATime) {
+  Mutex mutex;
+  AtomicCounterWithMutex locked_counter(&mutex);
+
+  typedef ThreadWithParam<pair<AtomicCounterWithMutex*, int> > ThreadType;
+  const int kCycleCount = 20;
+  const int kThreadCount = 7;
+  std::unique_ptr<ThreadType> counting_threads[kThreadCount];
+  Notification threads_can_start;
+  // Creates and runs kThreadCount threads that increment locked_counter
+  // kCycleCount times each.
+  for (int i = 0; i < kThreadCount; ++i) {
+    counting_threads[i].reset(new ThreadType(&CountingThreadFunc,
+                                             make_pair(&locked_counter,
+                                                       kCycleCount),
+                                             &threads_can_start));
+  }
+  threads_can_start.Notify();
+  for (int i = 0; i < kThreadCount; ++i)
+    counting_threads[i]->Join();
+
+  // If the mutex lets more than one thread to increment the counter at a
+  // time, they are likely to encounter a race condition and have some
+  // increments overwritten, resulting in the lower then expected counter
+  // value.
+  EXPECT_EQ(kCycleCount * kThreadCount, locked_counter.value());
+}
+
+template <typename T>
+void RunFromThread(void (func)(T), T param) {
+  ThreadWithParam<T> thread(func, param, nullptr);
+  thread.Join();
+}
+
+void RetrieveThreadLocalValue(
+    pair<ThreadLocal<std::string>*, std::string*> param) {
+  *param.second = param.first->get();
+}
+
+TEST(ThreadLocalTest, ParameterizedConstructorSetsDefault) {
+  ThreadLocal<std::string> thread_local_string("foo");
+  EXPECT_STREQ("foo", thread_local_string.get().c_str());
+
+  thread_local_string.set("bar");
+  EXPECT_STREQ("bar", thread_local_string.get().c_str());
+
+  std::string result;
+  RunFromThread(&RetrieveThreadLocalValue,
+                make_pair(&thread_local_string, &result));
+  EXPECT_STREQ("foo", result.c_str());
+}
+
+// Keeps track of whether of destructors being called on instances of
+// DestructorTracker.  On Windows, waits for the destructor call reports.
+class DestructorCall {
+ public:
+  DestructorCall() {
+    invoked_ = false;
+#if GTEST_OS_WINDOWS
+    wait_event_.Reset(::CreateEvent(NULL, TRUE, FALSE, NULL));
+    GTEST_CHECK_(wait_event_.Get() != NULL);
+#endif
+  }
+
+  bool CheckDestroyed() const {
+#if GTEST_OS_WINDOWS
+    if (::WaitForSingleObject(wait_event_.Get(), 1000) != WAIT_OBJECT_0)
+      return false;
+#endif
+    return invoked_;
+  }
+
+  void ReportDestroyed() {
+    invoked_ = true;
+#if GTEST_OS_WINDOWS
+    ::SetEvent(wait_event_.Get());
+#endif
+  }
+
+  static std::vector<DestructorCall*>& List() { return *list_; }
+
+  static void ResetList() {
+    for (size_t i = 0; i < list_->size(); ++i) {
+      delete list_->at(i);
+    }
+    list_->clear();
+  }
+
+ private:
+  bool invoked_;
+#if GTEST_OS_WINDOWS
+  AutoHandle wait_event_;
+#endif
+  static std::vector<DestructorCall*>* const list_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(DestructorCall);
+};
+
+std::vector<DestructorCall*>* const DestructorCall::list_ =
+    new std::vector<DestructorCall*>;
+
+// DestructorTracker keeps track of whether its instances have been
+// destroyed.
+class DestructorTracker {
+ public:
+  DestructorTracker() : index_(GetNewIndex()) {}
+  DestructorTracker(const DestructorTracker& /* rhs */)
+      : index_(GetNewIndex()) {}
+  ~DestructorTracker() {
+    // We never access DestructorCall::List() concurrently, so we don't need
+    // to protect this access with a mutex.
+    DestructorCall::List()[index_]->ReportDestroyed();
+  }
+
+ private:
+  static size_t GetNewIndex() {
+    DestructorCall::List().push_back(new DestructorCall);
+    return DestructorCall::List().size() - 1;
+  }
+  const size_t index_;
+
+  GTEST_DISALLOW_ASSIGN_(DestructorTracker);
+};
+
+typedef ThreadLocal<DestructorTracker>* ThreadParam;
+
+void CallThreadLocalGet(ThreadParam thread_local_param) {
+  thread_local_param->get();
+}
+
+// Tests that when a ThreadLocal object dies in a thread, it destroys
+// the managed object for that thread.
+TEST(ThreadLocalTest, DestroysManagedObjectForOwnThreadWhenDying) {
+  DestructorCall::ResetList();
+
+  {
+    ThreadLocal<DestructorTracker> thread_local_tracker;
+    ASSERT_EQ(0U, DestructorCall::List().size());
+
+    // This creates another DestructorTracker object for the main thread.
+    thread_local_tracker.get();
+    ASSERT_EQ(1U, DestructorCall::List().size());
+    ASSERT_FALSE(DestructorCall::List()[0]->CheckDestroyed());
+  }
+
+  // Now thread_local_tracker has died.
+  ASSERT_EQ(1U, DestructorCall::List().size());
+  EXPECT_TRUE(DestructorCall::List()[0]->CheckDestroyed());
+
+  DestructorCall::ResetList();
+}
+
+// Tests that when a thread exits, the thread-local object for that
+// thread is destroyed.
+TEST(ThreadLocalTest, DestroysManagedObjectAtThreadExit) {
+  DestructorCall::ResetList();
+
+  {
+    ThreadLocal<DestructorTracker> thread_local_tracker;
+    ASSERT_EQ(0U, DestructorCall::List().size());
+
+    // This creates another DestructorTracker object in the new thread.
+    ThreadWithParam<ThreadParam> thread(&CallThreadLocalGet,
+                                        &thread_local_tracker, nullptr);
+    thread.Join();
+
+    // The thread has exited, and we should have a DestroyedTracker
+    // instance created for it. But it may not have been destroyed yet.
+    ASSERT_EQ(1U, DestructorCall::List().size());
+  }
+
+  // The thread has exited and thread_local_tracker has died.
+  ASSERT_EQ(1U, DestructorCall::List().size());
+  EXPECT_TRUE(DestructorCall::List()[0]->CheckDestroyed());
+
+  DestructorCall::ResetList();
+}
+
+TEST(ThreadLocalTest, ThreadLocalMutationsAffectOnlyCurrentThread) {
+  ThreadLocal<std::string> thread_local_string;
+  thread_local_string.set("Foo");
+  EXPECT_STREQ("Foo", thread_local_string.get().c_str());
+
+  std::string result;
+  RunFromThread(&RetrieveThreadLocalValue,
+                make_pair(&thread_local_string, &result));
+  EXPECT_TRUE(result.empty());
+}
+
+#endif  // GTEST_IS_THREADSAFE
+
+#if GTEST_OS_WINDOWS
+TEST(WindowsTypesTest, HANDLEIsVoidStar) {
+  StaticAssertTypeEq<HANDLE, void*>();
+}
+
+#if GTEST_OS_WINDOWS_MINGW && !defined(__MINGW64_VERSION_MAJOR)
+TEST(WindowsTypesTest, _CRITICAL_SECTIONIs_CRITICAL_SECTION) {
+  StaticAssertTypeEq<CRITICAL_SECTION, _CRITICAL_SECTION>();
+}
+#else
+TEST(WindowsTypesTest, CRITICAL_SECTIONIs_RTL_CRITICAL_SECTION) {
+  StaticAssertTypeEq<CRITICAL_SECTION, _RTL_CRITICAL_SECTION>();
+}
+#endif
+
+#endif  // GTEST_OS_WINDOWS
+
+}  // namespace internal
+}  // namespace testing
diff --git a/3rdparty/gtest/test/googletest-printers-test.cc b/3rdparty/gtest/test/googletest-printers-test.cc
new file mode 100644
index 0000000..4bdc9ad
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-printers-test.cc
@@ -0,0 +1,1620 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Google Test - The Google C++ Testing and Mocking Framework
+//
+// This file tests the universal value printer.
+
+#include <ctype.h>
+#include <limits.h>
+#include <string.h>
+#include <algorithm>
+#include <deque>
+#include <forward_list>
+#include <list>
+#include <map>
+#include <set>
+#include <sstream>
+#include <string>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+#include "gtest/gtest-printers.h"
+#include "gtest/gtest.h"
+
+// Some user-defined types for testing the universal value printer.
+
+// An anonymous enum type.
+enum AnonymousEnum {
+  kAE1 = -1,
+  kAE2 = 1
+};
+
+// An enum without a user-defined printer.
+enum EnumWithoutPrinter {
+  kEWP1 = -2,
+  kEWP2 = 42
+};
+
+// An enum with a << operator.
+enum EnumWithStreaming {
+  kEWS1 = 10
+};
+
+std::ostream& operator<<(std::ostream& os, EnumWithStreaming e) {
+  return os << (e == kEWS1 ? "kEWS1" : "invalid");
+}
+
+// An enum with a PrintTo() function.
+enum EnumWithPrintTo {
+  kEWPT1 = 1
+};
+
+void PrintTo(EnumWithPrintTo e, std::ostream* os) {
+  *os << (e == kEWPT1 ? "kEWPT1" : "invalid");
+}
+
+// A class implicitly convertible to BiggestInt.
+class BiggestIntConvertible {
+ public:
+  operator ::testing::internal::BiggestInt() const { return 42; }
+};
+
+// A user-defined unprintable class template in the global namespace.
+template <typename T>
+class UnprintableTemplateInGlobal {
+ public:
+  UnprintableTemplateInGlobal() : value_() {}
+ private:
+  T value_;
+};
+
+// A user-defined streamable type in the global namespace.
+class StreamableInGlobal {
+ public:
+  virtual ~StreamableInGlobal() {}
+};
+
+inline void operator<<(::std::ostream& os, const StreamableInGlobal& /* x */) {
+  os << "StreamableInGlobal";
+}
+
+void operator<<(::std::ostream& os, const StreamableInGlobal* /* x */) {
+  os << "StreamableInGlobal*";
+}
+
+namespace foo {
+
+// A user-defined unprintable type in a user namespace.
+class UnprintableInFoo {
+ public:
+  UnprintableInFoo() : z_(0) { memcpy(xy_, "\xEF\x12\x0\x0\x34\xAB\x0\x0", 8); }
+  double z() const { return z_; }
+ private:
+  char xy_[8];
+  double z_;
+};
+
+// A user-defined printable type in a user-chosen namespace.
+struct PrintableViaPrintTo {
+  PrintableViaPrintTo() : value() {}
+  int value;
+};
+
+void PrintTo(const PrintableViaPrintTo& x, ::std::ostream* os) {
+  *os << "PrintableViaPrintTo: " << x.value;
+}
+
+// A type with a user-defined << for printing its pointer.
+struct PointerPrintable {
+};
+
+::std::ostream& operator<<(::std::ostream& os,
+                           const PointerPrintable* /* x */) {
+  return os << "PointerPrintable*";
+}
+
+// A user-defined printable class template in a user-chosen namespace.
+template <typename T>
+class PrintableViaPrintToTemplate {
+ public:
+  explicit PrintableViaPrintToTemplate(const T& a_value) : value_(a_value) {}
+
+  const T& value() const { return value_; }
+ private:
+  T value_;
+};
+
+template <typename T>
+void PrintTo(const PrintableViaPrintToTemplate<T>& x, ::std::ostream* os) {
+  *os << "PrintableViaPrintToTemplate: " << x.value();
+}
+
+// A user-defined streamable class template in a user namespace.
+template <typename T>
+class StreamableTemplateInFoo {
+ public:
+  StreamableTemplateInFoo() : value_() {}
+
+  const T& value() const { return value_; }
+ private:
+  T value_;
+};
+
+template <typename T>
+inline ::std::ostream& operator<<(::std::ostream& os,
+                                  const StreamableTemplateInFoo<T>& x) {
+  return os << "StreamableTemplateInFoo: " << x.value();
+}
+
+// A user-defined streamable but recursivly-defined container type in
+// a user namespace, it mimics therefore std::filesystem::path or
+// boost::filesystem::path.
+class PathLike {
+ public:
+  struct iterator {
+    typedef PathLike value_type;
+
+    iterator& operator++();
+    PathLike& operator*();
+  };
+
+  using value_type = char;
+  using const_iterator = iterator;
+
+  PathLike() {}
+
+  iterator begin() const { return iterator(); }
+  iterator end() const { return iterator(); }
+
+  friend ::std::ostream& operator<<(::std::ostream& os, const PathLike&) {
+    return os << "Streamable-PathLike";
+  }
+};
+
+}  // namespace foo
+
+namespace testing {
+namespace gtest_printers_test {
+
+using ::std::deque;
+using ::std::list;
+using ::std::make_pair;
+using ::std::map;
+using ::std::multimap;
+using ::std::multiset;
+using ::std::pair;
+using ::std::set;
+using ::std::vector;
+using ::testing::PrintToString;
+using ::testing::internal::FormatForComparisonFailureMessage;
+using ::testing::internal::ImplicitCast_;
+using ::testing::internal::NativeArray;
+using ::testing::internal::RE;
+using ::testing::internal::RelationToSourceReference;
+using ::testing::internal::Strings;
+using ::testing::internal::UniversalPrint;
+using ::testing::internal::UniversalPrinter;
+using ::testing::internal::UniversalTersePrint;
+using ::testing::internal::UniversalTersePrintTupleFieldsToStrings;
+
+// Prints a value to a string using the universal value printer.  This
+// is a helper for testing UniversalPrinter<T>::Print() for various types.
+template <typename T>
+std::string Print(const T& value) {
+  ::std::stringstream ss;
+  UniversalPrinter<T>::Print(value, &ss);
+  return ss.str();
+}
+
+// Prints a value passed by reference to a string, using the universal
+// value printer.  This is a helper for testing
+// UniversalPrinter<T&>::Print() for various types.
+template <typename T>
+std::string PrintByRef(const T& value) {
+  ::std::stringstream ss;
+  UniversalPrinter<T&>::Print(value, &ss);
+  return ss.str();
+}
+
+// Tests printing various enum types.
+
+TEST(PrintEnumTest, AnonymousEnum) {
+  EXPECT_EQ("-1", Print(kAE1));
+  EXPECT_EQ("1", Print(kAE2));
+}
+
+TEST(PrintEnumTest, EnumWithoutPrinter) {
+  EXPECT_EQ("-2", Print(kEWP1));
+  EXPECT_EQ("42", Print(kEWP2));
+}
+
+TEST(PrintEnumTest, EnumWithStreaming) {
+  EXPECT_EQ("kEWS1", Print(kEWS1));
+  EXPECT_EQ("invalid", Print(static_cast<EnumWithStreaming>(0)));
+}
+
+TEST(PrintEnumTest, EnumWithPrintTo) {
+  EXPECT_EQ("kEWPT1", Print(kEWPT1));
+  EXPECT_EQ("invalid", Print(static_cast<EnumWithPrintTo>(0)));
+}
+
+// Tests printing a class implicitly convertible to BiggestInt.
+
+TEST(PrintClassTest, BiggestIntConvertible) {
+  EXPECT_EQ("42", Print(BiggestIntConvertible()));
+}
+
+// Tests printing various char types.
+
+// char.
+TEST(PrintCharTest, PlainChar) {
+  EXPECT_EQ("'\\0'", Print('\0'));
+  EXPECT_EQ("'\\'' (39, 0x27)", Print('\''));
+  EXPECT_EQ("'\"' (34, 0x22)", Print('"'));
+  EXPECT_EQ("'?' (63, 0x3F)", Print('?'));
+  EXPECT_EQ("'\\\\' (92, 0x5C)", Print('\\'));
+  EXPECT_EQ("'\\a' (7)", Print('\a'));
+  EXPECT_EQ("'\\b' (8)", Print('\b'));
+  EXPECT_EQ("'\\f' (12, 0xC)", Print('\f'));
+  EXPECT_EQ("'\\n' (10, 0xA)", Print('\n'));
+  EXPECT_EQ("'\\r' (13, 0xD)", Print('\r'));
+  EXPECT_EQ("'\\t' (9)", Print('\t'));
+  EXPECT_EQ("'\\v' (11, 0xB)", Print('\v'));
+  EXPECT_EQ("'\\x7F' (127)", Print('\x7F'));
+  EXPECT_EQ("'\\xFF' (255)", Print('\xFF'));
+  EXPECT_EQ("' ' (32, 0x20)", Print(' '));
+  EXPECT_EQ("'a' (97, 0x61)", Print('a'));
+}
+
+// signed char.
+TEST(PrintCharTest, SignedChar) {
+  EXPECT_EQ("'\\0'", Print(static_cast<signed char>('\0')));
+  EXPECT_EQ("'\\xCE' (-50)",
+            Print(static_cast<signed char>(-50)));
+}
+
+// unsigned char.
+TEST(PrintCharTest, UnsignedChar) {
+  EXPECT_EQ("'\\0'", Print(static_cast<unsigned char>('\0')));
+  EXPECT_EQ("'b' (98, 0x62)",
+            Print(static_cast<unsigned char>('b')));
+}
+
+// Tests printing other simple, built-in types.
+
+// bool.
+TEST(PrintBuiltInTypeTest, Bool) {
+  EXPECT_EQ("false", Print(false));
+  EXPECT_EQ("true", Print(true));
+}
+
+// wchar_t.
+TEST(PrintBuiltInTypeTest, Wchar_t) {
+  EXPECT_EQ("L'\\0'", Print(L'\0'));
+  EXPECT_EQ("L'\\'' (39, 0x27)", Print(L'\''));
+  EXPECT_EQ("L'\"' (34, 0x22)", Print(L'"'));
+  EXPECT_EQ("L'?' (63, 0x3F)", Print(L'?'));
+  EXPECT_EQ("L'\\\\' (92, 0x5C)", Print(L'\\'));
+  EXPECT_EQ("L'\\a' (7)", Print(L'\a'));
+  EXPECT_EQ("L'\\b' (8)", Print(L'\b'));
+  EXPECT_EQ("L'\\f' (12, 0xC)", Print(L'\f'));
+  EXPECT_EQ("L'\\n' (10, 0xA)", Print(L'\n'));
+  EXPECT_EQ("L'\\r' (13, 0xD)", Print(L'\r'));
+  EXPECT_EQ("L'\\t' (9)", Print(L'\t'));
+  EXPECT_EQ("L'\\v' (11, 0xB)", Print(L'\v'));
+  EXPECT_EQ("L'\\x7F' (127)", Print(L'\x7F'));
+  EXPECT_EQ("L'\\xFF' (255)", Print(L'\xFF'));
+  EXPECT_EQ("L' ' (32, 0x20)", Print(L' '));
+  EXPECT_EQ("L'a' (97, 0x61)", Print(L'a'));
+  EXPECT_EQ("L'\\x576' (1398)", Print(static_cast<wchar_t>(0x576)));
+  EXPECT_EQ("L'\\xC74D' (51021)", Print(static_cast<wchar_t>(0xC74D)));
+}
+
+// Test that Int64 provides more storage than wchar_t.
+TEST(PrintTypeSizeTest, Wchar_t) {
+  EXPECT_LT(sizeof(wchar_t), sizeof(testing::internal::Int64));
+}
+
+// Various integer types.
+TEST(PrintBuiltInTypeTest, Integer) {
+  EXPECT_EQ("'\\xFF' (255)", Print(static_cast<unsigned char>(255)));  // uint8
+  EXPECT_EQ("'\\x80' (-128)", Print(static_cast<signed char>(-128)));  // int8
+  EXPECT_EQ("65535", Print(USHRT_MAX));  // uint16
+  EXPECT_EQ("-32768", Print(SHRT_MIN));  // int16
+  EXPECT_EQ("4294967295", Print(UINT_MAX));  // uint32
+  EXPECT_EQ("-2147483648", Print(INT_MIN));  // int32
+  EXPECT_EQ("18446744073709551615",
+            Print(static_cast<testing::internal::UInt64>(-1)));  // uint64
+  EXPECT_EQ("-9223372036854775808",
+            Print(static_cast<testing::internal::Int64>(1) << 63));  // int64
+}
+
+// Size types.
+TEST(PrintBuiltInTypeTest, Size_t) {
+  EXPECT_EQ("1", Print(sizeof('a')));  // size_t.
+#if !GTEST_OS_WINDOWS
+  // Windows has no ssize_t type.
+  EXPECT_EQ("-2", Print(static_cast<ssize_t>(-2)));  // ssize_t.
+#endif  // !GTEST_OS_WINDOWS
+}
+
+// Floating-points.
+TEST(PrintBuiltInTypeTest, FloatingPoints) {
+  EXPECT_EQ("1.5", Print(1.5f));   // float
+  EXPECT_EQ("-2.5", Print(-2.5));  // double
+}
+
+// Since ::std::stringstream::operator<<(const void *) formats the pointer
+// output differently with different compilers, we have to create the expected
+// output first and use it as our expectation.
+static std::string PrintPointer(const void* p) {
+  ::std::stringstream expected_result_stream;
+  expected_result_stream << p;
+  return expected_result_stream.str();
+}
+
+// Tests printing C strings.
+
+// const char*.
+TEST(PrintCStringTest, Const) {
+  const char* p = "World";
+  EXPECT_EQ(PrintPointer(p) + " pointing to \"World\"", Print(p));
+}
+
+// char*.
+TEST(PrintCStringTest, NonConst) {
+  char p[] = "Hi";
+  EXPECT_EQ(PrintPointer(p) + " pointing to \"Hi\"",
+            Print(static_cast<char*>(p)));
+}
+
+// NULL C string.
+TEST(PrintCStringTest, Null) {
+  const char* p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// Tests that C strings are escaped properly.
+TEST(PrintCStringTest, EscapesProperly) {
+  const char* p = "'\"?\\\a\b\f\n\r\t\v\x7F\xFF a";
+  EXPECT_EQ(PrintPointer(p) + " pointing to \"'\\\"?\\\\\\a\\b\\f"
+            "\\n\\r\\t\\v\\x7F\\xFF a\"",
+            Print(p));
+}
+
+// MSVC compiler can be configured to define whar_t as a typedef
+// of unsigned short. Defining an overload for const wchar_t* in that case
+// would cause pointers to unsigned shorts be printed as wide strings,
+// possibly accessing more memory than intended and causing invalid
+// memory accesses. MSVC defines _NATIVE_WCHAR_T_DEFINED symbol when
+// wchar_t is implemented as a native type.
+#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
+
+// const wchar_t*.
+TEST(PrintWideCStringTest, Const) {
+  const wchar_t* p = L"World";
+  EXPECT_EQ(PrintPointer(p) + " pointing to L\"World\"", Print(p));
+}
+
+// wchar_t*.
+TEST(PrintWideCStringTest, NonConst) {
+  wchar_t p[] = L"Hi";
+  EXPECT_EQ(PrintPointer(p) + " pointing to L\"Hi\"",
+            Print(static_cast<wchar_t*>(p)));
+}
+
+// NULL wide C string.
+TEST(PrintWideCStringTest, Null) {
+  const wchar_t* p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// Tests that wide C strings are escaped properly.
+TEST(PrintWideCStringTest, EscapesProperly) {
+  const wchar_t s[] = {'\'', '"', '?', '\\', '\a', '\b', '\f', '\n', '\r',
+                       '\t', '\v', 0xD3, 0x576, 0x8D3, 0xC74D, ' ', 'a', '\0'};
+  EXPECT_EQ(PrintPointer(s) + " pointing to L\"'\\\"?\\\\\\a\\b\\f"
+            "\\n\\r\\t\\v\\xD3\\x576\\x8D3\\xC74D a\"",
+            Print(static_cast<const wchar_t*>(s)));
+}
+#endif  // native wchar_t
+
+// Tests printing pointers to other char types.
+
+// signed char*.
+TEST(PrintCharPointerTest, SignedChar) {
+  signed char* p = reinterpret_cast<signed char*>(0x1234);
+  EXPECT_EQ(PrintPointer(p), Print(p));
+  p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// const signed char*.
+TEST(PrintCharPointerTest, ConstSignedChar) {
+  signed char* p = reinterpret_cast<signed char*>(0x1234);
+  EXPECT_EQ(PrintPointer(p), Print(p));
+  p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// unsigned char*.
+TEST(PrintCharPointerTest, UnsignedChar) {
+  unsigned char* p = reinterpret_cast<unsigned char*>(0x1234);
+  EXPECT_EQ(PrintPointer(p), Print(p));
+  p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// const unsigned char*.
+TEST(PrintCharPointerTest, ConstUnsignedChar) {
+  const unsigned char* p = reinterpret_cast<const unsigned char*>(0x1234);
+  EXPECT_EQ(PrintPointer(p), Print(p));
+  p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// Tests printing pointers to simple, built-in types.
+
+// bool*.
+TEST(PrintPointerToBuiltInTypeTest, Bool) {
+  bool* p = reinterpret_cast<bool*>(0xABCD);
+  EXPECT_EQ(PrintPointer(p), Print(p));
+  p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// void*.
+TEST(PrintPointerToBuiltInTypeTest, Void) {
+  void* p = reinterpret_cast<void*>(0xABCD);
+  EXPECT_EQ(PrintPointer(p), Print(p));
+  p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// const void*.
+TEST(PrintPointerToBuiltInTypeTest, ConstVoid) {
+  const void* p = reinterpret_cast<const void*>(0xABCD);
+  EXPECT_EQ(PrintPointer(p), Print(p));
+  p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// Tests printing pointers to pointers.
+TEST(PrintPointerToPointerTest, IntPointerPointer) {
+  int** p = reinterpret_cast<int**>(0xABCD);
+  EXPECT_EQ(PrintPointer(p), Print(p));
+  p = nullptr;
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// Tests printing (non-member) function pointers.
+
+void MyFunction(int /* n */) {}
+
+TEST(PrintPointerTest, NonMemberFunctionPointer) {
+  // We cannot directly cast &MyFunction to const void* because the
+  // standard disallows casting between pointers to functions and
+  // pointers to objects, and some compilers (e.g. GCC 3.4) enforce
+  // this limitation.
+  EXPECT_EQ(
+      PrintPointer(reinterpret_cast<const void*>(
+          reinterpret_cast<internal::BiggestInt>(&MyFunction))),
+      Print(&MyFunction));
+  int (*p)(bool) = NULL;  // NOLINT
+  EXPECT_EQ("NULL", Print(p));
+}
+
+// An assertion predicate determining whether a one string is a prefix for
+// another.
+template <typename StringType>
+AssertionResult HasPrefix(const StringType& str, const StringType& prefix) {
+  if (str.find(prefix, 0) == 0)
+    return AssertionSuccess();
+
+  const bool is_wide_string = sizeof(prefix[0]) > 1;
+  const char* const begin_string_quote = is_wide_string ? "L\"" : "\"";
+  return AssertionFailure()
+      << begin_string_quote << prefix << "\" is not a prefix of "
+      << begin_string_quote << str << "\"\n";
+}
+
+// Tests printing member variable pointers.  Although they are called
+// pointers, they don't point to a location in the address space.
+// Their representation is implementation-defined.  Thus they will be
+// printed as raw bytes.
+
+struct Foo {
+ public:
+  virtual ~Foo() {}
+  int MyMethod(char x) { return x + 1; }
+  virtual char MyVirtualMethod(int /* n */) { return 'a'; }
+
+  int value;
+};
+
+TEST(PrintPointerTest, MemberVariablePointer) {
+  EXPECT_TRUE(HasPrefix(Print(&Foo::value),
+                        Print(sizeof(&Foo::value)) + "-byte object "));
+  int Foo::*p = NULL;  // NOLINT
+  EXPECT_TRUE(HasPrefix(Print(p),
+                        Print(sizeof(p)) + "-byte object "));
+}
+
+// Tests printing member function pointers.  Although they are called
+// pointers, they don't point to a location in the address space.
+// Their representation is implementation-defined.  Thus they will be
+// printed as raw bytes.
+TEST(PrintPointerTest, MemberFunctionPointer) {
+  EXPECT_TRUE(HasPrefix(Print(&Foo::MyMethod),
+                        Print(sizeof(&Foo::MyMethod)) + "-byte object "));
+  EXPECT_TRUE(
+      HasPrefix(Print(&Foo::MyVirtualMethod),
+                Print(sizeof((&Foo::MyVirtualMethod))) + "-byte object "));
+  int (Foo::*p)(char) = NULL;  // NOLINT
+  EXPECT_TRUE(HasPrefix(Print(p),
+                        Print(sizeof(p)) + "-byte object "));
+}
+
+// Tests printing C arrays.
+
+// The difference between this and Print() is that it ensures that the
+// argument is a reference to an array.
+template <typename T, size_t N>
+std::string PrintArrayHelper(T (&a)[N]) {
+  return Print(a);
+}
+
+// One-dimensional array.
+TEST(PrintArrayTest, OneDimensionalArray) {
+  int a[5] = { 1, 2, 3, 4, 5 };
+  EXPECT_EQ("{ 1, 2, 3, 4, 5 }", PrintArrayHelper(a));
+}
+
+// Two-dimensional array.
+TEST(PrintArrayTest, TwoDimensionalArray) {
+  int a[2][5] = {
+    { 1, 2, 3, 4, 5 },
+    { 6, 7, 8, 9, 0 }
+  };
+  EXPECT_EQ("{ { 1, 2, 3, 4, 5 }, { 6, 7, 8, 9, 0 } }", PrintArrayHelper(a));
+}
+
+// Array of const elements.
+TEST(PrintArrayTest, ConstArray) {
+  const bool a[1] = { false };
+  EXPECT_EQ("{ false }", PrintArrayHelper(a));
+}
+
+// char array without terminating NUL.
+TEST(PrintArrayTest, CharArrayWithNoTerminatingNul) {
+  // Array a contains '\0' in the middle and doesn't end with '\0'.
+  char a[] = { 'H', '\0', 'i' };
+  EXPECT_EQ("\"H\\0i\" (no terminating NUL)", PrintArrayHelper(a));
+}
+
+// const char array with terminating NUL.
+TEST(PrintArrayTest, ConstCharArrayWithTerminatingNul) {
+  const char a[] = "\0Hi";
+  EXPECT_EQ("\"\\0Hi\"", PrintArrayHelper(a));
+}
+
+// const wchar_t array without terminating NUL.
+TEST(PrintArrayTest, WCharArrayWithNoTerminatingNul) {
+  // Array a contains '\0' in the middle and doesn't end with '\0'.
+  const wchar_t a[] = { L'H', L'\0', L'i' };
+  EXPECT_EQ("L\"H\\0i\" (no terminating NUL)", PrintArrayHelper(a));
+}
+
+// wchar_t array with terminating NUL.
+TEST(PrintArrayTest, WConstCharArrayWithTerminatingNul) {
+  const wchar_t a[] = L"\0Hi";
+  EXPECT_EQ("L\"\\0Hi\"", PrintArrayHelper(a));
+}
+
+// Array of objects.
+TEST(PrintArrayTest, ObjectArray) {
+  std::string a[3] = {"Hi", "Hello", "Ni hao"};
+  EXPECT_EQ("{ \"Hi\", \"Hello\", \"Ni hao\" }", PrintArrayHelper(a));
+}
+
+// Array with many elements.
+TEST(PrintArrayTest, BigArray) {
+  int a[100] = { 1, 2, 3 };
+  EXPECT_EQ("{ 1, 2, 3, 0, 0, 0, 0, 0, ..., 0, 0, 0, 0, 0, 0, 0, 0 }",
+            PrintArrayHelper(a));
+}
+
+// Tests printing ::string and ::std::string.
+
+// ::std::string.
+TEST(PrintStringTest, StringInStdNamespace) {
+  const char s[] = "'\"?\\\a\b\f\n\0\r\t\v\x7F\xFF a";
+  const ::std::string str(s, sizeof(s));
+  EXPECT_EQ("\"'\\\"?\\\\\\a\\b\\f\\n\\0\\r\\t\\v\\x7F\\xFF a\\0\"",
+            Print(str));
+}
+
+TEST(PrintStringTest, StringAmbiguousHex) {
+  // "\x6BANANA" is ambiguous, it can be interpreted as starting with either of:
+  // '\x6', '\x6B', or '\x6BA'.
+
+  // a hex escaping sequence following by a decimal digit
+  EXPECT_EQ("\"0\\x12\" \"3\"", Print(::std::string("0\x12" "3")));
+  // a hex escaping sequence following by a hex digit (lower-case)
+  EXPECT_EQ("\"mm\\x6\" \"bananas\"", Print(::std::string("mm\x6" "bananas")));
+  // a hex escaping sequence following by a hex digit (upper-case)
+  EXPECT_EQ("\"NOM\\x6\" \"BANANA\"", Print(::std::string("NOM\x6" "BANANA")));
+  // a hex escaping sequence following by a non-xdigit
+  EXPECT_EQ("\"!\\x5-!\"", Print(::std::string("!\x5-!")));
+}
+
+// Tests printing ::std::wstring.
+#if GTEST_HAS_STD_WSTRING
+// ::std::wstring.
+TEST(PrintWideStringTest, StringInStdNamespace) {
+  const wchar_t s[] = L"'\"?\\\a\b\f\n\0\r\t\v\xD3\x576\x8D3\xC74D a";
+  const ::std::wstring str(s, sizeof(s)/sizeof(wchar_t));
+  EXPECT_EQ("L\"'\\\"?\\\\\\a\\b\\f\\n\\0\\r\\t\\v"
+            "\\xD3\\x576\\x8D3\\xC74D a\\0\"",
+            Print(str));
+}
+
+TEST(PrintWideStringTest, StringAmbiguousHex) {
+  // same for wide strings.
+  EXPECT_EQ("L\"0\\x12\" L\"3\"", Print(::std::wstring(L"0\x12" L"3")));
+  EXPECT_EQ("L\"mm\\x6\" L\"bananas\"",
+            Print(::std::wstring(L"mm\x6" L"bananas")));
+  EXPECT_EQ("L\"NOM\\x6\" L\"BANANA\"",
+            Print(::std::wstring(L"NOM\x6" L"BANANA")));
+  EXPECT_EQ("L\"!\\x5-!\"", Print(::std::wstring(L"!\x5-!")));
+}
+#endif  // GTEST_HAS_STD_WSTRING
+
+// Tests printing types that support generic streaming (i.e. streaming
+// to std::basic_ostream<Char, CharTraits> for any valid Char and
+// CharTraits types).
+
+// Tests printing a non-template type that supports generic streaming.
+
+class AllowsGenericStreaming {};
+
+template <typename Char, typename CharTraits>
+std::basic_ostream<Char, CharTraits>& operator<<(
+    std::basic_ostream<Char, CharTraits>& os,
+    const AllowsGenericStreaming& /* a */) {
+  return os << "AllowsGenericStreaming";
+}
+
+TEST(PrintTypeWithGenericStreamingTest, NonTemplateType) {
+  AllowsGenericStreaming a;
+  EXPECT_EQ("AllowsGenericStreaming", Print(a));
+}
+
+// Tests printing a template type that supports generic streaming.
+
+template <typename T>
+class AllowsGenericStreamingTemplate {};
+
+template <typename Char, typename CharTraits, typename T>
+std::basic_ostream<Char, CharTraits>& operator<<(
+    std::basic_ostream<Char, CharTraits>& os,
+    const AllowsGenericStreamingTemplate<T>& /* a */) {
+  return os << "AllowsGenericStreamingTemplate";
+}
+
+TEST(PrintTypeWithGenericStreamingTest, TemplateType) {
+  AllowsGenericStreamingTemplate<int> a;
+  EXPECT_EQ("AllowsGenericStreamingTemplate", Print(a));
+}
+
+// Tests printing a type that supports generic streaming and can be
+// implicitly converted to another printable type.
+
+template <typename T>
+class AllowsGenericStreamingAndImplicitConversionTemplate {
+ public:
+  operator bool() const { return false; }
+};
+
+template <typename Char, typename CharTraits, typename T>
+std::basic_ostream<Char, CharTraits>& operator<<(
+    std::basic_ostream<Char, CharTraits>& os,
+    const AllowsGenericStreamingAndImplicitConversionTemplate<T>& /* a */) {
+  return os << "AllowsGenericStreamingAndImplicitConversionTemplate";
+}
+
+TEST(PrintTypeWithGenericStreamingTest, TypeImplicitlyConvertible) {
+  AllowsGenericStreamingAndImplicitConversionTemplate<int> a;
+  EXPECT_EQ("AllowsGenericStreamingAndImplicitConversionTemplate", Print(a));
+}
+
+#if GTEST_HAS_ABSL
+
+// Tests printing ::absl::string_view.
+
+TEST(PrintStringViewTest, SimpleStringView) {
+  const ::absl::string_view sp = "Hello";
+  EXPECT_EQ("\"Hello\"", Print(sp));
+}
+
+TEST(PrintStringViewTest, UnprintableCharacters) {
+  const char str[] = "NUL (\0) and \r\t";
+  const ::absl::string_view sp(str, sizeof(str) - 1);
+  EXPECT_EQ("\"NUL (\\0) and \\r\\t\"", Print(sp));
+}
+
+#endif  // GTEST_HAS_ABSL
+
+// Tests printing STL containers.
+
+TEST(PrintStlContainerTest, EmptyDeque) {
+  deque<char> empty;
+  EXPECT_EQ("{}", Print(empty));
+}
+
+TEST(PrintStlContainerTest, NonEmptyDeque) {
+  deque<int> non_empty;
+  non_empty.push_back(1);
+  non_empty.push_back(3);
+  EXPECT_EQ("{ 1, 3 }", Print(non_empty));
+}
+
+
+TEST(PrintStlContainerTest, OneElementHashMap) {
+  ::std::unordered_map<int, char> map1;
+  map1[1] = 'a';
+  EXPECT_EQ("{ (1, 'a' (97, 0x61)) }", Print(map1));
+}
+
+TEST(PrintStlContainerTest, HashMultiMap) {
+  ::std::unordered_multimap<int, bool> map1;
+  map1.insert(make_pair(5, true));
+  map1.insert(make_pair(5, false));
+
+  // Elements of hash_multimap can be printed in any order.
+  const std::string result = Print(map1);
+  EXPECT_TRUE(result == "{ (5, true), (5, false) }" ||
+              result == "{ (5, false), (5, true) }")
+                  << " where Print(map1) returns \"" << result << "\".";
+}
+
+
+
+TEST(PrintStlContainerTest, HashSet) {
+  ::std::unordered_set<int> set1;
+  set1.insert(1);
+  EXPECT_EQ("{ 1 }", Print(set1));
+}
+
+TEST(PrintStlContainerTest, HashMultiSet) {
+  const int kSize = 5;
+  int a[kSize] = { 1, 1, 2, 5, 1 };
+  ::std::unordered_multiset<int> set1(a, a + kSize);
+
+  // Elements of hash_multiset can be printed in any order.
+  const std::string result = Print(set1);
+  const std::string expected_pattern = "{ d, d, d, d, d }";  // d means a digit.
+
+  // Verifies the result matches the expected pattern; also extracts
+  // the numbers in the result.
+  ASSERT_EQ(expected_pattern.length(), result.length());
+  std::vector<int> numbers;
+  for (size_t i = 0; i != result.length(); i++) {
+    if (expected_pattern[i] == 'd') {
+      ASSERT_NE(isdigit(static_cast<unsigned char>(result[i])), 0);
+      numbers.push_back(result[i] - '0');
+    } else {
+      EXPECT_EQ(expected_pattern[i], result[i]) << " where result is "
+                                                << result;
+    }
+  }
+
+  // Makes sure the result contains the right numbers.
+  std::sort(numbers.begin(), numbers.end());
+  std::sort(a, a + kSize);
+  EXPECT_TRUE(std::equal(a, a + kSize, numbers.begin()));
+}
+
+
+TEST(PrintStlContainerTest, List) {
+  const std::string a[] = {"hello", "world"};
+  const list<std::string> strings(a, a + 2);
+  EXPECT_EQ("{ \"hello\", \"world\" }", Print(strings));
+}
+
+TEST(PrintStlContainerTest, Map) {
+  map<int, bool> map1;
+  map1[1] = true;
+  map1[5] = false;
+  map1[3] = true;
+  EXPECT_EQ("{ (1, true), (3, true), (5, false) }", Print(map1));
+}
+
+TEST(PrintStlContainerTest, MultiMap) {
+  multimap<bool, int> map1;
+  // The make_pair template function would deduce the type as
+  // pair<bool, int> here, and since the key part in a multimap has to
+  // be constant, without a templated ctor in the pair class (as in
+  // libCstd on Solaris), make_pair call would fail to compile as no
+  // implicit conversion is found.  Thus explicit typename is used
+  // here instead.
+  map1.insert(pair<const bool, int>(true, 0));
+  map1.insert(pair<const bool, int>(true, 1));
+  map1.insert(pair<const bool, int>(false, 2));
+  EXPECT_EQ("{ (false, 2), (true, 0), (true, 1) }", Print(map1));
+}
+
+TEST(PrintStlContainerTest, Set) {
+  const unsigned int a[] = { 3, 0, 5 };
+  set<unsigned int> set1(a, a + 3);
+  EXPECT_EQ("{ 0, 3, 5 }", Print(set1));
+}
+
+TEST(PrintStlContainerTest, MultiSet) {
+  const int a[] = { 1, 1, 2, 5, 1 };
+  multiset<int> set1(a, a + 5);
+  EXPECT_EQ("{ 1, 1, 1, 2, 5 }", Print(set1));
+}
+
+
+TEST(PrintStlContainerTest, SinglyLinkedList) {
+  int a[] = { 9, 2, 8 };
+  const std::forward_list<int> ints(a, a + 3);
+  EXPECT_EQ("{ 9, 2, 8 }", Print(ints));
+}
+
+TEST(PrintStlContainerTest, Pair) {
+  pair<const bool, int> p(true, 5);
+  EXPECT_EQ("(true, 5)", Print(p));
+}
+
+TEST(PrintStlContainerTest, Vector) {
+  vector<int> v;
+  v.push_back(1);
+  v.push_back(2);
+  EXPECT_EQ("{ 1, 2 }", Print(v));
+}
+
+TEST(PrintStlContainerTest, LongSequence) {
+  const int a[100] = { 1, 2, 3 };
+  const vector<int> v(a, a + 100);
+  EXPECT_EQ("{ 1, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, "
+            "0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ... }", Print(v));
+}
+
+TEST(PrintStlContainerTest, NestedContainer) {
+  const int a1[] = { 1, 2 };
+  const int a2[] = { 3, 4, 5 };
+  const list<int> l1(a1, a1 + 2);
+  const list<int> l2(a2, a2 + 3);
+
+  vector<list<int> > v;
+  v.push_back(l1);
+  v.push_back(l2);
+  EXPECT_EQ("{ { 1, 2 }, { 3, 4, 5 } }", Print(v));
+}
+
+TEST(PrintStlContainerTest, OneDimensionalNativeArray) {
+  const int a[3] = { 1, 2, 3 };
+  NativeArray<int> b(a, 3, RelationToSourceReference());
+  EXPECT_EQ("{ 1, 2, 3 }", Print(b));
+}
+
+TEST(PrintStlContainerTest, TwoDimensionalNativeArray) {
+  const int a[2][3] = { { 1, 2, 3 }, { 4, 5, 6 } };
+  NativeArray<int[3]> b(a, 2, RelationToSourceReference());
+  EXPECT_EQ("{ { 1, 2, 3 }, { 4, 5, 6 } }", Print(b));
+}
+
+// Tests that a class named iterator isn't treated as a container.
+
+struct iterator {
+  char x;
+};
+
+TEST(PrintStlContainerTest, Iterator) {
+  iterator it = {};
+  EXPECT_EQ("1-byte object <00>", Print(it));
+}
+
+// Tests that a class named const_iterator isn't treated as a container.
+
+struct const_iterator {
+  char x;
+};
+
+TEST(PrintStlContainerTest, ConstIterator) {
+  const_iterator it = {};
+  EXPECT_EQ("1-byte object <00>", Print(it));
+}
+
+// Tests printing ::std::tuples.
+
+// Tuples of various arities.
+TEST(PrintStdTupleTest, VariousSizes) {
+  ::std::tuple<> t0;
+  EXPECT_EQ("()", Print(t0));
+
+  ::std::tuple<int> t1(5);
+  EXPECT_EQ("(5)", Print(t1));
+
+  ::std::tuple<char, bool> t2('a', true);
+  EXPECT_EQ("('a' (97, 0x61), true)", Print(t2));
+
+  ::std::tuple<bool, int, int> t3(false, 2, 3);
+  EXPECT_EQ("(false, 2, 3)", Print(t3));
+
+  ::std::tuple<bool, int, int, int> t4(false, 2, 3, 4);
+  EXPECT_EQ("(false, 2, 3, 4)", Print(t4));
+
+  const char* const str = "8";
+  ::std::tuple<bool, char, short, testing::internal::Int32,  // NOLINT
+               testing::internal::Int64, float, double, const char*, void*,
+               std::string>
+      t10(false, 'a', static_cast<short>(3), 4, 5, 1.5F, -2.5, str,  // NOLINT
+          nullptr, "10");
+  EXPECT_EQ("(false, 'a' (97, 0x61), 3, 4, 5, 1.5, -2.5, " + PrintPointer(str) +
+            " pointing to \"8\", NULL, \"10\")",
+            Print(t10));
+}
+
+// Nested tuples.
+TEST(PrintStdTupleTest, NestedTuple) {
+  ::std::tuple< ::std::tuple<int, bool>, char> nested(
+      ::std::make_tuple(5, true), 'a');
+  EXPECT_EQ("((5, true), 'a' (97, 0x61))", Print(nested));
+}
+
+TEST(PrintNullptrT, Basic) {
+  EXPECT_EQ("(nullptr)", Print(nullptr));
+}
+
+TEST(PrintReferenceWrapper, Printable) {
+  int x = 5;
+  EXPECT_EQ("@" + PrintPointer(&x) + " 5", Print(std::ref(x)));
+  EXPECT_EQ("@" + PrintPointer(&x) + " 5", Print(std::cref(x)));
+}
+
+TEST(PrintReferenceWrapper, Unprintable) {
+  ::foo::UnprintableInFoo up;
+  EXPECT_EQ(
+      "@" + PrintPointer(&up) +
+          " 16-byte object <EF-12 00-00 34-AB 00-00 00-00 00-00 00-00 00-00>",
+      Print(std::ref(up)));
+  EXPECT_EQ(
+      "@" + PrintPointer(&up) +
+          " 16-byte object <EF-12 00-00 34-AB 00-00 00-00 00-00 00-00 00-00>",
+      Print(std::cref(up)));
+}
+
+// Tests printing user-defined unprintable types.
+
+// Unprintable types in the global namespace.
+TEST(PrintUnprintableTypeTest, InGlobalNamespace) {
+  EXPECT_EQ("1-byte object <00>",
+            Print(UnprintableTemplateInGlobal<char>()));
+}
+
+// Unprintable types in a user namespace.
+TEST(PrintUnprintableTypeTest, InUserNamespace) {
+  EXPECT_EQ("16-byte object <EF-12 00-00 34-AB 00-00 00-00 00-00 00-00 00-00>",
+            Print(::foo::UnprintableInFoo()));
+}
+
+// Unprintable types are that too big to be printed completely.
+
+struct Big {
+  Big() { memset(array, 0, sizeof(array)); }
+  char array[257];
+};
+
+TEST(PrintUnpritableTypeTest, BigObject) {
+  EXPECT_EQ("257-byte object <00-00 00-00 00-00 00-00 00-00 00-00 "
+            "00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 "
+            "00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 "
+            "00-00 00-00 00-00 00-00 00-00 00-00 ... 00-00 00-00 00-00 "
+            "00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 "
+            "00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 "
+            "00-00 00-00 00-00 00-00 00-00 00-00 00-00 00-00 00>",
+            Print(Big()));
+}
+
+// Tests printing user-defined streamable types.
+
+// Streamable types in the global namespace.
+TEST(PrintStreamableTypeTest, InGlobalNamespace) {
+  StreamableInGlobal x;
+  EXPECT_EQ("StreamableInGlobal", Print(x));
+  EXPECT_EQ("StreamableInGlobal*", Print(&x));
+}
+
+// Printable template types in a user namespace.
+TEST(PrintStreamableTypeTest, TemplateTypeInUserNamespace) {
+  EXPECT_EQ("StreamableTemplateInFoo: 0",
+            Print(::foo::StreamableTemplateInFoo<int>()));
+}
+
+// Tests printing a user-defined recursive container type that has a <<
+// operator.
+TEST(PrintStreamableTypeTest, PathLikeInUserNamespace) {
+  ::foo::PathLike x;
+  EXPECT_EQ("Streamable-PathLike", Print(x));
+  const ::foo::PathLike cx;
+  EXPECT_EQ("Streamable-PathLike", Print(cx));
+}
+
+// Tests printing user-defined types that have a PrintTo() function.
+TEST(PrintPrintableTypeTest, InUserNamespace) {
+  EXPECT_EQ("PrintableViaPrintTo: 0",
+            Print(::foo::PrintableViaPrintTo()));
+}
+
+// Tests printing a pointer to a user-defined type that has a <<
+// operator for its pointer.
+TEST(PrintPrintableTypeTest, PointerInUserNamespace) {
+  ::foo::PointerPrintable x;
+  EXPECT_EQ("PointerPrintable*", Print(&x));
+}
+
+// Tests printing user-defined class template that have a PrintTo() function.
+TEST(PrintPrintableTypeTest, TemplateInUserNamespace) {
+  EXPECT_EQ("PrintableViaPrintToTemplate: 5",
+            Print(::foo::PrintableViaPrintToTemplate<int>(5)));
+}
+
+// Tests that the universal printer prints both the address and the
+// value of a reference.
+TEST(PrintReferenceTest, PrintsAddressAndValue) {
+  int n = 5;
+  EXPECT_EQ("@" + PrintPointer(&n) + " 5", PrintByRef(n));
+
+  int a[2][3] = {
+    { 0, 1, 2 },
+    { 3, 4, 5 }
+  };
+  EXPECT_EQ("@" + PrintPointer(a) + " { { 0, 1, 2 }, { 3, 4, 5 } }",
+            PrintByRef(a));
+
+  const ::foo::UnprintableInFoo x;
+  EXPECT_EQ("@" + PrintPointer(&x) + " 16-byte object "
+            "<EF-12 00-00 34-AB 00-00 00-00 00-00 00-00 00-00>",
+            PrintByRef(x));
+}
+
+// Tests that the universal printer prints a function pointer passed by
+// reference.
+TEST(PrintReferenceTest, HandlesFunctionPointer) {
+  void (*fp)(int n) = &MyFunction;
+  const std::string fp_pointer_string =
+      PrintPointer(reinterpret_cast<const void*>(&fp));
+  // We cannot directly cast &MyFunction to const void* because the
+  // standard disallows casting between pointers to functions and
+  // pointers to objects, and some compilers (e.g. GCC 3.4) enforce
+  // this limitation.
+  const std::string fp_string = PrintPointer(reinterpret_cast<const void*>(
+      reinterpret_cast<internal::BiggestInt>(fp)));
+  EXPECT_EQ("@" + fp_pointer_string + " " + fp_string,
+            PrintByRef(fp));
+}
+
+// Tests that the universal printer prints a member function pointer
+// passed by reference.
+TEST(PrintReferenceTest, HandlesMemberFunctionPointer) {
+  int (Foo::*p)(char ch) = &Foo::MyMethod;
+  EXPECT_TRUE(HasPrefix(
+      PrintByRef(p),
+      "@" + PrintPointer(reinterpret_cast<const void*>(&p)) + " " +
+          Print(sizeof(p)) + "-byte object "));
+
+  char (Foo::*p2)(int n) = &Foo::MyVirtualMethod;
+  EXPECT_TRUE(HasPrefix(
+      PrintByRef(p2),
+      "@" + PrintPointer(reinterpret_cast<const void*>(&p2)) + " " +
+          Print(sizeof(p2)) + "-byte object "));
+}
+
+// Tests that the universal printer prints a member variable pointer
+// passed by reference.
+TEST(PrintReferenceTest, HandlesMemberVariablePointer) {
+  int Foo::*p = &Foo::value;  // NOLINT
+  EXPECT_TRUE(HasPrefix(
+      PrintByRef(p),
+      "@" + PrintPointer(&p) + " " + Print(sizeof(p)) + "-byte object "));
+}
+
+// Tests that FormatForComparisonFailureMessage(), which is used to print
+// an operand in a comparison assertion (e.g. ASSERT_EQ) when the assertion
+// fails, formats the operand in the desired way.
+
+// scalar
+TEST(FormatForComparisonFailureMessageTest, WorksForScalar) {
+  EXPECT_STREQ("123",
+               FormatForComparisonFailureMessage(123, 124).c_str());
+}
+
+// non-char pointer
+TEST(FormatForComparisonFailureMessageTest, WorksForNonCharPointer) {
+  int n = 0;
+  EXPECT_EQ(PrintPointer(&n),
+            FormatForComparisonFailureMessage(&n, &n).c_str());
+}
+
+// non-char array
+TEST(FormatForComparisonFailureMessageTest, FormatsNonCharArrayAsPointer) {
+  // In expression 'array == x', 'array' is compared by pointer.
+  // Therefore we want to print an array operand as a pointer.
+  int n[] = { 1, 2, 3 };
+  EXPECT_EQ(PrintPointer(n),
+            FormatForComparisonFailureMessage(n, n).c_str());
+}
+
+// Tests formatting a char pointer when it's compared with another pointer.
+// In this case we want to print it as a raw pointer, as the comparison is by
+// pointer.
+
+// char pointer vs pointer
+TEST(FormatForComparisonFailureMessageTest, WorksForCharPointerVsPointer) {
+  // In expression 'p == x', where 'p' and 'x' are (const or not) char
+  // pointers, the operands are compared by pointer.  Therefore we
+  // want to print 'p' as a pointer instead of a C string (we don't
+  // even know if it's supposed to point to a valid C string).
+
+  // const char*
+  const char* s = "hello";
+  EXPECT_EQ(PrintPointer(s),
+            FormatForComparisonFailureMessage(s, s).c_str());
+
+  // char*
+  char ch = 'a';
+  EXPECT_EQ(PrintPointer(&ch),
+            FormatForComparisonFailureMessage(&ch, &ch).c_str());
+}
+
+// wchar_t pointer vs pointer
+TEST(FormatForComparisonFailureMessageTest, WorksForWCharPointerVsPointer) {
+  // In expression 'p == x', where 'p' and 'x' are (const or not) char
+  // pointers, the operands are compared by pointer.  Therefore we
+  // want to print 'p' as a pointer instead of a wide C string (we don't
+  // even know if it's supposed to point to a valid wide C string).
+
+  // const wchar_t*
+  const wchar_t* s = L"hello";
+  EXPECT_EQ(PrintPointer(s),
+            FormatForComparisonFailureMessage(s, s).c_str());
+
+  // wchar_t*
+  wchar_t ch = L'a';
+  EXPECT_EQ(PrintPointer(&ch),
+            FormatForComparisonFailureMessage(&ch, &ch).c_str());
+}
+
+// Tests formatting a char pointer when it's compared to a string object.
+// In this case we want to print the char pointer as a C string.
+
+// char pointer vs std::string
+TEST(FormatForComparisonFailureMessageTest, WorksForCharPointerVsStdString) {
+  const char* s = "hello \"world";
+  EXPECT_STREQ("\"hello \\\"world\"",  // The string content should be escaped.
+               FormatForComparisonFailureMessage(s, ::std::string()).c_str());
+
+  // char*
+  char str[] = "hi\1";
+  char* p = str;
+  EXPECT_STREQ("\"hi\\x1\"",  // The string content should be escaped.
+               FormatForComparisonFailureMessage(p, ::std::string()).c_str());
+}
+
+#if GTEST_HAS_STD_WSTRING
+// wchar_t pointer vs std::wstring
+TEST(FormatForComparisonFailureMessageTest, WorksForWCharPointerVsStdWString) {
+  const wchar_t* s = L"hi \"world";
+  EXPECT_STREQ("L\"hi \\\"world\"",  // The string content should be escaped.
+               FormatForComparisonFailureMessage(s, ::std::wstring()).c_str());
+
+  // wchar_t*
+  wchar_t str[] = L"hi\1";
+  wchar_t* p = str;
+  EXPECT_STREQ("L\"hi\\x1\"",  // The string content should be escaped.
+               FormatForComparisonFailureMessage(p, ::std::wstring()).c_str());
+}
+#endif
+
+// Tests formatting a char array when it's compared with a pointer or array.
+// In this case we want to print the array as a row pointer, as the comparison
+// is by pointer.
+
+// char array vs pointer
+TEST(FormatForComparisonFailureMessageTest, WorksForCharArrayVsPointer) {
+  char str[] = "hi \"world\"";
+  char* p = nullptr;
+  EXPECT_EQ(PrintPointer(str),
+            FormatForComparisonFailureMessage(str, p).c_str());
+}
+
+// char array vs char array
+TEST(FormatForComparisonFailureMessageTest, WorksForCharArrayVsCharArray) {
+  const char str[] = "hi \"world\"";
+  EXPECT_EQ(PrintPointer(str),
+            FormatForComparisonFailureMessage(str, str).c_str());
+}
+
+// wchar_t array vs pointer
+TEST(FormatForComparisonFailureMessageTest, WorksForWCharArrayVsPointer) {
+  wchar_t str[] = L"hi \"world\"";
+  wchar_t* p = nullptr;
+  EXPECT_EQ(PrintPointer(str),
+            FormatForComparisonFailureMessage(str, p).c_str());
+}
+
+// wchar_t array vs wchar_t array
+TEST(FormatForComparisonFailureMessageTest, WorksForWCharArrayVsWCharArray) {
+  const wchar_t str[] = L"hi \"world\"";
+  EXPECT_EQ(PrintPointer(str),
+            FormatForComparisonFailureMessage(str, str).c_str());
+}
+
+// Tests formatting a char array when it's compared with a string object.
+// In this case we want to print the array as a C string.
+
+// char array vs std::string
+TEST(FormatForComparisonFailureMessageTest, WorksForCharArrayVsStdString) {
+  const char str[] = "hi \"world\"";
+  EXPECT_STREQ("\"hi \\\"world\\\"\"",  // The content should be escaped.
+               FormatForComparisonFailureMessage(str, ::std::string()).c_str());
+}
+
+#if GTEST_HAS_STD_WSTRING
+// wchar_t array vs std::wstring
+TEST(FormatForComparisonFailureMessageTest, WorksForWCharArrayVsStdWString) {
+  const wchar_t str[] = L"hi \"w\0rld\"";
+  EXPECT_STREQ(
+      "L\"hi \\\"w\"",  // The content should be escaped.
+                        // Embedded NUL terminates the string.
+      FormatForComparisonFailureMessage(str, ::std::wstring()).c_str());
+}
+#endif
+
+// Useful for testing PrintToString().  We cannot use EXPECT_EQ()
+// there as its implementation uses PrintToString().  The caller must
+// ensure that 'value' has no side effect.
+#define EXPECT_PRINT_TO_STRING_(value, expected_string)         \
+  EXPECT_TRUE(PrintToString(value) == (expected_string))        \
+      << " where " #value " prints as " << (PrintToString(value))
+
+TEST(PrintToStringTest, WorksForScalar) {
+  EXPECT_PRINT_TO_STRING_(123, "123");
+}
+
+TEST(PrintToStringTest, WorksForPointerToConstChar) {
+  const char* p = "hello";
+  EXPECT_PRINT_TO_STRING_(p, "\"hello\"");
+}
+
+TEST(PrintToStringTest, WorksForPointerToNonConstChar) {
+  char s[] = "hello";
+  char* p = s;
+  EXPECT_PRINT_TO_STRING_(p, "\"hello\"");
+}
+
+TEST(PrintToStringTest, EscapesForPointerToConstChar) {
+  const char* p = "hello\n";
+  EXPECT_PRINT_TO_STRING_(p, "\"hello\\n\"");
+}
+
+TEST(PrintToStringTest, EscapesForPointerToNonConstChar) {
+  char s[] = "hello\1";
+  char* p = s;
+  EXPECT_PRINT_TO_STRING_(p, "\"hello\\x1\"");
+}
+
+TEST(PrintToStringTest, WorksForArray) {
+  int n[3] = { 1, 2, 3 };
+  EXPECT_PRINT_TO_STRING_(n, "{ 1, 2, 3 }");
+}
+
+TEST(PrintToStringTest, WorksForCharArray) {
+  char s[] = "hello";
+  EXPECT_PRINT_TO_STRING_(s, "\"hello\"");
+}
+
+TEST(PrintToStringTest, WorksForCharArrayWithEmbeddedNul) {
+  const char str_with_nul[] = "hello\0 world";
+  EXPECT_PRINT_TO_STRING_(str_with_nul, "\"hello\\0 world\"");
+
+  char mutable_str_with_nul[] = "hello\0 world";
+  EXPECT_PRINT_TO_STRING_(mutable_str_with_nul, "\"hello\\0 world\"");
+}
+
+  TEST(PrintToStringTest, ContainsNonLatin) {
+  // Sanity test with valid UTF-8. Prints both in hex and as text.
+  std::string non_ascii_str = ::std::string("오전 4:30");
+  EXPECT_PRINT_TO_STRING_(non_ascii_str,
+                          "\"\\xEC\\x98\\xA4\\xEC\\xA0\\x84 4:30\"\n"
+                          "    As Text: \"오전 4:30\"");
+  non_ascii_str = ::std::string("From ä — ẑ");
+  EXPECT_PRINT_TO_STRING_(non_ascii_str,
+                          "\"From \\xC3\\xA4 \\xE2\\x80\\x94 \\xE1\\xBA\\x91\""
+                          "\n    As Text: \"From ä — ẑ\"");
+}
+
+TEST(IsValidUTF8Test, IllFormedUTF8) {
+  // The following test strings are ill-formed UTF-8 and are printed
+  // as hex only (or ASCII, in case of ASCII bytes) because IsValidUTF8() is
+  // expected to fail, thus output does not contain "As Text:".
+
+  static const char *const kTestdata[][2] = {
+    // 2-byte lead byte followed by a single-byte character.
+    {"\xC3\x74", "\"\\xC3t\""},
+    // Valid 2-byte character followed by an orphan trail byte.
+    {"\xC3\x84\xA4", "\"\\xC3\\x84\\xA4\""},
+    // Lead byte without trail byte.
+    {"abc\xC3", "\"abc\\xC3\""},
+    // 3-byte lead byte, single-byte character, orphan trail byte.
+    {"x\xE2\x70\x94", "\"x\\xE2p\\x94\""},
+    // Truncated 3-byte character.
+    {"\xE2\x80", "\"\\xE2\\x80\""},
+    // Truncated 3-byte character followed by valid 2-byte char.
+    {"\xE2\x80\xC3\x84", "\"\\xE2\\x80\\xC3\\x84\""},
+    // Truncated 3-byte character followed by a single-byte character.
+    {"\xE2\x80\x7A", "\"\\xE2\\x80z\""},
+    // 3-byte lead byte followed by valid 3-byte character.
+    {"\xE2\xE2\x80\x94", "\"\\xE2\\xE2\\x80\\x94\""},
+    // 4-byte lead byte followed by valid 3-byte character.
+    {"\xF0\xE2\x80\x94", "\"\\xF0\\xE2\\x80\\x94\""},
+    // Truncated 4-byte character.
+    {"\xF0\xE2\x80", "\"\\xF0\\xE2\\x80\""},
+     // Invalid UTF-8 byte sequences embedded in other chars.
+    {"abc\xE2\x80\x94\xC3\x74xyc", "\"abc\\xE2\\x80\\x94\\xC3txyc\""},
+    {"abc\xC3\x84\xE2\x80\xC3\x84xyz",
+     "\"abc\\xC3\\x84\\xE2\\x80\\xC3\\x84xyz\""},
+    // Non-shortest UTF-8 byte sequences are also ill-formed.
+    // The classics: xC0, xC1 lead byte.
+    {"\xC0\x80", "\"\\xC0\\x80\""},
+    {"\xC1\x81", "\"\\xC1\\x81\""},
+    // Non-shortest sequences.
+    {"\xE0\x80\x80", "\"\\xE0\\x80\\x80\""},
+    {"\xf0\x80\x80\x80", "\"\\xF0\\x80\\x80\\x80\""},
+    // Last valid code point before surrogate range, should be printed as text,
+    // too.
+    {"\xED\x9F\xBF", "\"\\xED\\x9F\\xBF\"\n    As Text: \"퟿\""},
+    // Start of surrogate lead. Surrogates are not printed as text.
+    {"\xED\xA0\x80", "\"\\xED\\xA0\\x80\""},
+    // Last non-private surrogate lead.
+    {"\xED\xAD\xBF", "\"\\xED\\xAD\\xBF\""},
+    // First private-use surrogate lead.
+    {"\xED\xAE\x80", "\"\\xED\\xAE\\x80\""},
+    // Last private-use surrogate lead.
+    {"\xED\xAF\xBF", "\"\\xED\\xAF\\xBF\""},
+    // Mid-point of surrogate trail.
+    {"\xED\xB3\xBF", "\"\\xED\\xB3\\xBF\""},
+    // First valid code point after surrogate range, should be printed as text,
+    // too.
+    {"\xEE\x80\x80", "\"\\xEE\\x80\\x80\"\n    As Text: \"\""}
+  };
+
+  for (int i = 0; i < int(sizeof(kTestdata)/sizeof(kTestdata[0])); ++i) {
+    EXPECT_PRINT_TO_STRING_(kTestdata[i][0], kTestdata[i][1]);
+  }
+}
+
+#undef EXPECT_PRINT_TO_STRING_
+
+TEST(UniversalTersePrintTest, WorksForNonReference) {
+  ::std::stringstream ss;
+  UniversalTersePrint(123, &ss);
+  EXPECT_EQ("123", ss.str());
+}
+
+TEST(UniversalTersePrintTest, WorksForReference) {
+  const int& n = 123;
+  ::std::stringstream ss;
+  UniversalTersePrint(n, &ss);
+  EXPECT_EQ("123", ss.str());
+}
+
+TEST(UniversalTersePrintTest, WorksForCString) {
+  const char* s1 = "abc";
+  ::std::stringstream ss1;
+  UniversalTersePrint(s1, &ss1);
+  EXPECT_EQ("\"abc\"", ss1.str());
+
+  char* s2 = const_cast<char*>(s1);
+  ::std::stringstream ss2;
+  UniversalTersePrint(s2, &ss2);
+  EXPECT_EQ("\"abc\"", ss2.str());
+
+  const char* s3 = nullptr;
+  ::std::stringstream ss3;
+  UniversalTersePrint(s3, &ss3);
+  EXPECT_EQ("NULL", ss3.str());
+}
+
+TEST(UniversalPrintTest, WorksForNonReference) {
+  ::std::stringstream ss;
+  UniversalPrint(123, &ss);
+  EXPECT_EQ("123", ss.str());
+}
+
+TEST(UniversalPrintTest, WorksForReference) {
+  const int& n = 123;
+  ::std::stringstream ss;
+  UniversalPrint(n, &ss);
+  EXPECT_EQ("123", ss.str());
+}
+
+TEST(UniversalPrintTest, WorksForCString) {
+  const char* s1 = "abc";
+  ::std::stringstream ss1;
+  UniversalPrint(s1, &ss1);
+  EXPECT_EQ(PrintPointer(s1) + " pointing to \"abc\"", std::string(ss1.str()));
+
+  char* s2 = const_cast<char*>(s1);
+  ::std::stringstream ss2;
+  UniversalPrint(s2, &ss2);
+  EXPECT_EQ(PrintPointer(s2) + " pointing to \"abc\"", std::string(ss2.str()));
+
+  const char* s3 = nullptr;
+  ::std::stringstream ss3;
+  UniversalPrint(s3, &ss3);
+  EXPECT_EQ("NULL", ss3.str());
+}
+
+TEST(UniversalPrintTest, WorksForCharArray) {
+  const char str[] = "\"Line\0 1\"\nLine 2";
+  ::std::stringstream ss1;
+  UniversalPrint(str, &ss1);
+  EXPECT_EQ("\"\\\"Line\\0 1\\\"\\nLine 2\"", ss1.str());
+
+  const char mutable_str[] = "\"Line\0 1\"\nLine 2";
+  ::std::stringstream ss2;
+  UniversalPrint(mutable_str, &ss2);
+  EXPECT_EQ("\"\\\"Line\\0 1\\\"\\nLine 2\"", ss2.str());
+}
+
+TEST(UniversalTersePrintTupleFieldsToStringsTestWithStd, PrintsEmptyTuple) {
+  Strings result = UniversalTersePrintTupleFieldsToStrings(::std::make_tuple());
+  EXPECT_EQ(0u, result.size());
+}
+
+TEST(UniversalTersePrintTupleFieldsToStringsTestWithStd, PrintsOneTuple) {
+  Strings result = UniversalTersePrintTupleFieldsToStrings(
+      ::std::make_tuple(1));
+  ASSERT_EQ(1u, result.size());
+  EXPECT_EQ("1", result[0]);
+}
+
+TEST(UniversalTersePrintTupleFieldsToStringsTestWithStd, PrintsTwoTuple) {
+  Strings result = UniversalTersePrintTupleFieldsToStrings(
+      ::std::make_tuple(1, 'a'));
+  ASSERT_EQ(2u, result.size());
+  EXPECT_EQ("1", result[0]);
+  EXPECT_EQ("'a' (97, 0x61)", result[1]);
+}
+
+TEST(UniversalTersePrintTupleFieldsToStringsTestWithStd, PrintsTersely) {
+  const int n = 1;
+  Strings result = UniversalTersePrintTupleFieldsToStrings(
+      ::std::tuple<const int&, const char*>(n, "a"));
+  ASSERT_EQ(2u, result.size());
+  EXPECT_EQ("1", result[0]);
+  EXPECT_EQ("\"a\"", result[1]);
+}
+
+#if GTEST_HAS_ABSL
+
+TEST(PrintOptionalTest, Basic) {
+  absl::optional<int> value;
+  EXPECT_EQ("(nullopt)", PrintToString(value));
+  value = {7};
+  EXPECT_EQ("(7)", PrintToString(value));
+  EXPECT_EQ("(1.1)", PrintToString(absl::optional<double>{1.1}));
+  EXPECT_EQ("(\"A\")", PrintToString(absl::optional<std::string>{"A"}));
+}
+
+struct NonPrintable {
+  unsigned char contents = 17;
+};
+
+TEST(PrintOneofTest, Basic) {
+  using Type = absl::variant<int, StreamableInGlobal, NonPrintable>;
+  EXPECT_EQ("('int' with value 7)", PrintToString(Type(7)));
+  EXPECT_EQ("('StreamableInGlobal' with value StreamableInGlobal)",
+            PrintToString(Type(StreamableInGlobal{})));
+  EXPECT_EQ(
+      "('testing::gtest_printers_test::NonPrintable' with value 1-byte object "
+      "<11>)",
+      PrintToString(Type(NonPrintable{})));
+}
+#endif  // GTEST_HAS_ABSL
+namespace {
+class string_ref;
+
+/**
+ * This is a synthetic pointer to a fixed size string.
+ */
+class string_ptr {
+ public:
+  string_ptr(const char* data, size_t size) : data_(data), size_(size) {}
+
+  string_ptr& operator++() noexcept {
+    data_ += size_;
+    return *this;
+  }
+
+  string_ref operator*() const noexcept;
+
+ private:
+  const char* data_;
+  size_t size_;
+};
+
+/**
+ * This is a synthetic reference of a fixed size string.
+ */
+class string_ref {
+ public:
+  string_ref(const char* data, size_t size) : data_(data), size_(size) {}
+
+  string_ptr operator&() const noexcept { return {data_, size_}; }  // NOLINT
+
+  bool operator==(const char* s) const noexcept {
+    if (size_ > 0 && data_[size_ - 1] != 0) {
+      return std::string(data_, size_) == std::string(s);
+    } else {
+      return std::string(data_) == std::string(s);
+    }
+  }
+
+ private:
+  const char* data_;
+  size_t size_;
+};
+
+string_ref string_ptr::operator*() const noexcept { return {data_, size_}; }
+
+TEST(string_ref, compare) {
+  const char* s = "alex\0davidjohn\0";
+  string_ptr ptr(s, 5);
+  EXPECT_EQ(*ptr, "alex");
+  EXPECT_TRUE(*ptr == "alex");
+  ++ptr;
+  EXPECT_EQ(*ptr, "david");
+  EXPECT_TRUE(*ptr == "david");
+  ++ptr;
+  EXPECT_EQ(*ptr, "john");
+}
+
+}  // namespace
+
+}  // namespace gtest_printers_test
+}  // namespace testing
diff --git a/3rdparty/gtest/test/googletest-shuffle-test.py b/3rdparty/gtest/test/googletest-shuffle-test.py
new file mode 100644
index 0000000..573cc5e
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-shuffle-test.py
@@ -0,0 +1,323 @@
+#!/usr/bin/env python
+#
+# Copyright 2009 Google Inc. All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Verifies that test shuffling works."""
+
+import os
+import gtest_test_utils
+
+# Command to run the googletest-shuffle-test_ program.
+COMMAND = gtest_test_utils.GetTestExecutablePath('googletest-shuffle-test_')
+
+# The environment variables for test sharding.
+TOTAL_SHARDS_ENV_VAR = 'GTEST_TOTAL_SHARDS'
+SHARD_INDEX_ENV_VAR = 'GTEST_SHARD_INDEX'
+
+TEST_FILTER = 'A*.A:A*.B:C*'
+
+ALL_TESTS = []
+ACTIVE_TESTS = []
+FILTERED_TESTS = []
+SHARDED_TESTS = []
+
+SHUFFLED_ALL_TESTS = []
+SHUFFLED_ACTIVE_TESTS = []
+SHUFFLED_FILTERED_TESTS = []
+SHUFFLED_SHARDED_TESTS = []
+
+
+def AlsoRunDisabledTestsFlag():
+  return '--gtest_also_run_disabled_tests'
+
+
+def FilterFlag(test_filter):
+  return '--gtest_filter=%s' % (test_filter,)
+
+
+def RepeatFlag(n):
+  return '--gtest_repeat=%s' % (n,)
+
+
+def ShuffleFlag():
+  return '--gtest_shuffle'
+
+
+def RandomSeedFlag(n):
+  return '--gtest_random_seed=%s' % (n,)
+
+
+def RunAndReturnOutput(extra_env, args):
+  """Runs the test program and returns its output."""
+
+  environ_copy = os.environ.copy()
+  environ_copy.update(extra_env)
+
+  return gtest_test_utils.Subprocess([COMMAND] + args, env=environ_copy).output
+
+
+def GetTestsForAllIterations(extra_env, args):
+  """Runs the test program and returns a list of test lists.
+
+  Args:
+    extra_env: a map from environment variables to their values
+    args: command line flags to pass to googletest-shuffle-test_
+
+  Returns:
+    A list where the i-th element is the list of tests run in the i-th
+    test iteration.
+  """
+
+  test_iterations = []
+  for line in RunAndReturnOutput(extra_env, args).split('\n'):
+    if line.startswith('----'):
+      tests = []
+      test_iterations.append(tests)
+    elif line.strip():
+      tests.append(line.strip())  # 'TestCaseName.TestName'
+
+  return test_iterations
+
+
+def GetTestCases(tests):
+  """Returns a list of test cases in the given full test names.
+
+  Args:
+    tests: a list of full test names
+
+  Returns:
+    A list of test cases from 'tests', in their original order.
+    Consecutive duplicates are removed.
+  """
+
+  test_cases = []
+  for test in tests:
+    test_case = test.split('.')[0]
+    if not test_case in test_cases:
+      test_cases.append(test_case)
+
+  return test_cases
+
+
+def CalculateTestLists():
+  """Calculates the list of tests run under different flags."""
+
+  if not ALL_TESTS:
+    ALL_TESTS.extend(
+        GetTestsForAllIterations({}, [AlsoRunDisabledTestsFlag()])[0])
+
+  if not ACTIVE_TESTS:
+    ACTIVE_TESTS.extend(GetTestsForAllIterations({}, [])[0])
+
+  if not FILTERED_TESTS:
+    FILTERED_TESTS.extend(
+        GetTestsForAllIterations({}, [FilterFlag(TEST_FILTER)])[0])
+
+  if not SHARDED_TESTS:
+    SHARDED_TESTS.extend(
+        GetTestsForAllIterations({TOTAL_SHARDS_ENV_VAR: '3',
+                                  SHARD_INDEX_ENV_VAR: '1'},
+                                 [])[0])
+
+  if not SHUFFLED_ALL_TESTS:
+    SHUFFLED_ALL_TESTS.extend(GetTestsForAllIterations(
+        {}, [AlsoRunDisabledTestsFlag(), ShuffleFlag(), RandomSeedFlag(1)])[0])
+
+  if not SHUFFLED_ACTIVE_TESTS:
+    SHUFFLED_ACTIVE_TESTS.extend(GetTestsForAllIterations(
+        {}, [ShuffleFlag(), RandomSeedFlag(1)])[0])
+
+  if not SHUFFLED_FILTERED_TESTS:
+    SHUFFLED_FILTERED_TESTS.extend(GetTestsForAllIterations(
+        {}, [ShuffleFlag(), RandomSeedFlag(1), FilterFlag(TEST_FILTER)])[0])
+
+  if not SHUFFLED_SHARDED_TESTS:
+    SHUFFLED_SHARDED_TESTS.extend(
+        GetTestsForAllIterations({TOTAL_SHARDS_ENV_VAR: '3',
+                                  SHARD_INDEX_ENV_VAR: '1'},
+                                 [ShuffleFlag(), RandomSeedFlag(1)])[0])
+
+
+class GTestShuffleUnitTest(gtest_test_utils.TestCase):
+  """Tests test shuffling."""
+
+  def setUp(self):
+    CalculateTestLists()
+
+  def testShufflePreservesNumberOfTests(self):
+    self.assertEqual(len(ALL_TESTS), len(SHUFFLED_ALL_TESTS))
+    self.assertEqual(len(ACTIVE_TESTS), len(SHUFFLED_ACTIVE_TESTS))
+    self.assertEqual(len(FILTERED_TESTS), len(SHUFFLED_FILTERED_TESTS))
+    self.assertEqual(len(SHARDED_TESTS), len(SHUFFLED_SHARDED_TESTS))
+
+  def testShuffleChangesTestOrder(self):
+    self.assert_(SHUFFLED_ALL_TESTS != ALL_TESTS, SHUFFLED_ALL_TESTS)
+    self.assert_(SHUFFLED_ACTIVE_TESTS != ACTIVE_TESTS, SHUFFLED_ACTIVE_TESTS)
+    self.assert_(SHUFFLED_FILTERED_TESTS != FILTERED_TESTS,
+                 SHUFFLED_FILTERED_TESTS)
+    self.assert_(SHUFFLED_SHARDED_TESTS != SHARDED_TESTS,
+                 SHUFFLED_SHARDED_TESTS)
+
+  def testShuffleChangesTestCaseOrder(self):
+    self.assert_(GetTestCases(SHUFFLED_ALL_TESTS) != GetTestCases(ALL_TESTS),
+                 GetTestCases(SHUFFLED_ALL_TESTS))
+    self.assert_(
+        GetTestCases(SHUFFLED_ACTIVE_TESTS) != GetTestCases(ACTIVE_TESTS),
+        GetTestCases(SHUFFLED_ACTIVE_TESTS))
+    self.assert_(
+        GetTestCases(SHUFFLED_FILTERED_TESTS) != GetTestCases(FILTERED_TESTS),
+        GetTestCases(SHUFFLED_FILTERED_TESTS))
+    self.assert_(
+        GetTestCases(SHUFFLED_SHARDED_TESTS) != GetTestCases(SHARDED_TESTS),
+        GetTestCases(SHUFFLED_SHARDED_TESTS))
+
+  def testShuffleDoesNotRepeatTest(self):
+    for test in SHUFFLED_ALL_TESTS:
+      self.assertEqual(1, SHUFFLED_ALL_TESTS.count(test),
+                       '%s appears more than once' % (test,))
+    for test in SHUFFLED_ACTIVE_TESTS:
+      self.assertEqual(1, SHUFFLED_ACTIVE_TESTS.count(test),
+                       '%s appears more than once' % (test,))
+    for test in SHUFFLED_FILTERED_TESTS:
+      self.assertEqual(1, SHUFFLED_FILTERED_TESTS.count(test),
+                       '%s appears more than once' % (test,))
+    for test in SHUFFLED_SHARDED_TESTS:
+      self.assertEqual(1, SHUFFLED_SHARDED_TESTS.count(test),
+                       '%s appears more than once' % (test,))
+
+  def testShuffleDoesNotCreateNewTest(self):
+    for test in SHUFFLED_ALL_TESTS:
+      self.assert_(test in ALL_TESTS, '%s is an invalid test' % (test,))
+    for test in SHUFFLED_ACTIVE_TESTS:
+      self.assert_(test in ACTIVE_TESTS, '%s is an invalid test' % (test,))
+    for test in SHUFFLED_FILTERED_TESTS:
+      self.assert_(test in FILTERED_TESTS, '%s is an invalid test' % (test,))
+    for test in SHUFFLED_SHARDED_TESTS:
+      self.assert_(test in SHARDED_TESTS, '%s is an invalid test' % (test,))
+
+  def testShuffleIncludesAllTests(self):
+    for test in ALL_TESTS:
+      self.assert_(test in SHUFFLED_ALL_TESTS, '%s is missing' % (test,))
+    for test in ACTIVE_TESTS:
+      self.assert_(test in SHUFFLED_ACTIVE_TESTS, '%s is missing' % (test,))
+    for test in FILTERED_TESTS:
+      self.assert_(test in SHUFFLED_FILTERED_TESTS, '%s is missing' % (test,))
+    for test in SHARDED_TESTS:
+      self.assert_(test in SHUFFLED_SHARDED_TESTS, '%s is missing' % (test,))
+
+  def testShuffleLeavesDeathTestsAtFront(self):
+    non_death_test_found = False
+    for test in SHUFFLED_ACTIVE_TESTS:
+      if 'DeathTest.' in test:
+        self.assert_(not non_death_test_found,
+                     '%s appears after a non-death test' % (test,))
+      else:
+        non_death_test_found = True
+
+  def _VerifyTestCasesDoNotInterleave(self, tests):
+    test_cases = []
+    for test in tests:
+      [test_case, _] = test.split('.')
+      if test_cases and test_cases[-1] != test_case:
+        test_cases.append(test_case)
+        self.assertEqual(1, test_cases.count(test_case),
+                         'Test case %s is not grouped together in %s' %
+                         (test_case, tests))
+
+  def testShuffleDoesNotInterleaveTestCases(self):
+    self._VerifyTestCasesDoNotInterleave(SHUFFLED_ALL_TESTS)
+    self._VerifyTestCasesDoNotInterleave(SHUFFLED_ACTIVE_TESTS)
+    self._VerifyTestCasesDoNotInterleave(SHUFFLED_FILTERED_TESTS)
+    self._VerifyTestCasesDoNotInterleave(SHUFFLED_SHARDED_TESTS)
+
+  def testShuffleRestoresOrderAfterEachIteration(self):
+    # Get the test lists in all 3 iterations, using random seed 1, 2,
+    # and 3 respectively.  Google Test picks a different seed in each
+    # iteration, and this test depends on the current implementation
+    # picking successive numbers.  This dependency is not ideal, but
+    # makes the test much easier to write.
+    [tests_in_iteration1, tests_in_iteration2, tests_in_iteration3] = (
+        GetTestsForAllIterations(
+            {}, [ShuffleFlag(), RandomSeedFlag(1), RepeatFlag(3)]))
+
+    # Make sure running the tests with random seed 1 gets the same
+    # order as in iteration 1 above.
+    [tests_with_seed1] = GetTestsForAllIterations(
+        {}, [ShuffleFlag(), RandomSeedFlag(1)])
+    self.assertEqual(tests_in_iteration1, tests_with_seed1)
+
+    # Make sure running the tests with random seed 2 gets the same
+    # order as in iteration 2 above.  Success means that Google Test
+    # correctly restores the test order before re-shuffling at the
+    # beginning of iteration 2.
+    [tests_with_seed2] = GetTestsForAllIterations(
+        {}, [ShuffleFlag(), RandomSeedFlag(2)])
+    self.assertEqual(tests_in_iteration2, tests_with_seed2)
+
+    # Make sure running the tests with random seed 3 gets the same
+    # order as in iteration 3 above.  Success means that Google Test
+    # correctly restores the test order before re-shuffling at the
+    # beginning of iteration 3.
+    [tests_with_seed3] = GetTestsForAllIterations(
+        {}, [ShuffleFlag(), RandomSeedFlag(3)])
+    self.assertEqual(tests_in_iteration3, tests_with_seed3)
+
+  def testShuffleGeneratesNewOrderInEachIteration(self):
+    [tests_in_iteration1, tests_in_iteration2, tests_in_iteration3] = (
+        GetTestsForAllIterations(
+            {}, [ShuffleFlag(), RandomSeedFlag(1), RepeatFlag(3)]))
+
+    self.assert_(tests_in_iteration1 != tests_in_iteration2,
+                 tests_in_iteration1)
+    self.assert_(tests_in_iteration1 != tests_in_iteration3,
+                 tests_in_iteration1)
+    self.assert_(tests_in_iteration2 != tests_in_iteration3,
+                 tests_in_iteration2)
+
+  def testShuffleShardedTestsPreservesPartition(self):
+    # If we run M tests on N shards, the same M tests should be run in
+    # total, regardless of the random seeds used by the shards.
+    [tests1] = GetTestsForAllIterations({TOTAL_SHARDS_ENV_VAR: '3',
+                                         SHARD_INDEX_ENV_VAR: '0'},
+                                        [ShuffleFlag(), RandomSeedFlag(1)])
+    [tests2] = GetTestsForAllIterations({TOTAL_SHARDS_ENV_VAR: '3',
+                                         SHARD_INDEX_ENV_VAR: '1'},
+                                        [ShuffleFlag(), RandomSeedFlag(20)])
+    [tests3] = GetTestsForAllIterations({TOTAL_SHARDS_ENV_VAR: '3',
+                                         SHARD_INDEX_ENV_VAR: '2'},
+                                        [ShuffleFlag(), RandomSeedFlag(25)])
+    sorted_sharded_tests = tests1 + tests2 + tests3
+    sorted_sharded_tests.sort()
+    sorted_active_tests = []
+    sorted_active_tests.extend(ACTIVE_TESTS)
+    sorted_active_tests.sort()
+    self.assertEqual(sorted_active_tests, sorted_sharded_tests)
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-shuffle-test_.cc b/3rdparty/gtest/test/googletest-shuffle-test_.cc
new file mode 100644
index 0000000..c1fc106
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-shuffle-test_.cc
@@ -0,0 +1,101 @@
+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Verifies that test shuffling works.
+
+#include "gtest/gtest.h"
+
+namespace {
+
+using ::testing::EmptyTestEventListener;
+using ::testing::InitGoogleTest;
+using ::testing::Message;
+using ::testing::Test;
+using ::testing::TestEventListeners;
+using ::testing::TestInfo;
+using ::testing::UnitTest;
+
+// The test methods are empty, as the sole purpose of this program is
+// to print the test names before/after shuffling.
+
+class A : public Test {};
+TEST_F(A, A) {}
+TEST_F(A, B) {}
+
+TEST(ADeathTest, A) {}
+TEST(ADeathTest, B) {}
+TEST(ADeathTest, C) {}
+
+TEST(B, A) {}
+TEST(B, B) {}
+TEST(B, C) {}
+TEST(B, DISABLED_D) {}
+TEST(B, DISABLED_E) {}
+
+TEST(BDeathTest, A) {}
+TEST(BDeathTest, B) {}
+
+TEST(C, A) {}
+TEST(C, B) {}
+TEST(C, C) {}
+TEST(C, DISABLED_D) {}
+
+TEST(CDeathTest, A) {}
+
+TEST(DISABLED_D, A) {}
+TEST(DISABLED_D, DISABLED_B) {}
+
+// This printer prints the full test names only, starting each test
+// iteration with a "----" marker.
+class TestNamePrinter : public EmptyTestEventListener {
+ public:
+  void OnTestIterationStart(const UnitTest& /* unit_test */,
+                            int /* iteration */) override {
+    printf("----\n");
+  }
+
+  void OnTestStart(const TestInfo& test_info) override {
+    printf("%s.%s\n", test_info.test_case_name(), test_info.name());
+  }
+};
+
+}  // namespace
+
+int main(int argc, char **argv) {
+  InitGoogleTest(&argc, argv);
+
+  // Replaces the default printer with TestNamePrinter, which prints
+  // the test name only.
+  TestEventListeners& listeners = UnitTest::GetInstance()->listeners();
+  delete listeners.Release(listeners.default_result_printer());
+  listeners.Append(new TestNamePrinter);
+
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/googletest-test-part-test.cc b/3rdparty/gtest/test/googletest-test-part-test.cc
new file mode 100644
index 0000000..44cf7ca
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-test-part-test.cc
@@ -0,0 +1,230 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "gtest/gtest-test-part.h"
+
+#include "gtest/gtest.h"
+
+using testing::Message;
+using testing::Test;
+using testing::TestPartResult;
+using testing::TestPartResultArray;
+
+namespace {
+
+// Tests the TestPartResult class.
+
+// The test fixture for testing TestPartResult.
+class TestPartResultTest : public Test {
+ protected:
+  TestPartResultTest()
+      : r1_(TestPartResult::kSuccess, "foo/bar.cc", 10, "Success!"),
+        r2_(TestPartResult::kNonFatalFailure, "foo/bar.cc", -1, "Failure!"),
+        r3_(TestPartResult::kFatalFailure, nullptr, -1, "Failure!"),
+        r4_(TestPartResult::kSkip, "foo/bar.cc", 2, "Skipped!") {}
+
+  TestPartResult r1_, r2_, r3_, r4_;
+};
+
+
+TEST_F(TestPartResultTest, ConstructorWorks) {
+  Message message;
+  message << "something is terribly wrong";
+  message << static_cast<const char*>(testing::internal::kStackTraceMarker);
+  message << "some unimportant stack trace";
+
+  const TestPartResult result(TestPartResult::kNonFatalFailure,
+                              "some_file.cc",
+                              42,
+                              message.GetString().c_str());
+
+  EXPECT_EQ(TestPartResult::kNonFatalFailure, result.type());
+  EXPECT_STREQ("some_file.cc", result.file_name());
+  EXPECT_EQ(42, result.line_number());
+  EXPECT_STREQ(message.GetString().c_str(), result.message());
+  EXPECT_STREQ("something is terribly wrong", result.summary());
+}
+
+TEST_F(TestPartResultTest, ResultAccessorsWork) {
+  const TestPartResult success(TestPartResult::kSuccess,
+                               "file.cc",
+                               42,
+                               "message");
+  EXPECT_TRUE(success.passed());
+  EXPECT_FALSE(success.failed());
+  EXPECT_FALSE(success.nonfatally_failed());
+  EXPECT_FALSE(success.fatally_failed());
+  EXPECT_FALSE(success.skipped());
+
+  const TestPartResult nonfatal_failure(TestPartResult::kNonFatalFailure,
+                                        "file.cc",
+                                        42,
+                                        "message");
+  EXPECT_FALSE(nonfatal_failure.passed());
+  EXPECT_TRUE(nonfatal_failure.failed());
+  EXPECT_TRUE(nonfatal_failure.nonfatally_failed());
+  EXPECT_FALSE(nonfatal_failure.fatally_failed());
+  EXPECT_FALSE(nonfatal_failure.skipped());
+
+  const TestPartResult fatal_failure(TestPartResult::kFatalFailure,
+                                     "file.cc",
+                                     42,
+                                     "message");
+  EXPECT_FALSE(fatal_failure.passed());
+  EXPECT_TRUE(fatal_failure.failed());
+  EXPECT_FALSE(fatal_failure.nonfatally_failed());
+  EXPECT_TRUE(fatal_failure.fatally_failed());
+  EXPECT_FALSE(fatal_failure.skipped());
+
+  const TestPartResult skip(TestPartResult::kSkip, "file.cc", 42, "message");
+  EXPECT_FALSE(skip.passed());
+  EXPECT_FALSE(skip.failed());
+  EXPECT_FALSE(skip.nonfatally_failed());
+  EXPECT_FALSE(skip.fatally_failed());
+  EXPECT_TRUE(skip.skipped());
+}
+
+// Tests TestPartResult::type().
+TEST_F(TestPartResultTest, type) {
+  EXPECT_EQ(TestPartResult::kSuccess, r1_.type());
+  EXPECT_EQ(TestPartResult::kNonFatalFailure, r2_.type());
+  EXPECT_EQ(TestPartResult::kFatalFailure, r3_.type());
+  EXPECT_EQ(TestPartResult::kSkip, r4_.type());
+}
+
+// Tests TestPartResult::file_name().
+TEST_F(TestPartResultTest, file_name) {
+  EXPECT_STREQ("foo/bar.cc", r1_.file_name());
+  EXPECT_STREQ(nullptr, r3_.file_name());
+  EXPECT_STREQ("foo/bar.cc", r4_.file_name());
+}
+
+// Tests TestPartResult::line_number().
+TEST_F(TestPartResultTest, line_number) {
+  EXPECT_EQ(10, r1_.line_number());
+  EXPECT_EQ(-1, r2_.line_number());
+  EXPECT_EQ(2, r4_.line_number());
+}
+
+// Tests TestPartResult::message().
+TEST_F(TestPartResultTest, message) {
+  EXPECT_STREQ("Success!", r1_.message());
+  EXPECT_STREQ("Skipped!", r4_.message());
+}
+
+// Tests TestPartResult::passed().
+TEST_F(TestPartResultTest, Passed) {
+  EXPECT_TRUE(r1_.passed());
+  EXPECT_FALSE(r2_.passed());
+  EXPECT_FALSE(r3_.passed());
+  EXPECT_FALSE(r4_.passed());
+}
+
+// Tests TestPartResult::failed().
+TEST_F(TestPartResultTest, Failed) {
+  EXPECT_FALSE(r1_.failed());
+  EXPECT_TRUE(r2_.failed());
+  EXPECT_TRUE(r3_.failed());
+  EXPECT_FALSE(r4_.failed());
+}
+
+// Tests TestPartResult::failed().
+TEST_F(TestPartResultTest, Skipped) {
+  EXPECT_FALSE(r1_.skipped());
+  EXPECT_FALSE(r2_.skipped());
+  EXPECT_FALSE(r3_.skipped());
+  EXPECT_TRUE(r4_.skipped());
+}
+
+// Tests TestPartResult::fatally_failed().
+TEST_F(TestPartResultTest, FatallyFailed) {
+  EXPECT_FALSE(r1_.fatally_failed());
+  EXPECT_FALSE(r2_.fatally_failed());
+  EXPECT_TRUE(r3_.fatally_failed());
+  EXPECT_FALSE(r4_.fatally_failed());
+}
+
+// Tests TestPartResult::nonfatally_failed().
+TEST_F(TestPartResultTest, NonfatallyFailed) {
+  EXPECT_FALSE(r1_.nonfatally_failed());
+  EXPECT_TRUE(r2_.nonfatally_failed());
+  EXPECT_FALSE(r3_.nonfatally_failed());
+  EXPECT_FALSE(r4_.nonfatally_failed());
+}
+
+// Tests the TestPartResultArray class.
+
+class TestPartResultArrayTest : public Test {
+ protected:
+  TestPartResultArrayTest()
+      : r1_(TestPartResult::kNonFatalFailure, "foo/bar.cc", -1, "Failure 1"),
+        r2_(TestPartResult::kFatalFailure, "foo/bar.cc", -1, "Failure 2") {}
+
+  const TestPartResult r1_, r2_;
+};
+
+// Tests that TestPartResultArray initially has size 0.
+TEST_F(TestPartResultArrayTest, InitialSizeIsZero) {
+  TestPartResultArray results;
+  EXPECT_EQ(0, results.size());
+}
+
+// Tests that TestPartResultArray contains the given TestPartResult
+// after one Append() operation.
+TEST_F(TestPartResultArrayTest, ContainsGivenResultAfterAppend) {
+  TestPartResultArray results;
+  results.Append(r1_);
+  EXPECT_EQ(1, results.size());
+  EXPECT_STREQ("Failure 1", results.GetTestPartResult(0).message());
+}
+
+// Tests that TestPartResultArray contains the given TestPartResults
+// after two Append() operations.
+TEST_F(TestPartResultArrayTest, ContainsGivenResultsAfterTwoAppends) {
+  TestPartResultArray results;
+  results.Append(r1_);
+  results.Append(r2_);
+  EXPECT_EQ(2, results.size());
+  EXPECT_STREQ("Failure 1", results.GetTestPartResult(0).message());
+  EXPECT_STREQ("Failure 2", results.GetTestPartResult(1).message());
+}
+
+typedef TestPartResultArrayTest TestPartResultArrayDeathTest;
+
+// Tests that the program dies when GetTestPartResult() is called with
+// an invalid index.
+TEST_F(TestPartResultArrayDeathTest, DiesWhenIndexIsOutOfBound) {
+  TestPartResultArray results;
+  results.Append(r1_);
+
+  EXPECT_DEATH_IF_SUPPORTED(results.GetTestPartResult(-1), "");
+  EXPECT_DEATH_IF_SUPPORTED(results.GetTestPartResult(1), "");
+}
+
+}  // namespace
diff --git a/3rdparty/gtest/test/googletest-test2_test.cc b/3rdparty/gtest/test/googletest-test2_test.cc
new file mode 100644
index 0000000..2e425da
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-test2_test.cc
@@ -0,0 +1,61 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests for Google Test itself.  This verifies that the basic constructs of
+// Google Test work.
+
+#include "gtest/gtest.h"
+#include "googletest-param-test-test.h"
+
+using ::testing::Values;
+using ::testing::internal::ParamGenerator;
+
+// Tests that generators defined in a different translation unit
+// are functional. The test using extern_gen_2 is defined
+// in googletest-param-test-test.cc.
+ParamGenerator<int> extern_gen_2 = Values(33);
+
+// Tests that a parameterized test case can be defined in one translation unit
+// and instantiated in another. The test is defined in
+// googletest-param-test-test.cc and ExternalInstantiationTest fixture class is
+// defined in gtest-param-test_test.h.
+INSTANTIATE_TEST_SUITE_P(MultiplesOf33,
+                         ExternalInstantiationTest,
+                         Values(33, 66));
+
+// Tests that a parameterized test case can be instantiated
+// in multiple translation units. Another instantiation is defined
+// in googletest-param-test-test.cc and
+// InstantiationInMultipleTranslationUnitsTest fixture is defined in
+// gtest-param-test_test.h
+INSTANTIATE_TEST_SUITE_P(Sequence2,
+                         InstantiationInMultipleTranslationUnitsTest,
+                         Values(42*3, 42*4, 42*5));
+
diff --git a/3rdparty/gtest/test/googletest-throw-on-failure-test.py b/3rdparty/gtest/test/googletest-throw-on-failure-test.py
new file mode 100644
index 0000000..ea627c4
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-throw-on-failure-test.py
@@ -0,0 +1,168 @@
+#!/usr/bin/env python
+#
+# Copyright 2009, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Tests Google Test's throw-on-failure mode with exceptions disabled.
+
+This script invokes googletest-throw-on-failure-test_ (a program written with
+Google Test) with different environments and command line flags.
+"""
+
+import os
+import gtest_test_utils
+
+
+# Constants.
+
+# The command line flag for enabling/disabling the throw-on-failure mode.
+THROW_ON_FAILURE = 'gtest_throw_on_failure'
+
+# Path to the googletest-throw-on-failure-test_ program, compiled with
+# exceptions disabled.
+EXE_PATH = gtest_test_utils.GetTestExecutablePath(
+    'googletest-throw-on-failure-test_')
+
+
+# Utilities.
+
+
+def SetEnvVar(env_var, value):
+  """Sets an environment variable to a given value; unsets it when the
+  given value is None.
+  """
+
+  env_var = env_var.upper()
+  if value is not None:
+    os.environ[env_var] = value
+  elif env_var in os.environ:
+    del os.environ[env_var]
+
+
+def Run(command):
+  """Runs a command; returns True/False if its exit code is/isn't 0."""
+
+  print('Running "%s". . .' % ' '.join(command))
+  p = gtest_test_utils.Subprocess(command)
+  return p.exited and p.exit_code == 0
+
+
+# The tests.
+class ThrowOnFailureTest(gtest_test_utils.TestCase):
+  """Tests the throw-on-failure mode."""
+
+  def RunAndVerify(self, env_var_value, flag_value, should_fail):
+    """Runs googletest-throw-on-failure-test_ and verifies that it does
+    (or does not) exit with a non-zero code.
+
+    Args:
+      env_var_value:    value of the GTEST_BREAK_ON_FAILURE environment
+                        variable; None if the variable should be unset.
+      flag_value:       value of the --gtest_break_on_failure flag;
+                        None if the flag should not be present.
+      should_fail:      True if and only if the program is expected to fail.
+    """
+
+    SetEnvVar(THROW_ON_FAILURE, env_var_value)
+
+    if env_var_value is None:
+      env_var_value_msg = ' is not set'
+    else:
+      env_var_value_msg = '=' + env_var_value
+
+    if flag_value is None:
+      flag = ''
+    elif flag_value == '0':
+      flag = '--%s=0' % THROW_ON_FAILURE
+    else:
+      flag = '--%s' % THROW_ON_FAILURE
+
+    command = [EXE_PATH]
+    if flag:
+      command.append(flag)
+
+    if should_fail:
+      should_or_not = 'should'
+    else:
+      should_or_not = 'should not'
+
+    failed = not Run(command)
+
+    SetEnvVar(THROW_ON_FAILURE, None)
+
+    msg = ('when %s%s, an assertion failure in "%s" %s cause a non-zero '
+           'exit code.' %
+           (THROW_ON_FAILURE, env_var_value_msg, ' '.join(command),
+            should_or_not))
+    self.assert_(failed == should_fail, msg)
+
+  def testDefaultBehavior(self):
+    """Tests the behavior of the default mode."""
+
+    self.RunAndVerify(env_var_value=None, flag_value=None, should_fail=False)
+
+  def testThrowOnFailureEnvVar(self):
+    """Tests using the GTEST_THROW_ON_FAILURE environment variable."""
+
+    self.RunAndVerify(env_var_value='0',
+                      flag_value=None,
+                      should_fail=False)
+    self.RunAndVerify(env_var_value='1',
+                      flag_value=None,
+                      should_fail=True)
+
+  def testThrowOnFailureFlag(self):
+    """Tests using the --gtest_throw_on_failure flag."""
+
+    self.RunAndVerify(env_var_value=None,
+                      flag_value='0',
+                      should_fail=False)
+    self.RunAndVerify(env_var_value=None,
+                      flag_value='1',
+                      should_fail=True)
+
+  def testThrowOnFailureFlagOverridesEnvVar(self):
+    """Tests that --gtest_throw_on_failure overrides GTEST_THROW_ON_FAILURE."""
+
+    self.RunAndVerify(env_var_value='0',
+                      flag_value='0',
+                      should_fail=False)
+    self.RunAndVerify(env_var_value='0',
+                      flag_value='1',
+                      should_fail=True)
+    self.RunAndVerify(env_var_value='1',
+                      flag_value='0',
+                      should_fail=False)
+    self.RunAndVerify(env_var_value='1',
+                      flag_value='1',
+                      should_fail=True)
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-throw-on-failure-test_.cc b/3rdparty/gtest/test/googletest-throw-on-failure-test_.cc
new file mode 100644
index 0000000..83bb914
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-throw-on-failure-test_.cc
@@ -0,0 +1,71 @@
+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Tests Google Test's throw-on-failure mode with exceptions disabled.
+//
+// This program must be compiled with exceptions disabled.  It will be
+// invoked by googletest-throw-on-failure-test.py, and is expected to exit
+// with non-zero in the throw-on-failure mode or 0 otherwise.
+
+#include "gtest/gtest.h"
+
+#include <stdio.h>                      // for fflush, fprintf, NULL, etc.
+#include <stdlib.h>                     // for exit
+#include <exception>                    // for set_terminate
+
+// This terminate handler aborts the program using exit() rather than abort().
+// This avoids showing pop-ups on Windows systems and core dumps on Unix-like
+// ones.
+void TerminateHandler() {
+  fprintf(stderr, "%s\n", "Unhandled C++ exception terminating the program.");
+  fflush(nullptr);
+  exit(1);
+}
+
+int main(int argc, char** argv) {
+#if GTEST_HAS_EXCEPTIONS
+  std::set_terminate(&TerminateHandler);
+#endif
+  testing::InitGoogleTest(&argc, argv);
+
+  // We want to ensure that people can use Google Test assertions in
+  // other testing frameworks, as long as they initialize Google Test
+  // properly and set the throw-on-failure mode.  Therefore, we don't
+  // use Google Test's constructs for defining and running tests
+  // (e.g. TEST and RUN_ALL_TESTS) here.
+
+  // In the throw-on-failure mode with exceptions disabled, this
+  // assertion will cause the program to exit with a non-zero code.
+  EXPECT_EQ(2, 3);
+
+  // When not in the throw-on-failure mode, the control will reach
+  // here.
+  return 0;
+}
diff --git a/3rdparty/gtest/test/googletest-uninitialized-test.py b/3rdparty/gtest/test/googletest-uninitialized-test.py
new file mode 100644
index 0000000..69595a0
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-uninitialized-test.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+#
+# Copyright 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Verifies that Google Test warns the user when not initialized properly."""
+
+import gtest_test_utils
+
+COMMAND = gtest_test_utils.GetTestExecutablePath('googletest-uninitialized-test_')
+
+
+def Assert(condition):
+  if not condition:
+    raise AssertionError
+
+
+def AssertEq(expected, actual):
+  if expected != actual:
+    print('Expected: %s' % (expected,))
+    print('  Actual: %s' % (actual,))
+    raise AssertionError
+
+
+def TestExitCodeAndOutput(command):
+  """Runs the given command and verifies its exit code and output."""
+
+  # Verifies that 'command' exits with code 1.
+  p = gtest_test_utils.Subprocess(command)
+  if p.exited and p.exit_code == 0:
+    Assert('IMPORTANT NOTICE' in p.output);
+  Assert('InitGoogleTest' in p.output)
+
+
+class GTestUninitializedTest(gtest_test_utils.TestCase):
+  def testExitCodeAndOutput(self):
+    TestExitCodeAndOutput(COMMAND)
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/googletest-uninitialized-test_.cc b/3rdparty/gtest/test/googletest-uninitialized-test_.cc
new file mode 100644
index 0000000..b4434d5
--- /dev/null
+++ b/3rdparty/gtest/test/googletest-uninitialized-test_.cc
@@ -0,0 +1,42 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include "gtest/gtest.h"
+
+TEST(DummyTest, Dummy) {
+  // This test doesn't verify anything.  We just need it to create a
+  // realistic stage for testing the behavior of Google Test when
+  // RUN_ALL_TESTS() is called without
+  // testing::InitGoogleTest() being called first.
+}
+
+int main() {
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/gtest-typed-test2_test.cc b/3rdparty/gtest/test/gtest-typed-test2_test.cc
new file mode 100644
index 0000000..7000160
--- /dev/null
+++ b/3rdparty/gtest/test/gtest-typed-test2_test.cc
@@ -0,0 +1,44 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include <vector>
+
+#include "test/gtest-typed-test_test.h"
+#include "gtest/gtest.h"
+
+#if GTEST_HAS_TYPED_TEST_P
+
+// Tests that the same type-parameterized test case can be
+// instantiated in different translation units linked together.
+// (ContainerTest is also instantiated in gtest-typed-test_test.cc.)
+INSTANTIATE_TYPED_TEST_SUITE_P(Vector, ContainerTest,
+                               testing::Types<std::vector<int> >);
+
+#endif  // GTEST_HAS_TYPED_TEST_P
diff --git a/3rdparty/gtest/test/gtest-typed-test_test.cc b/3rdparty/gtest/test/gtest-typed-test_test.cc
new file mode 100644
index 0000000..5411832
--- /dev/null
+++ b/3rdparty/gtest/test/gtest-typed-test_test.cc
@@ -0,0 +1,462 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include "test/gtest-typed-test_test.h"
+
+#include <set>
+#include <type_traits>
+#include <vector>
+
+#include "gtest/gtest.h"
+
+#if _MSC_VER
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4127 /* conditional expression is constant */)
+#endif  //  _MSC_VER
+
+using testing::Test;
+
+// Used for testing that SetUpTestSuite()/TearDownTestSuite(), fixture
+// ctor/dtor, and SetUp()/TearDown() work correctly in typed tests and
+// type-parameterized test.
+template <typename T>
+class CommonTest : public Test {
+  // For some technical reason, SetUpTestSuite() and TearDownTestSuite()
+  // must be public.
+ public:
+  static void SetUpTestSuite() {
+    shared_ = new T(5);
+  }
+
+  static void TearDownTestSuite() {
+    delete shared_;
+    shared_ = nullptr;
+  }
+
+  // This 'protected:' is optional.  There's no harm in making all
+  // members of this fixture class template public.
+ protected:
+  // We used to use std::list here, but switched to std::vector since
+  // MSVC's <list> doesn't compile cleanly with /W4.
+  typedef std::vector<T> Vector;
+  typedef std::set<int> IntSet;
+
+  CommonTest() : value_(1) {}
+
+  ~CommonTest() override { EXPECT_EQ(3, value_); }
+
+  void SetUp() override {
+    EXPECT_EQ(1, value_);
+    value_++;
+  }
+
+  void TearDown() override {
+    EXPECT_EQ(2, value_);
+    value_++;
+  }
+
+  T value_;
+  static T* shared_;
+};
+
+template <typename T>
+T* CommonTest<T>::shared_ = nullptr;
+
+// This #ifdef block tests typed tests.
+#if GTEST_HAS_TYPED_TEST
+
+using testing::Types;
+
+// Tests that SetUpTestSuite()/TearDownTestSuite(), fixture ctor/dtor,
+// and SetUp()/TearDown() work correctly in typed tests
+
+typedef Types<char, int> TwoTypes;
+TYPED_TEST_SUITE(CommonTest, TwoTypes);
+
+TYPED_TEST(CommonTest, ValuesAreCorrect) {
+  // Static members of the fixture class template can be visited via
+  // the TestFixture:: prefix.
+  EXPECT_EQ(5, *TestFixture::shared_);
+
+  // Typedefs in the fixture class template can be visited via the
+  // "typename TestFixture::" prefix.
+  typename TestFixture::Vector empty;
+  EXPECT_EQ(0U, empty.size());
+
+  typename TestFixture::IntSet empty2;
+  EXPECT_EQ(0U, empty2.size());
+
+  // Non-static members of the fixture class must be visited via
+  // 'this', as required by C++ for class templates.
+  EXPECT_EQ(2, this->value_);
+}
+
+// The second test makes sure shared_ is not deleted after the first
+// test.
+TYPED_TEST(CommonTest, ValuesAreStillCorrect) {
+  // Static members of the fixture class template can also be visited
+  // via 'this'.
+  ASSERT_TRUE(this->shared_ != nullptr);
+  EXPECT_EQ(5, *this->shared_);
+
+  // TypeParam can be used to refer to the type parameter.
+  EXPECT_EQ(static_cast<TypeParam>(2), this->value_);
+}
+
+// Tests that multiple TYPED_TEST_SUITE's can be defined in the same
+// translation unit.
+
+template <typename T>
+class TypedTest1 : public Test {
+};
+
+// Verifies that the second argument of TYPED_TEST_SUITE can be a
+// single type.
+TYPED_TEST_SUITE(TypedTest1, int);
+TYPED_TEST(TypedTest1, A) {}
+
+template <typename T>
+class TypedTest2 : public Test {
+};
+
+// Verifies that the second argument of TYPED_TEST_SUITE can be a
+// Types<...> type list.
+TYPED_TEST_SUITE(TypedTest2, Types<int>);
+
+// This also verifies that tests from different typed test cases can
+// share the same name.
+TYPED_TEST(TypedTest2, A) {}
+
+// Tests that a typed test case can be defined in a namespace.
+
+namespace library1 {
+
+template <typename T>
+class NumericTest : public Test {
+};
+
+typedef Types<int, long> NumericTypes;
+TYPED_TEST_SUITE(NumericTest, NumericTypes);
+
+TYPED_TEST(NumericTest, DefaultIsZero) {
+  EXPECT_EQ(0, TypeParam());
+}
+
+}  // namespace library1
+
+// Tests that custom names work.
+template <typename T>
+class TypedTestWithNames : public Test {};
+
+class TypedTestNames {
+ public:
+  template <typename T>
+  static std::string GetName(int i) {
+    if (std::is_same<T, char>::value) {
+      return std::string("char") + ::testing::PrintToString(i);
+    }
+    if (std::is_same<T, int>::value) {
+      return std::string("int") + ::testing::PrintToString(i);
+    }
+  }
+};
+
+TYPED_TEST_SUITE(TypedTestWithNames, TwoTypes, TypedTestNames);
+
+TYPED_TEST(TypedTestWithNames, TestSuiteName) {
+  if (std::is_same<TypeParam, char>::value) {
+    EXPECT_STREQ(::testing::UnitTest::GetInstance()
+                     ->current_test_info()
+                     ->test_case_name(),
+                 "TypedTestWithNames/char0");
+  }
+  if (std::is_same<TypeParam, int>::value) {
+    EXPECT_STREQ(::testing::UnitTest::GetInstance()
+                     ->current_test_info()
+                     ->test_case_name(),
+                 "TypedTestWithNames/int1");
+  }
+}
+
+#endif  // GTEST_HAS_TYPED_TEST
+
+// This #ifdef block tests type-parameterized tests.
+#if GTEST_HAS_TYPED_TEST_P
+
+using testing::Types;
+using testing::internal::TypedTestSuitePState;
+
+// Tests TypedTestSuitePState.
+
+class TypedTestSuitePStateTest : public Test {
+ protected:
+  void SetUp() override {
+    state_.AddTestName("foo.cc", 0, "FooTest", "A");
+    state_.AddTestName("foo.cc", 0, "FooTest", "B");
+    state_.AddTestName("foo.cc", 0, "FooTest", "C");
+  }
+
+  TypedTestSuitePState state_;
+};
+
+TEST_F(TypedTestSuitePStateTest, SucceedsForMatchingList) {
+  const char* tests = "A, B, C";
+  EXPECT_EQ(tests,
+            state_.VerifyRegisteredTestNames("foo.cc", 1, tests));
+}
+
+// Makes sure that the order of the tests and spaces around the names
+// don't matter.
+TEST_F(TypedTestSuitePStateTest, IgnoresOrderAndSpaces) {
+  const char* tests = "A,C,   B";
+  EXPECT_EQ(tests,
+            state_.VerifyRegisteredTestNames("foo.cc", 1, tests));
+}
+
+using TypedTestSuitePStateDeathTest = TypedTestSuitePStateTest;
+
+TEST_F(TypedTestSuitePStateDeathTest, DetectsDuplicates) {
+  EXPECT_DEATH_IF_SUPPORTED(
+      state_.VerifyRegisteredTestNames("foo.cc", 1, "A, B, A, C"),
+      "foo\\.cc.1.?: Test A is listed more than once\\.");
+}
+
+TEST_F(TypedTestSuitePStateDeathTest, DetectsExtraTest) {
+  EXPECT_DEATH_IF_SUPPORTED(
+      state_.VerifyRegisteredTestNames("foo.cc", 1, "A, B, C, D"),
+      "foo\\.cc.1.?: No test named D can be found in this test suite\\.");
+}
+
+TEST_F(TypedTestSuitePStateDeathTest, DetectsMissedTest) {
+  EXPECT_DEATH_IF_SUPPORTED(
+      state_.VerifyRegisteredTestNames("foo.cc", 1, "A, C"),
+      "foo\\.cc.1.?: You forgot to list test B\\.");
+}
+
+// Tests that defining a test for a parameterized test case generates
+// a run-time error if the test case has been registered.
+TEST_F(TypedTestSuitePStateDeathTest, DetectsTestAfterRegistration) {
+  state_.VerifyRegisteredTestNames("foo.cc", 1, "A, B, C");
+  EXPECT_DEATH_IF_SUPPORTED(
+      state_.AddTestName("foo.cc", 2, "FooTest", "D"),
+      "foo\\.cc.2.?: Test D must be defined before REGISTER_TYPED_TEST_SUITE_P"
+      "\\(FooTest, \\.\\.\\.\\)\\.");
+}
+
+// Tests that SetUpTestSuite()/TearDownTestSuite(), fixture ctor/dtor,
+// and SetUp()/TearDown() work correctly in type-parameterized tests.
+
+template <typename T>
+class DerivedTest : public CommonTest<T> {
+};
+
+TYPED_TEST_SUITE_P(DerivedTest);
+
+TYPED_TEST_P(DerivedTest, ValuesAreCorrect) {
+  // Static members of the fixture class template can be visited via
+  // the TestFixture:: prefix.
+  EXPECT_EQ(5, *TestFixture::shared_);
+
+  // Non-static members of the fixture class must be visited via
+  // 'this', as required by C++ for class templates.
+  EXPECT_EQ(2, this->value_);
+}
+
+// The second test makes sure shared_ is not deleted after the first
+// test.
+TYPED_TEST_P(DerivedTest, ValuesAreStillCorrect) {
+  // Static members of the fixture class template can also be visited
+  // via 'this'.
+  ASSERT_TRUE(this->shared_ != nullptr);
+  EXPECT_EQ(5, *this->shared_);
+  EXPECT_EQ(2, this->value_);
+}
+
+REGISTER_TYPED_TEST_SUITE_P(DerivedTest,
+                           ValuesAreCorrect, ValuesAreStillCorrect);
+
+typedef Types<short, long> MyTwoTypes;
+INSTANTIATE_TYPED_TEST_SUITE_P(My, DerivedTest, MyTwoTypes);
+
+// Tests that custom names work with type parametrized tests. We reuse the
+// TwoTypes from above here.
+template <typename T>
+class TypeParametrizedTestWithNames : public Test {};
+
+TYPED_TEST_SUITE_P(TypeParametrizedTestWithNames);
+
+TYPED_TEST_P(TypeParametrizedTestWithNames, TestSuiteName) {
+  if (std::is_same<TypeParam, char>::value) {
+    EXPECT_STREQ(::testing::UnitTest::GetInstance()
+                     ->current_test_info()
+                     ->test_case_name(),
+                 "CustomName/TypeParametrizedTestWithNames/parChar0");
+  }
+  if (std::is_same<TypeParam, int>::value) {
+    EXPECT_STREQ(::testing::UnitTest::GetInstance()
+                     ->current_test_info()
+                     ->test_case_name(),
+                 "CustomName/TypeParametrizedTestWithNames/parInt1");
+  }
+}
+
+REGISTER_TYPED_TEST_SUITE_P(TypeParametrizedTestWithNames, TestSuiteName);
+
+class TypeParametrizedTestNames {
+ public:
+  template <typename T>
+  static std::string GetName(int i) {
+    if (std::is_same<T, char>::value) {
+      return std::string("parChar") + ::testing::PrintToString(i);
+    }
+    if (std::is_same<T, int>::value) {
+      return std::string("parInt") + ::testing::PrintToString(i);
+    }
+  }
+};
+
+INSTANTIATE_TYPED_TEST_SUITE_P(CustomName, TypeParametrizedTestWithNames,
+                              TwoTypes, TypeParametrizedTestNames);
+
+// Tests that multiple TYPED_TEST_SUITE_P's can be defined in the same
+// translation unit.
+
+template <typename T>
+class TypedTestP1 : public Test {
+};
+
+TYPED_TEST_SUITE_P(TypedTestP1);
+
+// For testing that the code between TYPED_TEST_SUITE_P() and
+// TYPED_TEST_P() is not enclosed in a namespace.
+using IntAfterTypedTestSuiteP = int;
+
+TYPED_TEST_P(TypedTestP1, A) {}
+TYPED_TEST_P(TypedTestP1, B) {}
+
+// For testing that the code between TYPED_TEST_P() and
+// REGISTER_TYPED_TEST_SUITE_P() is not enclosed in a namespace.
+using IntBeforeRegisterTypedTestSuiteP = int;
+
+REGISTER_TYPED_TEST_SUITE_P(TypedTestP1, A, B);
+
+template <typename T>
+class TypedTestP2 : public Test {
+};
+
+TYPED_TEST_SUITE_P(TypedTestP2);
+
+// This also verifies that tests from different type-parameterized
+// test cases can share the same name.
+TYPED_TEST_P(TypedTestP2, A) {}
+
+REGISTER_TYPED_TEST_SUITE_P(TypedTestP2, A);
+
+// Verifies that the code between TYPED_TEST_SUITE_P() and
+// REGISTER_TYPED_TEST_SUITE_P() is not enclosed in a namespace.
+IntAfterTypedTestSuiteP after = 0;
+IntBeforeRegisterTypedTestSuiteP before = 0;
+
+// Verifies that the last argument of INSTANTIATE_TYPED_TEST_SUITE_P()
+// can be either a single type or a Types<...> type list.
+INSTANTIATE_TYPED_TEST_SUITE_P(Int, TypedTestP1, int);
+INSTANTIATE_TYPED_TEST_SUITE_P(Int, TypedTestP2, Types<int>);
+
+// Tests that the same type-parameterized test case can be
+// instantiated more than once in the same translation unit.
+INSTANTIATE_TYPED_TEST_SUITE_P(Double, TypedTestP2, Types<double>);
+
+// Tests that the same type-parameterized test case can be
+// instantiated in different translation units linked together.
+// (ContainerTest is also instantiated in gtest-typed-test_test.cc.)
+typedef Types<std::vector<double>, std::set<char> > MyContainers;
+INSTANTIATE_TYPED_TEST_SUITE_P(My, ContainerTest, MyContainers);
+
+// Tests that a type-parameterized test case can be defined and
+// instantiated in a namespace.
+
+namespace library2 {
+
+template <typename T>
+class NumericTest : public Test {
+};
+
+TYPED_TEST_SUITE_P(NumericTest);
+
+TYPED_TEST_P(NumericTest, DefaultIsZero) {
+  EXPECT_EQ(0, TypeParam());
+}
+
+TYPED_TEST_P(NumericTest, ZeroIsLessThanOne) {
+  EXPECT_LT(TypeParam(0), TypeParam(1));
+}
+
+REGISTER_TYPED_TEST_SUITE_P(NumericTest,
+                           DefaultIsZero, ZeroIsLessThanOne);
+typedef Types<int, double> NumericTypes;
+INSTANTIATE_TYPED_TEST_SUITE_P(My, NumericTest, NumericTypes);
+
+static const char* GetTestName() {
+  return testing::UnitTest::GetInstance()->current_test_info()->name();
+}
+// Test the stripping of space from test names
+template <typename T> class TrimmedTest : public Test { };
+TYPED_TEST_SUITE_P(TrimmedTest);
+TYPED_TEST_P(TrimmedTest, Test1) { EXPECT_STREQ("Test1", GetTestName()); }
+TYPED_TEST_P(TrimmedTest, Test2) { EXPECT_STREQ("Test2", GetTestName()); }
+TYPED_TEST_P(TrimmedTest, Test3) { EXPECT_STREQ("Test3", GetTestName()); }
+TYPED_TEST_P(TrimmedTest, Test4) { EXPECT_STREQ("Test4", GetTestName()); }
+TYPED_TEST_P(TrimmedTest, Test5) { EXPECT_STREQ("Test5", GetTestName()); }
+REGISTER_TYPED_TEST_SUITE_P(
+    TrimmedTest,
+    Test1, Test2,Test3 , Test4 ,Test5 );  // NOLINT
+template <typename T1, typename T2> struct MyPair {};
+// Be sure to try a type with a comma in its name just in case it matters.
+typedef Types<int, double, MyPair<int, int> > TrimTypes;
+INSTANTIATE_TYPED_TEST_SUITE_P(My, TrimmedTest, TrimTypes);
+
+}  // namespace library2
+
+#endif  // GTEST_HAS_TYPED_TEST_P
+
+#if !defined(GTEST_HAS_TYPED_TEST) && !defined(GTEST_HAS_TYPED_TEST_P)
+
+// Google Test may not support type-parameterized tests with some
+// compilers. If we use conditional compilation to compile out all
+// code referring to the gtest_main library, MSVC linker will not link
+// that library at all and consequently complain about missing entry
+// point defined in that library (fatal error LNK1561: entry point
+// must be defined). This dummy test keeps gtest_main linked in.
+TEST(DummyTest, TypedTestsAreNotSupportedOnThisPlatform) {}
+
+#if _MSC_VER
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4127
+#endif                             //  _MSC_VER
+
+#endif  // #if !defined(GTEST_HAS_TYPED_TEST) && !defined(GTEST_HAS_TYPED_TEST_P)
diff --git a/3rdparty/gtest/test/gtest-typed-test_test.h b/3rdparty/gtest/test/gtest-typed-test_test.h
new file mode 100644
index 0000000..23137b7
--- /dev/null
+++ b/3rdparty/gtest/test/gtest-typed-test_test.h
@@ -0,0 +1,65 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#ifndef GTEST_TEST_GTEST_TYPED_TEST_TEST_H_
+#define GTEST_TEST_GTEST_TYPED_TEST_TEST_H_
+
+#include "gtest/gtest.h"
+
+#if GTEST_HAS_TYPED_TEST_P
+
+using testing::Test;
+
+// For testing that the same type-parameterized test case can be
+// instantiated in different translation units linked together.
+// ContainerTest will be instantiated in both gtest-typed-test_test.cc
+// and gtest-typed-test2_test.cc.
+
+template <typename T>
+class ContainerTest : public Test {
+};
+
+TYPED_TEST_SUITE_P(ContainerTest);
+
+TYPED_TEST_P(ContainerTest, CanBeDefaultConstructed) {
+  TypeParam container;
+}
+
+TYPED_TEST_P(ContainerTest, InitialSizeIsZero) {
+  TypeParam container;
+  EXPECT_EQ(0U, container.size());
+}
+
+REGISTER_TYPED_TEST_SUITE_P(ContainerTest,
+                            CanBeDefaultConstructed, InitialSizeIsZero);
+
+#endif  // GTEST_HAS_TYPED_TEST_P
+
+#endif  // GTEST_TEST_GTEST_TYPED_TEST_TEST_H_
diff --git a/3rdparty/gtest/test/gtest-unittest-api_test.cc b/3rdparty/gtest/test/gtest-unittest-api_test.cc
new file mode 100644
index 0000000..480a41f
--- /dev/null
+++ b/3rdparty/gtest/test/gtest-unittest-api_test.cc
@@ -0,0 +1,340 @@
+// Copyright 2009 Google Inc.  All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// The Google C++ Testing and Mocking Framework (Google Test)
+//
+// This file contains tests verifying correctness of data provided via
+// UnitTest's public methods.
+
+#include "gtest/gtest.h"
+
+#include <string.h>  // For strcmp.
+#include <algorithm>
+
+using ::testing::InitGoogleTest;
+
+namespace testing {
+namespace internal {
+
+template <typename T>
+struct LessByName {
+  bool operator()(const T* a, const T* b) {
+    return strcmp(a->name(), b->name()) < 0;
+  }
+};
+
+class UnitTestHelper {
+ public:
+  // Returns the array of pointers to all test suites sorted by the test suite
+  // name.  The caller is responsible for deleting the array.
+  static TestSuite const** GetSortedTestSuites() {
+    UnitTest& unit_test = *UnitTest::GetInstance();
+    auto const** const test_suites =
+        new const TestSuite*[unit_test.total_test_suite_count()];
+
+    for (int i = 0; i < unit_test.total_test_suite_count(); ++i)
+      test_suites[i] = unit_test.GetTestSuite(i);
+
+    std::sort(test_suites,
+              test_suites + unit_test.total_test_suite_count(),
+              LessByName<TestSuite>());
+    return test_suites;
+  }
+
+  // Returns the test suite by its name.  The caller doesn't own the returned
+  // pointer.
+  static const TestSuite* FindTestSuite(const char* name) {
+    UnitTest& unit_test = *UnitTest::GetInstance();
+    for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
+      const TestSuite* test_suite = unit_test.GetTestSuite(i);
+      if (0 == strcmp(test_suite->name(), name))
+        return test_suite;
+    }
+    return nullptr;
+  }
+
+  // Returns the array of pointers to all tests in a particular test suite
+  // sorted by the test name.  The caller is responsible for deleting the
+  // array.
+  static TestInfo const** GetSortedTests(const TestSuite* test_suite) {
+    TestInfo const** const tests =
+        new const TestInfo*[test_suite->total_test_count()];
+
+    for (int i = 0; i < test_suite->total_test_count(); ++i)
+      tests[i] = test_suite->GetTestInfo(i);
+
+    std::sort(tests, tests + test_suite->total_test_count(),
+              LessByName<TestInfo>());
+    return tests;
+  }
+};
+
+#if GTEST_HAS_TYPED_TEST
+template <typename T> class TestSuiteWithCommentTest : public Test {};
+TYPED_TEST_SUITE(TestSuiteWithCommentTest, Types<int>);
+TYPED_TEST(TestSuiteWithCommentTest, Dummy) {}
+
+const int kTypedTestSuites = 1;
+const int kTypedTests = 1;
+#else
+const int kTypedTestSuites = 0;
+const int kTypedTests = 0;
+#endif  // GTEST_HAS_TYPED_TEST
+
+// We can only test the accessors that do not change value while tests run.
+// Since tests can be run in any order, the values the accessors that track
+// test execution (such as failed_test_count) can not be predicted.
+TEST(ApiTest, UnitTestImmutableAccessorsWork) {
+  UnitTest* unit_test = UnitTest::GetInstance();
+
+  ASSERT_EQ(2 + kTypedTestSuites, unit_test->total_test_suite_count());
+  EXPECT_EQ(1 + kTypedTestSuites, unit_test->test_suite_to_run_count());
+  EXPECT_EQ(2, unit_test->disabled_test_count());
+  EXPECT_EQ(5 + kTypedTests, unit_test->total_test_count());
+  EXPECT_EQ(3 + kTypedTests, unit_test->test_to_run_count());
+
+  const TestSuite** const test_suites = UnitTestHelper::GetSortedTestSuites();
+
+  EXPECT_STREQ("ApiTest", test_suites[0]->name());
+  EXPECT_STREQ("DISABLED_Test", test_suites[1]->name());
+#if GTEST_HAS_TYPED_TEST
+  EXPECT_STREQ("TestSuiteWithCommentTest/0", test_suites[2]->name());
+#endif  // GTEST_HAS_TYPED_TEST
+
+  delete[] test_suites;
+
+  // The following lines initiate actions to verify certain methods in
+  // FinalSuccessChecker::TearDown.
+
+  // Records a test property to verify TestResult::GetTestProperty().
+  RecordProperty("key", "value");
+}
+
+AssertionResult IsNull(const char* str) {
+  if (str != nullptr) {
+    return testing::AssertionFailure() << "argument is " << str;
+  }
+  return AssertionSuccess();
+}
+
+TEST(ApiTest, TestSuiteImmutableAccessorsWork) {
+  const TestSuite* test_suite = UnitTestHelper::FindTestSuite("ApiTest");
+  ASSERT_TRUE(test_suite != nullptr);
+
+  EXPECT_STREQ("ApiTest", test_suite->name());
+  EXPECT_TRUE(IsNull(test_suite->type_param()));
+  EXPECT_TRUE(test_suite->should_run());
+  EXPECT_EQ(1, test_suite->disabled_test_count());
+  EXPECT_EQ(3, test_suite->test_to_run_count());
+  ASSERT_EQ(4, test_suite->total_test_count());
+
+  const TestInfo** tests = UnitTestHelper::GetSortedTests(test_suite);
+
+  EXPECT_STREQ("DISABLED_Dummy1", tests[0]->name());
+  EXPECT_STREQ("ApiTest", tests[0]->test_suite_name());
+  EXPECT_TRUE(IsNull(tests[0]->value_param()));
+  EXPECT_TRUE(IsNull(tests[0]->type_param()));
+  EXPECT_FALSE(tests[0]->should_run());
+
+  EXPECT_STREQ("TestSuiteDisabledAccessorsWork", tests[1]->name());
+  EXPECT_STREQ("ApiTest", tests[1]->test_suite_name());
+  EXPECT_TRUE(IsNull(tests[1]->value_param()));
+  EXPECT_TRUE(IsNull(tests[1]->type_param()));
+  EXPECT_TRUE(tests[1]->should_run());
+
+  EXPECT_STREQ("TestSuiteImmutableAccessorsWork", tests[2]->name());
+  EXPECT_STREQ("ApiTest", tests[2]->test_suite_name());
+  EXPECT_TRUE(IsNull(tests[2]->value_param()));
+  EXPECT_TRUE(IsNull(tests[2]->type_param()));
+  EXPECT_TRUE(tests[2]->should_run());
+
+  EXPECT_STREQ("UnitTestImmutableAccessorsWork", tests[3]->name());
+  EXPECT_STREQ("ApiTest", tests[3]->test_suite_name());
+  EXPECT_TRUE(IsNull(tests[3]->value_param()));
+  EXPECT_TRUE(IsNull(tests[3]->type_param()));
+  EXPECT_TRUE(tests[3]->should_run());
+
+  delete[] tests;
+  tests = nullptr;
+
+#if GTEST_HAS_TYPED_TEST
+  test_suite = UnitTestHelper::FindTestSuite("TestSuiteWithCommentTest/0");
+  ASSERT_TRUE(test_suite != nullptr);
+
+  EXPECT_STREQ("TestSuiteWithCommentTest/0", test_suite->name());
+  EXPECT_STREQ(GetTypeName<int>().c_str(), test_suite->type_param());
+  EXPECT_TRUE(test_suite->should_run());
+  EXPECT_EQ(0, test_suite->disabled_test_count());
+  EXPECT_EQ(1, test_suite->test_to_run_count());
+  ASSERT_EQ(1, test_suite->total_test_count());
+
+  tests = UnitTestHelper::GetSortedTests(test_suite);
+
+  EXPECT_STREQ("Dummy", tests[0]->name());
+  EXPECT_STREQ("TestSuiteWithCommentTest/0", tests[0]->test_suite_name());
+  EXPECT_TRUE(IsNull(tests[0]->value_param()));
+  EXPECT_STREQ(GetTypeName<int>().c_str(), tests[0]->type_param());
+  EXPECT_TRUE(tests[0]->should_run());
+
+  delete[] tests;
+#endif  // GTEST_HAS_TYPED_TEST
+}
+
+TEST(ApiTest, TestSuiteDisabledAccessorsWork) {
+  const TestSuite* test_suite = UnitTestHelper::FindTestSuite("DISABLED_Test");
+  ASSERT_TRUE(test_suite != nullptr);
+
+  EXPECT_STREQ("DISABLED_Test", test_suite->name());
+  EXPECT_TRUE(IsNull(test_suite->type_param()));
+  EXPECT_FALSE(test_suite->should_run());
+  EXPECT_EQ(1, test_suite->disabled_test_count());
+  EXPECT_EQ(0, test_suite->test_to_run_count());
+  ASSERT_EQ(1, test_suite->total_test_count());
+
+  const TestInfo* const test_info = test_suite->GetTestInfo(0);
+  EXPECT_STREQ("Dummy2", test_info->name());
+  EXPECT_STREQ("DISABLED_Test", test_info->test_suite_name());
+  EXPECT_TRUE(IsNull(test_info->value_param()));
+  EXPECT_TRUE(IsNull(test_info->type_param()));
+  EXPECT_FALSE(test_info->should_run());
+}
+
+// These two tests are here to provide support for testing
+// test_suite_to_run_count, disabled_test_count, and test_to_run_count.
+TEST(ApiTest, DISABLED_Dummy1) {}
+TEST(DISABLED_Test, Dummy2) {}
+
+class FinalSuccessChecker : public Environment {
+ protected:
+  void TearDown() override {
+    UnitTest* unit_test = UnitTest::GetInstance();
+
+    EXPECT_EQ(1 + kTypedTestSuites, unit_test->successful_test_suite_count());
+    EXPECT_EQ(3 + kTypedTests, unit_test->successful_test_count());
+    EXPECT_EQ(0, unit_test->failed_test_suite_count());
+    EXPECT_EQ(0, unit_test->failed_test_count());
+    EXPECT_TRUE(unit_test->Passed());
+    EXPECT_FALSE(unit_test->Failed());
+    ASSERT_EQ(2 + kTypedTestSuites, unit_test->total_test_suite_count());
+
+    const TestSuite** const test_suites = UnitTestHelper::GetSortedTestSuites();
+
+    EXPECT_STREQ("ApiTest", test_suites[0]->name());
+    EXPECT_TRUE(IsNull(test_suites[0]->type_param()));
+    EXPECT_TRUE(test_suites[0]->should_run());
+    EXPECT_EQ(1, test_suites[0]->disabled_test_count());
+    ASSERT_EQ(4, test_suites[0]->total_test_count());
+    EXPECT_EQ(3, test_suites[0]->successful_test_count());
+    EXPECT_EQ(0, test_suites[0]->failed_test_count());
+    EXPECT_TRUE(test_suites[0]->Passed());
+    EXPECT_FALSE(test_suites[0]->Failed());
+
+    EXPECT_STREQ("DISABLED_Test", test_suites[1]->name());
+    EXPECT_TRUE(IsNull(test_suites[1]->type_param()));
+    EXPECT_FALSE(test_suites[1]->should_run());
+    EXPECT_EQ(1, test_suites[1]->disabled_test_count());
+    ASSERT_EQ(1, test_suites[1]->total_test_count());
+    EXPECT_EQ(0, test_suites[1]->successful_test_count());
+    EXPECT_EQ(0, test_suites[1]->failed_test_count());
+
+#if GTEST_HAS_TYPED_TEST
+    EXPECT_STREQ("TestSuiteWithCommentTest/0", test_suites[2]->name());
+    EXPECT_STREQ(GetTypeName<int>().c_str(), test_suites[2]->type_param());
+    EXPECT_TRUE(test_suites[2]->should_run());
+    EXPECT_EQ(0, test_suites[2]->disabled_test_count());
+    ASSERT_EQ(1, test_suites[2]->total_test_count());
+    EXPECT_EQ(1, test_suites[2]->successful_test_count());
+    EXPECT_EQ(0, test_suites[2]->failed_test_count());
+    EXPECT_TRUE(test_suites[2]->Passed());
+    EXPECT_FALSE(test_suites[2]->Failed());
+#endif  // GTEST_HAS_TYPED_TEST
+
+    const TestSuite* test_suite = UnitTestHelper::FindTestSuite("ApiTest");
+    const TestInfo** tests = UnitTestHelper::GetSortedTests(test_suite);
+    EXPECT_STREQ("DISABLED_Dummy1", tests[0]->name());
+    EXPECT_STREQ("ApiTest", tests[0]->test_suite_name());
+    EXPECT_FALSE(tests[0]->should_run());
+
+    EXPECT_STREQ("TestSuiteDisabledAccessorsWork", tests[1]->name());
+    EXPECT_STREQ("ApiTest", tests[1]->test_suite_name());
+    EXPECT_TRUE(IsNull(tests[1]->value_param()));
+    EXPECT_TRUE(IsNull(tests[1]->type_param()));
+    EXPECT_TRUE(tests[1]->should_run());
+    EXPECT_TRUE(tests[1]->result()->Passed());
+    EXPECT_EQ(0, tests[1]->result()->test_property_count());
+
+    EXPECT_STREQ("TestSuiteImmutableAccessorsWork", tests[2]->name());
+    EXPECT_STREQ("ApiTest", tests[2]->test_suite_name());
+    EXPECT_TRUE(IsNull(tests[2]->value_param()));
+    EXPECT_TRUE(IsNull(tests[2]->type_param()));
+    EXPECT_TRUE(tests[2]->should_run());
+    EXPECT_TRUE(tests[2]->result()->Passed());
+    EXPECT_EQ(0, tests[2]->result()->test_property_count());
+
+    EXPECT_STREQ("UnitTestImmutableAccessorsWork", tests[3]->name());
+    EXPECT_STREQ("ApiTest", tests[3]->test_suite_name());
+    EXPECT_TRUE(IsNull(tests[3]->value_param()));
+    EXPECT_TRUE(IsNull(tests[3]->type_param()));
+    EXPECT_TRUE(tests[3]->should_run());
+    EXPECT_TRUE(tests[3]->result()->Passed());
+    EXPECT_EQ(1, tests[3]->result()->test_property_count());
+    const TestProperty& property = tests[3]->result()->GetTestProperty(0);
+    EXPECT_STREQ("key", property.key());
+    EXPECT_STREQ("value", property.value());
+
+    delete[] tests;
+
+#if GTEST_HAS_TYPED_TEST
+    test_suite = UnitTestHelper::FindTestSuite("TestSuiteWithCommentTest/0");
+    tests = UnitTestHelper::GetSortedTests(test_suite);
+
+    EXPECT_STREQ("Dummy", tests[0]->name());
+    EXPECT_STREQ("TestSuiteWithCommentTest/0", tests[0]->test_suite_name());
+    EXPECT_TRUE(IsNull(tests[0]->value_param()));
+    EXPECT_STREQ(GetTypeName<int>().c_str(), tests[0]->type_param());
+    EXPECT_TRUE(tests[0]->should_run());
+    EXPECT_TRUE(tests[0]->result()->Passed());
+    EXPECT_EQ(0, tests[0]->result()->test_property_count());
+
+    delete[] tests;
+#endif  // GTEST_HAS_TYPED_TEST
+    delete[] test_suites;
+  }
+};
+
+}  // namespace internal
+}  // namespace testing
+
+int main(int argc, char **argv) {
+  InitGoogleTest(&argc, argv);
+
+  AddGlobalTestEnvironment(new testing::internal::FinalSuccessChecker());
+
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/gtest_all_test.cc b/3rdparty/gtest/test/gtest_all_test.cc
new file mode 100644
index 0000000..615b29b
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_all_test.cc
@@ -0,0 +1,46 @@
+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests for Google C++ Testing and Mocking Framework (Google Test)
+//
+// Sometimes it's desirable to build most of Google Test's own tests
+// by compiling a single file.  This file serves this purpose.
+#include "test/googletest-filepath-test.cc"
+#include "test/googletest-message-test.cc"
+#include "test/googletest-options-test.cc"
+#include "test/googletest-port-test.cc"
+#include "test/googletest-test-part-test.cc"
+#include "test/gtest-typed-test2_test.cc"
+#include "test/gtest-typed-test_test.cc"
+#include "test/gtest_pred_impl_unittest.cc"
+#include "test/gtest_prod_test.cc"
+#include "test/gtest_skip_test.cc"
+#include "test/gtest_unittest.cc"
+#include "test/production.cc"
diff --git a/3rdparty/gtest/test/gtest_assert_by_exception_test.cc b/3rdparty/gtest/test/gtest_assert_by_exception_test.cc
new file mode 100644
index 0000000..ada4cb3
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_assert_by_exception_test.cc
@@ -0,0 +1,116 @@
+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Tests Google Test's assert-by-exception mode with exceptions enabled.
+
+#include "gtest/gtest.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdexcept>
+
+class ThrowListener : public testing::EmptyTestEventListener {
+  void OnTestPartResult(const testing::TestPartResult& result) override {
+    if (result.type() == testing::TestPartResult::kFatalFailure) {
+      throw testing::AssertionException(result);
+    }
+  }
+};
+
+// Prints the given failure message and exits the program with
+// non-zero.  We use this instead of a Google Test assertion to
+// indicate a failure, as the latter is been tested and cannot be
+// relied on.
+void Fail(const char* msg) {
+  printf("FAILURE: %s\n", msg);
+  fflush(stdout);
+  exit(1);
+}
+
+static void AssertFalse() {
+  ASSERT_EQ(2, 3) << "Expected failure";
+}
+
+// Tests that an assertion failure throws a subclass of
+// std::runtime_error.
+TEST(Test, Test) {
+  // A successful assertion shouldn't throw.
+  try {
+    EXPECT_EQ(3, 3);
+  } catch(...) {
+    Fail("A successful assertion wrongfully threw.");
+  }
+
+  // A successful assertion shouldn't throw.
+  try {
+    EXPECT_EQ(3, 4);
+  } catch(...) {
+    Fail("A failed non-fatal assertion wrongfully threw.");
+  }
+
+  // A failed assertion should throw.
+  try {
+    AssertFalse();
+  } catch(const testing::AssertionException& e) {
+    if (strstr(e.what(), "Expected failure") != nullptr) throw;
+
+    printf("%s",
+           "A failed assertion did throw an exception of the right type, "
+           "but the message is incorrect.  Instead of containing \"Expected "
+           "failure\", it is:\n");
+    Fail(e.what());
+  } catch(...) {
+    Fail("A failed assertion threw the wrong type of exception.");
+  }
+  Fail("A failed assertion should've thrown but didn't.");
+}
+
+int kTestForContinuingTest = 0;
+
+TEST(Test, Test2) {
+  kTestForContinuingTest = 1;
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  testing::UnitTest::GetInstance()->listeners().Append(new ThrowListener);
+
+  int result = RUN_ALL_TESTS();
+  if (result == 0) {
+    printf("RUN_ALL_TESTS returned %d\n", result);
+    Fail("Expected failure instead.");
+  }
+
+  if (kTestForContinuingTest == 0) {
+    Fail("Should have continued with other tests, but did not.");
+  }
+  return 0;
+}
diff --git a/3rdparty/gtest/test/gtest_environment_test.cc b/3rdparty/gtest/test/gtest_environment_test.cc
new file mode 100644
index 0000000..064bfc5
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_environment_test.cc
@@ -0,0 +1,188 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests using global test environments.
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "gtest/gtest.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+GTEST_DECLARE_string_(filter);
+}
+
+namespace {
+
+enum FailureType {
+  NO_FAILURE, NON_FATAL_FAILURE, FATAL_FAILURE
+};
+
+// For testing using global test environments.
+class MyEnvironment : public testing::Environment {
+ public:
+  MyEnvironment() { Reset(); }
+
+  // Depending on the value of failure_in_set_up_, SetUp() will
+  // generate a non-fatal failure, generate a fatal failure, or
+  // succeed.
+  void SetUp() override {
+    set_up_was_run_ = true;
+
+    switch (failure_in_set_up_) {
+      case NON_FATAL_FAILURE:
+        ADD_FAILURE() << "Expected non-fatal failure in global set-up.";
+        break;
+      case FATAL_FAILURE:
+        FAIL() << "Expected fatal failure in global set-up.";
+        break;
+      default:
+        break;
+    }
+  }
+
+  // Generates a non-fatal failure.
+  void TearDown() override {
+    tear_down_was_run_ = true;
+    ADD_FAILURE() << "Expected non-fatal failure in global tear-down.";
+  }
+
+  // Resets the state of the environment s.t. it can be reused.
+  void Reset() {
+    failure_in_set_up_ = NO_FAILURE;
+    set_up_was_run_ = false;
+    tear_down_was_run_ = false;
+  }
+
+  // We call this function to set the type of failure SetUp() should
+  // generate.
+  void set_failure_in_set_up(FailureType type) {
+    failure_in_set_up_ = type;
+  }
+
+  // Was SetUp() run?
+  bool set_up_was_run() const { return set_up_was_run_; }
+
+  // Was TearDown() run?
+  bool tear_down_was_run() const { return tear_down_was_run_; }
+
+ private:
+  FailureType failure_in_set_up_;
+  bool set_up_was_run_;
+  bool tear_down_was_run_;
+};
+
+// Was the TEST run?
+bool test_was_run;
+
+// The sole purpose of this TEST is to enable us to check whether it
+// was run.
+TEST(FooTest, Bar) {
+  test_was_run = true;
+}
+
+// Prints the message and aborts the program if condition is false.
+void Check(bool condition, const char* msg) {
+  if (!condition) {
+    printf("FAILED: %s\n", msg);
+    testing::internal::posix::Abort();
+  }
+}
+
+// Runs the tests.  Return true if and only if successful.
+//
+// The 'failure' parameter specifies the type of failure that should
+// be generated by the global set-up.
+int RunAllTests(MyEnvironment* env, FailureType failure) {
+  env->Reset();
+  env->set_failure_in_set_up(failure);
+  test_was_run = false;
+  testing::internal::GetUnitTestImpl()->ClearAdHocTestResult();
+  return RUN_ALL_TESTS();
+}
+
+}  // namespace
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  // Registers a global test environment, and verifies that the
+  // registration function returns its argument.
+  MyEnvironment* const env = new MyEnvironment;
+  Check(testing::AddGlobalTestEnvironment(env) == env,
+        "AddGlobalTestEnvironment() should return its argument.");
+
+  // Verifies that RUN_ALL_TESTS() runs the tests when the global
+  // set-up is successful.
+  Check(RunAllTests(env, NO_FAILURE) != 0,
+        "RUN_ALL_TESTS() should return non-zero, as the global tear-down "
+        "should generate a failure.");
+  Check(test_was_run,
+        "The tests should run, as the global set-up should generate no "
+        "failure");
+  Check(env->tear_down_was_run(),
+        "The global tear-down should run, as the global set-up was run.");
+
+  // Verifies that RUN_ALL_TESTS() runs the tests when the global
+  // set-up generates no fatal failure.
+  Check(RunAllTests(env, NON_FATAL_FAILURE) != 0,
+        "RUN_ALL_TESTS() should return non-zero, as both the global set-up "
+        "and the global tear-down should generate a non-fatal failure.");
+  Check(test_was_run,
+        "The tests should run, as the global set-up should generate no "
+        "fatal failure.");
+  Check(env->tear_down_was_run(),
+        "The global tear-down should run, as the global set-up was run.");
+
+  // Verifies that RUN_ALL_TESTS() runs no test when the global set-up
+  // generates a fatal failure.
+  Check(RunAllTests(env, FATAL_FAILURE) != 0,
+        "RUN_ALL_TESTS() should return non-zero, as the global set-up "
+        "should generate a fatal failure.");
+  Check(!test_was_run,
+        "The tests should not run, as the global set-up should generate "
+        "a fatal failure.");
+  Check(env->tear_down_was_run(),
+        "The global tear-down should run, as the global set-up was run.");
+
+  // Verifies that RUN_ALL_TESTS() doesn't do global set-up or
+  // tear-down when there is no test to run.
+  testing::GTEST_FLAG(filter) = "-*";
+  Check(RunAllTests(env, NO_FAILURE) == 0,
+        "RUN_ALL_TESTS() should return zero, as there is no test to run.");
+  Check(!env->set_up_was_run(),
+        "The global set-up should not run, as there is no test to run.");
+  Check(!env->tear_down_was_run(),
+        "The global tear-down should not run, "
+        "as the global set-up was not run.");
+
+  printf("PASS\n");
+  return 0;
+}
diff --git a/3rdparty/gtest/test/gtest_help_test.py b/3rdparty/gtest/test/gtest_help_test.py
new file mode 100644
index 0000000..582d24c
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_help_test.py
@@ -0,0 +1,170 @@
+#!/usr/bin/env python
+#
+# Copyright 2009, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Tests the --help flag of Google C++ Testing and Mocking Framework.
+
+SYNOPSIS
+       gtest_help_test.py --build_dir=BUILD/DIR
+         # where BUILD/DIR contains the built gtest_help_test_ file.
+       gtest_help_test.py
+"""
+
+import os
+import re
+import gtest_test_utils
+
+
+IS_LINUX = os.name == 'posix' and os.uname()[0] == 'Linux'
+IS_WINDOWS = os.name == 'nt'
+
+PROGRAM_PATH = gtest_test_utils.GetTestExecutablePath('gtest_help_test_')
+FLAG_PREFIX = '--gtest_'
+DEATH_TEST_STYLE_FLAG = FLAG_PREFIX + 'death_test_style'
+STREAM_RESULT_TO_FLAG = FLAG_PREFIX + 'stream_result_to'
+UNKNOWN_FLAG = FLAG_PREFIX + 'unknown_flag_for_testing'
+LIST_TESTS_FLAG = FLAG_PREFIX + 'list_tests'
+INCORRECT_FLAG_VARIANTS = [re.sub('^--', '-', LIST_TESTS_FLAG),
+                           re.sub('^--', '/', LIST_TESTS_FLAG),
+                           re.sub('_', '-', LIST_TESTS_FLAG)]
+INTERNAL_FLAG_FOR_TESTING = FLAG_PREFIX + 'internal_flag_for_testing'
+
+SUPPORTS_DEATH_TESTS = "DeathTest" in gtest_test_utils.Subprocess(
+    [PROGRAM_PATH, LIST_TESTS_FLAG]).output
+
+# The help message must match this regex.
+HELP_REGEX = re.compile(
+    FLAG_PREFIX + r'list_tests.*' +
+    FLAG_PREFIX + r'filter=.*' +
+    FLAG_PREFIX + r'also_run_disabled_tests.*' +
+    FLAG_PREFIX + r'repeat=.*' +
+    FLAG_PREFIX + r'shuffle.*' +
+    FLAG_PREFIX + r'random_seed=.*' +
+    FLAG_PREFIX + r'color=.*' +
+    FLAG_PREFIX + r'print_time.*' +
+    FLAG_PREFIX + r'output=.*' +
+    FLAG_PREFIX + r'break_on_failure.*' +
+    FLAG_PREFIX + r'throw_on_failure.*' +
+    FLAG_PREFIX + r'catch_exceptions=0.*',
+    re.DOTALL)
+
+
+def RunWithFlag(flag):
+  """Runs gtest_help_test_ with the given flag.
+
+  Returns:
+    the exit code and the text output as a tuple.
+  Args:
+    flag: the command-line flag to pass to gtest_help_test_, or None.
+  """
+
+  if flag is None:
+    command = [PROGRAM_PATH]
+  else:
+    command = [PROGRAM_PATH, flag]
+  child = gtest_test_utils.Subprocess(command)
+  return child.exit_code, child.output
+
+
+class GTestHelpTest(gtest_test_utils.TestCase):
+  """Tests the --help flag and its equivalent forms."""
+
+  def TestHelpFlag(self, flag):
+    """Verifies correct behavior when help flag is specified.
+
+    The right message must be printed and the tests must
+    skipped when the given flag is specified.
+
+    Args:
+      flag:  A flag to pass to the binary or None.
+    """
+
+    exit_code, output = RunWithFlag(flag)
+    self.assertEquals(0, exit_code)
+    self.assert_(HELP_REGEX.search(output), output)
+
+    if IS_LINUX:
+      self.assert_(STREAM_RESULT_TO_FLAG in output, output)
+    else:
+      self.assert_(STREAM_RESULT_TO_FLAG not in output, output)
+
+    if SUPPORTS_DEATH_TESTS and not IS_WINDOWS:
+      self.assert_(DEATH_TEST_STYLE_FLAG in output, output)
+    else:
+      self.assert_(DEATH_TEST_STYLE_FLAG not in output, output)
+
+  def TestNonHelpFlag(self, flag):
+    """Verifies correct behavior when no help flag is specified.
+
+    Verifies that when no help flag is specified, the tests are run
+    and the help message is not printed.
+
+    Args:
+      flag:  A flag to pass to the binary or None.
+    """
+
+    exit_code, output = RunWithFlag(flag)
+    self.assert_(exit_code != 0)
+    self.assert_(not HELP_REGEX.search(output), output)
+
+  def testPrintsHelpWithFullFlag(self):
+    self.TestHelpFlag('--help')
+
+  def testPrintsHelpWithShortFlag(self):
+    self.TestHelpFlag('-h')
+
+  def testPrintsHelpWithQuestionFlag(self):
+    self.TestHelpFlag('-?')
+
+  def testPrintsHelpWithWindowsStyleQuestionFlag(self):
+    self.TestHelpFlag('/?')
+
+  def testPrintsHelpWithUnrecognizedGoogleTestFlag(self):
+    self.TestHelpFlag(UNKNOWN_FLAG)
+
+  def testPrintsHelpWithIncorrectFlagStyle(self):
+    for incorrect_flag in INCORRECT_FLAG_VARIANTS:
+      self.TestHelpFlag(incorrect_flag)
+
+  def testRunsTestsWithoutHelpFlag(self):
+    """Verifies that when no help flag is specified, the tests are run
+    and the help message is not printed."""
+
+    self.TestNonHelpFlag(None)
+
+  def testRunsTestsWithGtestInternalFlag(self):
+    """Verifies that the tests are run and no help message is printed when
+    a flag starting with Google Test prefix and 'internal_' is supplied."""
+
+    self.TestNonHelpFlag(INTERNAL_FLAG_FOR_TESTING)
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/gtest_help_test_.cc b/3rdparty/gtest/test/gtest_help_test_.cc
new file mode 100644
index 0000000..750ae6c
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_help_test_.cc
@@ -0,0 +1,45 @@
+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// This program is meant to be run by gtest_help_test.py.  Do not run
+// it directly.
+
+#include "gtest/gtest.h"
+
+// When a help flag is specified, this program should skip the tests
+// and exit with 0; otherwise the following test will be executed,
+// causing this program to exit with a non-zero code.
+TEST(HelpFlagTest, ShouldNotBeRun) {
+  ASSERT_TRUE(false) << "Tests shouldn't be run when --help is specified.";
+}
+
+#if GTEST_HAS_DEATH_TEST
+TEST(DeathTest, UsedByPythonScriptToDetectSupportForDeathTestsInThisBinary) {}
+#endif
diff --git a/3rdparty/gtest/test/gtest_json_test_utils.py b/3rdparty/gtest/test/gtest_json_test_utils.py
new file mode 100644
index 0000000..62bbfc2
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_json_test_utils.py
@@ -0,0 +1,60 @@
+# Copyright 2018, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test utilities for gtest_json_output."""
+
+import re
+
+
+def normalize(obj):
+  """Normalize output object.
+
+  Args:
+     obj: Google Test's JSON output object to normalize.
+
+  Returns:
+     Normalized output without any references to transient information that may
+     change from run to run.
+  """
+  def _normalize(key, value):
+    if key == 'time':
+      return re.sub(r'^\d+(\.\d+)?s$', '*', value)
+    elif key == 'timestamp':
+      return re.sub(r'^\d{4}-\d\d-\d\dT\d\d:\d\d:\d\dZ$', '*', value)
+    elif key == 'failure':
+      value = re.sub(r'^.*[/\\](.*:)\d+\n', '\\1*\n', value)
+      return re.sub(r'Stack trace:\n(.|\n)*', 'Stack trace:\n*', value)
+    else:
+      return normalize(value)
+  if isinstance(obj, dict):
+    return {k: _normalize(k, v) for k, v in obj.items()}
+  if isinstance(obj, list):
+    return [normalize(x) for x in obj]
+  else:
+    return obj
diff --git a/3rdparty/gtest/test/gtest_list_output_unittest.py b/3rdparty/gtest/test/gtest_list_output_unittest.py
new file mode 100644
index 0000000..3bba7ea
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_list_output_unittest.py
@@ -0,0 +1,141 @@
+#!/usr/bin/env python
+#
+# Copyright 2006, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"""Unit test for Google Test's --gtest_list_tests flag.
+
+A user can ask Google Test to list all tests by specifying the
+--gtest_list_tests flag. If output is requested, via --gtest_output=xml
+or --gtest_output=json, the tests are listed, with extra information in the
+output file.
+This script tests such functionality by invoking gtest_list_output_unittest_
+ (a program written with Google Test) the command line flags.
+"""
+
+import os
+import re
+import gtest_test_utils
+
+GTEST_LIST_TESTS_FLAG = '--gtest_list_tests'
+GTEST_OUTPUT_FLAG = '--gtest_output'
+
+EXPECTED_XML = """<\?xml version="1.0" encoding="UTF-8"\?>
+<testsuites tests="2" name="AllTests">
+  <testsuite name="FooTest" tests="2">
+    <testcase name="Test1" file=".*gtest_list_output_unittest_.cc" line="43" />
+    <testcase name="Test2" file=".*gtest_list_output_unittest_.cc" line="45" />
+  </testsuite>
+</testsuites>
+"""
+
+EXPECTED_JSON = """{
+  "tests": 2,
+  "name": "AllTests",
+  "testsuites": \[
+    {
+      "name": "FooTest",
+      "tests": 2,
+      "testsuite": \[
+        {
+          "name": "Test1",
+          "file": ".*gtest_list_output_unittest_.cc",
+          "line": 43
+        },
+        {
+          "name": "Test2",
+          "file": ".*gtest_list_output_unittest_.cc",
+          "line": 45
+        }
+      \]
+    }
+  \]
+}
+"""
+
+
+class GTestListTestsOutputUnitTest(gtest_test_utils.TestCase):
+  """Unit test for Google Test's list tests with output to file functionality.
+  """
+
+  def testXml(self):
+    """Verifies XML output for listing tests in a Google Test binary.
+
+    Runs a test program that generates an empty XML output, and
+    tests that the XML output is expected.
+    """
+    self._TestOutput('xml', EXPECTED_XML)
+
+  def testJSON(self):
+    """Verifies XML output for listing tests in a Google Test binary.
+
+    Runs a test program that generates an empty XML output, and
+    tests that the XML output is expected.
+    """
+    self._TestOutput('json', EXPECTED_JSON)
+
+  def _GetOutput(self, out_format):
+    file_path = os.path.join(gtest_test_utils.GetTempDir(),
+                             'test_out.' + out_format)
+    gtest_prog_path = gtest_test_utils.GetTestExecutablePath(
+        'gtest_list_output_unittest_')
+
+    command = ([
+        gtest_prog_path,
+        '%s=%s:%s' % (GTEST_OUTPUT_FLAG, out_format, file_path),
+        '--gtest_list_tests'
+    ])
+    environ_copy = os.environ.copy()
+    p = gtest_test_utils.Subprocess(
+        command, env=environ_copy, working_dir=gtest_test_utils.GetTempDir())
+
+    self.assert_(p.exited)
+    self.assertEquals(0, p.exit_code)
+    with open(file_path) as f:
+      result = f.read()
+    return result
+
+  def _TestOutput(self, test_format, expected_output):
+    actual = self._GetOutput(test_format)
+    actual_lines = actual.splitlines()
+    expected_lines = expected_output.splitlines()
+    line_count = 0
+    for actual_line in actual_lines:
+      expected_line = expected_lines[line_count]
+      expected_line_re = re.compile(expected_line.strip())
+      self.assert_(
+          expected_line_re.match(actual_line.strip()),
+          ('actual output of "%s",\n'
+           'which does not match expected regex of "%s"\n'
+           'on line %d' % (actual, expected_output, line_count)))
+      line_count = line_count + 1
+
+
+if __name__ == '__main__':
+  os.environ['GTEST_STACK_TRACE_DEPTH'] = '1'
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/gtest_list_output_unittest_.cc b/3rdparty/gtest/test/gtest_list_output_unittest_.cc
new file mode 100644
index 0000000..b1c7b4d
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_list_output_unittest_.cc
@@ -0,0 +1,51 @@
+// Copyright 2018, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: david.schuldenfrei@gmail.com (David Schuldenfrei)
+
+// Unit test for Google Test's --gtest_list_tests and --gtest_output flag.
+//
+// A user can ask Google Test to list all tests that will run,
+// and have the output saved in a Json/Xml file.
+// The tests will not be run after listing.
+//
+// This program will be invoked from a Python unit test.
+// Don't run it directly.
+
+#include "gtest/gtest.h"
+
+TEST(FooTest, Test1) {}
+
+TEST(FooTest, Test2) {}
+
+int main(int argc, char **argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/gtest_main_unittest.cc b/3rdparty/gtest/test/gtest_main_unittest.cc
new file mode 100644
index 0000000..eddedea
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_main_unittest.cc
@@ -0,0 +1,44 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#include "gtest/gtest.h"
+
+// Tests that we don't have to define main() when we link to
+// gtest_main instead of gtest.
+
+namespace {
+
+TEST(GTestMainTest, ShouldSucceed) {
+}
+
+}  // namespace
+
+// We are using the main() function defined in gtest_main.cc, so we
+// don't define it here.
diff --git a/3rdparty/gtest/test/gtest_no_test_unittest.cc b/3rdparty/gtest/test/gtest_no_test_unittest.cc
new file mode 100644
index 0000000..d4f88db
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_no_test_unittest.cc
@@ -0,0 +1,54 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Tests that a Google Test program that has no test defined can run
+// successfully.
+
+#include "gtest/gtest.h"
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  // An ad-hoc assertion outside of all tests.
+  //
+  // This serves three purposes:
+  //
+  // 1. It verifies that an ad-hoc assertion can be executed even if
+  //    no test is defined.
+  // 2. It verifies that a failed ad-hoc assertion causes the test
+  //    program to fail.
+  // 3. We had a bug where the XML output won't be generated if an
+  //    assertion is executed before RUN_ALL_TESTS() is called, even
+  //    though --gtest_output=xml is specified.  This makes sure the
+  //    bug is fixed and doesn't regress.
+  EXPECT_EQ(1, 2);
+
+  // The above EXPECT_EQ() should cause RUN_ALL_TESTS() to return non-zero.
+  return RUN_ALL_TESTS() ? 0 : 1;
+}
diff --git a/3rdparty/gtest/test/gtest_pred_impl_unittest.cc b/3rdparty/gtest/test/gtest_pred_impl_unittest.cc
new file mode 100644
index 0000000..1afe5e2
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_pred_impl_unittest.cc
@@ -0,0 +1,2427 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// This file is AUTOMATICALLY GENERATED on 01/02/2019 by command
+// 'gen_gtest_pred_impl.py 5'.  DO NOT EDIT BY HAND!
+
+// Regression test for gtest_pred_impl.h
+//
+// This file is generated by a script and quite long.  If you intend to
+// learn how Google Test works by reading its unit tests, read
+// gtest_unittest.cc instead.
+//
+// This is intended as a regression test for the Google Test predicate
+// assertions.  We compile it as part of the gtest_unittest target
+// only to keep the implementation tidy and compact, as it is quite
+// involved to set up the stage for testing Google Test using Google
+// Test itself.
+//
+// Currently, gtest_unittest takes ~11 seconds to run in the testing
+// daemon.  In the future, if it grows too large and needs much more
+// time to finish, we should consider separating this file into a
+// stand-alone regression test.
+
+#include <iostream>
+
+#include "gtest/gtest.h"
+#include "gtest/gtest-spi.h"
+
+// A user-defined data type.
+struct Bool {
+  explicit Bool(int val) : value(val != 0) {}
+
+  bool operator>(int n) const { return value > Bool(n).value; }
+
+  Bool operator+(const Bool& rhs) const { return Bool(value + rhs.value); }
+
+  bool operator==(const Bool& rhs) const { return value == rhs.value; }
+
+  bool value;
+};
+
+// Enables Bool to be used in assertions.
+std::ostream& operator<<(std::ostream& os, const Bool& x) {
+  return os << (x.value ? "true" : "false");
+}
+
+// Sample functions/functors for testing unary predicate assertions.
+
+// A unary predicate function.
+template <typename T1>
+bool PredFunction1(T1 v1) {
+  return v1 > 0;
+}
+
+// The following two functions are needed to circumvent a bug in
+// gcc 2.95.3, which sometimes has problem with the above template
+// function.
+bool PredFunction1Int(int v1) {
+  return v1 > 0;
+}
+bool PredFunction1Bool(Bool v1) {
+  return v1 > 0;
+}
+
+// A unary predicate functor.
+struct PredFunctor1 {
+  template <typename T1>
+  bool operator()(const T1& v1) {
+    return v1 > 0;
+  }
+};
+
+// A unary predicate-formatter function.
+template <typename T1>
+testing::AssertionResult PredFormatFunction1(const char* e1,
+                                             const T1& v1) {
+  if (PredFunction1(v1))
+    return testing::AssertionSuccess();
+
+  return testing::AssertionFailure()
+      << e1
+      << " is expected to be positive, but evaluates to "
+      << v1 << ".";
+}
+
+// A unary predicate-formatter functor.
+struct PredFormatFunctor1 {
+  template <typename T1>
+  testing::AssertionResult operator()(const char* e1,
+                                      const T1& v1) const {
+    return PredFormatFunction1(e1, v1);
+  }
+};
+
+// Tests for {EXPECT|ASSERT}_PRED_FORMAT1.
+
+class Predicate1Test : public testing::Test {
+ protected:
+  void SetUp() override {
+    expected_to_finish_ = true;
+    finished_ = false;
+    n1_ = 0;
+  }
+
+  void TearDown() override {
+    // Verifies that each of the predicate's arguments was evaluated
+    // exactly once.
+    EXPECT_EQ(1, n1_) <<
+        "The predicate assertion didn't evaluate argument 2 "
+        "exactly once.";
+
+    // Verifies that the control flow in the test function is expected.
+    if (expected_to_finish_ && !finished_) {
+      FAIL() << "The predicate assertion unexpactedly aborted the test.";
+    } else if (!expected_to_finish_ && finished_) {
+      FAIL() << "The failed predicate assertion didn't abort the test "
+                "as expected.";
+    }
+  }
+
+  // true if and only if the test function is expected to run to finish.
+  static bool expected_to_finish_;
+
+  // true if and only if the test function did run to finish.
+  static bool finished_;
+
+  static int n1_;
+};
+
+bool Predicate1Test::expected_to_finish_;
+bool Predicate1Test::finished_;
+int Predicate1Test::n1_;
+
+typedef Predicate1Test EXPECT_PRED_FORMAT1Test;
+typedef Predicate1Test ASSERT_PRED_FORMAT1Test;
+typedef Predicate1Test EXPECT_PRED1Test;
+typedef Predicate1Test ASSERT_PRED1Test;
+
+// Tests a successful EXPECT_PRED1 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED1Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED1(PredFunction1Int,
+               ++n1_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED1 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED1Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED1(PredFunction1Bool,
+               Bool(++n1_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED1 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED1Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED1(PredFunctor1(),
+               ++n1_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED1 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED1Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED1(PredFunctor1(),
+               Bool(++n1_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED1 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED1Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED1(PredFunction1Int,
+                 n1_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED1 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED1Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED1(PredFunction1Bool,
+                 Bool(n1_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED1 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED1Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED1(PredFunctor1(),
+                 n1_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED1 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED1Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED1(PredFunctor1(),
+                 Bool(n1_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED1 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED1Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED1(PredFunction1Int,
+               ++n1_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED1 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED1Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED1(PredFunction1Bool,
+               Bool(++n1_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED1 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED1Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED1(PredFunctor1(),
+               ++n1_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED1 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED1Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED1(PredFunctor1(),
+               Bool(++n1_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED1 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED1Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED1(PredFunction1Int,
+                 n1_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED1 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED1Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED1(PredFunction1Bool,
+                 Bool(n1_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED1 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED1Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED1(PredFunctor1(),
+                 n1_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED1 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED1Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED1(PredFunctor1(),
+                 Bool(n1_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful EXPECT_PRED_FORMAT1 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT1Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT1(PredFormatFunction1,
+                      ++n1_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT1 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT1Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT1(PredFormatFunction1,
+                      Bool(++n1_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT1 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT1Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT1(PredFormatFunctor1(),
+                      ++n1_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT1 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT1Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT1(PredFormatFunctor1(),
+                      Bool(++n1_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED_FORMAT1 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT1Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT1(PredFormatFunction1,
+                        n1_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT1 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT1Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT1(PredFormatFunction1,
+                        Bool(n1_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT1 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT1Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT1(PredFormatFunctor1(),
+                        n1_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT1 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT1Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT1(PredFormatFunctor1(),
+                        Bool(n1_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED_FORMAT1 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT1Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT1(PredFormatFunction1,
+                      ++n1_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT1 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT1Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT1(PredFormatFunction1,
+                      Bool(++n1_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT1 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT1Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT1(PredFormatFunctor1(),
+                      ++n1_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT1 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT1Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT1(PredFormatFunctor1(),
+                      Bool(++n1_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED_FORMAT1 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT1Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT1(PredFormatFunction1,
+                        n1_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT1 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT1Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT1(PredFormatFunction1,
+                        Bool(n1_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT1 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT1Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT1(PredFormatFunctor1(),
+                        n1_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT1 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT1Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT1(PredFormatFunctor1(),
+                        Bool(n1_++));
+    finished_ = true;
+  }, "");
+}
+// Sample functions/functors for testing binary predicate assertions.
+
+// A binary predicate function.
+template <typename T1, typename T2>
+bool PredFunction2(T1 v1, T2 v2) {
+  return v1 + v2 > 0;
+}
+
+// The following two functions are needed to circumvent a bug in
+// gcc 2.95.3, which sometimes has problem with the above template
+// function.
+bool PredFunction2Int(int v1, int v2) {
+  return v1 + v2 > 0;
+}
+bool PredFunction2Bool(Bool v1, Bool v2) {
+  return v1 + v2 > 0;
+}
+
+// A binary predicate functor.
+struct PredFunctor2 {
+  template <typename T1, typename T2>
+  bool operator()(const T1& v1,
+                  const T2& v2) {
+    return v1 + v2 > 0;
+  }
+};
+
+// A binary predicate-formatter function.
+template <typename T1, typename T2>
+testing::AssertionResult PredFormatFunction2(const char* e1,
+                                             const char* e2,
+                                             const T1& v1,
+                                             const T2& v2) {
+  if (PredFunction2(v1, v2))
+    return testing::AssertionSuccess();
+
+  return testing::AssertionFailure()
+      << e1 << " + " << e2
+      << " is expected to be positive, but evaluates to "
+      << v1 + v2 << ".";
+}
+
+// A binary predicate-formatter functor.
+struct PredFormatFunctor2 {
+  template <typename T1, typename T2>
+  testing::AssertionResult operator()(const char* e1,
+                                      const char* e2,
+                                      const T1& v1,
+                                      const T2& v2) const {
+    return PredFormatFunction2(e1, e2, v1, v2);
+  }
+};
+
+// Tests for {EXPECT|ASSERT}_PRED_FORMAT2.
+
+class Predicate2Test : public testing::Test {
+ protected:
+  void SetUp() override {
+    expected_to_finish_ = true;
+    finished_ = false;
+    n1_ = n2_ = 0;
+  }
+
+  void TearDown() override {
+    // Verifies that each of the predicate's arguments was evaluated
+    // exactly once.
+    EXPECT_EQ(1, n1_) <<
+        "The predicate assertion didn't evaluate argument 2 "
+        "exactly once.";
+    EXPECT_EQ(1, n2_) <<
+        "The predicate assertion didn't evaluate argument 3 "
+        "exactly once.";
+
+    // Verifies that the control flow in the test function is expected.
+    if (expected_to_finish_ && !finished_) {
+      FAIL() << "The predicate assertion unexpactedly aborted the test.";
+    } else if (!expected_to_finish_ && finished_) {
+      FAIL() << "The failed predicate assertion didn't abort the test "
+                "as expected.";
+    }
+  }
+
+  // true if and only if the test function is expected to run to finish.
+  static bool expected_to_finish_;
+
+  // true if and only if the test function did run to finish.
+  static bool finished_;
+
+  static int n1_;
+  static int n2_;
+};
+
+bool Predicate2Test::expected_to_finish_;
+bool Predicate2Test::finished_;
+int Predicate2Test::n1_;
+int Predicate2Test::n2_;
+
+typedef Predicate2Test EXPECT_PRED_FORMAT2Test;
+typedef Predicate2Test ASSERT_PRED_FORMAT2Test;
+typedef Predicate2Test EXPECT_PRED2Test;
+typedef Predicate2Test ASSERT_PRED2Test;
+
+// Tests a successful EXPECT_PRED2 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED2Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED2(PredFunction2Int,
+               ++n1_,
+               ++n2_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED2 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED2Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED2(PredFunction2Bool,
+               Bool(++n1_),
+               Bool(++n2_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED2 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED2Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED2(PredFunctor2(),
+               ++n1_,
+               ++n2_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED2 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED2Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED2(PredFunctor2(),
+               Bool(++n1_),
+               Bool(++n2_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED2 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED2Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED2(PredFunction2Int,
+                 n1_++,
+                 n2_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED2 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED2Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED2(PredFunction2Bool,
+                 Bool(n1_++),
+                 Bool(n2_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED2 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED2Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED2(PredFunctor2(),
+                 n1_++,
+                 n2_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED2 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED2Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED2(PredFunctor2(),
+                 Bool(n1_++),
+                 Bool(n2_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED2 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED2Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED2(PredFunction2Int,
+               ++n1_,
+               ++n2_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED2 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED2Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED2(PredFunction2Bool,
+               Bool(++n1_),
+               Bool(++n2_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED2 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED2Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED2(PredFunctor2(),
+               ++n1_,
+               ++n2_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED2 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED2Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED2(PredFunctor2(),
+               Bool(++n1_),
+               Bool(++n2_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED2 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED2Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED2(PredFunction2Int,
+                 n1_++,
+                 n2_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED2 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED2Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED2(PredFunction2Bool,
+                 Bool(n1_++),
+                 Bool(n2_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED2 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED2Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED2(PredFunctor2(),
+                 n1_++,
+                 n2_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED2 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED2Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED2(PredFunctor2(),
+                 Bool(n1_++),
+                 Bool(n2_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful EXPECT_PRED_FORMAT2 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT2Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT2(PredFormatFunction2,
+                      ++n1_,
+                      ++n2_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT2 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT2Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT2(PredFormatFunction2,
+                      Bool(++n1_),
+                      Bool(++n2_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT2 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT2Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT2(PredFormatFunctor2(),
+                      ++n1_,
+                      ++n2_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT2 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT2Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT2(PredFormatFunctor2(),
+                      Bool(++n1_),
+                      Bool(++n2_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED_FORMAT2 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT2Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(PredFormatFunction2,
+                        n1_++,
+                        n2_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT2 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT2Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(PredFormatFunction2,
+                        Bool(n1_++),
+                        Bool(n2_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT2 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT2Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(PredFormatFunctor2(),
+                        n1_++,
+                        n2_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT2 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT2Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(PredFormatFunctor2(),
+                        Bool(n1_++),
+                        Bool(n2_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED_FORMAT2 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT2Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT2(PredFormatFunction2,
+                      ++n1_,
+                      ++n2_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT2 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT2Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT2(PredFormatFunction2,
+                      Bool(++n1_),
+                      Bool(++n2_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT2 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT2Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT2(PredFormatFunctor2(),
+                      ++n1_,
+                      ++n2_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT2 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT2Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT2(PredFormatFunctor2(),
+                      Bool(++n1_),
+                      Bool(++n2_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED_FORMAT2 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT2Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT2(PredFormatFunction2,
+                        n1_++,
+                        n2_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT2 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT2Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT2(PredFormatFunction2,
+                        Bool(n1_++),
+                        Bool(n2_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT2 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT2Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT2(PredFormatFunctor2(),
+                        n1_++,
+                        n2_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT2 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT2Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT2(PredFormatFunctor2(),
+                        Bool(n1_++),
+                        Bool(n2_++));
+    finished_ = true;
+  }, "");
+}
+// Sample functions/functors for testing ternary predicate assertions.
+
+// A ternary predicate function.
+template <typename T1, typename T2, typename T3>
+bool PredFunction3(T1 v1, T2 v2, T3 v3) {
+  return v1 + v2 + v3 > 0;
+}
+
+// The following two functions are needed to circumvent a bug in
+// gcc 2.95.3, which sometimes has problem with the above template
+// function.
+bool PredFunction3Int(int v1, int v2, int v3) {
+  return v1 + v2 + v3 > 0;
+}
+bool PredFunction3Bool(Bool v1, Bool v2, Bool v3) {
+  return v1 + v2 + v3 > 0;
+}
+
+// A ternary predicate functor.
+struct PredFunctor3 {
+  template <typename T1, typename T2, typename T3>
+  bool operator()(const T1& v1,
+                  const T2& v2,
+                  const T3& v3) {
+    return v1 + v2 + v3 > 0;
+  }
+};
+
+// A ternary predicate-formatter function.
+template <typename T1, typename T2, typename T3>
+testing::AssertionResult PredFormatFunction3(const char* e1,
+                                             const char* e2,
+                                             const char* e3,
+                                             const T1& v1,
+                                             const T2& v2,
+                                             const T3& v3) {
+  if (PredFunction3(v1, v2, v3))
+    return testing::AssertionSuccess();
+
+  return testing::AssertionFailure()
+      << e1 << " + " << e2 << " + " << e3
+      << " is expected to be positive, but evaluates to "
+      << v1 + v2 + v3 << ".";
+}
+
+// A ternary predicate-formatter functor.
+struct PredFormatFunctor3 {
+  template <typename T1, typename T2, typename T3>
+  testing::AssertionResult operator()(const char* e1,
+                                      const char* e2,
+                                      const char* e3,
+                                      const T1& v1,
+                                      const T2& v2,
+                                      const T3& v3) const {
+    return PredFormatFunction3(e1, e2, e3, v1, v2, v3);
+  }
+};
+
+// Tests for {EXPECT|ASSERT}_PRED_FORMAT3.
+
+class Predicate3Test : public testing::Test {
+ protected:
+  void SetUp() override {
+    expected_to_finish_ = true;
+    finished_ = false;
+    n1_ = n2_ = n3_ = 0;
+  }
+
+  void TearDown() override {
+    // Verifies that each of the predicate's arguments was evaluated
+    // exactly once.
+    EXPECT_EQ(1, n1_) <<
+        "The predicate assertion didn't evaluate argument 2 "
+        "exactly once.";
+    EXPECT_EQ(1, n2_) <<
+        "The predicate assertion didn't evaluate argument 3 "
+        "exactly once.";
+    EXPECT_EQ(1, n3_) <<
+        "The predicate assertion didn't evaluate argument 4 "
+        "exactly once.";
+
+    // Verifies that the control flow in the test function is expected.
+    if (expected_to_finish_ && !finished_) {
+      FAIL() << "The predicate assertion unexpactedly aborted the test.";
+    } else if (!expected_to_finish_ && finished_) {
+      FAIL() << "The failed predicate assertion didn't abort the test "
+                "as expected.";
+    }
+  }
+
+  // true if and only if the test function is expected to run to finish.
+  static bool expected_to_finish_;
+
+  // true if and only if the test function did run to finish.
+  static bool finished_;
+
+  static int n1_;
+  static int n2_;
+  static int n3_;
+};
+
+bool Predicate3Test::expected_to_finish_;
+bool Predicate3Test::finished_;
+int Predicate3Test::n1_;
+int Predicate3Test::n2_;
+int Predicate3Test::n3_;
+
+typedef Predicate3Test EXPECT_PRED_FORMAT3Test;
+typedef Predicate3Test ASSERT_PRED_FORMAT3Test;
+typedef Predicate3Test EXPECT_PRED3Test;
+typedef Predicate3Test ASSERT_PRED3Test;
+
+// Tests a successful EXPECT_PRED3 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED3Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED3(PredFunction3Int,
+               ++n1_,
+               ++n2_,
+               ++n3_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED3 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED3Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED3(PredFunction3Bool,
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED3 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED3Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED3(PredFunctor3(),
+               ++n1_,
+               ++n2_,
+               ++n3_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED3 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED3Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED3(PredFunctor3(),
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED3 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED3Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED3(PredFunction3Int,
+                 n1_++,
+                 n2_++,
+                 n3_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED3 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED3Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED3(PredFunction3Bool,
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED3 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED3Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED3(PredFunctor3(),
+                 n1_++,
+                 n2_++,
+                 n3_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED3 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED3Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED3(PredFunctor3(),
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED3 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED3Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED3(PredFunction3Int,
+               ++n1_,
+               ++n2_,
+               ++n3_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED3 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED3Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED3(PredFunction3Bool,
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED3 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED3Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED3(PredFunctor3(),
+               ++n1_,
+               ++n2_,
+               ++n3_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED3 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED3Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED3(PredFunctor3(),
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED3 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED3Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED3(PredFunction3Int,
+                 n1_++,
+                 n2_++,
+                 n3_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED3 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED3Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED3(PredFunction3Bool,
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED3 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED3Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED3(PredFunctor3(),
+                 n1_++,
+                 n2_++,
+                 n3_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED3 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED3Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED3(PredFunctor3(),
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful EXPECT_PRED_FORMAT3 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT3Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT3(PredFormatFunction3,
+                      ++n1_,
+                      ++n2_,
+                      ++n3_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT3 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT3Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT3(PredFormatFunction3,
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT3 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT3Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT3(PredFormatFunctor3(),
+                      ++n1_,
+                      ++n2_,
+                      ++n3_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT3 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT3Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT3(PredFormatFunctor3(),
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED_FORMAT3 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT3Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT3(PredFormatFunction3,
+                        n1_++,
+                        n2_++,
+                        n3_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT3 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT3Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT3(PredFormatFunction3,
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT3 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT3Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT3(PredFormatFunctor3(),
+                        n1_++,
+                        n2_++,
+                        n3_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT3 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT3Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT3(PredFormatFunctor3(),
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED_FORMAT3 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT3Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT3(PredFormatFunction3,
+                      ++n1_,
+                      ++n2_,
+                      ++n3_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT3 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT3Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT3(PredFormatFunction3,
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT3 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT3Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT3(PredFormatFunctor3(),
+                      ++n1_,
+                      ++n2_,
+                      ++n3_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT3 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT3Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT3(PredFormatFunctor3(),
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED_FORMAT3 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT3Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT3(PredFormatFunction3,
+                        n1_++,
+                        n2_++,
+                        n3_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT3 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT3Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT3(PredFormatFunction3,
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT3 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT3Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT3(PredFormatFunctor3(),
+                        n1_++,
+                        n2_++,
+                        n3_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT3 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT3Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT3(PredFormatFunctor3(),
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++));
+    finished_ = true;
+  }, "");
+}
+// Sample functions/functors for testing 4-ary predicate assertions.
+
+// A 4-ary predicate function.
+template <typename T1, typename T2, typename T3, typename T4>
+bool PredFunction4(T1 v1, T2 v2, T3 v3, T4 v4) {
+  return v1 + v2 + v3 + v4 > 0;
+}
+
+// The following two functions are needed to circumvent a bug in
+// gcc 2.95.3, which sometimes has problem with the above template
+// function.
+bool PredFunction4Int(int v1, int v2, int v3, int v4) {
+  return v1 + v2 + v3 + v4 > 0;
+}
+bool PredFunction4Bool(Bool v1, Bool v2, Bool v3, Bool v4) {
+  return v1 + v2 + v3 + v4 > 0;
+}
+
+// A 4-ary predicate functor.
+struct PredFunctor4 {
+  template <typename T1, typename T2, typename T3, typename T4>
+  bool operator()(const T1& v1,
+                  const T2& v2,
+                  const T3& v3,
+                  const T4& v4) {
+    return v1 + v2 + v3 + v4 > 0;
+  }
+};
+
+// A 4-ary predicate-formatter function.
+template <typename T1, typename T2, typename T3, typename T4>
+testing::AssertionResult PredFormatFunction4(const char* e1,
+                                             const char* e2,
+                                             const char* e3,
+                                             const char* e4,
+                                             const T1& v1,
+                                             const T2& v2,
+                                             const T3& v3,
+                                             const T4& v4) {
+  if (PredFunction4(v1, v2, v3, v4))
+    return testing::AssertionSuccess();
+
+  return testing::AssertionFailure()
+      << e1 << " + " << e2 << " + " << e3 << " + " << e4
+      << " is expected to be positive, but evaluates to "
+      << v1 + v2 + v3 + v4 << ".";
+}
+
+// A 4-ary predicate-formatter functor.
+struct PredFormatFunctor4 {
+  template <typename T1, typename T2, typename T3, typename T4>
+  testing::AssertionResult operator()(const char* e1,
+                                      const char* e2,
+                                      const char* e3,
+                                      const char* e4,
+                                      const T1& v1,
+                                      const T2& v2,
+                                      const T3& v3,
+                                      const T4& v4) const {
+    return PredFormatFunction4(e1, e2, e3, e4, v1, v2, v3, v4);
+  }
+};
+
+// Tests for {EXPECT|ASSERT}_PRED_FORMAT4.
+
+class Predicate4Test : public testing::Test {
+ protected:
+  void SetUp() override {
+    expected_to_finish_ = true;
+    finished_ = false;
+    n1_ = n2_ = n3_ = n4_ = 0;
+  }
+
+  void TearDown() override {
+    // Verifies that each of the predicate's arguments was evaluated
+    // exactly once.
+    EXPECT_EQ(1, n1_) <<
+        "The predicate assertion didn't evaluate argument 2 "
+        "exactly once.";
+    EXPECT_EQ(1, n2_) <<
+        "The predicate assertion didn't evaluate argument 3 "
+        "exactly once.";
+    EXPECT_EQ(1, n3_) <<
+        "The predicate assertion didn't evaluate argument 4 "
+        "exactly once.";
+    EXPECT_EQ(1, n4_) <<
+        "The predicate assertion didn't evaluate argument 5 "
+        "exactly once.";
+
+    // Verifies that the control flow in the test function is expected.
+    if (expected_to_finish_ && !finished_) {
+      FAIL() << "The predicate assertion unexpactedly aborted the test.";
+    } else if (!expected_to_finish_ && finished_) {
+      FAIL() << "The failed predicate assertion didn't abort the test "
+                "as expected.";
+    }
+  }
+
+  // true if and only if the test function is expected to run to finish.
+  static bool expected_to_finish_;
+
+  // true if and only if the test function did run to finish.
+  static bool finished_;
+
+  static int n1_;
+  static int n2_;
+  static int n3_;
+  static int n4_;
+};
+
+bool Predicate4Test::expected_to_finish_;
+bool Predicate4Test::finished_;
+int Predicate4Test::n1_;
+int Predicate4Test::n2_;
+int Predicate4Test::n3_;
+int Predicate4Test::n4_;
+
+typedef Predicate4Test EXPECT_PRED_FORMAT4Test;
+typedef Predicate4Test ASSERT_PRED_FORMAT4Test;
+typedef Predicate4Test EXPECT_PRED4Test;
+typedef Predicate4Test ASSERT_PRED4Test;
+
+// Tests a successful EXPECT_PRED4 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED4Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED4(PredFunction4Int,
+               ++n1_,
+               ++n2_,
+               ++n3_,
+               ++n4_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED4 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED4Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED4(PredFunction4Bool,
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_),
+               Bool(++n4_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED4 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED4Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED4(PredFunctor4(),
+               ++n1_,
+               ++n2_,
+               ++n3_,
+               ++n4_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED4 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED4Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED4(PredFunctor4(),
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_),
+               Bool(++n4_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED4 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED4Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED4(PredFunction4Int,
+                 n1_++,
+                 n2_++,
+                 n3_++,
+                 n4_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED4 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED4Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED4(PredFunction4Bool,
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++),
+                 Bool(n4_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED4 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED4Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED4(PredFunctor4(),
+                 n1_++,
+                 n2_++,
+                 n3_++,
+                 n4_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED4 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED4Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED4(PredFunctor4(),
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++),
+                 Bool(n4_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED4 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED4Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED4(PredFunction4Int,
+               ++n1_,
+               ++n2_,
+               ++n3_,
+               ++n4_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED4 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED4Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED4(PredFunction4Bool,
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_),
+               Bool(++n4_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED4 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED4Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED4(PredFunctor4(),
+               ++n1_,
+               ++n2_,
+               ++n3_,
+               ++n4_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED4 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED4Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED4(PredFunctor4(),
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_),
+               Bool(++n4_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED4 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED4Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED4(PredFunction4Int,
+                 n1_++,
+                 n2_++,
+                 n3_++,
+                 n4_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED4 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED4Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED4(PredFunction4Bool,
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++),
+                 Bool(n4_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED4 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED4Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED4(PredFunctor4(),
+                 n1_++,
+                 n2_++,
+                 n3_++,
+                 n4_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED4 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED4Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED4(PredFunctor4(),
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++),
+                 Bool(n4_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful EXPECT_PRED_FORMAT4 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT4Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT4(PredFormatFunction4,
+                      ++n1_,
+                      ++n2_,
+                      ++n3_,
+                      ++n4_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT4 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT4Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT4(PredFormatFunction4,
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_),
+                      Bool(++n4_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT4 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT4Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT4(PredFormatFunctor4(),
+                      ++n1_,
+                      ++n2_,
+                      ++n3_,
+                      ++n4_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT4 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT4Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT4(PredFormatFunctor4(),
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_),
+                      Bool(++n4_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED_FORMAT4 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT4Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT4(PredFormatFunction4,
+                        n1_++,
+                        n2_++,
+                        n3_++,
+                        n4_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT4 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT4Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT4(PredFormatFunction4,
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++),
+                        Bool(n4_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT4 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT4Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT4(PredFormatFunctor4(),
+                        n1_++,
+                        n2_++,
+                        n3_++,
+                        n4_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT4 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT4Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT4(PredFormatFunctor4(),
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++),
+                        Bool(n4_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED_FORMAT4 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT4Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT4(PredFormatFunction4,
+                      ++n1_,
+                      ++n2_,
+                      ++n3_,
+                      ++n4_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT4 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT4Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT4(PredFormatFunction4,
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_),
+                      Bool(++n4_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT4 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT4Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT4(PredFormatFunctor4(),
+                      ++n1_,
+                      ++n2_,
+                      ++n3_,
+                      ++n4_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT4 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT4Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT4(PredFormatFunctor4(),
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_),
+                      Bool(++n4_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED_FORMAT4 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT4Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT4(PredFormatFunction4,
+                        n1_++,
+                        n2_++,
+                        n3_++,
+                        n4_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT4 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT4Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT4(PredFormatFunction4,
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++),
+                        Bool(n4_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT4 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT4Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT4(PredFormatFunctor4(),
+                        n1_++,
+                        n2_++,
+                        n3_++,
+                        n4_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT4 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT4Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT4(PredFormatFunctor4(),
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++),
+                        Bool(n4_++));
+    finished_ = true;
+  }, "");
+}
+// Sample functions/functors for testing 5-ary predicate assertions.
+
+// A 5-ary predicate function.
+template <typename T1, typename T2, typename T3, typename T4, typename T5>
+bool PredFunction5(T1 v1, T2 v2, T3 v3, T4 v4, T5 v5) {
+  return v1 + v2 + v3 + v4 + v5 > 0;
+}
+
+// The following two functions are needed to circumvent a bug in
+// gcc 2.95.3, which sometimes has problem with the above template
+// function.
+bool PredFunction5Int(int v1, int v2, int v3, int v4, int v5) {
+  return v1 + v2 + v3 + v4 + v5 > 0;
+}
+bool PredFunction5Bool(Bool v1, Bool v2, Bool v3, Bool v4, Bool v5) {
+  return v1 + v2 + v3 + v4 + v5 > 0;
+}
+
+// A 5-ary predicate functor.
+struct PredFunctor5 {
+  template <typename T1, typename T2, typename T3, typename T4, typename T5>
+  bool operator()(const T1& v1,
+                  const T2& v2,
+                  const T3& v3,
+                  const T4& v4,
+                  const T5& v5) {
+    return v1 + v2 + v3 + v4 + v5 > 0;
+  }
+};
+
+// A 5-ary predicate-formatter function.
+template <typename T1, typename T2, typename T3, typename T4, typename T5>
+testing::AssertionResult PredFormatFunction5(const char* e1,
+                                             const char* e2,
+                                             const char* e3,
+                                             const char* e4,
+                                             const char* e5,
+                                             const T1& v1,
+                                             const T2& v2,
+                                             const T3& v3,
+                                             const T4& v4,
+                                             const T5& v5) {
+  if (PredFunction5(v1, v2, v3, v4, v5))
+    return testing::AssertionSuccess();
+
+  return testing::AssertionFailure()
+      << e1 << " + " << e2 << " + " << e3 << " + " << e4 << " + " << e5
+      << " is expected to be positive, but evaluates to "
+      << v1 + v2 + v3 + v4 + v5 << ".";
+}
+
+// A 5-ary predicate-formatter functor.
+struct PredFormatFunctor5 {
+  template <typename T1, typename T2, typename T3, typename T4, typename T5>
+  testing::AssertionResult operator()(const char* e1,
+                                      const char* e2,
+                                      const char* e3,
+                                      const char* e4,
+                                      const char* e5,
+                                      const T1& v1,
+                                      const T2& v2,
+                                      const T3& v3,
+                                      const T4& v4,
+                                      const T5& v5) const {
+    return PredFormatFunction5(e1, e2, e3, e4, e5, v1, v2, v3, v4, v5);
+  }
+};
+
+// Tests for {EXPECT|ASSERT}_PRED_FORMAT5.
+
+class Predicate5Test : public testing::Test {
+ protected:
+  void SetUp() override {
+    expected_to_finish_ = true;
+    finished_ = false;
+    n1_ = n2_ = n3_ = n4_ = n5_ = 0;
+  }
+
+  void TearDown() override {
+    // Verifies that each of the predicate's arguments was evaluated
+    // exactly once.
+    EXPECT_EQ(1, n1_) <<
+        "The predicate assertion didn't evaluate argument 2 "
+        "exactly once.";
+    EXPECT_EQ(1, n2_) <<
+        "The predicate assertion didn't evaluate argument 3 "
+        "exactly once.";
+    EXPECT_EQ(1, n3_) <<
+        "The predicate assertion didn't evaluate argument 4 "
+        "exactly once.";
+    EXPECT_EQ(1, n4_) <<
+        "The predicate assertion didn't evaluate argument 5 "
+        "exactly once.";
+    EXPECT_EQ(1, n5_) <<
+        "The predicate assertion didn't evaluate argument 6 "
+        "exactly once.";
+
+    // Verifies that the control flow in the test function is expected.
+    if (expected_to_finish_ && !finished_) {
+      FAIL() << "The predicate assertion unexpactedly aborted the test.";
+    } else if (!expected_to_finish_ && finished_) {
+      FAIL() << "The failed predicate assertion didn't abort the test "
+                "as expected.";
+    }
+  }
+
+  // true if and only if the test function is expected to run to finish.
+  static bool expected_to_finish_;
+
+  // true if and only if the test function did run to finish.
+  static bool finished_;
+
+  static int n1_;
+  static int n2_;
+  static int n3_;
+  static int n4_;
+  static int n5_;
+};
+
+bool Predicate5Test::expected_to_finish_;
+bool Predicate5Test::finished_;
+int Predicate5Test::n1_;
+int Predicate5Test::n2_;
+int Predicate5Test::n3_;
+int Predicate5Test::n4_;
+int Predicate5Test::n5_;
+
+typedef Predicate5Test EXPECT_PRED_FORMAT5Test;
+typedef Predicate5Test ASSERT_PRED_FORMAT5Test;
+typedef Predicate5Test EXPECT_PRED5Test;
+typedef Predicate5Test ASSERT_PRED5Test;
+
+// Tests a successful EXPECT_PRED5 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED5Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED5(PredFunction5Int,
+               ++n1_,
+               ++n2_,
+               ++n3_,
+               ++n4_,
+               ++n5_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED5 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED5Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED5(PredFunction5Bool,
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_),
+               Bool(++n4_),
+               Bool(++n5_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED5 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED5Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED5(PredFunctor5(),
+               ++n1_,
+               ++n2_,
+               ++n3_,
+               ++n4_,
+               ++n5_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED5 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED5Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED5(PredFunctor5(),
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_),
+               Bool(++n4_),
+               Bool(++n5_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED5 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED5Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED5(PredFunction5Int,
+                 n1_++,
+                 n2_++,
+                 n3_++,
+                 n4_++,
+                 n5_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED5 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED5Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED5(PredFunction5Bool,
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++),
+                 Bool(n4_++),
+                 Bool(n5_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED5 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED5Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED5(PredFunctor5(),
+                 n1_++,
+                 n2_++,
+                 n3_++,
+                 n4_++,
+                 n5_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED5 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED5Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED5(PredFunctor5(),
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++),
+                 Bool(n4_++),
+                 Bool(n5_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED5 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED5Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED5(PredFunction5Int,
+               ++n1_,
+               ++n2_,
+               ++n3_,
+               ++n4_,
+               ++n5_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED5 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED5Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED5(PredFunction5Bool,
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_),
+               Bool(++n4_),
+               Bool(++n5_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED5 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED5Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED5(PredFunctor5(),
+               ++n1_,
+               ++n2_,
+               ++n3_,
+               ++n4_,
+               ++n5_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED5 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED5Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED5(PredFunctor5(),
+               Bool(++n1_),
+               Bool(++n2_),
+               Bool(++n3_),
+               Bool(++n4_),
+               Bool(++n5_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED5 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED5Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED5(PredFunction5Int,
+                 n1_++,
+                 n2_++,
+                 n3_++,
+                 n4_++,
+                 n5_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED5 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED5Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED5(PredFunction5Bool,
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++),
+                 Bool(n4_++),
+                 Bool(n5_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED5 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED5Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED5(PredFunctor5(),
+                 n1_++,
+                 n2_++,
+                 n3_++,
+                 n4_++,
+                 n5_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED5 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED5Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED5(PredFunctor5(),
+                 Bool(n1_++),
+                 Bool(n2_++),
+                 Bool(n3_++),
+                 Bool(n4_++),
+                 Bool(n5_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful EXPECT_PRED_FORMAT5 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT5Test, FunctionOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT5(PredFormatFunction5,
+                      ++n1_,
+                      ++n2_,
+                      ++n3_,
+                      ++n4_,
+                      ++n5_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT5 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT5Test, FunctionOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT5(PredFormatFunction5,
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_),
+                      Bool(++n4_),
+                      Bool(++n5_));
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT5 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT5Test, FunctorOnBuiltInTypeSuccess) {
+  EXPECT_PRED_FORMAT5(PredFormatFunctor5(),
+                      ++n1_,
+                      ++n2_,
+                      ++n3_,
+                      ++n4_,
+                      ++n5_);
+  finished_ = true;
+}
+
+// Tests a successful EXPECT_PRED_FORMAT5 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT5Test, FunctorOnUserTypeSuccess) {
+  EXPECT_PRED_FORMAT5(PredFormatFunctor5(),
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_),
+                      Bool(++n4_),
+                      Bool(++n5_));
+  finished_ = true;
+}
+
+// Tests a failed EXPECT_PRED_FORMAT5 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT5Test, FunctionOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT5(PredFormatFunction5,
+                        n1_++,
+                        n2_++,
+                        n3_++,
+                        n4_++,
+                        n5_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT5 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT5Test, FunctionOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT5(PredFormatFunction5,
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++),
+                        Bool(n4_++),
+                        Bool(n5_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT5 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(EXPECT_PRED_FORMAT5Test, FunctorOnBuiltInTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT5(PredFormatFunctor5(),
+                        n1_++,
+                        n2_++,
+                        n3_++,
+                        n4_++,
+                        n5_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed EXPECT_PRED_FORMAT5 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(EXPECT_PRED_FORMAT5Test, FunctorOnUserTypeFailure) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT5(PredFormatFunctor5(),
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++),
+                        Bool(n4_++),
+                        Bool(n5_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a successful ASSERT_PRED_FORMAT5 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT5Test, FunctionOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT5(PredFormatFunction5,
+                      ++n1_,
+                      ++n2_,
+                      ++n3_,
+                      ++n4_,
+                      ++n5_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT5 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT5Test, FunctionOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT5(PredFormatFunction5,
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_),
+                      Bool(++n4_),
+                      Bool(++n5_));
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT5 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT5Test, FunctorOnBuiltInTypeSuccess) {
+  ASSERT_PRED_FORMAT5(PredFormatFunctor5(),
+                      ++n1_,
+                      ++n2_,
+                      ++n3_,
+                      ++n4_,
+                      ++n5_);
+  finished_ = true;
+}
+
+// Tests a successful ASSERT_PRED_FORMAT5 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT5Test, FunctorOnUserTypeSuccess) {
+  ASSERT_PRED_FORMAT5(PredFormatFunctor5(),
+                      Bool(++n1_),
+                      Bool(++n2_),
+                      Bool(++n3_),
+                      Bool(++n4_),
+                      Bool(++n5_));
+  finished_ = true;
+}
+
+// Tests a failed ASSERT_PRED_FORMAT5 where the
+// predicate-formatter is a function on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT5Test, FunctionOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT5(PredFormatFunction5,
+                        n1_++,
+                        n2_++,
+                        n3_++,
+                        n4_++,
+                        n5_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT5 where the
+// predicate-formatter is a function on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT5Test, FunctionOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT5(PredFormatFunction5,
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++),
+                        Bool(n4_++),
+                        Bool(n5_++));
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT5 where the
+// predicate-formatter is a functor on a built-in type (int).
+TEST_F(ASSERT_PRED_FORMAT5Test, FunctorOnBuiltInTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT5(PredFormatFunctor5(),
+                        n1_++,
+                        n2_++,
+                        n3_++,
+                        n4_++,
+                        n5_++);
+    finished_ = true;
+  }, "");
+}
+
+// Tests a failed ASSERT_PRED_FORMAT5 where the
+// predicate-formatter is a functor on a user-defined type (Bool).
+TEST_F(ASSERT_PRED_FORMAT5Test, FunctorOnUserTypeFailure) {
+  expected_to_finish_ = false;
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT5(PredFormatFunctor5(),
+                        Bool(n1_++),
+                        Bool(n2_++),
+                        Bool(n3_++),
+                        Bool(n4_++),
+                        Bool(n5_++));
+    finished_ = true;
+  }, "");
+}
diff --git a/3rdparty/gtest/test/gtest_premature_exit_test.cc b/3rdparty/gtest/test/gtest_premature_exit_test.cc
new file mode 100644
index 0000000..1d1187e
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_premature_exit_test.cc
@@ -0,0 +1,126 @@
+// Copyright 2013, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests that Google Test manipulates the premature-exit-detection
+// file correctly.
+
+#include <stdio.h>
+
+#include "gtest/gtest.h"
+
+using ::testing::InitGoogleTest;
+using ::testing::Test;
+using ::testing::internal::posix::GetEnv;
+using ::testing::internal::posix::Stat;
+using ::testing::internal::posix::StatStruct;
+
+namespace {
+
+class PrematureExitTest : public Test {
+ public:
+  // Returns true if and only if the given file exists.
+  static bool FileExists(const char* filepath) {
+    StatStruct stat;
+    return Stat(filepath, &stat) == 0;
+  }
+
+ protected:
+  PrematureExitTest() {
+    premature_exit_file_path_ = GetEnv("TEST_PREMATURE_EXIT_FILE");
+
+    // Normalize NULL to "" for ease of handling.
+    if (premature_exit_file_path_ == nullptr) {
+      premature_exit_file_path_ = "";
+    }
+  }
+
+  // Returns true if and only if the premature-exit file exists.
+  bool PrematureExitFileExists() const {
+    return FileExists(premature_exit_file_path_);
+  }
+
+  const char* premature_exit_file_path_;
+};
+
+typedef PrematureExitTest PrematureExitDeathTest;
+
+// Tests that:
+//   - the premature-exit file exists during the execution of a
+//     death test (EXPECT_DEATH*), and
+//   - a death test doesn't interfere with the main test process's
+//     handling of the premature-exit file.
+TEST_F(PrematureExitDeathTest, FileExistsDuringExecutionOfDeathTest) {
+  if (*premature_exit_file_path_ == '\0') {
+    return;
+  }
+
+  EXPECT_DEATH_IF_SUPPORTED({
+      // If the file exists, crash the process such that the main test
+      // process will catch the (expected) crash and report a success;
+      // otherwise don't crash, which will cause the main test process
+      // to report that the death test has failed.
+      if (PrematureExitFileExists()) {
+        exit(1);
+      }
+    }, "");
+}
+
+// Tests that the premature-exit file exists during the execution of a
+// normal (non-death) test.
+TEST_F(PrematureExitTest, PrematureExitFileExistsDuringTestExecution) {
+  if (*premature_exit_file_path_ == '\0') {
+    return;
+  }
+
+  EXPECT_TRUE(PrematureExitFileExists())
+      << " file " << premature_exit_file_path_
+      << " should exist during test execution, but doesn't.";
+}
+
+}  // namespace
+
+int main(int argc, char **argv) {
+  InitGoogleTest(&argc, argv);
+  const int exit_code = RUN_ALL_TESTS();
+
+  // Test that the premature-exit file is deleted upon return from
+  // RUN_ALL_TESTS().
+  const char* const filepath = GetEnv("TEST_PREMATURE_EXIT_FILE");
+  if (filepath != nullptr && *filepath != '\0') {
+    if (PrematureExitTest::FileExists(filepath)) {
+      printf(
+          "File %s shouldn't exist after the test program finishes, but does.",
+          filepath);
+      return 1;
+    }
+  }
+
+  return exit_code;
+}
diff --git a/3rdparty/gtest/test/gtest_prod_test.cc b/3rdparty/gtest/test/gtest_prod_test.cc
new file mode 100644
index 0000000..ede81a0
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_prod_test.cc
@@ -0,0 +1,56 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Unit test for gtest_prod.h.
+
+#include "production.h"
+#include "gtest/gtest.h"
+
+// Tests that private members can be accessed from a TEST declared as
+// a friend of the class.
+TEST(PrivateCodeTest, CanAccessPrivateMembers) {
+  PrivateCode a;
+  EXPECT_EQ(0, a.x_);
+
+  a.set_x(1);
+  EXPECT_EQ(1, a.x_);
+}
+
+typedef testing::Test PrivateCodeFixtureTest;
+
+// Tests that private members can be accessed from a TEST_F declared
+// as a friend of the class.
+TEST_F(PrivateCodeFixtureTest, CanAccessPrivateMembers) {
+  PrivateCode a;
+  EXPECT_EQ(0, a.x_);
+
+  a.set_x(2);
+  EXPECT_EQ(2, a.x_);
+}
diff --git a/3rdparty/gtest/test/gtest_repeat_test.cc b/3rdparty/gtest/test/gtest_repeat_test.cc
new file mode 100644
index 0000000..7da4a15
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_repeat_test.cc
@@ -0,0 +1,233 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Tests the --gtest_repeat=number flag.
+
+#include <stdlib.h>
+#include <iostream>
+#include "gtest/gtest.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+
+GTEST_DECLARE_string_(death_test_style);
+GTEST_DECLARE_string_(filter);
+GTEST_DECLARE_int32_(repeat);
+
+}  // namespace testing
+
+using testing::GTEST_FLAG(death_test_style);
+using testing::GTEST_FLAG(filter);
+using testing::GTEST_FLAG(repeat);
+
+namespace {
+
+// We need this when we are testing Google Test itself and therefore
+// cannot use Google Test assertions.
+#define GTEST_CHECK_INT_EQ_(expected, actual) \
+  do {\
+    const int expected_val = (expected);\
+    const int actual_val = (actual);\
+    if (::testing::internal::IsTrue(expected_val != actual_val)) {\
+      ::std::cout << "Value of: " #actual "\n"\
+                  << "  Actual: " << actual_val << "\n"\
+                  << "Expected: " #expected "\n"\
+                  << "Which is: " << expected_val << "\n";\
+      ::testing::internal::posix::Abort();\
+    }\
+  } while (::testing::internal::AlwaysFalse())
+
+
+// Used for verifying that global environment set-up and tear-down are
+// inside the --gtest_repeat loop.
+
+int g_environment_set_up_count = 0;
+int g_environment_tear_down_count = 0;
+
+class MyEnvironment : public testing::Environment {
+ public:
+  MyEnvironment() {}
+  void SetUp() override { g_environment_set_up_count++; }
+  void TearDown() override { g_environment_tear_down_count++; }
+};
+
+// A test that should fail.
+
+int g_should_fail_count = 0;
+
+TEST(FooTest, ShouldFail) {
+  g_should_fail_count++;
+  EXPECT_EQ(0, 1) << "Expected failure.";
+}
+
+// A test that should pass.
+
+int g_should_pass_count = 0;
+
+TEST(FooTest, ShouldPass) {
+  g_should_pass_count++;
+}
+
+// A test that contains a thread-safe death test and a fast death
+// test.  It should pass.
+
+int g_death_test_count = 0;
+
+TEST(BarDeathTest, ThreadSafeAndFast) {
+  g_death_test_count++;
+
+  GTEST_FLAG(death_test_style) = "threadsafe";
+  EXPECT_DEATH_IF_SUPPORTED(::testing::internal::posix::Abort(), "");
+
+  GTEST_FLAG(death_test_style) = "fast";
+  EXPECT_DEATH_IF_SUPPORTED(::testing::internal::posix::Abort(), "");
+}
+
+int g_param_test_count = 0;
+
+const int kNumberOfParamTests = 10;
+
+class MyParamTest : public testing::TestWithParam<int> {};
+
+TEST_P(MyParamTest, ShouldPass) {
+  GTEST_CHECK_INT_EQ_(g_param_test_count % kNumberOfParamTests, GetParam());
+  g_param_test_count++;
+}
+INSTANTIATE_TEST_SUITE_P(MyParamSequence,
+                         MyParamTest,
+                         testing::Range(0, kNumberOfParamTests));
+
+// Resets the count for each test.
+void ResetCounts() {
+  g_environment_set_up_count = 0;
+  g_environment_tear_down_count = 0;
+  g_should_fail_count = 0;
+  g_should_pass_count = 0;
+  g_death_test_count = 0;
+  g_param_test_count = 0;
+}
+
+// Checks that the count for each test is expected.
+void CheckCounts(int expected) {
+  GTEST_CHECK_INT_EQ_(expected, g_environment_set_up_count);
+  GTEST_CHECK_INT_EQ_(expected, g_environment_tear_down_count);
+  GTEST_CHECK_INT_EQ_(expected, g_should_fail_count);
+  GTEST_CHECK_INT_EQ_(expected, g_should_pass_count);
+  GTEST_CHECK_INT_EQ_(expected, g_death_test_count);
+  GTEST_CHECK_INT_EQ_(expected * kNumberOfParamTests, g_param_test_count);
+}
+
+// Tests the behavior of Google Test when --gtest_repeat is not specified.
+void TestRepeatUnspecified() {
+  ResetCounts();
+  GTEST_CHECK_INT_EQ_(1, RUN_ALL_TESTS());
+  CheckCounts(1);
+}
+
+// Tests the behavior of Google Test when --gtest_repeat has the given value.
+void TestRepeat(int repeat) {
+  GTEST_FLAG(repeat) = repeat;
+
+  ResetCounts();
+  GTEST_CHECK_INT_EQ_(repeat > 0 ? 1 : 0, RUN_ALL_TESTS());
+  CheckCounts(repeat);
+}
+
+// Tests using --gtest_repeat when --gtest_filter specifies an empty
+// set of tests.
+void TestRepeatWithEmptyFilter(int repeat) {
+  GTEST_FLAG(repeat) = repeat;
+  GTEST_FLAG(filter) = "None";
+
+  ResetCounts();
+  GTEST_CHECK_INT_EQ_(0, RUN_ALL_TESTS());
+  CheckCounts(0);
+}
+
+// Tests using --gtest_repeat when --gtest_filter specifies a set of
+// successful tests.
+void TestRepeatWithFilterForSuccessfulTests(int repeat) {
+  GTEST_FLAG(repeat) = repeat;
+  GTEST_FLAG(filter) = "*-*ShouldFail";
+
+  ResetCounts();
+  GTEST_CHECK_INT_EQ_(0, RUN_ALL_TESTS());
+  GTEST_CHECK_INT_EQ_(repeat, g_environment_set_up_count);
+  GTEST_CHECK_INT_EQ_(repeat, g_environment_tear_down_count);
+  GTEST_CHECK_INT_EQ_(0, g_should_fail_count);
+  GTEST_CHECK_INT_EQ_(repeat, g_should_pass_count);
+  GTEST_CHECK_INT_EQ_(repeat, g_death_test_count);
+  GTEST_CHECK_INT_EQ_(repeat * kNumberOfParamTests, g_param_test_count);
+}
+
+// Tests using --gtest_repeat when --gtest_filter specifies a set of
+// failed tests.
+void TestRepeatWithFilterForFailedTests(int repeat) {
+  GTEST_FLAG(repeat) = repeat;
+  GTEST_FLAG(filter) = "*ShouldFail";
+
+  ResetCounts();
+  GTEST_CHECK_INT_EQ_(1, RUN_ALL_TESTS());
+  GTEST_CHECK_INT_EQ_(repeat, g_environment_set_up_count);
+  GTEST_CHECK_INT_EQ_(repeat, g_environment_tear_down_count);
+  GTEST_CHECK_INT_EQ_(repeat, g_should_fail_count);
+  GTEST_CHECK_INT_EQ_(0, g_should_pass_count);
+  GTEST_CHECK_INT_EQ_(0, g_death_test_count);
+  GTEST_CHECK_INT_EQ_(0, g_param_test_count);
+}
+
+}  // namespace
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  testing::AddGlobalTestEnvironment(new MyEnvironment);
+
+  TestRepeatUnspecified();
+  TestRepeat(0);
+  TestRepeat(1);
+  TestRepeat(5);
+
+  TestRepeatWithEmptyFilter(2);
+  TestRepeatWithEmptyFilter(3);
+
+  TestRepeatWithFilterForSuccessfulTests(3);
+
+  TestRepeatWithFilterForFailedTests(4);
+
+  // It would be nice to verify that the tests indeed loop forever
+  // when GTEST_FLAG(repeat) is negative, but this test will be quite
+  // complicated to write.  Since this flag is for interactive
+  // debugging only and doesn't affect the normal test result, such a
+  // test would be an overkill.
+
+  printf("PASS\n");
+  return 0;
+}
diff --git a/3rdparty/gtest/test/gtest_skip_environment_check_output_test.py b/3rdparty/gtest/test/gtest_skip_environment_check_output_test.py
new file mode 100644
index 0000000..6e79155
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_skip_environment_check_output_test.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python
+#
+# Copyright 2019 Google LLC.  All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"""Tests Google Test's gtest skip in environment setup  behavior.
+
+This script invokes gtest_skip_in_environment_setup_test_ and verifies its
+output.
+"""
+
+import gtest_test_utils
+
+# Path to the gtest_skip_in_environment_setup_test binary
+EXE_PATH = gtest_test_utils.GetTestExecutablePath(
+    'gtest_skip_in_environment_setup_test')
+
+OUTPUT = gtest_test_utils.Subprocess([EXE_PATH]).output
+
+
+# Test.
+class SkipEntireEnvironmentTest(gtest_test_utils.TestCase):
+
+  def testSkipEntireEnvironmentTest(self):
+    self.assertIn('Skipping the entire environment', OUTPUT)
+    self.assertNotIn('FAILED', OUTPUT)
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/gtest_skip_in_environment_setup_test.cc b/3rdparty/gtest/test/gtest_skip_in_environment_setup_test.cc
new file mode 100644
index 0000000..9372310
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_skip_in_environment_setup_test.cc
@@ -0,0 +1,49 @@
+// Copyright 2019, Google LLC.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google LLC. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// This test verifies that skipping in the environment results in the
+// testcases being skipped.
+
+#include <iostream>
+#include "gtest/gtest.h"
+
+class SetupEnvironment : public testing::Environment {
+ public:
+  void SetUp() override { GTEST_SKIP() << "Skipping the entire environment"; }
+};
+
+TEST(Test, AlwaysFails) { EXPECT_EQ(true, false); }
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  testing::AddGlobalTestEnvironment(new SetupEnvironment());
+
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/gtest_skip_test.cc b/3rdparty/gtest/test/gtest_skip_test.cc
new file mode 100644
index 0000000..717e105
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_skip_test.cc
@@ -0,0 +1,55 @@
+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: arseny.aprelev@gmail.com (Arseny Aprelev)
+//
+
+#include "gtest/gtest.h"
+
+using ::testing::Test;
+
+TEST(SkipTest, DoesSkip) {
+  GTEST_SKIP();
+  EXPECT_EQ(0, 1);
+}
+
+class Fixture : public Test {
+ protected:
+  void SetUp() override {
+    GTEST_SKIP() << "skipping all tests for this fixture";
+  }
+};
+
+TEST_F(Fixture, SkipsOneTest) {
+  EXPECT_EQ(5, 7);
+}
+
+TEST_F(Fixture, SkipsAnotherTest) {
+  EXPECT_EQ(99, 100);
+}
diff --git a/3rdparty/gtest/test/gtest_sole_header_test.cc b/3rdparty/gtest/test/gtest_sole_header_test.cc
new file mode 100644
index 0000000..1d94ac6
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_sole_header_test.cc
@@ -0,0 +1,56 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// This test verifies that it's possible to use Google Test by including
+// the gtest.h header file alone.
+
+#include "gtest/gtest.h"
+
+namespace {
+
+void Subroutine() {
+  EXPECT_EQ(42, 42);
+}
+
+TEST(NoFatalFailureTest, ExpectNoFatalFailure) {
+  EXPECT_NO_FATAL_FAILURE(;);
+  EXPECT_NO_FATAL_FAILURE(SUCCEED());
+  EXPECT_NO_FATAL_FAILURE(Subroutine());
+  EXPECT_NO_FATAL_FAILURE({ SUCCEED(); });
+}
+
+TEST(NoFatalFailureTest, AssertNoFatalFailure) {
+  ASSERT_NO_FATAL_FAILURE(;);
+  ASSERT_NO_FATAL_FAILURE(SUCCEED());
+  ASSERT_NO_FATAL_FAILURE(Subroutine());
+  ASSERT_NO_FATAL_FAILURE({ SUCCEED(); });
+}
+
+}  // namespace
diff --git a/3rdparty/gtest/test/gtest_stress_test.cc b/3rdparty/gtest/test/gtest_stress_test.cc
new file mode 100644
index 0000000..8434819
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_stress_test.cc
@@ -0,0 +1,248 @@
+// Copyright 2007, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Tests that SCOPED_TRACE() and various Google Test assertions can be
+// used in a large number of threads concurrently.
+
+#include "gtest/gtest.h"
+
+#include <vector>
+
+#include "src/gtest-internal-inl.h"
+
+#if GTEST_IS_THREADSAFE
+
+namespace testing {
+namespace {
+
+using internal::Notification;
+using internal::TestPropertyKeyIs;
+using internal::ThreadWithParam;
+
+// In order to run tests in this file, for platforms where Google Test is
+// thread safe, implement ThreadWithParam. See the description of its API
+// in gtest-port.h, where it is defined for already supported platforms.
+
+// How many threads to create?
+const int kThreadCount = 50;
+
+std::string IdToKey(int id, const char* suffix) {
+  Message key;
+  key << "key_" << id << "_" << suffix;
+  return key.GetString();
+}
+
+std::string IdToString(int id) {
+  Message id_message;
+  id_message << id;
+  return id_message.GetString();
+}
+
+void ExpectKeyAndValueWereRecordedForId(
+    const std::vector<TestProperty>& properties,
+    int id, const char* suffix) {
+  TestPropertyKeyIs matches_key(IdToKey(id, suffix).c_str());
+  const std::vector<TestProperty>::const_iterator property =
+      std::find_if(properties.begin(), properties.end(), matches_key);
+  ASSERT_TRUE(property != properties.end())
+      << "expecting " << suffix << " value for id " << id;
+  EXPECT_STREQ(IdToString(id).c_str(), property->value());
+}
+
+// Calls a large number of Google Test assertions, where exactly one of them
+// will fail.
+void ManyAsserts(int id) {
+  GTEST_LOG_(INFO) << "Thread #" << id << " running...";
+
+  SCOPED_TRACE(Message() << "Thread #" << id);
+
+  for (int i = 0; i < kThreadCount; i++) {
+    SCOPED_TRACE(Message() << "Iteration #" << i);
+
+    // A bunch of assertions that should succeed.
+    EXPECT_TRUE(true);
+    ASSERT_FALSE(false) << "This shouldn't fail.";
+    EXPECT_STREQ("a", "a");
+    ASSERT_LE(5, 6);
+    EXPECT_EQ(i, i) << "This shouldn't fail.";
+
+    // RecordProperty() should interact safely with other threads as well.
+    // The shared_key forces property updates.
+    Test::RecordProperty(IdToKey(id, "string").c_str(), IdToString(id).c_str());
+    Test::RecordProperty(IdToKey(id, "int").c_str(), id);
+    Test::RecordProperty("shared_key", IdToString(id).c_str());
+
+    // This assertion should fail kThreadCount times per thread.  It
+    // is for testing whether Google Test can handle failed assertions in a
+    // multi-threaded context.
+    EXPECT_LT(i, 0) << "This should always fail.";
+  }
+}
+
+void CheckTestFailureCount(int expected_failures) {
+  const TestInfo* const info = UnitTest::GetInstance()->current_test_info();
+  const TestResult* const result = info->result();
+  GTEST_CHECK_(expected_failures == result->total_part_count())
+      << "Logged " << result->total_part_count() << " failures "
+      << " vs. " << expected_failures << " expected";
+}
+
+// Tests using SCOPED_TRACE() and Google Test assertions in many threads
+// concurrently.
+TEST(StressTest, CanUseScopedTraceAndAssertionsInManyThreads) {
+  {
+    std::unique_ptr<ThreadWithParam<int> > threads[kThreadCount];
+    Notification threads_can_start;
+    for (int i = 0; i != kThreadCount; i++)
+      threads[i].reset(new ThreadWithParam<int>(&ManyAsserts,
+                                                i,
+                                                &threads_can_start));
+
+    threads_can_start.Notify();
+
+    // Blocks until all the threads are done.
+    for (int i = 0; i != kThreadCount; i++)
+      threads[i]->Join();
+  }
+
+  // Ensures that kThreadCount*kThreadCount failures have been reported.
+  const TestInfo* const info = UnitTest::GetInstance()->current_test_info();
+  const TestResult* const result = info->result();
+
+  std::vector<TestProperty> properties;
+  // We have no access to the TestResult's list of properties but we can
+  // copy them one by one.
+  for (int i = 0; i < result->test_property_count(); ++i)
+    properties.push_back(result->GetTestProperty(i));
+
+  EXPECT_EQ(kThreadCount * 2 + 1, result->test_property_count())
+      << "String and int values recorded on each thread, "
+      << "as well as one shared_key";
+  for (int i = 0; i < kThreadCount; ++i) {
+    ExpectKeyAndValueWereRecordedForId(properties, i, "string");
+    ExpectKeyAndValueWereRecordedForId(properties, i, "int");
+  }
+  CheckTestFailureCount(kThreadCount*kThreadCount);
+}
+
+void FailingThread(bool is_fatal) {
+  if (is_fatal)
+    FAIL() << "Fatal failure in some other thread. "
+           << "(This failure is expected.)";
+  else
+    ADD_FAILURE() << "Non-fatal failure in some other thread. "
+                  << "(This failure is expected.)";
+}
+
+void GenerateFatalFailureInAnotherThread(bool is_fatal) {
+  ThreadWithParam<bool> thread(&FailingThread, is_fatal, nullptr);
+  thread.Join();
+}
+
+TEST(NoFatalFailureTest, ExpectNoFatalFailureIgnoresFailuresInOtherThreads) {
+  EXPECT_NO_FATAL_FAILURE(GenerateFatalFailureInAnotherThread(true));
+  // We should only have one failure (the one from
+  // GenerateFatalFailureInAnotherThread()), since the EXPECT_NO_FATAL_FAILURE
+  // should succeed.
+  CheckTestFailureCount(1);
+}
+
+void AssertNoFatalFailureIgnoresFailuresInOtherThreads() {
+  ASSERT_NO_FATAL_FAILURE(GenerateFatalFailureInAnotherThread(true));
+}
+TEST(NoFatalFailureTest, AssertNoFatalFailureIgnoresFailuresInOtherThreads) {
+  // Using a subroutine, to make sure, that the test continues.
+  AssertNoFatalFailureIgnoresFailuresInOtherThreads();
+  // We should only have one failure (the one from
+  // GenerateFatalFailureInAnotherThread()), since the EXPECT_NO_FATAL_FAILURE
+  // should succeed.
+  CheckTestFailureCount(1);
+}
+
+TEST(FatalFailureTest, ExpectFatalFailureIgnoresFailuresInOtherThreads) {
+  // This statement should fail, since the current thread doesn't generate a
+  // fatal failure, only another one does.
+  EXPECT_FATAL_FAILURE(GenerateFatalFailureInAnotherThread(true), "expected");
+  CheckTestFailureCount(2);
+}
+
+TEST(FatalFailureOnAllThreadsTest, ExpectFatalFailureOnAllThreads) {
+  // This statement should succeed, because failures in all threads are
+  // considered.
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(
+      GenerateFatalFailureInAnotherThread(true), "expected");
+  CheckTestFailureCount(0);
+  // We need to add a failure, because main() checks that there are failures.
+  // But when only this test is run, we shouldn't have any failures.
+  ADD_FAILURE() << "This is an expected non-fatal failure.";
+}
+
+TEST(NonFatalFailureTest, ExpectNonFatalFailureIgnoresFailuresInOtherThreads) {
+  // This statement should fail, since the current thread doesn't generate a
+  // fatal failure, only another one does.
+  EXPECT_NONFATAL_FAILURE(GenerateFatalFailureInAnotherThread(false),
+                          "expected");
+  CheckTestFailureCount(2);
+}
+
+TEST(NonFatalFailureOnAllThreadsTest, ExpectNonFatalFailureOnAllThreads) {
+  // This statement should succeed, because failures in all threads are
+  // considered.
+  EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(
+      GenerateFatalFailureInAnotherThread(false), "expected");
+  CheckTestFailureCount(0);
+  // We need to add a failure, because main() checks that there are failures,
+  // But when only this test is run, we shouldn't have any failures.
+  ADD_FAILURE() << "This is an expected non-fatal failure.";
+}
+
+}  // namespace
+}  // namespace testing
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  const int result = RUN_ALL_TESTS();  // Expected to fail.
+  GTEST_CHECK_(result == 1) << "RUN_ALL_TESTS() did not fail as expected";
+
+  printf("\nPASS\n");
+  return 0;
+}
+
+#else
+TEST(StressTest,
+     DISABLED_ThreadSafetyTestsAreSkippedWhenGoogleTestIsNotThreadSafe) {
+}
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+#endif  // GTEST_IS_THREADSAFE
diff --git a/3rdparty/gtest/test/gtest_test_macro_stack_footprint_test.cc b/3rdparty/gtest/test/gtest_test_macro_stack_footprint_test.cc
new file mode 100644
index 0000000..a48db05
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_test_macro_stack_footprint_test.cc
@@ -0,0 +1,89 @@
+// Copyright 2013, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Each TEST() expands to some static registration logic.  GCC puts all
+// such static initialization logic for a translation unit in a common,
+// internal function.  Since Google's build system restricts how much
+// stack space a function can use, there's a limit on how many TEST()s
+// one can put in a single C++ test file.  This test ensures that a large
+// number of TEST()s can be defined in the same translation unit.
+
+#include "gtest/gtest.h"
+
+// This macro defines 10 dummy tests.
+#define TEN_TESTS_(test_case_name) \
+  TEST(test_case_name, T0) {} \
+  TEST(test_case_name, T1) {} \
+  TEST(test_case_name, T2) {} \
+  TEST(test_case_name, T3) {} \
+  TEST(test_case_name, T4) {} \
+  TEST(test_case_name, T5) {} \
+  TEST(test_case_name, T6) {} \
+  TEST(test_case_name, T7) {} \
+  TEST(test_case_name, T8) {} \
+  TEST(test_case_name, T9) {}
+
+// This macro defines 100 dummy tests.
+#define HUNDRED_TESTS_(test_case_name_prefix) \
+  TEN_TESTS_(test_case_name_prefix ## 0) \
+  TEN_TESTS_(test_case_name_prefix ## 1) \
+  TEN_TESTS_(test_case_name_prefix ## 2) \
+  TEN_TESTS_(test_case_name_prefix ## 3) \
+  TEN_TESTS_(test_case_name_prefix ## 4) \
+  TEN_TESTS_(test_case_name_prefix ## 5) \
+  TEN_TESTS_(test_case_name_prefix ## 6) \
+  TEN_TESTS_(test_case_name_prefix ## 7) \
+  TEN_TESTS_(test_case_name_prefix ## 8) \
+  TEN_TESTS_(test_case_name_prefix ## 9)
+
+// This macro defines 1000 dummy tests.
+#define THOUSAND_TESTS_(test_case_name_prefix) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 0) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 1) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 2) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 3) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 4) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 5) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 6) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 7) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 8) \
+  HUNDRED_TESTS_(test_case_name_prefix ## 9)
+
+// Ensures that we can define 1000 TEST()s in the same translation
+// unit.
+THOUSAND_TESTS_(T)
+
+int main(int argc, char **argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  // We don't actually need to run the dummy tests - the purpose is to
+  // ensure that they compile.
+  return 0;
+}
diff --git a/3rdparty/gtest/test/gtest_test_utils.py b/3rdparty/gtest/test/gtest_test_utils.py
new file mode 100644
index 0000000..ef9363c
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_test_utils.py
@@ -0,0 +1,314 @@
+# Copyright 2006, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test utilities for Google C++ Testing and Mocking Framework."""
+# Suppresses the 'Import not at the top of the file' lint complaint.
+# pylint: disable-msg=C6204
+
+import os
+import sys
+
+IS_WINDOWS = os.name == 'nt'
+IS_CYGWIN = os.name == 'posix' and 'CYGWIN' in os.uname()[0]
+IS_OS2 = os.name == 'os2'
+
+import atexit
+import shutil
+import tempfile
+import unittest as _test_module
+
+try:
+  import subprocess
+  _SUBPROCESS_MODULE_AVAILABLE = True
+except:
+  import popen2
+  _SUBPROCESS_MODULE_AVAILABLE = False
+# pylint: enable-msg=C6204
+
+GTEST_OUTPUT_VAR_NAME = 'GTEST_OUTPUT'
+
+# The environment variable for specifying the path to the premature-exit file.
+PREMATURE_EXIT_FILE_ENV_VAR = 'TEST_PREMATURE_EXIT_FILE'
+
+environ = os.environ.copy()
+
+
+def SetEnvVar(env_var, value):
+  """Sets/unsets an environment variable to a given value."""
+
+  if value is not None:
+    environ[env_var] = value
+  elif env_var in environ:
+    del environ[env_var]
+
+
+# Here we expose a class from a particular module, depending on the
+# environment. The comment suppresses the 'Invalid variable name' lint
+# complaint.
+TestCase = _test_module.TestCase  # pylint: disable=C6409
+
+# Initially maps a flag to its default value. After
+# _ParseAndStripGTestFlags() is called, maps a flag to its actual value.
+_flag_map = {'source_dir': os.path.dirname(sys.argv[0]),
+             'build_dir': os.path.dirname(sys.argv[0])}
+_gtest_flags_are_parsed = False
+
+
+def _ParseAndStripGTestFlags(argv):
+  """Parses and strips Google Test flags from argv.  This is idempotent."""
+
+  # Suppresses the lint complaint about a global variable since we need it
+  # here to maintain module-wide state.
+  global _gtest_flags_are_parsed  # pylint: disable=W0603
+  if _gtest_flags_are_parsed:
+    return
+
+  _gtest_flags_are_parsed = True
+  for flag in _flag_map:
+    # The environment variable overrides the default value.
+    if flag.upper() in os.environ:
+      _flag_map[flag] = os.environ[flag.upper()]
+
+    # The command line flag overrides the environment variable.
+    i = 1  # Skips the program name.
+    while i < len(argv):
+      prefix = '--' + flag + '='
+      if argv[i].startswith(prefix):
+        _flag_map[flag] = argv[i][len(prefix):]
+        del argv[i]
+        break
+      else:
+        # We don't increment i in case we just found a --gtest_* flag
+        # and removed it from argv.
+        i += 1
+
+
+def GetFlag(flag):
+  """Returns the value of the given flag."""
+
+  # In case GetFlag() is called before Main(), we always call
+  # _ParseAndStripGTestFlags() here to make sure the --gtest_* flags
+  # are parsed.
+  _ParseAndStripGTestFlags(sys.argv)
+
+  return _flag_map[flag]
+
+
+def GetSourceDir():
+  """Returns the absolute path of the directory where the .py files are."""
+
+  return os.path.abspath(GetFlag('source_dir'))
+
+
+def GetBuildDir():
+  """Returns the absolute path of the directory where the test binaries are."""
+
+  return os.path.abspath(GetFlag('build_dir'))
+
+
+_temp_dir = None
+
+def _RemoveTempDir():
+  if _temp_dir:
+    shutil.rmtree(_temp_dir, ignore_errors=True)
+
+atexit.register(_RemoveTempDir)
+
+
+def GetTempDir():
+  global _temp_dir
+  if not _temp_dir:
+    _temp_dir = tempfile.mkdtemp()
+  return _temp_dir
+
+
+def GetTestExecutablePath(executable_name, build_dir=None):
+  """Returns the absolute path of the test binary given its name.
+
+  The function will print a message and abort the program if the resulting file
+  doesn't exist.
+
+  Args:
+    executable_name: name of the test binary that the test script runs.
+    build_dir:       directory where to look for executables, by default
+                     the result of GetBuildDir().
+
+  Returns:
+    The absolute path of the test binary.
+  """
+
+  path = os.path.abspath(os.path.join(build_dir or GetBuildDir(),
+                                      executable_name))
+  if (IS_WINDOWS or IS_CYGWIN or IS_OS2) and not path.endswith('.exe'):
+    path += '.exe'
+
+  if not os.path.exists(path):
+    message = (
+        'Unable to find the test binary "%s". Please make sure to provide\n'
+        'a path to the binary via the --build_dir flag or the BUILD_DIR\n'
+        'environment variable.' % path)
+    print >> sys.stderr, message
+    sys.exit(1)
+
+  return path
+
+
+def GetExitStatus(exit_code):
+  """Returns the argument to exit(), or -1 if exit() wasn't called.
+
+  Args:
+    exit_code: the result value of os.system(command).
+  """
+
+  if os.name == 'nt':
+    # On Windows, os.WEXITSTATUS() doesn't work and os.system() returns
+    # the argument to exit() directly.
+    return exit_code
+  else:
+    # On Unix, os.WEXITSTATUS() must be used to extract the exit status
+    # from the result of os.system().
+    if os.WIFEXITED(exit_code):
+      return os.WEXITSTATUS(exit_code)
+    else:
+      return -1
+
+
+class Subprocess:
+  def __init__(self, command, working_dir=None, capture_stderr=True, env=None):
+    """Changes into a specified directory, if provided, and executes a command.
+
+    Restores the old directory afterwards.
+
+    Args:
+      command:        The command to run, in the form of sys.argv.
+      working_dir:    The directory to change into.
+      capture_stderr: Determines whether to capture stderr in the output member
+                      or to discard it.
+      env:            Dictionary with environment to pass to the subprocess.
+
+    Returns:
+      An object that represents outcome of the executed process. It has the
+      following attributes:
+        terminated_by_signal   True if and only if the child process has been
+                               terminated by a signal.
+        signal                 Sygnal that terminated the child process.
+        exited                 True if and only if the child process exited
+                               normally.
+        exit_code              The code with which the child process exited.
+        output                 Child process's stdout and stderr output
+                               combined in a string.
+    """
+
+    # The subprocess module is the preferrable way of running programs
+    # since it is available and behaves consistently on all platforms,
+    # including Windows. But it is only available starting in python 2.4.
+    # In earlier python versions, we revert to the popen2 module, which is
+    # available in python 2.0 and later but doesn't provide required
+    # functionality (Popen4) under Windows. This allows us to support Mac
+    # OS X 10.4 Tiger, which has python 2.3 installed.
+    if _SUBPROCESS_MODULE_AVAILABLE:
+      if capture_stderr:
+        stderr = subprocess.STDOUT
+      else:
+        stderr = subprocess.PIPE
+
+      p = subprocess.Popen(command,
+                           stdout=subprocess.PIPE, stderr=stderr,
+                           cwd=working_dir, universal_newlines=True, env=env)
+      # communicate returns a tuple with the file object for the child's
+      # output.
+      self.output = p.communicate()[0]
+      self._return_code = p.returncode
+    else:
+      old_dir = os.getcwd()
+
+      def _ReplaceEnvDict(dest, src):
+        # Changes made by os.environ.clear are not inheritable by child
+        # processes until Python 2.6. To produce inheritable changes we have
+        # to delete environment items with the del statement.
+        for key in dest.keys():
+          del dest[key]
+        dest.update(src)
+
+      # When 'env' is not None, backup the environment variables and replace
+      # them with the passed 'env'. When 'env' is None, we simply use the
+      # current 'os.environ' for compatibility with the subprocess.Popen
+      # semantics used above.
+      if env is not None:
+        old_environ = os.environ.copy()
+        _ReplaceEnvDict(os.environ, env)
+
+      try:
+        if working_dir is not None:
+          os.chdir(working_dir)
+        if capture_stderr:
+          p = popen2.Popen4(command)
+        else:
+          p = popen2.Popen3(command)
+        p.tochild.close()
+        self.output = p.fromchild.read()
+        ret_code = p.wait()
+      finally:
+        os.chdir(old_dir)
+
+        # Restore the old environment variables
+        # if they were replaced.
+        if env is not None:
+          _ReplaceEnvDict(os.environ, old_environ)
+
+      # Converts ret_code to match the semantics of
+      # subprocess.Popen.returncode.
+      if os.WIFSIGNALED(ret_code):
+        self._return_code = -os.WTERMSIG(ret_code)
+      else:  # os.WIFEXITED(ret_code) should return True here.
+        self._return_code = os.WEXITSTATUS(ret_code)
+
+    if self._return_code < 0:
+      self.terminated_by_signal = True
+      self.exited = False
+      self.signal = -self._return_code
+    else:
+      self.terminated_by_signal = False
+      self.exited = True
+      self.exit_code = self._return_code
+
+
+def Main():
+  """Runs the unit test."""
+
+  # We must call _ParseAndStripGTestFlags() before calling
+  # unittest.main().  Otherwise the latter will be confused by the
+  # --gtest_* flags.
+  _ParseAndStripGTestFlags(sys.argv)
+  # The tested binaries should not be writing XML output files unless the
+  # script explicitly instructs them to.
+  if GTEST_OUTPUT_VAR_NAME in os.environ:
+    del os.environ[GTEST_OUTPUT_VAR_NAME]
+
+  _test_module.main()
diff --git a/3rdparty/gtest/test/gtest_testbridge_test.py b/3rdparty/gtest/test/gtest_testbridge_test.py
new file mode 100644
index 0000000..87ffad7
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_testbridge_test.py
@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+#
+# Copyright 2018 Google LLC. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"""Verifies that Google Test uses filter provided via testbridge."""
+
+import os
+
+import gtest_test_utils
+
+binary_name = 'gtest_testbridge_test_'
+COMMAND = gtest_test_utils.GetTestExecutablePath(binary_name)
+TESTBRIDGE_NAME = 'TESTBRIDGE_TEST_ONLY'
+
+
+def Assert(condition):
+  if not condition:
+    raise AssertionError
+
+
+class GTestTestFilterTest(gtest_test_utils.TestCase):
+
+  def testTestExecutionIsFiltered(self):
+    """Tests that the test filter is picked up from the testbridge env var."""
+    subprocess_env = os.environ.copy()
+
+    subprocess_env[TESTBRIDGE_NAME] = '*.TestThatSucceeds'
+    p = gtest_test_utils.Subprocess(COMMAND, env=subprocess_env)
+
+    self.assertEquals(0, p.exit_code)
+
+    Assert('filter = *.TestThatSucceeds' in p.output)
+    Assert('[       OK ] TestFilterTest.TestThatSucceeds' in p.output)
+    Assert('[  PASSED  ] 1 test.' in p.output)
+
+
+if __name__ == '__main__':
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/gtest_testbridge_test_.cc b/3rdparty/gtest/test/gtest_testbridge_test_.cc
new file mode 100644
index 0000000..24617b2
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_testbridge_test_.cc
@@ -0,0 +1,43 @@
+// Copyright 2018, Google LLC.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// This program is meant to be run by gtest_test_filter_test.py.  Do not run
+// it directly.
+
+#include "gtest/gtest.h"
+
+// These tests are used to detect if filtering is working. Only
+// 'TestThatSucceeds' should ever run.
+
+TEST(TestFilterTest, TestThatSucceeds) {}
+
+TEST(TestFilterTest, TestThatFails) {
+  ASSERT_TRUE(false) << "This test should never be run.";
+}
diff --git a/3rdparty/gtest/test/gtest_throw_on_failure_ex_test.cc b/3rdparty/gtest/test/gtest_throw_on_failure_ex_test.cc
new file mode 100644
index 0000000..1d95adb
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_throw_on_failure_ex_test.cc
@@ -0,0 +1,90 @@
+// Copyright 2009, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+// Tests Google Test's throw-on-failure mode with exceptions enabled.
+
+#include "gtest/gtest.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdexcept>
+
+// Prints the given failure message and exits the program with
+// non-zero.  We use this instead of a Google Test assertion to
+// indicate a failure, as the latter is been tested and cannot be
+// relied on.
+void Fail(const char* msg) {
+  printf("FAILURE: %s\n", msg);
+  fflush(stdout);
+  exit(1);
+}
+
+// Tests that an assertion failure throws a subclass of
+// std::runtime_error.
+void TestFailureThrowsRuntimeError() {
+  testing::GTEST_FLAG(throw_on_failure) = true;
+
+  // A successful assertion shouldn't throw.
+  try {
+    EXPECT_EQ(3, 3);
+  } catch(...) {
+    Fail("A successful assertion wrongfully threw.");
+  }
+
+  // A failed assertion should throw a subclass of std::runtime_error.
+  try {
+    EXPECT_EQ(2, 3) << "Expected failure";
+  } catch(const std::runtime_error& e) {
+    if (strstr(e.what(), "Expected failure") != nullptr) return;
+
+    printf("%s",
+           "A failed assertion did throw an exception of the right type, "
+           "but the message is incorrect.  Instead of containing \"Expected "
+           "failure\", it is:\n");
+    Fail(e.what());
+  } catch(...) {
+    Fail("A failed assertion threw the wrong type of exception.");
+  }
+  Fail("A failed assertion should've thrown but didn't.");
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+
+  // We want to ensure that people can use Google Test assertions in
+  // other testing frameworks, as long as they initialize Google Test
+  // properly and set the thrown-on-failure mode.  Therefore, we don't
+  // use Google Test's constructs for defining and running tests
+  // (e.g. TEST and RUN_ALL_TESTS) here.
+
+  TestFailureThrowsRuntimeError();
+  return 0;
+}
diff --git a/3rdparty/gtest/test/gtest_unittest.cc b/3rdparty/gtest/test/gtest_unittest.cc
new file mode 100644
index 0000000..39749b7
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_unittest.cc
@@ -0,0 +1,7488 @@
+// Copyright 2005, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// Tests for Google Test itself.  This verifies that the basic constructs of
+// Google Test work.
+
+#include "gtest/gtest.h"
+
+// Verifies that the command line flag variables can be accessed in
+// code once "gtest.h" has been #included.
+// Do not move it after other gtest #includes.
+TEST(CommandLineFlagsTest, CanBeAccessedInCodeOnceGTestHIsIncluded) {
+  bool dummy = testing::GTEST_FLAG(also_run_disabled_tests)
+      || testing::GTEST_FLAG(break_on_failure)
+      || testing::GTEST_FLAG(catch_exceptions)
+      || testing::GTEST_FLAG(color) != "unknown"
+      || testing::GTEST_FLAG(filter) != "unknown"
+      || testing::GTEST_FLAG(list_tests)
+      || testing::GTEST_FLAG(output) != "unknown"
+      || testing::GTEST_FLAG(print_time)
+      || testing::GTEST_FLAG(random_seed)
+      || testing::GTEST_FLAG(repeat) > 0
+      || testing::GTEST_FLAG(show_internal_stack_frames)
+      || testing::GTEST_FLAG(shuffle)
+      || testing::GTEST_FLAG(stack_trace_depth) > 0
+      || testing::GTEST_FLAG(stream_result_to) != "unknown"
+      || testing::GTEST_FLAG(throw_on_failure);
+  EXPECT_TRUE(dummy || !dummy);  // Suppresses warning that dummy is unused.
+}
+
+#include <limits.h>  // For INT_MAX.
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include <map>
+#include <ostream>
+#include <type_traits>
+#include <unordered_set>
+#include <vector>
+
+#include "gtest/gtest-spi.h"
+#include "src/gtest-internal-inl.h"
+
+namespace testing {
+namespace internal {
+
+#if GTEST_CAN_STREAM_RESULTS_
+
+class StreamingListenerTest : public Test {
+ public:
+  class FakeSocketWriter : public StreamingListener::AbstractSocketWriter {
+   public:
+    // Sends a string to the socket.
+    void Send(const std::string& message) override { output_ += message; }
+
+    std::string output_;
+  };
+
+  StreamingListenerTest()
+      : fake_sock_writer_(new FakeSocketWriter),
+        streamer_(fake_sock_writer_),
+        test_info_obj_("FooTest", "Bar", nullptr, nullptr,
+                       CodeLocation(__FILE__, __LINE__), nullptr, nullptr) {}
+
+ protected:
+  std::string* output() { return &(fake_sock_writer_->output_); }
+
+  FakeSocketWriter* const fake_sock_writer_;
+  StreamingListener streamer_;
+  UnitTest unit_test_;
+  TestInfo test_info_obj_;  // The name test_info_ was taken by testing::Test.
+};
+
+TEST_F(StreamingListenerTest, OnTestProgramEnd) {
+  *output() = "";
+  streamer_.OnTestProgramEnd(unit_test_);
+  EXPECT_EQ("event=TestProgramEnd&passed=1\n", *output());
+}
+
+TEST_F(StreamingListenerTest, OnTestIterationEnd) {
+  *output() = "";
+  streamer_.OnTestIterationEnd(unit_test_, 42);
+  EXPECT_EQ("event=TestIterationEnd&passed=1&elapsed_time=0ms\n", *output());
+}
+
+TEST_F(StreamingListenerTest, OnTestCaseStart) {
+  *output() = "";
+  streamer_.OnTestCaseStart(TestCase("FooTest", "Bar", nullptr, nullptr));
+  EXPECT_EQ("event=TestCaseStart&name=FooTest\n", *output());
+}
+
+TEST_F(StreamingListenerTest, OnTestCaseEnd) {
+  *output() = "";
+  streamer_.OnTestCaseEnd(TestCase("FooTest", "Bar", nullptr, nullptr));
+  EXPECT_EQ("event=TestCaseEnd&passed=1&elapsed_time=0ms\n", *output());
+}
+
+TEST_F(StreamingListenerTest, OnTestStart) {
+  *output() = "";
+  streamer_.OnTestStart(test_info_obj_);
+  EXPECT_EQ("event=TestStart&name=Bar\n", *output());
+}
+
+TEST_F(StreamingListenerTest, OnTestEnd) {
+  *output() = "";
+  streamer_.OnTestEnd(test_info_obj_);
+  EXPECT_EQ("event=TestEnd&passed=1&elapsed_time=0ms\n", *output());
+}
+
+TEST_F(StreamingListenerTest, OnTestPartResult) {
+  *output() = "";
+  streamer_.OnTestPartResult(TestPartResult(
+      TestPartResult::kFatalFailure, "foo.cc", 42, "failed=\n&%"));
+
+  // Meta characters in the failure message should be properly escaped.
+  EXPECT_EQ(
+      "event=TestPartResult&file=foo.cc&line=42&message=failed%3D%0A%26%25\n",
+      *output());
+}
+
+#endif  // GTEST_CAN_STREAM_RESULTS_
+
+// Provides access to otherwise private parts of the TestEventListeners class
+// that are needed to test it.
+class TestEventListenersAccessor {
+ public:
+  static TestEventListener* GetRepeater(TestEventListeners* listeners) {
+    return listeners->repeater();
+  }
+
+  static void SetDefaultResultPrinter(TestEventListeners* listeners,
+                                      TestEventListener* listener) {
+    listeners->SetDefaultResultPrinter(listener);
+  }
+  static void SetDefaultXmlGenerator(TestEventListeners* listeners,
+                                     TestEventListener* listener) {
+    listeners->SetDefaultXmlGenerator(listener);
+  }
+
+  static bool EventForwardingEnabled(const TestEventListeners& listeners) {
+    return listeners.EventForwardingEnabled();
+  }
+
+  static void SuppressEventForwarding(TestEventListeners* listeners) {
+    listeners->SuppressEventForwarding();
+  }
+};
+
+class UnitTestRecordPropertyTestHelper : public Test {
+ protected:
+  UnitTestRecordPropertyTestHelper() {}
+
+  // Forwards to UnitTest::RecordProperty() to bypass access controls.
+  void UnitTestRecordProperty(const char* key, const std::string& value) {
+    unit_test_.RecordProperty(key, value);
+  }
+
+  UnitTest unit_test_;
+};
+
+}  // namespace internal
+}  // namespace testing
+
+using testing::AssertionFailure;
+using testing::AssertionResult;
+using testing::AssertionSuccess;
+using testing::DoubleLE;
+using testing::EmptyTestEventListener;
+using testing::Environment;
+using testing::FloatLE;
+using testing::GTEST_FLAG(also_run_disabled_tests);
+using testing::GTEST_FLAG(break_on_failure);
+using testing::GTEST_FLAG(catch_exceptions);
+using testing::GTEST_FLAG(color);
+using testing::GTEST_FLAG(death_test_use_fork);
+using testing::GTEST_FLAG(filter);
+using testing::GTEST_FLAG(list_tests);
+using testing::GTEST_FLAG(output);
+using testing::GTEST_FLAG(print_time);
+using testing::GTEST_FLAG(random_seed);
+using testing::GTEST_FLAG(repeat);
+using testing::GTEST_FLAG(show_internal_stack_frames);
+using testing::GTEST_FLAG(shuffle);
+using testing::GTEST_FLAG(stack_trace_depth);
+using testing::GTEST_FLAG(stream_result_to);
+using testing::GTEST_FLAG(throw_on_failure);
+using testing::IsNotSubstring;
+using testing::IsSubstring;
+using testing::Message;
+using testing::ScopedFakeTestPartResultReporter;
+using testing::StaticAssertTypeEq;
+using testing::Test;
+using testing::TestCase;
+using testing::TestEventListeners;
+using testing::TestInfo;
+using testing::TestPartResult;
+using testing::TestPartResultArray;
+using testing::TestProperty;
+using testing::TestResult;
+using testing::TimeInMillis;
+using testing::UnitTest;
+using testing::internal::AlwaysFalse;
+using testing::internal::AlwaysTrue;
+using testing::internal::AppendUserMessage;
+using testing::internal::ArrayAwareFind;
+using testing::internal::ArrayEq;
+using testing::internal::CodePointToUtf8;
+using testing::internal::CopyArray;
+using testing::internal::CountIf;
+using testing::internal::EqFailure;
+using testing::internal::FloatingPoint;
+using testing::internal::ForEach;
+using testing::internal::FormatEpochTimeInMillisAsIso8601;
+using testing::internal::FormatTimeInMillisAsSeconds;
+using testing::internal::GTestFlagSaver;
+using testing::internal::GetCurrentOsStackTraceExceptTop;
+using testing::internal::GetElementOr;
+using testing::internal::GetNextRandomSeed;
+using testing::internal::GetRandomSeedFromFlag;
+using testing::internal::GetTestTypeId;
+using testing::internal::GetTimeInMillis;
+using testing::internal::GetTypeId;
+using testing::internal::GetUnitTestImpl;
+using testing::internal::Int32;
+using testing::internal::Int32FromEnvOrDie;
+using testing::internal::IsAProtocolMessage;
+using testing::internal::IsContainer;
+using testing::internal::IsContainerTest;
+using testing::internal::IsNotContainer;
+using testing::internal::NativeArray;
+using testing::internal::OsStackTraceGetter;
+using testing::internal::OsStackTraceGetterInterface;
+using testing::internal::ParseInt32Flag;
+using testing::internal::RelationToSourceCopy;
+using testing::internal::RelationToSourceReference;
+using testing::internal::ShouldRunTestOnShard;
+using testing::internal::ShouldShard;
+using testing::internal::ShouldUseColor;
+using testing::internal::Shuffle;
+using testing::internal::ShuffleRange;
+using testing::internal::SkipPrefix;
+using testing::internal::StreamableToString;
+using testing::internal::String;
+using testing::internal::TestEventListenersAccessor;
+using testing::internal::TestResultAccessor;
+using testing::internal::UInt32;
+using testing::internal::UnitTestImpl;
+using testing::internal::WideStringToUtf8;
+using testing::internal::edit_distance::CalculateOptimalEdits;
+using testing::internal::edit_distance::CreateUnifiedDiff;
+using testing::internal::edit_distance::EditType;
+using testing::internal::kMaxRandomSeed;
+using testing::internal::kTestTypeIdInGoogleTest;
+using testing::kMaxStackTraceDepth;
+
+#if GTEST_HAS_STREAM_REDIRECTION
+using testing::internal::CaptureStdout;
+using testing::internal::GetCapturedStdout;
+#endif
+
+#if GTEST_IS_THREADSAFE
+using testing::internal::ThreadWithParam;
+#endif
+
+class TestingVector : public std::vector<int> {
+};
+
+::std::ostream& operator<<(::std::ostream& os,
+                           const TestingVector& vector) {
+  os << "{ ";
+  for (size_t i = 0; i < vector.size(); i++) {
+    os << vector[i] << " ";
+  }
+  os << "}";
+  return os;
+}
+
+// This line tests that we can define tests in an unnamed namespace.
+namespace {
+
+TEST(GetRandomSeedFromFlagTest, HandlesZero) {
+  const int seed = GetRandomSeedFromFlag(0);
+  EXPECT_LE(1, seed);
+  EXPECT_LE(seed, static_cast<int>(kMaxRandomSeed));
+}
+
+TEST(GetRandomSeedFromFlagTest, PreservesValidSeed) {
+  EXPECT_EQ(1, GetRandomSeedFromFlag(1));
+  EXPECT_EQ(2, GetRandomSeedFromFlag(2));
+  EXPECT_EQ(kMaxRandomSeed - 1, GetRandomSeedFromFlag(kMaxRandomSeed - 1));
+  EXPECT_EQ(static_cast<int>(kMaxRandomSeed),
+            GetRandomSeedFromFlag(kMaxRandomSeed));
+}
+
+TEST(GetRandomSeedFromFlagTest, NormalizesInvalidSeed) {
+  const int seed1 = GetRandomSeedFromFlag(-1);
+  EXPECT_LE(1, seed1);
+  EXPECT_LE(seed1, static_cast<int>(kMaxRandomSeed));
+
+  const int seed2 = GetRandomSeedFromFlag(kMaxRandomSeed + 1);
+  EXPECT_LE(1, seed2);
+  EXPECT_LE(seed2, static_cast<int>(kMaxRandomSeed));
+}
+
+TEST(GetNextRandomSeedTest, WorksForValidInput) {
+  EXPECT_EQ(2, GetNextRandomSeed(1));
+  EXPECT_EQ(3, GetNextRandomSeed(2));
+  EXPECT_EQ(static_cast<int>(kMaxRandomSeed),
+            GetNextRandomSeed(kMaxRandomSeed - 1));
+  EXPECT_EQ(1, GetNextRandomSeed(kMaxRandomSeed));
+
+  // We deliberately don't test GetNextRandomSeed() with invalid
+  // inputs, as that requires death tests, which are expensive.  This
+  // is fine as GetNextRandomSeed() is internal and has a
+  // straightforward definition.
+}
+
+static void ClearCurrentTestPartResults() {
+  TestResultAccessor::ClearTestPartResults(
+      GetUnitTestImpl()->current_test_result());
+}
+
+// Tests GetTypeId.
+
+TEST(GetTypeIdTest, ReturnsSameValueForSameType) {
+  EXPECT_EQ(GetTypeId<int>(), GetTypeId<int>());
+  EXPECT_EQ(GetTypeId<Test>(), GetTypeId<Test>());
+}
+
+class SubClassOfTest : public Test {};
+class AnotherSubClassOfTest : public Test {};
+
+TEST(GetTypeIdTest, ReturnsDifferentValuesForDifferentTypes) {
+  EXPECT_NE(GetTypeId<int>(), GetTypeId<const int>());
+  EXPECT_NE(GetTypeId<int>(), GetTypeId<char>());
+  EXPECT_NE(GetTypeId<int>(), GetTestTypeId());
+  EXPECT_NE(GetTypeId<SubClassOfTest>(), GetTestTypeId());
+  EXPECT_NE(GetTypeId<AnotherSubClassOfTest>(), GetTestTypeId());
+  EXPECT_NE(GetTypeId<AnotherSubClassOfTest>(), GetTypeId<SubClassOfTest>());
+}
+
+// Verifies that GetTestTypeId() returns the same value, no matter it
+// is called from inside Google Test or outside of it.
+TEST(GetTestTypeIdTest, ReturnsTheSameValueInsideOrOutsideOfGoogleTest) {
+  EXPECT_EQ(kTestTypeIdInGoogleTest, GetTestTypeId());
+}
+
+// Tests CanonicalizeForStdLibVersioning.
+
+using ::testing::internal::CanonicalizeForStdLibVersioning;
+
+TEST(CanonicalizeForStdLibVersioning, LeavesUnversionedNamesUnchanged) {
+  EXPECT_EQ("std::bind", CanonicalizeForStdLibVersioning("std::bind"));
+  EXPECT_EQ("std::_", CanonicalizeForStdLibVersioning("std::_"));
+  EXPECT_EQ("std::__foo", CanonicalizeForStdLibVersioning("std::__foo"));
+  EXPECT_EQ("gtl::__1::x", CanonicalizeForStdLibVersioning("gtl::__1::x"));
+  EXPECT_EQ("__1::x", CanonicalizeForStdLibVersioning("__1::x"));
+  EXPECT_EQ("::__1::x", CanonicalizeForStdLibVersioning("::__1::x"));
+}
+
+TEST(CanonicalizeForStdLibVersioning, ElidesDoubleUnderNames) {
+  EXPECT_EQ("std::bind", CanonicalizeForStdLibVersioning("std::__1::bind"));
+  EXPECT_EQ("std::_", CanonicalizeForStdLibVersioning("std::__1::_"));
+
+  EXPECT_EQ("std::bind", CanonicalizeForStdLibVersioning("std::__g::bind"));
+  EXPECT_EQ("std::_", CanonicalizeForStdLibVersioning("std::__g::_"));
+
+  EXPECT_EQ("std::bind",
+            CanonicalizeForStdLibVersioning("std::__google::bind"));
+  EXPECT_EQ("std::_", CanonicalizeForStdLibVersioning("std::__google::_"));
+}
+
+// Tests FormatTimeInMillisAsSeconds().
+
+TEST(FormatTimeInMillisAsSecondsTest, FormatsZero) {
+  EXPECT_EQ("0", FormatTimeInMillisAsSeconds(0));
+}
+
+TEST(FormatTimeInMillisAsSecondsTest, FormatsPositiveNumber) {
+  EXPECT_EQ("0.003", FormatTimeInMillisAsSeconds(3));
+  EXPECT_EQ("0.01", FormatTimeInMillisAsSeconds(10));
+  EXPECT_EQ("0.2", FormatTimeInMillisAsSeconds(200));
+  EXPECT_EQ("1.2", FormatTimeInMillisAsSeconds(1200));
+  EXPECT_EQ("3", FormatTimeInMillisAsSeconds(3000));
+}
+
+TEST(FormatTimeInMillisAsSecondsTest, FormatsNegativeNumber) {
+  EXPECT_EQ("-0.003", FormatTimeInMillisAsSeconds(-3));
+  EXPECT_EQ("-0.01", FormatTimeInMillisAsSeconds(-10));
+  EXPECT_EQ("-0.2", FormatTimeInMillisAsSeconds(-200));
+  EXPECT_EQ("-1.2", FormatTimeInMillisAsSeconds(-1200));
+  EXPECT_EQ("-3", FormatTimeInMillisAsSeconds(-3000));
+}
+
+// Tests FormatEpochTimeInMillisAsIso8601().  The correctness of conversion
+// for particular dates below was verified in Python using
+// datetime.datetime.fromutctimestamp(<timetamp>/1000).
+
+// FormatEpochTimeInMillisAsIso8601 depends on the current timezone, so we
+// have to set up a particular timezone to obtain predictable results.
+class FormatEpochTimeInMillisAsIso8601Test : public Test {
+ public:
+  // On Cygwin, GCC doesn't allow unqualified integer literals to exceed
+  // 32 bits, even when 64-bit integer types are available.  We have to
+  // force the constants to have a 64-bit type here.
+  static const TimeInMillis kMillisPerSec = 1000;
+
+ private:
+  void SetUp() override {
+    saved_tz_ = nullptr;
+
+    GTEST_DISABLE_MSC_DEPRECATED_PUSH_(/* getenv, strdup: deprecated */)
+    if (getenv("TZ"))
+      saved_tz_ = strdup(getenv("TZ"));
+    GTEST_DISABLE_MSC_DEPRECATED_POP_()
+
+    // Set up the time zone for FormatEpochTimeInMillisAsIso8601 to use.  We
+    // cannot use the local time zone because the function's output depends
+    // on the time zone.
+    SetTimeZone("UTC+00");
+  }
+
+  void TearDown() override {
+    SetTimeZone(saved_tz_);
+    free(const_cast<char*>(saved_tz_));
+    saved_tz_ = nullptr;
+  }
+
+  static void SetTimeZone(const char* time_zone) {
+    // tzset() distinguishes between the TZ variable being present and empty
+    // and not being present, so we have to consider the case of time_zone
+    // being NULL.
+#if _MSC_VER || GTEST_OS_WINDOWS_MINGW
+    // ...Unless it's MSVC, whose standard library's _putenv doesn't
+    // distinguish between an empty and a missing variable.
+    const std::string env_var =
+        std::string("TZ=") + (time_zone ? time_zone : "");
+    _putenv(env_var.c_str());
+    GTEST_DISABLE_MSC_WARNINGS_PUSH_(4996 /* deprecated function */)
+    tzset();
+    GTEST_DISABLE_MSC_WARNINGS_POP_()
+#else
+    if (time_zone) {
+      setenv(("TZ"), time_zone, 1);
+    } else {
+      unsetenv("TZ");
+    }
+    tzset();
+#endif
+  }
+
+  const char* saved_tz_;
+};
+
+const TimeInMillis FormatEpochTimeInMillisAsIso8601Test::kMillisPerSec;
+
+TEST_F(FormatEpochTimeInMillisAsIso8601Test, PrintsTwoDigitSegments) {
+  EXPECT_EQ("2011-10-31T18:52:42",
+            FormatEpochTimeInMillisAsIso8601(1320087162 * kMillisPerSec));
+}
+
+TEST_F(FormatEpochTimeInMillisAsIso8601Test, MillisecondsDoNotAffectResult) {
+  EXPECT_EQ(
+      "2011-10-31T18:52:42",
+      FormatEpochTimeInMillisAsIso8601(1320087162 * kMillisPerSec + 234));
+}
+
+TEST_F(FormatEpochTimeInMillisAsIso8601Test, PrintsLeadingZeroes) {
+  EXPECT_EQ("2011-09-03T05:07:02",
+            FormatEpochTimeInMillisAsIso8601(1315026422 * kMillisPerSec));
+}
+
+TEST_F(FormatEpochTimeInMillisAsIso8601Test, Prints24HourTime) {
+  EXPECT_EQ("2011-09-28T17:08:22",
+            FormatEpochTimeInMillisAsIso8601(1317229702 * kMillisPerSec));
+}
+
+TEST_F(FormatEpochTimeInMillisAsIso8601Test, PrintsEpochStart) {
+  EXPECT_EQ("1970-01-01T00:00:00", FormatEpochTimeInMillisAsIso8601(0));
+}
+
+# ifdef __BORLANDC__
+// Silences warnings: "Condition is always true", "Unreachable code"
+#  pragma option push -w-ccc -w-rch
+# endif
+
+// Tests that the LHS of EXPECT_EQ or ASSERT_EQ can be used as a null literal
+// when the RHS is a pointer type.
+TEST(NullLiteralTest, LHSAllowsNullLiterals) {
+  EXPECT_EQ(0, static_cast<void*>(nullptr));     // NOLINT
+  ASSERT_EQ(0, static_cast<void*>(nullptr));     // NOLINT
+  EXPECT_EQ(NULL, static_cast<void*>(nullptr));  // NOLINT
+  ASSERT_EQ(NULL, static_cast<void*>(nullptr));  // NOLINT
+  EXPECT_EQ(nullptr, static_cast<void*>(nullptr));
+  ASSERT_EQ(nullptr, static_cast<void*>(nullptr));
+
+  const int* const p = nullptr;
+  EXPECT_EQ(0, p);     // NOLINT
+  ASSERT_EQ(0, p);     // NOLINT
+  EXPECT_EQ(NULL, p);  // NOLINT
+  ASSERT_EQ(NULL, p);  // NOLINT
+  EXPECT_EQ(nullptr, p);
+  ASSERT_EQ(nullptr, p);
+}
+
+struct ConvertToAll {
+  template <typename T>
+  operator T() const {  // NOLINT
+    return T();
+  }
+};
+
+struct ConvertToPointer {
+  template <class T>
+  operator T*() const {  // NOLINT
+    return nullptr;
+  }
+};
+
+struct ConvertToAllButNoPointers {
+  template <typename T,
+            typename std::enable_if<!std::is_pointer<T>::value, int>::type = 0>
+  operator T() const {  // NOLINT
+    return T();
+  }
+};
+
+struct MyType {};
+inline bool operator==(MyType const&, MyType const&) { return true; }
+
+TEST(NullLiteralTest, ImplicitConversion) {
+  EXPECT_EQ(ConvertToPointer{}, static_cast<void*>(nullptr));
+#if !defined(__GNUC__) || defined(__clang__)
+  // Disabled due to GCC bug gcc.gnu.org/PR89580
+  EXPECT_EQ(ConvertToAll{}, static_cast<void*>(nullptr));
+#endif
+  EXPECT_EQ(ConvertToAll{}, MyType{});
+  EXPECT_EQ(ConvertToAllButNoPointers{}, MyType{});
+}
+
+#ifdef __clang__
+#pragma clang diagnostic push
+#if __has_warning("-Wzero-as-null-pointer-constant")
+#pragma clang diagnostic error "-Wzero-as-null-pointer-constant"
+#endif
+#endif
+
+TEST(NullLiteralTest, NoConversionNoWarning) {
+  // Test that gtests detection and handling of null pointer constants
+  // doesn't trigger a warning when '0' isn't actually used as null.
+  EXPECT_EQ(0, 0);
+  ASSERT_EQ(0, 0);
+}
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+
+# ifdef __BORLANDC__
+// Restores warnings after previous "#pragma option push" suppressed them.
+#  pragma option pop
+# endif
+
+//
+// Tests CodePointToUtf8().
+
+// Tests that the NUL character L'\0' is encoded correctly.
+TEST(CodePointToUtf8Test, CanEncodeNul) {
+  EXPECT_EQ("", CodePointToUtf8(L'\0'));
+}
+
+// Tests that ASCII characters are encoded correctly.
+TEST(CodePointToUtf8Test, CanEncodeAscii) {
+  EXPECT_EQ("a", CodePointToUtf8(L'a'));
+  EXPECT_EQ("Z", CodePointToUtf8(L'Z'));
+  EXPECT_EQ("&", CodePointToUtf8(L'&'));
+  EXPECT_EQ("\x7F", CodePointToUtf8(L'\x7F'));
+}
+
+// Tests that Unicode code-points that have 8 to 11 bits are encoded
+// as 110xxxxx 10xxxxxx.
+TEST(CodePointToUtf8Test, CanEncode8To11Bits) {
+  // 000 1101 0011 => 110-00011 10-010011
+  EXPECT_EQ("\xC3\x93", CodePointToUtf8(L'\xD3'));
+
+  // 101 0111 0110 => 110-10101 10-110110
+  // Some compilers (e.g., GCC on MinGW) cannot handle non-ASCII codepoints
+  // in wide strings and wide chars. In order to accommodate them, we have to
+  // introduce such character constants as integers.
+  EXPECT_EQ("\xD5\xB6",
+            CodePointToUtf8(static_cast<wchar_t>(0x576)));
+}
+
+// Tests that Unicode code-points that have 12 to 16 bits are encoded
+// as 1110xxxx 10xxxxxx 10xxxxxx.
+TEST(CodePointToUtf8Test, CanEncode12To16Bits) {
+  // 0000 1000 1101 0011 => 1110-0000 10-100011 10-010011
+  EXPECT_EQ("\xE0\xA3\x93",
+            CodePointToUtf8(static_cast<wchar_t>(0x8D3)));
+
+  // 1100 0111 0100 1101 => 1110-1100 10-011101 10-001101
+  EXPECT_EQ("\xEC\x9D\x8D",
+            CodePointToUtf8(static_cast<wchar_t>(0xC74D)));
+}
+
+#if !GTEST_WIDE_STRING_USES_UTF16_
+// Tests in this group require a wchar_t to hold > 16 bits, and thus
+// are skipped on Windows, and Cygwin, where a wchar_t is
+// 16-bit wide. This code may not compile on those systems.
+
+// Tests that Unicode code-points that have 17 to 21 bits are encoded
+// as 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx.
+TEST(CodePointToUtf8Test, CanEncode17To21Bits) {
+  // 0 0001 0000 1000 1101 0011 => 11110-000 10-010000 10-100011 10-010011
+  EXPECT_EQ("\xF0\x90\xA3\x93", CodePointToUtf8(L'\x108D3'));
+
+  // 0 0001 0000 0100 0000 0000 => 11110-000 10-010000 10-010000 10-000000
+  EXPECT_EQ("\xF0\x90\x90\x80", CodePointToUtf8(L'\x10400'));
+
+  // 1 0000 1000 0110 0011 0100 => 11110-100 10-001000 10-011000 10-110100
+  EXPECT_EQ("\xF4\x88\x98\xB4", CodePointToUtf8(L'\x108634'));
+}
+
+// Tests that encoding an invalid code-point generates the expected result.
+TEST(CodePointToUtf8Test, CanEncodeInvalidCodePoint) {
+  EXPECT_EQ("(Invalid Unicode 0x1234ABCD)", CodePointToUtf8(L'\x1234ABCD'));
+}
+
+#endif  // !GTEST_WIDE_STRING_USES_UTF16_
+
+// Tests WideStringToUtf8().
+
+// Tests that the NUL character L'\0' is encoded correctly.
+TEST(WideStringToUtf8Test, CanEncodeNul) {
+  EXPECT_STREQ("", WideStringToUtf8(L"", 0).c_str());
+  EXPECT_STREQ("", WideStringToUtf8(L"", -1).c_str());
+}
+
+// Tests that ASCII strings are encoded correctly.
+TEST(WideStringToUtf8Test, CanEncodeAscii) {
+  EXPECT_STREQ("a", WideStringToUtf8(L"a", 1).c_str());
+  EXPECT_STREQ("ab", WideStringToUtf8(L"ab", 2).c_str());
+  EXPECT_STREQ("a", WideStringToUtf8(L"a", -1).c_str());
+  EXPECT_STREQ("ab", WideStringToUtf8(L"ab", -1).c_str());
+}
+
+// Tests that Unicode code-points that have 8 to 11 bits are encoded
+// as 110xxxxx 10xxxxxx.
+TEST(WideStringToUtf8Test, CanEncode8To11Bits) {
+  // 000 1101 0011 => 110-00011 10-010011
+  EXPECT_STREQ("\xC3\x93", WideStringToUtf8(L"\xD3", 1).c_str());
+  EXPECT_STREQ("\xC3\x93", WideStringToUtf8(L"\xD3", -1).c_str());
+
+  // 101 0111 0110 => 110-10101 10-110110
+  const wchar_t s[] = { 0x576, '\0' };
+  EXPECT_STREQ("\xD5\xB6", WideStringToUtf8(s, 1).c_str());
+  EXPECT_STREQ("\xD5\xB6", WideStringToUtf8(s, -1).c_str());
+}
+
+// Tests that Unicode code-points that have 12 to 16 bits are encoded
+// as 1110xxxx 10xxxxxx 10xxxxxx.
+TEST(WideStringToUtf8Test, CanEncode12To16Bits) {
+  // 0000 1000 1101 0011 => 1110-0000 10-100011 10-010011
+  const wchar_t s1[] = { 0x8D3, '\0' };
+  EXPECT_STREQ("\xE0\xA3\x93", WideStringToUtf8(s1, 1).c_str());
+  EXPECT_STREQ("\xE0\xA3\x93", WideStringToUtf8(s1, -1).c_str());
+
+  // 1100 0111 0100 1101 => 1110-1100 10-011101 10-001101
+  const wchar_t s2[] = { 0xC74D, '\0' };
+  EXPECT_STREQ("\xEC\x9D\x8D", WideStringToUtf8(s2, 1).c_str());
+  EXPECT_STREQ("\xEC\x9D\x8D", WideStringToUtf8(s2, -1).c_str());
+}
+
+// Tests that the conversion stops when the function encounters \0 character.
+TEST(WideStringToUtf8Test, StopsOnNulCharacter) {
+  EXPECT_STREQ("ABC", WideStringToUtf8(L"ABC\0XYZ", 100).c_str());
+}
+
+// Tests that the conversion stops when the function reaches the limit
+// specified by the 'length' parameter.
+TEST(WideStringToUtf8Test, StopsWhenLengthLimitReached) {
+  EXPECT_STREQ("ABC", WideStringToUtf8(L"ABCDEF", 3).c_str());
+}
+
+#if !GTEST_WIDE_STRING_USES_UTF16_
+// Tests that Unicode code-points that have 17 to 21 bits are encoded
+// as 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx. This code may not compile
+// on the systems using UTF-16 encoding.
+TEST(WideStringToUtf8Test, CanEncode17To21Bits) {
+  // 0 0001 0000 1000 1101 0011 => 11110-000 10-010000 10-100011 10-010011
+  EXPECT_STREQ("\xF0\x90\xA3\x93", WideStringToUtf8(L"\x108D3", 1).c_str());
+  EXPECT_STREQ("\xF0\x90\xA3\x93", WideStringToUtf8(L"\x108D3", -1).c_str());
+
+  // 1 0000 1000 0110 0011 0100 => 11110-100 10-001000 10-011000 10-110100
+  EXPECT_STREQ("\xF4\x88\x98\xB4", WideStringToUtf8(L"\x108634", 1).c_str());
+  EXPECT_STREQ("\xF4\x88\x98\xB4", WideStringToUtf8(L"\x108634", -1).c_str());
+}
+
+// Tests that encoding an invalid code-point generates the expected result.
+TEST(WideStringToUtf8Test, CanEncodeInvalidCodePoint) {
+  EXPECT_STREQ("(Invalid Unicode 0xABCDFF)",
+               WideStringToUtf8(L"\xABCDFF", -1).c_str());
+}
+#else  // !GTEST_WIDE_STRING_USES_UTF16_
+// Tests that surrogate pairs are encoded correctly on the systems using
+// UTF-16 encoding in the wide strings.
+TEST(WideStringToUtf8Test, CanEncodeValidUtf16SUrrogatePairs) {
+  const wchar_t s[] = { 0xD801, 0xDC00, '\0' };
+  EXPECT_STREQ("\xF0\x90\x90\x80", WideStringToUtf8(s, -1).c_str());
+}
+
+// Tests that encoding an invalid UTF-16 surrogate pair
+// generates the expected result.
+TEST(WideStringToUtf8Test, CanEncodeInvalidUtf16SurrogatePair) {
+  // Leading surrogate is at the end of the string.
+  const wchar_t s1[] = { 0xD800, '\0' };
+  EXPECT_STREQ("\xED\xA0\x80", WideStringToUtf8(s1, -1).c_str());
+  // Leading surrogate is not followed by the trailing surrogate.
+  const wchar_t s2[] = { 0xD800, 'M', '\0' };
+  EXPECT_STREQ("\xED\xA0\x80M", WideStringToUtf8(s2, -1).c_str());
+  // Trailing surrogate appearas without a leading surrogate.
+  const wchar_t s3[] = { 0xDC00, 'P', 'Q', 'R', '\0' };
+  EXPECT_STREQ("\xED\xB0\x80PQR", WideStringToUtf8(s3, -1).c_str());
+}
+#endif  // !GTEST_WIDE_STRING_USES_UTF16_
+
+// Tests that codepoint concatenation works correctly.
+#if !GTEST_WIDE_STRING_USES_UTF16_
+TEST(WideStringToUtf8Test, ConcatenatesCodepointsCorrectly) {
+  const wchar_t s[] = { 0x108634, 0xC74D, '\n', 0x576, 0x8D3, 0x108634, '\0'};
+  EXPECT_STREQ(
+      "\xF4\x88\x98\xB4"
+          "\xEC\x9D\x8D"
+          "\n"
+          "\xD5\xB6"
+          "\xE0\xA3\x93"
+          "\xF4\x88\x98\xB4",
+      WideStringToUtf8(s, -1).c_str());
+}
+#else
+TEST(WideStringToUtf8Test, ConcatenatesCodepointsCorrectly) {
+  const wchar_t s[] = { 0xC74D, '\n', 0x576, 0x8D3, '\0'};
+  EXPECT_STREQ(
+      "\xEC\x9D\x8D" "\n" "\xD5\xB6" "\xE0\xA3\x93",
+      WideStringToUtf8(s, -1).c_str());
+}
+#endif  // !GTEST_WIDE_STRING_USES_UTF16_
+
+// Tests the Random class.
+
+TEST(RandomDeathTest, GeneratesCrashesOnInvalidRange) {
+  testing::internal::Random random(42);
+  EXPECT_DEATH_IF_SUPPORTED(
+      random.Generate(0),
+      "Cannot generate a number in the range \\[0, 0\\)");
+  EXPECT_DEATH_IF_SUPPORTED(
+      random.Generate(testing::internal::Random::kMaxRange + 1),
+      "Generation of a number in \\[0, 2147483649\\) was requested, "
+      "but this can only generate numbers in \\[0, 2147483648\\)");
+}
+
+TEST(RandomTest, GeneratesNumbersWithinRange) {
+  const UInt32 kRange = 10000;
+  testing::internal::Random random(12345);
+  for (int i = 0; i < 10; i++) {
+    EXPECT_LT(random.Generate(kRange), kRange) << " for iteration " << i;
+  }
+
+  testing::internal::Random random2(testing::internal::Random::kMaxRange);
+  for (int i = 0; i < 10; i++) {
+    EXPECT_LT(random2.Generate(kRange), kRange) << " for iteration " << i;
+  }
+}
+
+TEST(RandomTest, RepeatsWhenReseeded) {
+  const int kSeed = 123;
+  const int kArraySize = 10;
+  const UInt32 kRange = 10000;
+  UInt32 values[kArraySize];
+
+  testing::internal::Random random(kSeed);
+  for (int i = 0; i < kArraySize; i++) {
+    values[i] = random.Generate(kRange);
+  }
+
+  random.Reseed(kSeed);
+  for (int i = 0; i < kArraySize; i++) {
+    EXPECT_EQ(values[i], random.Generate(kRange)) << " for iteration " << i;
+  }
+}
+
+// Tests STL container utilities.
+
+// Tests CountIf().
+
+static bool IsPositive(int n) { return n > 0; }
+
+TEST(ContainerUtilityTest, CountIf) {
+  std::vector<int> v;
+  EXPECT_EQ(0, CountIf(v, IsPositive));  // Works for an empty container.
+
+  v.push_back(-1);
+  v.push_back(0);
+  EXPECT_EQ(0, CountIf(v, IsPositive));  // Works when no value satisfies.
+
+  v.push_back(2);
+  v.push_back(-10);
+  v.push_back(10);
+  EXPECT_EQ(2, CountIf(v, IsPositive));
+}
+
+// Tests ForEach().
+
+static int g_sum = 0;
+static void Accumulate(int n) { g_sum += n; }
+
+TEST(ContainerUtilityTest, ForEach) {
+  std::vector<int> v;
+  g_sum = 0;
+  ForEach(v, Accumulate);
+  EXPECT_EQ(0, g_sum);  // Works for an empty container;
+
+  g_sum = 0;
+  v.push_back(1);
+  ForEach(v, Accumulate);
+  EXPECT_EQ(1, g_sum);  // Works for a container with one element.
+
+  g_sum = 0;
+  v.push_back(20);
+  v.push_back(300);
+  ForEach(v, Accumulate);
+  EXPECT_EQ(321, g_sum);
+}
+
+// Tests GetElementOr().
+TEST(ContainerUtilityTest, GetElementOr) {
+  std::vector<char> a;
+  EXPECT_EQ('x', GetElementOr(a, 0, 'x'));
+
+  a.push_back('a');
+  a.push_back('b');
+  EXPECT_EQ('a', GetElementOr(a, 0, 'x'));
+  EXPECT_EQ('b', GetElementOr(a, 1, 'x'));
+  EXPECT_EQ('x', GetElementOr(a, -2, 'x'));
+  EXPECT_EQ('x', GetElementOr(a, 2, 'x'));
+}
+
+TEST(ContainerUtilityDeathTest, ShuffleRange) {
+  std::vector<int> a;
+  a.push_back(0);
+  a.push_back(1);
+  a.push_back(2);
+  testing::internal::Random random(1);
+
+  EXPECT_DEATH_IF_SUPPORTED(
+      ShuffleRange(&random, -1, 1, &a),
+      "Invalid shuffle range start -1: must be in range \\[0, 3\\]");
+  EXPECT_DEATH_IF_SUPPORTED(
+      ShuffleRange(&random, 4, 4, &a),
+      "Invalid shuffle range start 4: must be in range \\[0, 3\\]");
+  EXPECT_DEATH_IF_SUPPORTED(
+      ShuffleRange(&random, 3, 2, &a),
+      "Invalid shuffle range finish 2: must be in range \\[3, 3\\]");
+  EXPECT_DEATH_IF_SUPPORTED(
+      ShuffleRange(&random, 3, 4, &a),
+      "Invalid shuffle range finish 4: must be in range \\[3, 3\\]");
+}
+
+class VectorShuffleTest : public Test {
+ protected:
+  static const size_t kVectorSize = 20;
+
+  VectorShuffleTest() : random_(1) {
+    for (int i = 0; i < static_cast<int>(kVectorSize); i++) {
+      vector_.push_back(i);
+    }
+  }
+
+  static bool VectorIsCorrupt(const TestingVector& vector) {
+    if (kVectorSize != vector.size()) {
+      return true;
+    }
+
+    bool found_in_vector[kVectorSize] = { false };
+    for (size_t i = 0; i < vector.size(); i++) {
+      const int e = vector[i];
+      if (e < 0 || e >= static_cast<int>(kVectorSize) || found_in_vector[e]) {
+        return true;
+      }
+      found_in_vector[e] = true;
+    }
+
+    // Vector size is correct, elements' range is correct, no
+    // duplicate elements.  Therefore no corruption has occurred.
+    return false;
+  }
+
+  static bool VectorIsNotCorrupt(const TestingVector& vector) {
+    return !VectorIsCorrupt(vector);
+  }
+
+  static bool RangeIsShuffled(const TestingVector& vector, int begin, int end) {
+    for (int i = begin; i < end; i++) {
+      if (i != vector[static_cast<size_t>(i)]) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  static bool RangeIsUnshuffled(
+      const TestingVector& vector, int begin, int end) {
+    return !RangeIsShuffled(vector, begin, end);
+  }
+
+  static bool VectorIsShuffled(const TestingVector& vector) {
+    return RangeIsShuffled(vector, 0, static_cast<int>(vector.size()));
+  }
+
+  static bool VectorIsUnshuffled(const TestingVector& vector) {
+    return !VectorIsShuffled(vector);
+  }
+
+  testing::internal::Random random_;
+  TestingVector vector_;
+};  // class VectorShuffleTest
+
+const size_t VectorShuffleTest::kVectorSize;
+
+TEST_F(VectorShuffleTest, HandlesEmptyRange) {
+  // Tests an empty range at the beginning...
+  ShuffleRange(&random_, 0, 0, &vector_);
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  ASSERT_PRED1(VectorIsUnshuffled, vector_);
+
+  // ...in the middle...
+  ShuffleRange(&random_, kVectorSize/2, kVectorSize/2, &vector_);
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  ASSERT_PRED1(VectorIsUnshuffled, vector_);
+
+  // ...at the end...
+  ShuffleRange(&random_, kVectorSize - 1, kVectorSize - 1, &vector_);
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  ASSERT_PRED1(VectorIsUnshuffled, vector_);
+
+  // ...and past the end.
+  ShuffleRange(&random_, kVectorSize, kVectorSize, &vector_);
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  ASSERT_PRED1(VectorIsUnshuffled, vector_);
+}
+
+TEST_F(VectorShuffleTest, HandlesRangeOfSizeOne) {
+  // Tests a size one range at the beginning...
+  ShuffleRange(&random_, 0, 1, &vector_);
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  ASSERT_PRED1(VectorIsUnshuffled, vector_);
+
+  // ...in the middle...
+  ShuffleRange(&random_, kVectorSize/2, kVectorSize/2 + 1, &vector_);
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  ASSERT_PRED1(VectorIsUnshuffled, vector_);
+
+  // ...and at the end.
+  ShuffleRange(&random_, kVectorSize - 1, kVectorSize, &vector_);
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  ASSERT_PRED1(VectorIsUnshuffled, vector_);
+}
+
+// Because we use our own random number generator and a fixed seed,
+// we can guarantee that the following "random" tests will succeed.
+
+TEST_F(VectorShuffleTest, ShufflesEntireVector) {
+  Shuffle(&random_, &vector_);
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  EXPECT_FALSE(VectorIsUnshuffled(vector_)) << vector_;
+
+  // Tests the first and last elements in particular to ensure that
+  // there are no off-by-one problems in our shuffle algorithm.
+  EXPECT_NE(0, vector_[0]);
+  EXPECT_NE(static_cast<int>(kVectorSize - 1), vector_[kVectorSize - 1]);
+}
+
+TEST_F(VectorShuffleTest, ShufflesStartOfVector) {
+  const int kRangeSize = kVectorSize/2;
+
+  ShuffleRange(&random_, 0, kRangeSize, &vector_);
+
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  EXPECT_PRED3(RangeIsShuffled, vector_, 0, kRangeSize);
+  EXPECT_PRED3(RangeIsUnshuffled, vector_, kRangeSize,
+               static_cast<int>(kVectorSize));
+}
+
+TEST_F(VectorShuffleTest, ShufflesEndOfVector) {
+  const int kRangeSize = kVectorSize / 2;
+  ShuffleRange(&random_, kRangeSize, kVectorSize, &vector_);
+
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  EXPECT_PRED3(RangeIsUnshuffled, vector_, 0, kRangeSize);
+  EXPECT_PRED3(RangeIsShuffled, vector_, kRangeSize,
+               static_cast<int>(kVectorSize));
+}
+
+TEST_F(VectorShuffleTest, ShufflesMiddleOfVector) {
+  const int kRangeSize = static_cast<int>(kVectorSize) / 3;
+  ShuffleRange(&random_, kRangeSize, 2*kRangeSize, &vector_);
+
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  EXPECT_PRED3(RangeIsUnshuffled, vector_, 0, kRangeSize);
+  EXPECT_PRED3(RangeIsShuffled, vector_, kRangeSize, 2*kRangeSize);
+  EXPECT_PRED3(RangeIsUnshuffled, vector_, 2 * kRangeSize,
+               static_cast<int>(kVectorSize));
+}
+
+TEST_F(VectorShuffleTest, ShufflesRepeatably) {
+  TestingVector vector2;
+  for (size_t i = 0; i < kVectorSize; i++) {
+    vector2.push_back(static_cast<int>(i));
+  }
+
+  random_.Reseed(1234);
+  Shuffle(&random_, &vector_);
+  random_.Reseed(1234);
+  Shuffle(&random_, &vector2);
+
+  ASSERT_PRED1(VectorIsNotCorrupt, vector_);
+  ASSERT_PRED1(VectorIsNotCorrupt, vector2);
+
+  for (size_t i = 0; i < kVectorSize; i++) {
+    EXPECT_EQ(vector_[i], vector2[i]) << " where i is " << i;
+  }
+}
+
+// Tests the size of the AssertHelper class.
+
+TEST(AssertHelperTest, AssertHelperIsSmall) {
+  // To avoid breaking clients that use lots of assertions in one
+  // function, we cannot grow the size of AssertHelper.
+  EXPECT_LE(sizeof(testing::internal::AssertHelper), sizeof(void*));
+}
+
+// Tests String::EndsWithCaseInsensitive().
+TEST(StringTest, EndsWithCaseInsensitive) {
+  EXPECT_TRUE(String::EndsWithCaseInsensitive("foobar", "BAR"));
+  EXPECT_TRUE(String::EndsWithCaseInsensitive("foobaR", "bar"));
+  EXPECT_TRUE(String::EndsWithCaseInsensitive("foobar", ""));
+  EXPECT_TRUE(String::EndsWithCaseInsensitive("", ""));
+
+  EXPECT_FALSE(String::EndsWithCaseInsensitive("Foobar", "foo"));
+  EXPECT_FALSE(String::EndsWithCaseInsensitive("foobar", "Foo"));
+  EXPECT_FALSE(String::EndsWithCaseInsensitive("", "foo"));
+}
+
+// C++Builder's preprocessor is buggy; it fails to expand macros that
+// appear in macro parameters after wide char literals.  Provide an alias
+// for NULL as a workaround.
+static const wchar_t* const kNull = nullptr;
+
+// Tests String::CaseInsensitiveWideCStringEquals
+TEST(StringTest, CaseInsensitiveWideCStringEquals) {
+  EXPECT_TRUE(String::CaseInsensitiveWideCStringEquals(nullptr, nullptr));
+  EXPECT_FALSE(String::CaseInsensitiveWideCStringEquals(kNull, L""));
+  EXPECT_FALSE(String::CaseInsensitiveWideCStringEquals(L"", kNull));
+  EXPECT_FALSE(String::CaseInsensitiveWideCStringEquals(kNull, L"foobar"));
+  EXPECT_FALSE(String::CaseInsensitiveWideCStringEquals(L"foobar", kNull));
+  EXPECT_TRUE(String::CaseInsensitiveWideCStringEquals(L"foobar", L"foobar"));
+  EXPECT_TRUE(String::CaseInsensitiveWideCStringEquals(L"foobar", L"FOOBAR"));
+  EXPECT_TRUE(String::CaseInsensitiveWideCStringEquals(L"FOOBAR", L"foobar"));
+}
+
+#if GTEST_OS_WINDOWS
+
+// Tests String::ShowWideCString().
+TEST(StringTest, ShowWideCString) {
+  EXPECT_STREQ("(null)",
+               String::ShowWideCString(NULL).c_str());
+  EXPECT_STREQ("", String::ShowWideCString(L"").c_str());
+  EXPECT_STREQ("foo", String::ShowWideCString(L"foo").c_str());
+}
+
+# if GTEST_OS_WINDOWS_MOBILE
+TEST(StringTest, AnsiAndUtf16Null) {
+  EXPECT_EQ(NULL, String::AnsiToUtf16(NULL));
+  EXPECT_EQ(NULL, String::Utf16ToAnsi(NULL));
+}
+
+TEST(StringTest, AnsiAndUtf16ConvertBasic) {
+  const char* ansi = String::Utf16ToAnsi(L"str");
+  EXPECT_STREQ("str", ansi);
+  delete [] ansi;
+  const WCHAR* utf16 = String::AnsiToUtf16("str");
+  EXPECT_EQ(0, wcsncmp(L"str", utf16, 3));
+  delete [] utf16;
+}
+
+TEST(StringTest, AnsiAndUtf16ConvertPathChars) {
+  const char* ansi = String::Utf16ToAnsi(L".:\\ \"*?");
+  EXPECT_STREQ(".:\\ \"*?", ansi);
+  delete [] ansi;
+  const WCHAR* utf16 = String::AnsiToUtf16(".:\\ \"*?");
+  EXPECT_EQ(0, wcsncmp(L".:\\ \"*?", utf16, 3));
+  delete [] utf16;
+}
+# endif  // GTEST_OS_WINDOWS_MOBILE
+
+#endif  // GTEST_OS_WINDOWS
+
+// Tests TestProperty construction.
+TEST(TestPropertyTest, StringValue) {
+  TestProperty property("key", "1");
+  EXPECT_STREQ("key", property.key());
+  EXPECT_STREQ("1", property.value());
+}
+
+// Tests TestProperty replacing a value.
+TEST(TestPropertyTest, ReplaceStringValue) {
+  TestProperty property("key", "1");
+  EXPECT_STREQ("1", property.value());
+  property.SetValue("2");
+  EXPECT_STREQ("2", property.value());
+}
+
+// AddFatalFailure() and AddNonfatalFailure() must be stand-alone
+// functions (i.e. their definitions cannot be inlined at the call
+// sites), or C++Builder won't compile the code.
+static void AddFatalFailure() {
+  FAIL() << "Expected fatal failure.";
+}
+
+static void AddNonfatalFailure() {
+  ADD_FAILURE() << "Expected non-fatal failure.";
+}
+
+class ScopedFakeTestPartResultReporterTest : public Test {
+ public:  // Must be public and not protected due to a bug in g++ 3.4.2.
+  enum FailureMode {
+    FATAL_FAILURE,
+    NONFATAL_FAILURE
+  };
+  static void AddFailure(FailureMode failure) {
+    if (failure == FATAL_FAILURE) {
+      AddFatalFailure();
+    } else {
+      AddNonfatalFailure();
+    }
+  }
+};
+
+// Tests that ScopedFakeTestPartResultReporter intercepts test
+// failures.
+TEST_F(ScopedFakeTestPartResultReporterTest, InterceptsTestFailures) {
+  TestPartResultArray results;
+  {
+    ScopedFakeTestPartResultReporter reporter(
+        ScopedFakeTestPartResultReporter::INTERCEPT_ONLY_CURRENT_THREAD,
+        &results);
+    AddFailure(NONFATAL_FAILURE);
+    AddFailure(FATAL_FAILURE);
+  }
+
+  EXPECT_EQ(2, results.size());
+  EXPECT_TRUE(results.GetTestPartResult(0).nonfatally_failed());
+  EXPECT_TRUE(results.GetTestPartResult(1).fatally_failed());
+}
+
+TEST_F(ScopedFakeTestPartResultReporterTest, DeprecatedConstructor) {
+  TestPartResultArray results;
+  {
+    // Tests, that the deprecated constructor still works.
+    ScopedFakeTestPartResultReporter reporter(&results);
+    AddFailure(NONFATAL_FAILURE);
+  }
+  EXPECT_EQ(1, results.size());
+}
+
+#if GTEST_IS_THREADSAFE
+
+class ScopedFakeTestPartResultReporterWithThreadsTest
+  : public ScopedFakeTestPartResultReporterTest {
+ protected:
+  static void AddFailureInOtherThread(FailureMode failure) {
+    ThreadWithParam<FailureMode> thread(&AddFailure, failure, nullptr);
+    thread.Join();
+  }
+};
+
+TEST_F(ScopedFakeTestPartResultReporterWithThreadsTest,
+       InterceptsTestFailuresInAllThreads) {
+  TestPartResultArray results;
+  {
+    ScopedFakeTestPartResultReporter reporter(
+        ScopedFakeTestPartResultReporter::INTERCEPT_ALL_THREADS, &results);
+    AddFailure(NONFATAL_FAILURE);
+    AddFailure(FATAL_FAILURE);
+    AddFailureInOtherThread(NONFATAL_FAILURE);
+    AddFailureInOtherThread(FATAL_FAILURE);
+  }
+
+  EXPECT_EQ(4, results.size());
+  EXPECT_TRUE(results.GetTestPartResult(0).nonfatally_failed());
+  EXPECT_TRUE(results.GetTestPartResult(1).fatally_failed());
+  EXPECT_TRUE(results.GetTestPartResult(2).nonfatally_failed());
+  EXPECT_TRUE(results.GetTestPartResult(3).fatally_failed());
+}
+
+#endif  // GTEST_IS_THREADSAFE
+
+// Tests EXPECT_FATAL_FAILURE{,ON_ALL_THREADS}.  Makes sure that they
+// work even if the failure is generated in a called function rather than
+// the current context.
+
+typedef ScopedFakeTestPartResultReporterTest ExpectFatalFailureTest;
+
+TEST_F(ExpectFatalFailureTest, CatchesFatalFaliure) {
+  EXPECT_FATAL_FAILURE(AddFatalFailure(), "Expected fatal failure.");
+}
+
+TEST_F(ExpectFatalFailureTest, AcceptsStdStringObject) {
+  EXPECT_FATAL_FAILURE(AddFatalFailure(),
+                       ::std::string("Expected fatal failure."));
+}
+
+TEST_F(ExpectFatalFailureTest, CatchesFatalFailureOnAllThreads) {
+  // We have another test below to verify that the macro catches fatal
+  // failures generated on another thread.
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(AddFatalFailure(),
+                                      "Expected fatal failure.");
+}
+
+#ifdef __BORLANDC__
+// Silences warnings: "Condition is always true"
+# pragma option push -w-ccc
+#endif
+
+// Tests that EXPECT_FATAL_FAILURE() can be used in a non-void
+// function even when the statement in it contains ASSERT_*.
+
+int NonVoidFunction() {
+  EXPECT_FATAL_FAILURE(ASSERT_TRUE(false), "");
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(FAIL(), "");
+  return 0;
+}
+
+TEST_F(ExpectFatalFailureTest, CanBeUsedInNonVoidFunction) {
+  NonVoidFunction();
+}
+
+// Tests that EXPECT_FATAL_FAILURE(statement, ...) doesn't abort the
+// current function even though 'statement' generates a fatal failure.
+
+void DoesNotAbortHelper(bool* aborted) {
+  EXPECT_FATAL_FAILURE(ASSERT_TRUE(false), "");
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(FAIL(), "");
+
+  *aborted = false;
+}
+
+#ifdef __BORLANDC__
+// Restores warnings after previous "#pragma option push" suppressed them.
+# pragma option pop
+#endif
+
+TEST_F(ExpectFatalFailureTest, DoesNotAbort) {
+  bool aborted = true;
+  DoesNotAbortHelper(&aborted);
+  EXPECT_FALSE(aborted);
+}
+
+// Tests that the EXPECT_FATAL_FAILURE{,_ON_ALL_THREADS} accepts a
+// statement that contains a macro which expands to code containing an
+// unprotected comma.
+
+static int global_var = 0;
+#define GTEST_USE_UNPROTECTED_COMMA_ global_var++, global_var++
+
+TEST_F(ExpectFatalFailureTest, AcceptsMacroThatExpandsToUnprotectedComma) {
+#ifndef __BORLANDC__
+  // ICE's in C++Builder.
+  EXPECT_FATAL_FAILURE({
+    GTEST_USE_UNPROTECTED_COMMA_;
+    AddFatalFailure();
+  }, "");
+#endif
+
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS({
+    GTEST_USE_UNPROTECTED_COMMA_;
+    AddFatalFailure();
+  }, "");
+}
+
+// Tests EXPECT_NONFATAL_FAILURE{,ON_ALL_THREADS}.
+
+typedef ScopedFakeTestPartResultReporterTest ExpectNonfatalFailureTest;
+
+TEST_F(ExpectNonfatalFailureTest, CatchesNonfatalFailure) {
+  EXPECT_NONFATAL_FAILURE(AddNonfatalFailure(),
+                          "Expected non-fatal failure.");
+}
+
+TEST_F(ExpectNonfatalFailureTest, AcceptsStdStringObject) {
+  EXPECT_NONFATAL_FAILURE(AddNonfatalFailure(),
+                          ::std::string("Expected non-fatal failure."));
+}
+
+TEST_F(ExpectNonfatalFailureTest, CatchesNonfatalFailureOnAllThreads) {
+  // We have another test below to verify that the macro catches
+  // non-fatal failures generated on another thread.
+  EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(AddNonfatalFailure(),
+                                         "Expected non-fatal failure.");
+}
+
+// Tests that the EXPECT_NONFATAL_FAILURE{,_ON_ALL_THREADS} accepts a
+// statement that contains a macro which expands to code containing an
+// unprotected comma.
+TEST_F(ExpectNonfatalFailureTest, AcceptsMacroThatExpandsToUnprotectedComma) {
+  EXPECT_NONFATAL_FAILURE({
+    GTEST_USE_UNPROTECTED_COMMA_;
+    AddNonfatalFailure();
+  }, "");
+
+  EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS({
+    GTEST_USE_UNPROTECTED_COMMA_;
+    AddNonfatalFailure();
+  }, "");
+}
+
+#if GTEST_IS_THREADSAFE
+
+typedef ScopedFakeTestPartResultReporterWithThreadsTest
+    ExpectFailureWithThreadsTest;
+
+TEST_F(ExpectFailureWithThreadsTest, ExpectFatalFailureOnAllThreads) {
+  EXPECT_FATAL_FAILURE_ON_ALL_THREADS(AddFailureInOtherThread(FATAL_FAILURE),
+                                      "Expected fatal failure.");
+}
+
+TEST_F(ExpectFailureWithThreadsTest, ExpectNonFatalFailureOnAllThreads) {
+  EXPECT_NONFATAL_FAILURE_ON_ALL_THREADS(
+      AddFailureInOtherThread(NONFATAL_FAILURE), "Expected non-fatal failure.");
+}
+
+#endif  // GTEST_IS_THREADSAFE
+
+// Tests the TestProperty class.
+
+TEST(TestPropertyTest, ConstructorWorks) {
+  const TestProperty property("key", "value");
+  EXPECT_STREQ("key", property.key());
+  EXPECT_STREQ("value", property.value());
+}
+
+TEST(TestPropertyTest, SetValue) {
+  TestProperty property("key", "value_1");
+  EXPECT_STREQ("key", property.key());
+  property.SetValue("value_2");
+  EXPECT_STREQ("key", property.key());
+  EXPECT_STREQ("value_2", property.value());
+}
+
+// Tests the TestResult class
+
+// The test fixture for testing TestResult.
+class TestResultTest : public Test {
+ protected:
+  typedef std::vector<TestPartResult> TPRVector;
+
+  // We make use of 2 TestPartResult objects,
+  TestPartResult * pr1, * pr2;
+
+  // ... and 3 TestResult objects.
+  TestResult * r0, * r1, * r2;
+
+  void SetUp() override {
+    // pr1 is for success.
+    pr1 = new TestPartResult(TestPartResult::kSuccess,
+                             "foo/bar.cc",
+                             10,
+                             "Success!");
+
+    // pr2 is for fatal failure.
+    pr2 = new TestPartResult(TestPartResult::kFatalFailure,
+                             "foo/bar.cc",
+                             -1,  // This line number means "unknown"
+                             "Failure!");
+
+    // Creates the TestResult objects.
+    r0 = new TestResult();
+    r1 = new TestResult();
+    r2 = new TestResult();
+
+    // In order to test TestResult, we need to modify its internal
+    // state, in particular the TestPartResult vector it holds.
+    // test_part_results() returns a const reference to this vector.
+    // We cast it to a non-const object s.t. it can be modified
+    TPRVector* results1 = const_cast<TPRVector*>(
+        &TestResultAccessor::test_part_results(*r1));
+    TPRVector* results2 = const_cast<TPRVector*>(
+        &TestResultAccessor::test_part_results(*r2));
+
+    // r0 is an empty TestResult.
+
+    // r1 contains a single SUCCESS TestPartResult.
+    results1->push_back(*pr1);
+
+    // r2 contains a SUCCESS, and a FAILURE.
+    results2->push_back(*pr1);
+    results2->push_back(*pr2);
+  }
+
+  void TearDown() override {
+    delete pr1;
+    delete pr2;
+
+    delete r0;
+    delete r1;
+    delete r2;
+  }
+
+  // Helper that compares two TestPartResults.
+  static void CompareTestPartResult(const TestPartResult& expected,
+                                    const TestPartResult& actual) {
+    EXPECT_EQ(expected.type(), actual.type());
+    EXPECT_STREQ(expected.file_name(), actual.file_name());
+    EXPECT_EQ(expected.line_number(), actual.line_number());
+    EXPECT_STREQ(expected.summary(), actual.summary());
+    EXPECT_STREQ(expected.message(), actual.message());
+    EXPECT_EQ(expected.passed(), actual.passed());
+    EXPECT_EQ(expected.failed(), actual.failed());
+    EXPECT_EQ(expected.nonfatally_failed(), actual.nonfatally_failed());
+    EXPECT_EQ(expected.fatally_failed(), actual.fatally_failed());
+  }
+};
+
+// Tests TestResult::total_part_count().
+TEST_F(TestResultTest, total_part_count) {
+  ASSERT_EQ(0, r0->total_part_count());
+  ASSERT_EQ(1, r1->total_part_count());
+  ASSERT_EQ(2, r2->total_part_count());
+}
+
+// Tests TestResult::Passed().
+TEST_F(TestResultTest, Passed) {
+  ASSERT_TRUE(r0->Passed());
+  ASSERT_TRUE(r1->Passed());
+  ASSERT_FALSE(r2->Passed());
+}
+
+// Tests TestResult::Failed().
+TEST_F(TestResultTest, Failed) {
+  ASSERT_FALSE(r0->Failed());
+  ASSERT_FALSE(r1->Failed());
+  ASSERT_TRUE(r2->Failed());
+}
+
+// Tests TestResult::GetTestPartResult().
+
+typedef TestResultTest TestResultDeathTest;
+
+TEST_F(TestResultDeathTest, GetTestPartResult) {
+  CompareTestPartResult(*pr1, r2->GetTestPartResult(0));
+  CompareTestPartResult(*pr2, r2->GetTestPartResult(1));
+  EXPECT_DEATH_IF_SUPPORTED(r2->GetTestPartResult(2), "");
+  EXPECT_DEATH_IF_SUPPORTED(r2->GetTestPartResult(-1), "");
+}
+
+// Tests TestResult has no properties when none are added.
+TEST(TestResultPropertyTest, NoPropertiesFoundWhenNoneAreAdded) {
+  TestResult test_result;
+  ASSERT_EQ(0, test_result.test_property_count());
+}
+
+// Tests TestResult has the expected property when added.
+TEST(TestResultPropertyTest, OnePropertyFoundWhenAdded) {
+  TestResult test_result;
+  TestProperty property("key_1", "1");
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property);
+  ASSERT_EQ(1, test_result.test_property_count());
+  const TestProperty& actual_property = test_result.GetTestProperty(0);
+  EXPECT_STREQ("key_1", actual_property.key());
+  EXPECT_STREQ("1", actual_property.value());
+}
+
+// Tests TestResult has multiple properties when added.
+TEST(TestResultPropertyTest, MultiplePropertiesFoundWhenAdded) {
+  TestResult test_result;
+  TestProperty property_1("key_1", "1");
+  TestProperty property_2("key_2", "2");
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property_1);
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property_2);
+  ASSERT_EQ(2, test_result.test_property_count());
+  const TestProperty& actual_property_1 = test_result.GetTestProperty(0);
+  EXPECT_STREQ("key_1", actual_property_1.key());
+  EXPECT_STREQ("1", actual_property_1.value());
+
+  const TestProperty& actual_property_2 = test_result.GetTestProperty(1);
+  EXPECT_STREQ("key_2", actual_property_2.key());
+  EXPECT_STREQ("2", actual_property_2.value());
+}
+
+// Tests TestResult::RecordProperty() overrides values for duplicate keys.
+TEST(TestResultPropertyTest, OverridesValuesForDuplicateKeys) {
+  TestResult test_result;
+  TestProperty property_1_1("key_1", "1");
+  TestProperty property_2_1("key_2", "2");
+  TestProperty property_1_2("key_1", "12");
+  TestProperty property_2_2("key_2", "22");
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property_1_1);
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property_2_1);
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property_1_2);
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property_2_2);
+
+  ASSERT_EQ(2, test_result.test_property_count());
+  const TestProperty& actual_property_1 = test_result.GetTestProperty(0);
+  EXPECT_STREQ("key_1", actual_property_1.key());
+  EXPECT_STREQ("12", actual_property_1.value());
+
+  const TestProperty& actual_property_2 = test_result.GetTestProperty(1);
+  EXPECT_STREQ("key_2", actual_property_2.key());
+  EXPECT_STREQ("22", actual_property_2.value());
+}
+
+// Tests TestResult::GetTestProperty().
+TEST(TestResultPropertyTest, GetTestProperty) {
+  TestResult test_result;
+  TestProperty property_1("key_1", "1");
+  TestProperty property_2("key_2", "2");
+  TestProperty property_3("key_3", "3");
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property_1);
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property_2);
+  TestResultAccessor::RecordProperty(&test_result, "testcase", property_3);
+
+  const TestProperty& fetched_property_1 = test_result.GetTestProperty(0);
+  const TestProperty& fetched_property_2 = test_result.GetTestProperty(1);
+  const TestProperty& fetched_property_3 = test_result.GetTestProperty(2);
+
+  EXPECT_STREQ("key_1", fetched_property_1.key());
+  EXPECT_STREQ("1", fetched_property_1.value());
+
+  EXPECT_STREQ("key_2", fetched_property_2.key());
+  EXPECT_STREQ("2", fetched_property_2.value());
+
+  EXPECT_STREQ("key_3", fetched_property_3.key());
+  EXPECT_STREQ("3", fetched_property_3.value());
+
+  EXPECT_DEATH_IF_SUPPORTED(test_result.GetTestProperty(3), "");
+  EXPECT_DEATH_IF_SUPPORTED(test_result.GetTestProperty(-1), "");
+}
+
+// Tests the Test class.
+//
+// It's difficult to test every public method of this class (we are
+// already stretching the limit of Google Test by using it to test itself!).
+// Fortunately, we don't have to do that, as we are already testing
+// the functionalities of the Test class extensively by using Google Test
+// alone.
+//
+// Therefore, this section only contains one test.
+
+// Tests that GTestFlagSaver works on Windows and Mac.
+
+class GTestFlagSaverTest : public Test {
+ protected:
+  // Saves the Google Test flags such that we can restore them later, and
+  // then sets them to their default values.  This will be called
+  // before the first test in this test case is run.
+  static void SetUpTestSuite() {
+    saver_ = new GTestFlagSaver;
+
+    GTEST_FLAG(also_run_disabled_tests) = false;
+    GTEST_FLAG(break_on_failure) = false;
+    GTEST_FLAG(catch_exceptions) = false;
+    GTEST_FLAG(death_test_use_fork) = false;
+    GTEST_FLAG(color) = "auto";
+    GTEST_FLAG(filter) = "";
+    GTEST_FLAG(list_tests) = false;
+    GTEST_FLAG(output) = "";
+    GTEST_FLAG(print_time) = true;
+    GTEST_FLAG(random_seed) = 0;
+    GTEST_FLAG(repeat) = 1;
+    GTEST_FLAG(shuffle) = false;
+    GTEST_FLAG(stack_trace_depth) = kMaxStackTraceDepth;
+    GTEST_FLAG(stream_result_to) = "";
+    GTEST_FLAG(throw_on_failure) = false;
+  }
+
+  // Restores the Google Test flags that the tests have modified.  This will
+  // be called after the last test in this test case is run.
+  static void TearDownTestSuite() {
+    delete saver_;
+    saver_ = nullptr;
+  }
+
+  // Verifies that the Google Test flags have their default values, and then
+  // modifies each of them.
+  void VerifyAndModifyFlags() {
+    EXPECT_FALSE(GTEST_FLAG(also_run_disabled_tests));
+    EXPECT_FALSE(GTEST_FLAG(break_on_failure));
+    EXPECT_FALSE(GTEST_FLAG(catch_exceptions));
+    EXPECT_STREQ("auto", GTEST_FLAG(color).c_str());
+    EXPECT_FALSE(GTEST_FLAG(death_test_use_fork));
+    EXPECT_STREQ("", GTEST_FLAG(filter).c_str());
+    EXPECT_FALSE(GTEST_FLAG(list_tests));
+    EXPECT_STREQ("", GTEST_FLAG(output).c_str());
+    EXPECT_TRUE(GTEST_FLAG(print_time));
+    EXPECT_EQ(0, GTEST_FLAG(random_seed));
+    EXPECT_EQ(1, GTEST_FLAG(repeat));
+    EXPECT_FALSE(GTEST_FLAG(shuffle));
+    EXPECT_EQ(kMaxStackTraceDepth, GTEST_FLAG(stack_trace_depth));
+    EXPECT_STREQ("", GTEST_FLAG(stream_result_to).c_str());
+    EXPECT_FALSE(GTEST_FLAG(throw_on_failure));
+
+    GTEST_FLAG(also_run_disabled_tests) = true;
+    GTEST_FLAG(break_on_failure) = true;
+    GTEST_FLAG(catch_exceptions) = true;
+    GTEST_FLAG(color) = "no";
+    GTEST_FLAG(death_test_use_fork) = true;
+    GTEST_FLAG(filter) = "abc";
+    GTEST_FLAG(list_tests) = true;
+    GTEST_FLAG(output) = "xml:foo.xml";
+    GTEST_FLAG(print_time) = false;
+    GTEST_FLAG(random_seed) = 1;
+    GTEST_FLAG(repeat) = 100;
+    GTEST_FLAG(shuffle) = true;
+    GTEST_FLAG(stack_trace_depth) = 1;
+    GTEST_FLAG(stream_result_to) = "localhost:1234";
+    GTEST_FLAG(throw_on_failure) = true;
+  }
+
+ private:
+  // For saving Google Test flags during this test case.
+  static GTestFlagSaver* saver_;
+};
+
+GTestFlagSaver* GTestFlagSaverTest::saver_ = nullptr;
+
+// Google Test doesn't guarantee the order of tests.  The following two
+// tests are designed to work regardless of their order.
+
+// Modifies the Google Test flags in the test body.
+TEST_F(GTestFlagSaverTest, ModifyGTestFlags) {
+  VerifyAndModifyFlags();
+}
+
+// Verifies that the Google Test flags in the body of the previous test were
+// restored to their original values.
+TEST_F(GTestFlagSaverTest, VerifyGTestFlags) {
+  VerifyAndModifyFlags();
+}
+
+// Sets an environment variable with the given name to the given
+// value.  If the value argument is "", unsets the environment
+// variable.  The caller must ensure that both arguments are not NULL.
+static void SetEnv(const char* name, const char* value) {
+#if GTEST_OS_WINDOWS_MOBILE
+  // Environment variables are not supported on Windows CE.
+  return;
+#elif defined(__BORLANDC__) || defined(__SunOS_5_8) || defined(__SunOS_5_9)
+  // C++Builder's putenv only stores a pointer to its parameter; we have to
+  // ensure that the string remains valid as long as it might be needed.
+  // We use an std::map to do so.
+  static std::map<std::string, std::string*> added_env;
+
+  // Because putenv stores a pointer to the string buffer, we can't delete the
+  // previous string (if present) until after it's replaced.
+  std::string *prev_env = NULL;
+  if (added_env.find(name) != added_env.end()) {
+    prev_env = added_env[name];
+  }
+  added_env[name] = new std::string(
+      (Message() << name << "=" << value).GetString());
+
+  // The standard signature of putenv accepts a 'char*' argument. Other
+  // implementations, like C++Builder's, accept a 'const char*'.
+  // We cast away the 'const' since that would work for both variants.
+  putenv(const_cast<char*>(added_env[name]->c_str()));
+  delete prev_env;
+#elif GTEST_OS_WINDOWS  // If we are on Windows proper.
+  _putenv((Message() << name << "=" << value).GetString().c_str());
+#else
+  if (*value == '\0') {
+    unsetenv(name);
+  } else {
+    setenv(name, value, 1);
+  }
+#endif  // GTEST_OS_WINDOWS_MOBILE
+}
+
+#if !GTEST_OS_WINDOWS_MOBILE
+// Environment variables are not supported on Windows CE.
+
+using testing::internal::Int32FromGTestEnv;
+
+// Tests Int32FromGTestEnv().
+
+// Tests that Int32FromGTestEnv() returns the default value when the
+// environment variable is not set.
+TEST(Int32FromGTestEnvTest, ReturnsDefaultWhenVariableIsNotSet) {
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "TEMP", "");
+  EXPECT_EQ(10, Int32FromGTestEnv("temp", 10));
+}
+
+# if !defined(GTEST_GET_INT32_FROM_ENV_)
+
+// Tests that Int32FromGTestEnv() returns the default value when the
+// environment variable overflows as an Int32.
+TEST(Int32FromGTestEnvTest, ReturnsDefaultWhenValueOverflows) {
+  printf("(expecting 2 warnings)\n");
+
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "TEMP", "12345678987654321");
+  EXPECT_EQ(20, Int32FromGTestEnv("temp", 20));
+
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "TEMP", "-12345678987654321");
+  EXPECT_EQ(30, Int32FromGTestEnv("temp", 30));
+}
+
+// Tests that Int32FromGTestEnv() returns the default value when the
+// environment variable does not represent a valid decimal integer.
+TEST(Int32FromGTestEnvTest, ReturnsDefaultWhenValueIsInvalid) {
+  printf("(expecting 2 warnings)\n");
+
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "TEMP", "A1");
+  EXPECT_EQ(40, Int32FromGTestEnv("temp", 40));
+
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "TEMP", "12X");
+  EXPECT_EQ(50, Int32FromGTestEnv("temp", 50));
+}
+
+# endif  // !defined(GTEST_GET_INT32_FROM_ENV_)
+
+// Tests that Int32FromGTestEnv() parses and returns the value of the
+// environment variable when it represents a valid decimal integer in
+// the range of an Int32.
+TEST(Int32FromGTestEnvTest, ParsesAndReturnsValidValue) {
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "TEMP", "123");
+  EXPECT_EQ(123, Int32FromGTestEnv("temp", 0));
+
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "TEMP", "-321");
+  EXPECT_EQ(-321, Int32FromGTestEnv("temp", 0));
+}
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+// Tests ParseInt32Flag().
+
+// Tests that ParseInt32Flag() returns false and doesn't change the
+// output value when the flag has wrong format
+TEST(ParseInt32FlagTest, ReturnsFalseForInvalidFlag) {
+  Int32 value = 123;
+  EXPECT_FALSE(ParseInt32Flag("--a=100", "b", &value));
+  EXPECT_EQ(123, value);
+
+  EXPECT_FALSE(ParseInt32Flag("a=100", "a", &value));
+  EXPECT_EQ(123, value);
+}
+
+// Tests that ParseInt32Flag() returns false and doesn't change the
+// output value when the flag overflows as an Int32.
+TEST(ParseInt32FlagTest, ReturnsDefaultWhenValueOverflows) {
+  printf("(expecting 2 warnings)\n");
+
+  Int32 value = 123;
+  EXPECT_FALSE(ParseInt32Flag("--abc=12345678987654321", "abc", &value));
+  EXPECT_EQ(123, value);
+
+  EXPECT_FALSE(ParseInt32Flag("--abc=-12345678987654321", "abc", &value));
+  EXPECT_EQ(123, value);
+}
+
+// Tests that ParseInt32Flag() returns false and doesn't change the
+// output value when the flag does not represent a valid decimal
+// integer.
+TEST(ParseInt32FlagTest, ReturnsDefaultWhenValueIsInvalid) {
+  printf("(expecting 2 warnings)\n");
+
+  Int32 value = 123;
+  EXPECT_FALSE(ParseInt32Flag("--abc=A1", "abc", &value));
+  EXPECT_EQ(123, value);
+
+  EXPECT_FALSE(ParseInt32Flag("--abc=12X", "abc", &value));
+  EXPECT_EQ(123, value);
+}
+
+// Tests that ParseInt32Flag() parses the value of the flag and
+// returns true when the flag represents a valid decimal integer in
+// the range of an Int32.
+TEST(ParseInt32FlagTest, ParsesAndReturnsValidValue) {
+  Int32 value = 123;
+  EXPECT_TRUE(ParseInt32Flag("--" GTEST_FLAG_PREFIX_ "abc=456", "abc", &value));
+  EXPECT_EQ(456, value);
+
+  EXPECT_TRUE(ParseInt32Flag("--" GTEST_FLAG_PREFIX_ "abc=-789",
+                             "abc", &value));
+  EXPECT_EQ(-789, value);
+}
+
+// Tests that Int32FromEnvOrDie() parses the value of the var or
+// returns the correct default.
+// Environment variables are not supported on Windows CE.
+#if !GTEST_OS_WINDOWS_MOBILE
+TEST(Int32FromEnvOrDieTest, ParsesAndReturnsValidValue) {
+  EXPECT_EQ(333, Int32FromEnvOrDie(GTEST_FLAG_PREFIX_UPPER_ "UnsetVar", 333));
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "UnsetVar", "123");
+  EXPECT_EQ(123, Int32FromEnvOrDie(GTEST_FLAG_PREFIX_UPPER_ "UnsetVar", 333));
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "UnsetVar", "-123");
+  EXPECT_EQ(-123, Int32FromEnvOrDie(GTEST_FLAG_PREFIX_UPPER_ "UnsetVar", 333));
+}
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+// Tests that Int32FromEnvOrDie() aborts with an error message
+// if the variable is not an Int32.
+TEST(Int32FromEnvOrDieDeathTest, AbortsOnFailure) {
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "VAR", "xxx");
+  EXPECT_DEATH_IF_SUPPORTED(
+      Int32FromEnvOrDie(GTEST_FLAG_PREFIX_UPPER_ "VAR", 123),
+      ".*");
+}
+
+// Tests that Int32FromEnvOrDie() aborts with an error message
+// if the variable cannot be represented by an Int32.
+TEST(Int32FromEnvOrDieDeathTest, AbortsOnInt32Overflow) {
+  SetEnv(GTEST_FLAG_PREFIX_UPPER_ "VAR", "1234567891234567891234");
+  EXPECT_DEATH_IF_SUPPORTED(
+      Int32FromEnvOrDie(GTEST_FLAG_PREFIX_UPPER_ "VAR", 123),
+      ".*");
+}
+
+// Tests that ShouldRunTestOnShard() selects all tests
+// where there is 1 shard.
+TEST(ShouldRunTestOnShardTest, IsPartitionWhenThereIsOneShard) {
+  EXPECT_TRUE(ShouldRunTestOnShard(1, 0, 0));
+  EXPECT_TRUE(ShouldRunTestOnShard(1, 0, 1));
+  EXPECT_TRUE(ShouldRunTestOnShard(1, 0, 2));
+  EXPECT_TRUE(ShouldRunTestOnShard(1, 0, 3));
+  EXPECT_TRUE(ShouldRunTestOnShard(1, 0, 4));
+}
+
+class ShouldShardTest : public testing::Test {
+ protected:
+  void SetUp() override {
+    index_var_ = GTEST_FLAG_PREFIX_UPPER_ "INDEX";
+    total_var_ = GTEST_FLAG_PREFIX_UPPER_ "TOTAL";
+  }
+
+  void TearDown() override {
+    SetEnv(index_var_, "");
+    SetEnv(total_var_, "");
+  }
+
+  const char* index_var_;
+  const char* total_var_;
+};
+
+// Tests that sharding is disabled if neither of the environment variables
+// are set.
+TEST_F(ShouldShardTest, ReturnsFalseWhenNeitherEnvVarIsSet) {
+  SetEnv(index_var_, "");
+  SetEnv(total_var_, "");
+
+  EXPECT_FALSE(ShouldShard(total_var_, index_var_, false));
+  EXPECT_FALSE(ShouldShard(total_var_, index_var_, true));
+}
+
+// Tests that sharding is not enabled if total_shards  == 1.
+TEST_F(ShouldShardTest, ReturnsFalseWhenTotalShardIsOne) {
+  SetEnv(index_var_, "0");
+  SetEnv(total_var_, "1");
+  EXPECT_FALSE(ShouldShard(total_var_, index_var_, false));
+  EXPECT_FALSE(ShouldShard(total_var_, index_var_, true));
+}
+
+// Tests that sharding is enabled if total_shards > 1 and
+// we are not in a death test subprocess.
+// Environment variables are not supported on Windows CE.
+#if !GTEST_OS_WINDOWS_MOBILE
+TEST_F(ShouldShardTest, WorksWhenShardEnvVarsAreValid) {
+  SetEnv(index_var_, "4");
+  SetEnv(total_var_, "22");
+  EXPECT_TRUE(ShouldShard(total_var_, index_var_, false));
+  EXPECT_FALSE(ShouldShard(total_var_, index_var_, true));
+
+  SetEnv(index_var_, "8");
+  SetEnv(total_var_, "9");
+  EXPECT_TRUE(ShouldShard(total_var_, index_var_, false));
+  EXPECT_FALSE(ShouldShard(total_var_, index_var_, true));
+
+  SetEnv(index_var_, "0");
+  SetEnv(total_var_, "9");
+  EXPECT_TRUE(ShouldShard(total_var_, index_var_, false));
+  EXPECT_FALSE(ShouldShard(total_var_, index_var_, true));
+}
+#endif  // !GTEST_OS_WINDOWS_MOBILE
+
+// Tests that we exit in error if the sharding values are not valid.
+
+typedef ShouldShardTest ShouldShardDeathTest;
+
+TEST_F(ShouldShardDeathTest, AbortsWhenShardingEnvVarsAreInvalid) {
+  SetEnv(index_var_, "4");
+  SetEnv(total_var_, "4");
+  EXPECT_DEATH_IF_SUPPORTED(ShouldShard(total_var_, index_var_, false), ".*");
+
+  SetEnv(index_var_, "4");
+  SetEnv(total_var_, "-2");
+  EXPECT_DEATH_IF_SUPPORTED(ShouldShard(total_var_, index_var_, false), ".*");
+
+  SetEnv(index_var_, "5");
+  SetEnv(total_var_, "");
+  EXPECT_DEATH_IF_SUPPORTED(ShouldShard(total_var_, index_var_, false), ".*");
+
+  SetEnv(index_var_, "");
+  SetEnv(total_var_, "5");
+  EXPECT_DEATH_IF_SUPPORTED(ShouldShard(total_var_, index_var_, false), ".*");
+}
+
+// Tests that ShouldRunTestOnShard is a partition when 5
+// shards are used.
+TEST(ShouldRunTestOnShardTest, IsPartitionWhenThereAreFiveShards) {
+  // Choose an arbitrary number of tests and shards.
+  const int num_tests = 17;
+  const int num_shards = 5;
+
+  // Check partitioning: each test should be on exactly 1 shard.
+  for (int test_id = 0; test_id < num_tests; test_id++) {
+    int prev_selected_shard_index = -1;
+    for (int shard_index = 0; shard_index < num_shards; shard_index++) {
+      if (ShouldRunTestOnShard(num_shards, shard_index, test_id)) {
+        if (prev_selected_shard_index < 0) {
+          prev_selected_shard_index = shard_index;
+        } else {
+          ADD_FAILURE() << "Shard " << prev_selected_shard_index << " and "
+            << shard_index << " are both selected to run test " << test_id;
+        }
+      }
+    }
+  }
+
+  // Check balance: This is not required by the sharding protocol, but is a
+  // desirable property for performance.
+  for (int shard_index = 0; shard_index < num_shards; shard_index++) {
+    int num_tests_on_shard = 0;
+    for (int test_id = 0; test_id < num_tests; test_id++) {
+      num_tests_on_shard +=
+        ShouldRunTestOnShard(num_shards, shard_index, test_id);
+    }
+    EXPECT_GE(num_tests_on_shard, num_tests / num_shards);
+  }
+}
+
+// For the same reason we are not explicitly testing everything in the
+// Test class, there are no separate tests for the following classes
+// (except for some trivial cases):
+//
+//   TestSuite, UnitTest, UnitTestResultPrinter.
+//
+// Similarly, there are no separate tests for the following macros:
+//
+//   TEST, TEST_F, RUN_ALL_TESTS
+
+TEST(UnitTestTest, CanGetOriginalWorkingDir) {
+  ASSERT_TRUE(UnitTest::GetInstance()->original_working_dir() != nullptr);
+  EXPECT_STRNE(UnitTest::GetInstance()->original_working_dir(), "");
+}
+
+TEST(UnitTestTest, ReturnsPlausibleTimestamp) {
+  EXPECT_LT(0, UnitTest::GetInstance()->start_timestamp());
+  EXPECT_LE(UnitTest::GetInstance()->start_timestamp(), GetTimeInMillis());
+}
+
+// When a property using a reserved key is supplied to this function, it
+// tests that a non-fatal failure is added, a fatal failure is not added,
+// and that the property is not recorded.
+void ExpectNonFatalFailureRecordingPropertyWithReservedKey(
+    const TestResult& test_result, const char* key) {
+  EXPECT_NONFATAL_FAILURE(Test::RecordProperty(key, "1"), "Reserved key");
+  ASSERT_EQ(0, test_result.test_property_count()) << "Property for key '" << key
+                                                  << "' recorded unexpectedly.";
+}
+
+void ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTest(
+    const char* key) {
+  const TestInfo* test_info = UnitTest::GetInstance()->current_test_info();
+  ASSERT_TRUE(test_info != nullptr);
+  ExpectNonFatalFailureRecordingPropertyWithReservedKey(*test_info->result(),
+                                                        key);
+}
+
+void ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTestSuite(
+    const char* key) {
+  const testing::TestSuite* test_suite =
+      UnitTest::GetInstance()->current_test_suite();
+  ASSERT_TRUE(test_suite != nullptr);
+  ExpectNonFatalFailureRecordingPropertyWithReservedKey(
+      test_suite->ad_hoc_test_result(), key);
+}
+
+void ExpectNonFatalFailureRecordingPropertyWithReservedKeyOutsideOfTestSuite(
+    const char* key) {
+  ExpectNonFatalFailureRecordingPropertyWithReservedKey(
+      UnitTest::GetInstance()->ad_hoc_test_result(), key);
+}
+
+// Tests that property recording functions in UnitTest outside of tests
+// functions correcly.  Creating a separate instance of UnitTest ensures it
+// is in a state similar to the UnitTest's singleton's between tests.
+class UnitTestRecordPropertyTest :
+    public testing::internal::UnitTestRecordPropertyTestHelper {
+ public:
+  static void SetUpTestSuite() {
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTestSuite(
+        "disabled");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTestSuite(
+        "errors");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTestSuite(
+        "failures");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTestSuite(
+        "name");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTestSuite(
+        "tests");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTestSuite(
+        "time");
+
+    Test::RecordProperty("test_case_key_1", "1");
+
+    const testing::TestSuite* test_suite =
+        UnitTest::GetInstance()->current_test_suite();
+
+    ASSERT_TRUE(test_suite != nullptr);
+
+    ASSERT_EQ(1, test_suite->ad_hoc_test_result().test_property_count());
+    EXPECT_STREQ("test_case_key_1",
+                 test_suite->ad_hoc_test_result().GetTestProperty(0).key());
+    EXPECT_STREQ("1",
+                 test_suite->ad_hoc_test_result().GetTestProperty(0).value());
+  }
+};
+
+// Tests TestResult has the expected property when added.
+TEST_F(UnitTestRecordPropertyTest, OnePropertyFoundWhenAdded) {
+  UnitTestRecordProperty("key_1", "1");
+
+  ASSERT_EQ(1, unit_test_.ad_hoc_test_result().test_property_count());
+
+  EXPECT_STREQ("key_1",
+               unit_test_.ad_hoc_test_result().GetTestProperty(0).key());
+  EXPECT_STREQ("1",
+               unit_test_.ad_hoc_test_result().GetTestProperty(0).value());
+}
+
+// Tests TestResult has multiple properties when added.
+TEST_F(UnitTestRecordPropertyTest, MultiplePropertiesFoundWhenAdded) {
+  UnitTestRecordProperty("key_1", "1");
+  UnitTestRecordProperty("key_2", "2");
+
+  ASSERT_EQ(2, unit_test_.ad_hoc_test_result().test_property_count());
+
+  EXPECT_STREQ("key_1",
+               unit_test_.ad_hoc_test_result().GetTestProperty(0).key());
+  EXPECT_STREQ("1", unit_test_.ad_hoc_test_result().GetTestProperty(0).value());
+
+  EXPECT_STREQ("key_2",
+               unit_test_.ad_hoc_test_result().GetTestProperty(1).key());
+  EXPECT_STREQ("2", unit_test_.ad_hoc_test_result().GetTestProperty(1).value());
+}
+
+// Tests TestResult::RecordProperty() overrides values for duplicate keys.
+TEST_F(UnitTestRecordPropertyTest, OverridesValuesForDuplicateKeys) {
+  UnitTestRecordProperty("key_1", "1");
+  UnitTestRecordProperty("key_2", "2");
+  UnitTestRecordProperty("key_1", "12");
+  UnitTestRecordProperty("key_2", "22");
+
+  ASSERT_EQ(2, unit_test_.ad_hoc_test_result().test_property_count());
+
+  EXPECT_STREQ("key_1",
+               unit_test_.ad_hoc_test_result().GetTestProperty(0).key());
+  EXPECT_STREQ("12",
+               unit_test_.ad_hoc_test_result().GetTestProperty(0).value());
+
+  EXPECT_STREQ("key_2",
+               unit_test_.ad_hoc_test_result().GetTestProperty(1).key());
+  EXPECT_STREQ("22",
+               unit_test_.ad_hoc_test_result().GetTestProperty(1).value());
+}
+
+TEST_F(UnitTestRecordPropertyTest,
+       AddFailureInsideTestsWhenUsingTestSuiteReservedKeys) {
+  ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTest(
+      "name");
+  ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTest(
+      "value_param");
+  ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTest(
+      "type_param");
+  ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTest(
+      "status");
+  ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTest(
+      "time");
+  ExpectNonFatalFailureRecordingPropertyWithReservedKeyForCurrentTest(
+      "classname");
+}
+
+TEST_F(UnitTestRecordPropertyTest,
+       AddRecordWithReservedKeysGeneratesCorrectPropertyList) {
+  EXPECT_NONFATAL_FAILURE(
+      Test::RecordProperty("name", "1"),
+      "'classname', 'name', 'status', 'time', 'type_param', 'value_param',"
+      " 'file', and 'line' are reserved");
+}
+
+class UnitTestRecordPropertyTestEnvironment : public Environment {
+ public:
+  void TearDown() override {
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyOutsideOfTestSuite(
+        "tests");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyOutsideOfTestSuite(
+        "failures");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyOutsideOfTestSuite(
+        "disabled");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyOutsideOfTestSuite(
+        "errors");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyOutsideOfTestSuite(
+        "name");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyOutsideOfTestSuite(
+        "timestamp");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyOutsideOfTestSuite(
+        "time");
+    ExpectNonFatalFailureRecordingPropertyWithReservedKeyOutsideOfTestSuite(
+        "random_seed");
+  }
+};
+
+// This will test property recording outside of any test or test case.
+static Environment* record_property_env GTEST_ATTRIBUTE_UNUSED_ =
+    AddGlobalTestEnvironment(new UnitTestRecordPropertyTestEnvironment);
+
+// This group of tests is for predicate assertions (ASSERT_PRED*, etc)
+// of various arities.  They do not attempt to be exhaustive.  Rather,
+// view them as smoke tests that can be easily reviewed and verified.
+// A more complete set of tests for predicate assertions can be found
+// in gtest_pred_impl_unittest.cc.
+
+// First, some predicates and predicate-formatters needed by the tests.
+
+// Returns true if and only if the argument is an even number.
+bool IsEven(int n) {
+  return (n % 2) == 0;
+}
+
+// A functor that returns true if and only if the argument is an even number.
+struct IsEvenFunctor {
+  bool operator()(int n) { return IsEven(n); }
+};
+
+// A predicate-formatter function that asserts the argument is an even
+// number.
+AssertionResult AssertIsEven(const char* expr, int n) {
+  if (IsEven(n)) {
+    return AssertionSuccess();
+  }
+
+  Message msg;
+  msg << expr << " evaluates to " << n << ", which is not even.";
+  return AssertionFailure(msg);
+}
+
+// A predicate function that returns AssertionResult for use in
+// EXPECT/ASSERT_TRUE/FALSE.
+AssertionResult ResultIsEven(int n) {
+  if (IsEven(n))
+    return AssertionSuccess() << n << " is even";
+  else
+    return AssertionFailure() << n << " is odd";
+}
+
+// A predicate function that returns AssertionResult but gives no
+// explanation why it succeeds. Needed for testing that
+// EXPECT/ASSERT_FALSE handles such functions correctly.
+AssertionResult ResultIsEvenNoExplanation(int n) {
+  if (IsEven(n))
+    return AssertionSuccess();
+  else
+    return AssertionFailure() << n << " is odd";
+}
+
+// A predicate-formatter functor that asserts the argument is an even
+// number.
+struct AssertIsEvenFunctor {
+  AssertionResult operator()(const char* expr, int n) {
+    return AssertIsEven(expr, n);
+  }
+};
+
+// Returns true if and only if the sum of the arguments is an even number.
+bool SumIsEven2(int n1, int n2) {
+  return IsEven(n1 + n2);
+}
+
+// A functor that returns true if and only if the sum of the arguments is an
+// even number.
+struct SumIsEven3Functor {
+  bool operator()(int n1, int n2, int n3) {
+    return IsEven(n1 + n2 + n3);
+  }
+};
+
+// A predicate-formatter function that asserts the sum of the
+// arguments is an even number.
+AssertionResult AssertSumIsEven4(
+    const char* e1, const char* e2, const char* e3, const char* e4,
+    int n1, int n2, int n3, int n4) {
+  const int sum = n1 + n2 + n3 + n4;
+  if (IsEven(sum)) {
+    return AssertionSuccess();
+  }
+
+  Message msg;
+  msg << e1 << " + " << e2 << " + " << e3 << " + " << e4
+      << " (" << n1 << " + " << n2 << " + " << n3 << " + " << n4
+      << ") evaluates to " << sum << ", which is not even.";
+  return AssertionFailure(msg);
+}
+
+// A predicate-formatter functor that asserts the sum of the arguments
+// is an even number.
+struct AssertSumIsEven5Functor {
+  AssertionResult operator()(
+      const char* e1, const char* e2, const char* e3, const char* e4,
+      const char* e5, int n1, int n2, int n3, int n4, int n5) {
+    const int sum = n1 + n2 + n3 + n4 + n5;
+    if (IsEven(sum)) {
+      return AssertionSuccess();
+    }
+
+    Message msg;
+    msg << e1 << " + " << e2 << " + " << e3 << " + " << e4 << " + " << e5
+        << " ("
+        << n1 << " + " << n2 << " + " << n3 << " + " << n4 << " + " << n5
+        << ") evaluates to " << sum << ", which is not even.";
+    return AssertionFailure(msg);
+  }
+};
+
+
+// Tests unary predicate assertions.
+
+// Tests unary predicate assertions that don't use a custom formatter.
+TEST(Pred1Test, WithoutFormat) {
+  // Success cases.
+  EXPECT_PRED1(IsEvenFunctor(), 2) << "This failure is UNEXPECTED!";
+  ASSERT_PRED1(IsEven, 4);
+
+  // Failure cases.
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED1(IsEven, 5) << "This failure is expected.";
+  }, "This failure is expected.");
+  EXPECT_FATAL_FAILURE(ASSERT_PRED1(IsEvenFunctor(), 5),
+                       "evaluates to false");
+}
+
+// Tests unary predicate assertions that use a custom formatter.
+TEST(Pred1Test, WithFormat) {
+  // Success cases.
+  EXPECT_PRED_FORMAT1(AssertIsEven, 2);
+  ASSERT_PRED_FORMAT1(AssertIsEvenFunctor(), 4)
+    << "This failure is UNEXPECTED!";
+
+  // Failure cases.
+  const int n = 5;
+  EXPECT_NONFATAL_FAILURE(EXPECT_PRED_FORMAT1(AssertIsEvenFunctor(), n),
+                          "n evaluates to 5, which is not even.");
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT1(AssertIsEven, 5) << "This failure is expected.";
+  }, "This failure is expected.");
+}
+
+// Tests that unary predicate assertions evaluates their arguments
+// exactly once.
+TEST(Pred1Test, SingleEvaluationOnFailure) {
+  // A success case.
+  static int n = 0;
+  EXPECT_PRED1(IsEven, n++);
+  EXPECT_EQ(1, n) << "The argument is not evaluated exactly once.";
+
+  // A failure case.
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT1(AssertIsEvenFunctor(), n++)
+        << "This failure is expected.";
+  }, "This failure is expected.");
+  EXPECT_EQ(2, n) << "The argument is not evaluated exactly once.";
+}
+
+
+// Tests predicate assertions whose arity is >= 2.
+
+// Tests predicate assertions that don't use a custom formatter.
+TEST(PredTest, WithoutFormat) {
+  // Success cases.
+  ASSERT_PRED2(SumIsEven2, 2, 4) << "This failure is UNEXPECTED!";
+  EXPECT_PRED3(SumIsEven3Functor(), 4, 6, 8);
+
+  // Failure cases.
+  const int n1 = 1;
+  const int n2 = 2;
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED2(SumIsEven2, n1, n2) << "This failure is expected.";
+  }, "This failure is expected.");
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED3(SumIsEven3Functor(), 1, 2, 4);
+  }, "evaluates to false");
+}
+
+// Tests predicate assertions that use a custom formatter.
+TEST(PredTest, WithFormat) {
+  // Success cases.
+  ASSERT_PRED_FORMAT4(AssertSumIsEven4, 4, 6, 8, 10) <<
+    "This failure is UNEXPECTED!";
+  EXPECT_PRED_FORMAT5(AssertSumIsEven5Functor(), 2, 4, 6, 8, 10);
+
+  // Failure cases.
+  const int n1 = 1;
+  const int n2 = 2;
+  const int n3 = 4;
+  const int n4 = 6;
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT4(AssertSumIsEven4, n1, n2, n3, n4);
+  }, "evaluates to 13, which is not even.");
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT5(AssertSumIsEven5Functor(), 1, 2, 4, 6, 8)
+        << "This failure is expected.";
+  }, "This failure is expected.");
+}
+
+// Tests that predicate assertions evaluates their arguments
+// exactly once.
+TEST(PredTest, SingleEvaluationOnFailure) {
+  // A success case.
+  int n1 = 0;
+  int n2 = 0;
+  EXPECT_PRED2(SumIsEven2, n1++, n2++);
+  EXPECT_EQ(1, n1) << "Argument 1 is not evaluated exactly once.";
+  EXPECT_EQ(1, n2) << "Argument 2 is not evaluated exactly once.";
+
+  // Another success case.
+  n1 = n2 = 0;
+  int n3 = 0;
+  int n4 = 0;
+  int n5 = 0;
+  ASSERT_PRED_FORMAT5(AssertSumIsEven5Functor(),
+                      n1++, n2++, n3++, n4++, n5++)
+                        << "This failure is UNEXPECTED!";
+  EXPECT_EQ(1, n1) << "Argument 1 is not evaluated exactly once.";
+  EXPECT_EQ(1, n2) << "Argument 2 is not evaluated exactly once.";
+  EXPECT_EQ(1, n3) << "Argument 3 is not evaluated exactly once.";
+  EXPECT_EQ(1, n4) << "Argument 4 is not evaluated exactly once.";
+  EXPECT_EQ(1, n5) << "Argument 5 is not evaluated exactly once.";
+
+  // A failure case.
+  n1 = n2 = n3 = 0;
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED3(SumIsEven3Functor(), ++n1, n2++, n3++)
+        << "This failure is expected.";
+  }, "This failure is expected.");
+  EXPECT_EQ(1, n1) << "Argument 1 is not evaluated exactly once.";
+  EXPECT_EQ(1, n2) << "Argument 2 is not evaluated exactly once.";
+  EXPECT_EQ(1, n3) << "Argument 3 is not evaluated exactly once.";
+
+  // Another failure case.
+  n1 = n2 = n3 = n4 = 0;
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT4(AssertSumIsEven4, ++n1, n2++, n3++, n4++);
+  }, "evaluates to 1, which is not even.");
+  EXPECT_EQ(1, n1) << "Argument 1 is not evaluated exactly once.";
+  EXPECT_EQ(1, n2) << "Argument 2 is not evaluated exactly once.";
+  EXPECT_EQ(1, n3) << "Argument 3 is not evaluated exactly once.";
+  EXPECT_EQ(1, n4) << "Argument 4 is not evaluated exactly once.";
+}
+
+// Test predicate assertions for sets
+TEST(PredTest, ExpectPredEvalFailure) {
+  std::set<int> set_a = {2, 1, 3, 4, 5};
+  std::set<int> set_b = {0, 4, 8};
+  const auto compare_sets = [] (std::set<int>, std::set<int>) { return false; };
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_PRED2(compare_sets, set_a, set_b),
+      "compare_sets(set_a, set_b) evaluates to false, where\nset_a evaluates "
+      "to { 1, 2, 3, 4, 5 }\nset_b evaluates to { 0, 4, 8 }");
+}
+
+// Some helper functions for testing using overloaded/template
+// functions with ASSERT_PREDn and EXPECT_PREDn.
+
+bool IsPositive(double x) {
+  return x > 0;
+}
+
+template <typename T>
+bool IsNegative(T x) {
+  return x < 0;
+}
+
+template <typename T1, typename T2>
+bool GreaterThan(T1 x1, T2 x2) {
+  return x1 > x2;
+}
+
+// Tests that overloaded functions can be used in *_PRED* as long as
+// their types are explicitly specified.
+TEST(PredicateAssertionTest, AcceptsOverloadedFunction) {
+  // C++Builder requires C-style casts rather than static_cast.
+  EXPECT_PRED1((bool (*)(int))(IsPositive), 5);  // NOLINT
+  ASSERT_PRED1((bool (*)(double))(IsPositive), 6.0);  // NOLINT
+}
+
+// Tests that template functions can be used in *_PRED* as long as
+// their types are explicitly specified.
+TEST(PredicateAssertionTest, AcceptsTemplateFunction) {
+  EXPECT_PRED1(IsNegative<int>, -5);
+  // Makes sure that we can handle templates with more than one
+  // parameter.
+  ASSERT_PRED2((GreaterThan<int, int>), 5, 0);
+}
+
+
+// Some helper functions for testing using overloaded/template
+// functions with ASSERT_PRED_FORMATn and EXPECT_PRED_FORMATn.
+
+AssertionResult IsPositiveFormat(const char* /* expr */, int n) {
+  return n > 0 ? AssertionSuccess() :
+      AssertionFailure(Message() << "Failure");
+}
+
+AssertionResult IsPositiveFormat(const char* /* expr */, double x) {
+  return x > 0 ? AssertionSuccess() :
+      AssertionFailure(Message() << "Failure");
+}
+
+template <typename T>
+AssertionResult IsNegativeFormat(const char* /* expr */, T x) {
+  return x < 0 ? AssertionSuccess() :
+      AssertionFailure(Message() << "Failure");
+}
+
+template <typename T1, typename T2>
+AssertionResult EqualsFormat(const char* /* expr1 */, const char* /* expr2 */,
+                             const T1& x1, const T2& x2) {
+  return x1 == x2 ? AssertionSuccess() :
+      AssertionFailure(Message() << "Failure");
+}
+
+// Tests that overloaded functions can be used in *_PRED_FORMAT*
+// without explicitly specifying their types.
+TEST(PredicateFormatAssertionTest, AcceptsOverloadedFunction) {
+  EXPECT_PRED_FORMAT1(IsPositiveFormat, 5);
+  ASSERT_PRED_FORMAT1(IsPositiveFormat, 6.0);
+}
+
+// Tests that template functions can be used in *_PRED_FORMAT* without
+// explicitly specifying their types.
+TEST(PredicateFormatAssertionTest, AcceptsTemplateFunction) {
+  EXPECT_PRED_FORMAT1(IsNegativeFormat, -5);
+  ASSERT_PRED_FORMAT2(EqualsFormat, 3, 3);
+}
+
+
+// Tests string assertions.
+
+// Tests ASSERT_STREQ with non-NULL arguments.
+TEST(StringAssertionTest, ASSERT_STREQ) {
+  const char * const p1 = "good";
+  ASSERT_STREQ(p1, p1);
+
+  // Let p2 have the same content as p1, but be at a different address.
+  const char p2[] = "good";
+  ASSERT_STREQ(p1, p2);
+
+  EXPECT_FATAL_FAILURE(ASSERT_STREQ("bad", "good"),
+                       "  \"bad\"\n  \"good\"");
+}
+
+// Tests ASSERT_STREQ with NULL arguments.
+TEST(StringAssertionTest, ASSERT_STREQ_Null) {
+  ASSERT_STREQ(static_cast<const char*>(nullptr), nullptr);
+  EXPECT_FATAL_FAILURE(ASSERT_STREQ(nullptr, "non-null"), "non-null");
+}
+
+// Tests ASSERT_STREQ with NULL arguments.
+TEST(StringAssertionTest, ASSERT_STREQ_Null2) {
+  EXPECT_FATAL_FAILURE(ASSERT_STREQ("non-null", nullptr), "non-null");
+}
+
+// Tests ASSERT_STRNE.
+TEST(StringAssertionTest, ASSERT_STRNE) {
+  ASSERT_STRNE("hi", "Hi");
+  ASSERT_STRNE("Hi", nullptr);
+  ASSERT_STRNE(nullptr, "Hi");
+  ASSERT_STRNE("", nullptr);
+  ASSERT_STRNE(nullptr, "");
+  ASSERT_STRNE("", "Hi");
+  ASSERT_STRNE("Hi", "");
+  EXPECT_FATAL_FAILURE(ASSERT_STRNE("Hi", "Hi"),
+                       "\"Hi\" vs \"Hi\"");
+}
+
+// Tests ASSERT_STRCASEEQ.
+TEST(StringAssertionTest, ASSERT_STRCASEEQ) {
+  ASSERT_STRCASEEQ("hi", "Hi");
+  ASSERT_STRCASEEQ(static_cast<const char*>(nullptr), nullptr);
+
+  ASSERT_STRCASEEQ("", "");
+  EXPECT_FATAL_FAILURE(ASSERT_STRCASEEQ("Hi", "hi2"),
+                       "Ignoring case");
+}
+
+// Tests ASSERT_STRCASENE.
+TEST(StringAssertionTest, ASSERT_STRCASENE) {
+  ASSERT_STRCASENE("hi1", "Hi2");
+  ASSERT_STRCASENE("Hi", nullptr);
+  ASSERT_STRCASENE(nullptr, "Hi");
+  ASSERT_STRCASENE("", nullptr);
+  ASSERT_STRCASENE(nullptr, "");
+  ASSERT_STRCASENE("", "Hi");
+  ASSERT_STRCASENE("Hi", "");
+  EXPECT_FATAL_FAILURE(ASSERT_STRCASENE("Hi", "hi"),
+                       "(ignoring case)");
+}
+
+// Tests *_STREQ on wide strings.
+TEST(StringAssertionTest, STREQ_Wide) {
+  // NULL strings.
+  ASSERT_STREQ(static_cast<const wchar_t*>(nullptr), nullptr);
+
+  // Empty strings.
+  ASSERT_STREQ(L"", L"");
+
+  // Non-null vs NULL.
+  EXPECT_NONFATAL_FAILURE(EXPECT_STREQ(L"non-null", nullptr), "non-null");
+
+  // Equal strings.
+  EXPECT_STREQ(L"Hi", L"Hi");
+
+  // Unequal strings.
+  EXPECT_NONFATAL_FAILURE(EXPECT_STREQ(L"abc", L"Abc"),
+                          "Abc");
+
+  // Strings containing wide characters.
+  EXPECT_NONFATAL_FAILURE(EXPECT_STREQ(L"abc\x8119", L"abc\x8120"),
+                          "abc");
+
+  // The streaming variation.
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_STREQ(L"abc\x8119", L"abc\x8121") << "Expected failure";
+  }, "Expected failure");
+}
+
+// Tests *_STRNE on wide strings.
+TEST(StringAssertionTest, STRNE_Wide) {
+  // NULL strings.
+  EXPECT_NONFATAL_FAILURE(
+      {  // NOLINT
+        EXPECT_STRNE(static_cast<const wchar_t*>(nullptr), nullptr);
+      },
+      "");
+
+  // Empty strings.
+  EXPECT_NONFATAL_FAILURE(EXPECT_STRNE(L"", L""),
+                          "L\"\"");
+
+  // Non-null vs NULL.
+  ASSERT_STRNE(L"non-null", nullptr);
+
+  // Equal strings.
+  EXPECT_NONFATAL_FAILURE(EXPECT_STRNE(L"Hi", L"Hi"),
+                          "L\"Hi\"");
+
+  // Unequal strings.
+  EXPECT_STRNE(L"abc", L"Abc");
+
+  // Strings containing wide characters.
+  EXPECT_NONFATAL_FAILURE(EXPECT_STRNE(L"abc\x8119", L"abc\x8119"),
+                          "abc");
+
+  // The streaming variation.
+  ASSERT_STRNE(L"abc\x8119", L"abc\x8120") << "This shouldn't happen";
+}
+
+// Tests for ::testing::IsSubstring().
+
+// Tests that IsSubstring() returns the correct result when the input
+// argument type is const char*.
+TEST(IsSubstringTest, ReturnsCorrectResultForCString) {
+  EXPECT_FALSE(IsSubstring("", "", nullptr, "a"));
+  EXPECT_FALSE(IsSubstring("", "", "b", nullptr));
+  EXPECT_FALSE(IsSubstring("", "", "needle", "haystack"));
+
+  EXPECT_TRUE(IsSubstring("", "", static_cast<const char*>(nullptr), nullptr));
+  EXPECT_TRUE(IsSubstring("", "", "needle", "two needles"));
+}
+
+// Tests that IsSubstring() returns the correct result when the input
+// argument type is const wchar_t*.
+TEST(IsSubstringTest, ReturnsCorrectResultForWideCString) {
+  EXPECT_FALSE(IsSubstring("", "", kNull, L"a"));
+  EXPECT_FALSE(IsSubstring("", "", L"b", kNull));
+  EXPECT_FALSE(IsSubstring("", "", L"needle", L"haystack"));
+
+  EXPECT_TRUE(
+      IsSubstring("", "", static_cast<const wchar_t*>(nullptr), nullptr));
+  EXPECT_TRUE(IsSubstring("", "", L"needle", L"two needles"));
+}
+
+// Tests that IsSubstring() generates the correct message when the input
+// argument type is const char*.
+TEST(IsSubstringTest, GeneratesCorrectMessageForCString) {
+  EXPECT_STREQ("Value of: needle_expr\n"
+               "  Actual: \"needle\"\n"
+               "Expected: a substring of haystack_expr\n"
+               "Which is: \"haystack\"",
+               IsSubstring("needle_expr", "haystack_expr",
+                           "needle", "haystack").failure_message());
+}
+
+// Tests that IsSubstring returns the correct result when the input
+// argument type is ::std::string.
+TEST(IsSubstringTest, ReturnsCorrectResultsForStdString) {
+  EXPECT_TRUE(IsSubstring("", "", std::string("hello"), "ahellob"));
+  EXPECT_FALSE(IsSubstring("", "", "hello", std::string("world")));
+}
+
+#if GTEST_HAS_STD_WSTRING
+// Tests that IsSubstring returns the correct result when the input
+// argument type is ::std::wstring.
+TEST(IsSubstringTest, ReturnsCorrectResultForStdWstring) {
+  EXPECT_TRUE(IsSubstring("", "", ::std::wstring(L"needle"), L"two needles"));
+  EXPECT_FALSE(IsSubstring("", "", L"needle", ::std::wstring(L"haystack")));
+}
+
+// Tests that IsSubstring() generates the correct message when the input
+// argument type is ::std::wstring.
+TEST(IsSubstringTest, GeneratesCorrectMessageForWstring) {
+  EXPECT_STREQ("Value of: needle_expr\n"
+               "  Actual: L\"needle\"\n"
+               "Expected: a substring of haystack_expr\n"
+               "Which is: L\"haystack\"",
+               IsSubstring(
+                   "needle_expr", "haystack_expr",
+                   ::std::wstring(L"needle"), L"haystack").failure_message());
+}
+
+#endif  // GTEST_HAS_STD_WSTRING
+
+// Tests for ::testing::IsNotSubstring().
+
+// Tests that IsNotSubstring() returns the correct result when the input
+// argument type is const char*.
+TEST(IsNotSubstringTest, ReturnsCorrectResultForCString) {
+  EXPECT_TRUE(IsNotSubstring("", "", "needle", "haystack"));
+  EXPECT_FALSE(IsNotSubstring("", "", "needle", "two needles"));
+}
+
+// Tests that IsNotSubstring() returns the correct result when the input
+// argument type is const wchar_t*.
+TEST(IsNotSubstringTest, ReturnsCorrectResultForWideCString) {
+  EXPECT_TRUE(IsNotSubstring("", "", L"needle", L"haystack"));
+  EXPECT_FALSE(IsNotSubstring("", "", L"needle", L"two needles"));
+}
+
+// Tests that IsNotSubstring() generates the correct message when the input
+// argument type is const wchar_t*.
+TEST(IsNotSubstringTest, GeneratesCorrectMessageForWideCString) {
+  EXPECT_STREQ("Value of: needle_expr\n"
+               "  Actual: L\"needle\"\n"
+               "Expected: not a substring of haystack_expr\n"
+               "Which is: L\"two needles\"",
+               IsNotSubstring(
+                   "needle_expr", "haystack_expr",
+                   L"needle", L"two needles").failure_message());
+}
+
+// Tests that IsNotSubstring returns the correct result when the input
+// argument type is ::std::string.
+TEST(IsNotSubstringTest, ReturnsCorrectResultsForStdString) {
+  EXPECT_FALSE(IsNotSubstring("", "", std::string("hello"), "ahellob"));
+  EXPECT_TRUE(IsNotSubstring("", "", "hello", std::string("world")));
+}
+
+// Tests that IsNotSubstring() generates the correct message when the input
+// argument type is ::std::string.
+TEST(IsNotSubstringTest, GeneratesCorrectMessageForStdString) {
+  EXPECT_STREQ("Value of: needle_expr\n"
+               "  Actual: \"needle\"\n"
+               "Expected: not a substring of haystack_expr\n"
+               "Which is: \"two needles\"",
+               IsNotSubstring(
+                   "needle_expr", "haystack_expr",
+                   ::std::string("needle"), "two needles").failure_message());
+}
+
+#if GTEST_HAS_STD_WSTRING
+
+// Tests that IsNotSubstring returns the correct result when the input
+// argument type is ::std::wstring.
+TEST(IsNotSubstringTest, ReturnsCorrectResultForStdWstring) {
+  EXPECT_FALSE(
+      IsNotSubstring("", "", ::std::wstring(L"needle"), L"two needles"));
+  EXPECT_TRUE(IsNotSubstring("", "", L"needle", ::std::wstring(L"haystack")));
+}
+
+#endif  // GTEST_HAS_STD_WSTRING
+
+// Tests floating-point assertions.
+
+template <typename RawType>
+class FloatingPointTest : public Test {
+ protected:
+  // Pre-calculated numbers to be used by the tests.
+  struct TestValues {
+    RawType close_to_positive_zero;
+    RawType close_to_negative_zero;
+    RawType further_from_negative_zero;
+
+    RawType close_to_one;
+    RawType further_from_one;
+
+    RawType infinity;
+    RawType close_to_infinity;
+    RawType further_from_infinity;
+
+    RawType nan1;
+    RawType nan2;
+  };
+
+  typedef typename testing::internal::FloatingPoint<RawType> Floating;
+  typedef typename Floating::Bits Bits;
+
+  void SetUp() override {
+    const size_t max_ulps = Floating::kMaxUlps;
+
+    // The bits that represent 0.0.
+    const Bits zero_bits = Floating(0).bits();
+
+    // Makes some numbers close to 0.0.
+    values_.close_to_positive_zero = Floating::ReinterpretBits(
+        zero_bits + max_ulps/2);
+    values_.close_to_negative_zero = -Floating::ReinterpretBits(
+        zero_bits + max_ulps - max_ulps/2);
+    values_.further_from_negative_zero = -Floating::ReinterpretBits(
+        zero_bits + max_ulps + 1 - max_ulps/2);
+
+    // The bits that represent 1.0.
+    const Bits one_bits = Floating(1).bits();
+
+    // Makes some numbers close to 1.0.
+    values_.close_to_one = Floating::ReinterpretBits(one_bits + max_ulps);
+    values_.further_from_one = Floating::ReinterpretBits(
+        one_bits + max_ulps + 1);
+
+    // +infinity.
+    values_.infinity = Floating::Infinity();
+
+    // The bits that represent +infinity.
+    const Bits infinity_bits = Floating(values_.infinity).bits();
+
+    // Makes some numbers close to infinity.
+    values_.close_to_infinity = Floating::ReinterpretBits(
+        infinity_bits - max_ulps);
+    values_.further_from_infinity = Floating::ReinterpretBits(
+        infinity_bits - max_ulps - 1);
+
+    // Makes some NAN's.  Sets the most significant bit of the fraction so that
+    // our NaN's are quiet; trying to process a signaling NaN would raise an
+    // exception if our environment enables floating point exceptions.
+    values_.nan1 = Floating::ReinterpretBits(Floating::kExponentBitMask
+        | (static_cast<Bits>(1) << (Floating::kFractionBitCount - 1)) | 1);
+    values_.nan2 = Floating::ReinterpretBits(Floating::kExponentBitMask
+        | (static_cast<Bits>(1) << (Floating::kFractionBitCount - 1)) | 200);
+  }
+
+  void TestSize() {
+    EXPECT_EQ(sizeof(RawType), sizeof(Bits));
+  }
+
+  static TestValues values_;
+};
+
+template <typename RawType>
+typename FloatingPointTest<RawType>::TestValues
+    FloatingPointTest<RawType>::values_;
+
+// Instantiates FloatingPointTest for testing *_FLOAT_EQ.
+typedef FloatingPointTest<float> FloatTest;
+
+// Tests that the size of Float::Bits matches the size of float.
+TEST_F(FloatTest, Size) {
+  TestSize();
+}
+
+// Tests comparing with +0 and -0.
+TEST_F(FloatTest, Zeros) {
+  EXPECT_FLOAT_EQ(0.0, -0.0);
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(-0.0, 1.0),
+                          "1.0");
+  EXPECT_FATAL_FAILURE(ASSERT_FLOAT_EQ(0.0, 1.5),
+                       "1.5");
+}
+
+// Tests comparing numbers close to 0.
+//
+// This ensures that *_FLOAT_EQ handles the sign correctly and no
+// overflow occurs when comparing numbers whose absolute value is very
+// small.
+TEST_F(FloatTest, AlmostZeros) {
+  // In C++Builder, names within local classes (such as used by
+  // EXPECT_FATAL_FAILURE) cannot be resolved against static members of the
+  // scoping class.  Use a static local alias as a workaround.
+  // We use the assignment syntax since some compilers, like Sun Studio,
+  // don't allow initializing references using construction syntax
+  // (parentheses).
+  static const FloatTest::TestValues& v = this->values_;
+
+  EXPECT_FLOAT_EQ(0.0, v.close_to_positive_zero);
+  EXPECT_FLOAT_EQ(-0.0, v.close_to_negative_zero);
+  EXPECT_FLOAT_EQ(v.close_to_positive_zero, v.close_to_negative_zero);
+
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_FLOAT_EQ(v.close_to_positive_zero,
+                    v.further_from_negative_zero);
+  }, "v.further_from_negative_zero");
+}
+
+// Tests comparing numbers close to each other.
+TEST_F(FloatTest, SmallDiff) {
+  EXPECT_FLOAT_EQ(1.0, values_.close_to_one);
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(1.0, values_.further_from_one),
+                          "values_.further_from_one");
+}
+
+// Tests comparing numbers far apart.
+TEST_F(FloatTest, LargeDiff) {
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(2.5, 3.0),
+                          "3.0");
+}
+
+// Tests comparing with infinity.
+//
+// This ensures that no overflow occurs when comparing numbers whose
+// absolute value is very large.
+TEST_F(FloatTest, Infinity) {
+  EXPECT_FLOAT_EQ(values_.infinity, values_.close_to_infinity);
+  EXPECT_FLOAT_EQ(-values_.infinity, -values_.close_to_infinity);
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(values_.infinity, -values_.infinity),
+                          "-values_.infinity");
+
+  // This is interesting as the representations of infinity and nan1
+  // are only 1 DLP apart.
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(values_.infinity, values_.nan1),
+                          "values_.nan1");
+}
+
+// Tests that comparing with NAN always returns false.
+TEST_F(FloatTest, NaN) {
+  // In C++Builder, names within local classes (such as used by
+  // EXPECT_FATAL_FAILURE) cannot be resolved against static members of the
+  // scoping class.  Use a static local alias as a workaround.
+  // We use the assignment syntax since some compilers, like Sun Studio,
+  // don't allow initializing references using construction syntax
+  // (parentheses).
+  static const FloatTest::TestValues& v = this->values_;
+
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(v.nan1, v.nan1),
+                          "v.nan1");
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(v.nan1, v.nan2),
+                          "v.nan2");
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(1.0, v.nan1),
+                          "v.nan1");
+
+  EXPECT_FATAL_FAILURE(ASSERT_FLOAT_EQ(v.nan1, v.infinity),
+                       "v.infinity");
+}
+
+// Tests that *_FLOAT_EQ are reflexive.
+TEST_F(FloatTest, Reflexive) {
+  EXPECT_FLOAT_EQ(0.0, 0.0);
+  EXPECT_FLOAT_EQ(1.0, 1.0);
+  ASSERT_FLOAT_EQ(values_.infinity, values_.infinity);
+}
+
+// Tests that *_FLOAT_EQ are commutative.
+TEST_F(FloatTest, Commutative) {
+  // We already tested EXPECT_FLOAT_EQ(1.0, values_.close_to_one).
+  EXPECT_FLOAT_EQ(values_.close_to_one, 1.0);
+
+  // We already tested EXPECT_FLOAT_EQ(1.0, values_.further_from_one).
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(values_.further_from_one, 1.0),
+                          "1.0");
+}
+
+// Tests EXPECT_NEAR.
+TEST_F(FloatTest, EXPECT_NEAR) {
+  EXPECT_NEAR(-1.0f, -1.1f, 0.2f);
+  EXPECT_NEAR(2.0f, 3.0f, 1.0f);
+  EXPECT_NONFATAL_FAILURE(EXPECT_NEAR(1.0f,1.5f, 0.25f),  // NOLINT
+                          "The difference between 1.0f and 1.5f is 0.5, "
+                          "which exceeds 0.25f");
+  // To work around a bug in gcc 2.95.0, there is intentionally no
+  // space after the first comma in the previous line.
+}
+
+// Tests ASSERT_NEAR.
+TEST_F(FloatTest, ASSERT_NEAR) {
+  ASSERT_NEAR(-1.0f, -1.1f, 0.2f);
+  ASSERT_NEAR(2.0f, 3.0f, 1.0f);
+  EXPECT_FATAL_FAILURE(ASSERT_NEAR(1.0f,1.5f, 0.25f),  // NOLINT
+                       "The difference between 1.0f and 1.5f is 0.5, "
+                       "which exceeds 0.25f");
+  // To work around a bug in gcc 2.95.0, there is intentionally no
+  // space after the first comma in the previous line.
+}
+
+// Tests the cases where FloatLE() should succeed.
+TEST_F(FloatTest, FloatLESucceeds) {
+  EXPECT_PRED_FORMAT2(FloatLE, 1.0f, 2.0f);  // When val1 < val2,
+  ASSERT_PRED_FORMAT2(FloatLE, 1.0f, 1.0f);  // val1 == val2,
+
+  // or when val1 is greater than, but almost equals to, val2.
+  EXPECT_PRED_FORMAT2(FloatLE, values_.close_to_positive_zero, 0.0f);
+}
+
+// Tests the cases where FloatLE() should fail.
+TEST_F(FloatTest, FloatLEFails) {
+  // When val1 is greater than val2 by a large margin,
+  EXPECT_NONFATAL_FAILURE(EXPECT_PRED_FORMAT2(FloatLE, 2.0f, 1.0f),
+                          "(2.0f) <= (1.0f)");
+
+  // or by a small yet non-negligible margin,
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(FloatLE, values_.further_from_one, 1.0f);
+  }, "(values_.further_from_one) <= (1.0f)");
+
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(FloatLE, values_.nan1, values_.infinity);
+  }, "(values_.nan1) <= (values_.infinity)");
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(FloatLE, -values_.infinity, values_.nan1);
+  }, "(-values_.infinity) <= (values_.nan1)");
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT2(FloatLE, values_.nan1, values_.nan1);
+  }, "(values_.nan1) <= (values_.nan1)");
+}
+
+// Instantiates FloatingPointTest for testing *_DOUBLE_EQ.
+typedef FloatingPointTest<double> DoubleTest;
+
+// Tests that the size of Double::Bits matches the size of double.
+TEST_F(DoubleTest, Size) {
+  TestSize();
+}
+
+// Tests comparing with +0 and -0.
+TEST_F(DoubleTest, Zeros) {
+  EXPECT_DOUBLE_EQ(0.0, -0.0);
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(-0.0, 1.0),
+                          "1.0");
+  EXPECT_FATAL_FAILURE(ASSERT_DOUBLE_EQ(0.0, 1.0),
+                       "1.0");
+}
+
+// Tests comparing numbers close to 0.
+//
+// This ensures that *_DOUBLE_EQ handles the sign correctly and no
+// overflow occurs when comparing numbers whose absolute value is very
+// small.
+TEST_F(DoubleTest, AlmostZeros) {
+  // In C++Builder, names within local classes (such as used by
+  // EXPECT_FATAL_FAILURE) cannot be resolved against static members of the
+  // scoping class.  Use a static local alias as a workaround.
+  // We use the assignment syntax since some compilers, like Sun Studio,
+  // don't allow initializing references using construction syntax
+  // (parentheses).
+  static const DoubleTest::TestValues& v = this->values_;
+
+  EXPECT_DOUBLE_EQ(0.0, v.close_to_positive_zero);
+  EXPECT_DOUBLE_EQ(-0.0, v.close_to_negative_zero);
+  EXPECT_DOUBLE_EQ(v.close_to_positive_zero, v.close_to_negative_zero);
+
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_DOUBLE_EQ(v.close_to_positive_zero,
+                     v.further_from_negative_zero);
+  }, "v.further_from_negative_zero");
+}
+
+// Tests comparing numbers close to each other.
+TEST_F(DoubleTest, SmallDiff) {
+  EXPECT_DOUBLE_EQ(1.0, values_.close_to_one);
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(1.0, values_.further_from_one),
+                          "values_.further_from_one");
+}
+
+// Tests comparing numbers far apart.
+TEST_F(DoubleTest, LargeDiff) {
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(2.0, 3.0),
+                          "3.0");
+}
+
+// Tests comparing with infinity.
+//
+// This ensures that no overflow occurs when comparing numbers whose
+// absolute value is very large.
+TEST_F(DoubleTest, Infinity) {
+  EXPECT_DOUBLE_EQ(values_.infinity, values_.close_to_infinity);
+  EXPECT_DOUBLE_EQ(-values_.infinity, -values_.close_to_infinity);
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(values_.infinity, -values_.infinity),
+                          "-values_.infinity");
+
+  // This is interesting as the representations of infinity_ and nan1_
+  // are only 1 DLP apart.
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(values_.infinity, values_.nan1),
+                          "values_.nan1");
+}
+
+// Tests that comparing with NAN always returns false.
+TEST_F(DoubleTest, NaN) {
+  static const DoubleTest::TestValues& v = this->values_;
+
+  // Nokia's STLport crashes if we try to output infinity or NaN.
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(v.nan1, v.nan1),
+                          "v.nan1");
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(v.nan1, v.nan2), "v.nan2");
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(1.0, v.nan1), "v.nan1");
+  EXPECT_FATAL_FAILURE(ASSERT_DOUBLE_EQ(v.nan1, v.infinity),
+                       "v.infinity");
+}
+
+// Tests that *_DOUBLE_EQ are reflexive.
+TEST_F(DoubleTest, Reflexive) {
+  EXPECT_DOUBLE_EQ(0.0, 0.0);
+  EXPECT_DOUBLE_EQ(1.0, 1.0);
+  ASSERT_DOUBLE_EQ(values_.infinity, values_.infinity);
+}
+
+// Tests that *_DOUBLE_EQ are commutative.
+TEST_F(DoubleTest, Commutative) {
+  // We already tested EXPECT_DOUBLE_EQ(1.0, values_.close_to_one).
+  EXPECT_DOUBLE_EQ(values_.close_to_one, 1.0);
+
+  // We already tested EXPECT_DOUBLE_EQ(1.0, values_.further_from_one).
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(values_.further_from_one, 1.0),
+                          "1.0");
+}
+
+// Tests EXPECT_NEAR.
+TEST_F(DoubleTest, EXPECT_NEAR) {
+  EXPECT_NEAR(-1.0, -1.1, 0.2);
+  EXPECT_NEAR(2.0, 3.0, 1.0);
+  EXPECT_NONFATAL_FAILURE(EXPECT_NEAR(1.0, 1.5, 0.25),  // NOLINT
+                          "The difference between 1.0 and 1.5 is 0.5, "
+                          "which exceeds 0.25");
+  // To work around a bug in gcc 2.95.0, there is intentionally no
+  // space after the first comma in the previous statement.
+}
+
+// Tests ASSERT_NEAR.
+TEST_F(DoubleTest, ASSERT_NEAR) {
+  ASSERT_NEAR(-1.0, -1.1, 0.2);
+  ASSERT_NEAR(2.0, 3.0, 1.0);
+  EXPECT_FATAL_FAILURE(ASSERT_NEAR(1.0, 1.5, 0.25),  // NOLINT
+                       "The difference between 1.0 and 1.5 is 0.5, "
+                       "which exceeds 0.25");
+  // To work around a bug in gcc 2.95.0, there is intentionally no
+  // space after the first comma in the previous statement.
+}
+
+// Tests the cases where DoubleLE() should succeed.
+TEST_F(DoubleTest, DoubleLESucceeds) {
+  EXPECT_PRED_FORMAT2(DoubleLE, 1.0, 2.0);  // When val1 < val2,
+  ASSERT_PRED_FORMAT2(DoubleLE, 1.0, 1.0);  // val1 == val2,
+
+  // or when val1 is greater than, but almost equals to, val2.
+  EXPECT_PRED_FORMAT2(DoubleLE, values_.close_to_positive_zero, 0.0);
+}
+
+// Tests the cases where DoubleLE() should fail.
+TEST_F(DoubleTest, DoubleLEFails) {
+  // When val1 is greater than val2 by a large margin,
+  EXPECT_NONFATAL_FAILURE(EXPECT_PRED_FORMAT2(DoubleLE, 2.0, 1.0),
+                          "(2.0) <= (1.0)");
+
+  // or by a small yet non-negligible margin,
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(DoubleLE, values_.further_from_one, 1.0);
+  }, "(values_.further_from_one) <= (1.0)");
+
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(DoubleLE, values_.nan1, values_.infinity);
+  }, "(values_.nan1) <= (values_.infinity)");
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_PRED_FORMAT2(DoubleLE, -values_.infinity, values_.nan1);
+  }, " (-values_.infinity) <= (values_.nan1)");
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_PRED_FORMAT2(DoubleLE, values_.nan1, values_.nan1);
+  }, "(values_.nan1) <= (values_.nan1)");
+}
+
+
+// Verifies that a test or test case whose name starts with DISABLED_ is
+// not run.
+
+// A test whose name starts with DISABLED_.
+// Should not run.
+TEST(DisabledTest, DISABLED_TestShouldNotRun) {
+  FAIL() << "Unexpected failure: Disabled test should not be run.";
+}
+
+// A test whose name does not start with DISABLED_.
+// Should run.
+TEST(DisabledTest, NotDISABLED_TestShouldRun) {
+  EXPECT_EQ(1, 1);
+}
+
+// A test case whose name starts with DISABLED_.
+// Should not run.
+TEST(DISABLED_TestSuite, TestShouldNotRun) {
+  FAIL() << "Unexpected failure: Test in disabled test case should not be run.";
+}
+
+// A test case and test whose names start with DISABLED_.
+// Should not run.
+TEST(DISABLED_TestSuite, DISABLED_TestShouldNotRun) {
+  FAIL() << "Unexpected failure: Test in disabled test case should not be run.";
+}
+
+// Check that when all tests in a test case are disabled, SetUpTestSuite() and
+// TearDownTestSuite() are not called.
+class DisabledTestsTest : public Test {
+ protected:
+  static void SetUpTestSuite() {
+    FAIL() << "Unexpected failure: All tests disabled in test case. "
+              "SetUpTestSuite() should not be called.";
+  }
+
+  static void TearDownTestSuite() {
+    FAIL() << "Unexpected failure: All tests disabled in test case. "
+              "TearDownTestSuite() should not be called.";
+  }
+};
+
+TEST_F(DisabledTestsTest, DISABLED_TestShouldNotRun_1) {
+  FAIL() << "Unexpected failure: Disabled test should not be run.";
+}
+
+TEST_F(DisabledTestsTest, DISABLED_TestShouldNotRun_2) {
+  FAIL() << "Unexpected failure: Disabled test should not be run.";
+}
+
+// Tests that disabled typed tests aren't run.
+
+#if GTEST_HAS_TYPED_TEST
+
+template <typename T>
+class TypedTest : public Test {
+};
+
+typedef testing::Types<int, double> NumericTypes;
+TYPED_TEST_SUITE(TypedTest, NumericTypes);
+
+TYPED_TEST(TypedTest, DISABLED_ShouldNotRun) {
+  FAIL() << "Unexpected failure: Disabled typed test should not run.";
+}
+
+template <typename T>
+class DISABLED_TypedTest : public Test {
+};
+
+TYPED_TEST_SUITE(DISABLED_TypedTest, NumericTypes);
+
+TYPED_TEST(DISABLED_TypedTest, ShouldNotRun) {
+  FAIL() << "Unexpected failure: Disabled typed test should not run.";
+}
+
+#endif  // GTEST_HAS_TYPED_TEST
+
+// Tests that disabled type-parameterized tests aren't run.
+
+#if GTEST_HAS_TYPED_TEST_P
+
+template <typename T>
+class TypedTestP : public Test {
+};
+
+TYPED_TEST_SUITE_P(TypedTestP);
+
+TYPED_TEST_P(TypedTestP, DISABLED_ShouldNotRun) {
+  FAIL() << "Unexpected failure: "
+         << "Disabled type-parameterized test should not run.";
+}
+
+REGISTER_TYPED_TEST_SUITE_P(TypedTestP, DISABLED_ShouldNotRun);
+
+INSTANTIATE_TYPED_TEST_SUITE_P(My, TypedTestP, NumericTypes);
+
+template <typename T>
+class DISABLED_TypedTestP : public Test {
+};
+
+TYPED_TEST_SUITE_P(DISABLED_TypedTestP);
+
+TYPED_TEST_P(DISABLED_TypedTestP, ShouldNotRun) {
+  FAIL() << "Unexpected failure: "
+         << "Disabled type-parameterized test should not run.";
+}
+
+REGISTER_TYPED_TEST_SUITE_P(DISABLED_TypedTestP, ShouldNotRun);
+
+INSTANTIATE_TYPED_TEST_SUITE_P(My, DISABLED_TypedTestP, NumericTypes);
+
+#endif  // GTEST_HAS_TYPED_TEST_P
+
+// Tests that assertion macros evaluate their arguments exactly once.
+
+class SingleEvaluationTest : public Test {
+ public:  // Must be public and not protected due to a bug in g++ 3.4.2.
+  // This helper function is needed by the FailedASSERT_STREQ test
+  // below.  It's public to work around C++Builder's bug with scoping local
+  // classes.
+  static void CompareAndIncrementCharPtrs() {
+    ASSERT_STREQ(p1_++, p2_++);
+  }
+
+  // This helper function is needed by the FailedASSERT_NE test below.  It's
+  // public to work around C++Builder's bug with scoping local classes.
+  static void CompareAndIncrementInts() {
+    ASSERT_NE(a_++, b_++);
+  }
+
+ protected:
+  SingleEvaluationTest() {
+    p1_ = s1_;
+    p2_ = s2_;
+    a_ = 0;
+    b_ = 0;
+  }
+
+  static const char* const s1_;
+  static const char* const s2_;
+  static const char* p1_;
+  static const char* p2_;
+
+  static int a_;
+  static int b_;
+};
+
+const char* const SingleEvaluationTest::s1_ = "01234";
+const char* const SingleEvaluationTest::s2_ = "abcde";
+const char* SingleEvaluationTest::p1_;
+const char* SingleEvaluationTest::p2_;
+int SingleEvaluationTest::a_;
+int SingleEvaluationTest::b_;
+
+// Tests that when ASSERT_STREQ fails, it evaluates its arguments
+// exactly once.
+TEST_F(SingleEvaluationTest, FailedASSERT_STREQ) {
+  EXPECT_FATAL_FAILURE(SingleEvaluationTest::CompareAndIncrementCharPtrs(),
+                       "p2_++");
+  EXPECT_EQ(s1_ + 1, p1_);
+  EXPECT_EQ(s2_ + 1, p2_);
+}
+
+// Tests that string assertion arguments are evaluated exactly once.
+TEST_F(SingleEvaluationTest, ASSERT_STR) {
+  // successful EXPECT_STRNE
+  EXPECT_STRNE(p1_++, p2_++);
+  EXPECT_EQ(s1_ + 1, p1_);
+  EXPECT_EQ(s2_ + 1, p2_);
+
+  // failed EXPECT_STRCASEEQ
+  EXPECT_NONFATAL_FAILURE(EXPECT_STRCASEEQ(p1_++, p2_++),
+                          "Ignoring case");
+  EXPECT_EQ(s1_ + 2, p1_);
+  EXPECT_EQ(s2_ + 2, p2_);
+}
+
+// Tests that when ASSERT_NE fails, it evaluates its arguments exactly
+// once.
+TEST_F(SingleEvaluationTest, FailedASSERT_NE) {
+  EXPECT_FATAL_FAILURE(SingleEvaluationTest::CompareAndIncrementInts(),
+                       "(a_++) != (b_++)");
+  EXPECT_EQ(1, a_);
+  EXPECT_EQ(1, b_);
+}
+
+// Tests that assertion arguments are evaluated exactly once.
+TEST_F(SingleEvaluationTest, OtherCases) {
+  // successful EXPECT_TRUE
+  EXPECT_TRUE(0 == a_++);  // NOLINT
+  EXPECT_EQ(1, a_);
+
+  // failed EXPECT_TRUE
+  EXPECT_NONFATAL_FAILURE(EXPECT_TRUE(-1 == a_++), "-1 == a_++");
+  EXPECT_EQ(2, a_);
+
+  // successful EXPECT_GT
+  EXPECT_GT(a_++, b_++);
+  EXPECT_EQ(3, a_);
+  EXPECT_EQ(1, b_);
+
+  // failed EXPECT_LT
+  EXPECT_NONFATAL_FAILURE(EXPECT_LT(a_++, b_++), "(a_++) < (b_++)");
+  EXPECT_EQ(4, a_);
+  EXPECT_EQ(2, b_);
+
+  // successful ASSERT_TRUE
+  ASSERT_TRUE(0 < a_++);  // NOLINT
+  EXPECT_EQ(5, a_);
+
+  // successful ASSERT_GT
+  ASSERT_GT(a_++, b_++);
+  EXPECT_EQ(6, a_);
+  EXPECT_EQ(3, b_);
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+void ThrowAnInteger() {
+  throw 1;
+}
+
+// Tests that assertion arguments are evaluated exactly once.
+TEST_F(SingleEvaluationTest, ExceptionTests) {
+  // successful EXPECT_THROW
+  EXPECT_THROW({  // NOLINT
+    a_++;
+    ThrowAnInteger();
+  }, int);
+  EXPECT_EQ(1, a_);
+
+  // failed EXPECT_THROW, throws different
+  EXPECT_NONFATAL_FAILURE(EXPECT_THROW({  // NOLINT
+    a_++;
+    ThrowAnInteger();
+  }, bool), "throws a different type");
+  EXPECT_EQ(2, a_);
+
+  // failed EXPECT_THROW, throws nothing
+  EXPECT_NONFATAL_FAILURE(EXPECT_THROW(a_++, bool), "throws nothing");
+  EXPECT_EQ(3, a_);
+
+  // successful EXPECT_NO_THROW
+  EXPECT_NO_THROW(a_++);
+  EXPECT_EQ(4, a_);
+
+  // failed EXPECT_NO_THROW
+  EXPECT_NONFATAL_FAILURE(EXPECT_NO_THROW({  // NOLINT
+    a_++;
+    ThrowAnInteger();
+  }), "it throws");
+  EXPECT_EQ(5, a_);
+
+  // successful EXPECT_ANY_THROW
+  EXPECT_ANY_THROW({  // NOLINT
+    a_++;
+    ThrowAnInteger();
+  });
+  EXPECT_EQ(6, a_);
+
+  // failed EXPECT_ANY_THROW
+  EXPECT_NONFATAL_FAILURE(EXPECT_ANY_THROW(a_++), "it doesn't");
+  EXPECT_EQ(7, a_);
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// Tests {ASSERT|EXPECT}_NO_FATAL_FAILURE.
+class NoFatalFailureTest : public Test {
+ protected:
+  void Succeeds() {}
+  void FailsNonFatal() {
+    ADD_FAILURE() << "some non-fatal failure";
+  }
+  void Fails() {
+    FAIL() << "some fatal failure";
+  }
+
+  void DoAssertNoFatalFailureOnFails() {
+    ASSERT_NO_FATAL_FAILURE(Fails());
+    ADD_FAILURE() << "should not reach here.";
+  }
+
+  void DoExpectNoFatalFailureOnFails() {
+    EXPECT_NO_FATAL_FAILURE(Fails());
+    ADD_FAILURE() << "other failure";
+  }
+};
+
+TEST_F(NoFatalFailureTest, NoFailure) {
+  EXPECT_NO_FATAL_FAILURE(Succeeds());
+  ASSERT_NO_FATAL_FAILURE(Succeeds());
+}
+
+TEST_F(NoFatalFailureTest, NonFatalIsNoFailure) {
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_NO_FATAL_FAILURE(FailsNonFatal()),
+      "some non-fatal failure");
+  EXPECT_NONFATAL_FAILURE(
+      ASSERT_NO_FATAL_FAILURE(FailsNonFatal()),
+      "some non-fatal failure");
+}
+
+TEST_F(NoFatalFailureTest, AssertNoFatalFailureOnFatalFailure) {
+  TestPartResultArray gtest_failures;
+  {
+    ScopedFakeTestPartResultReporter gtest_reporter(&gtest_failures);
+    DoAssertNoFatalFailureOnFails();
+  }
+  ASSERT_EQ(2, gtest_failures.size());
+  EXPECT_EQ(TestPartResult::kFatalFailure,
+            gtest_failures.GetTestPartResult(0).type());
+  EXPECT_EQ(TestPartResult::kFatalFailure,
+            gtest_failures.GetTestPartResult(1).type());
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, "some fatal failure",
+                      gtest_failures.GetTestPartResult(0).message());
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, "it does",
+                      gtest_failures.GetTestPartResult(1).message());
+}
+
+TEST_F(NoFatalFailureTest, ExpectNoFatalFailureOnFatalFailure) {
+  TestPartResultArray gtest_failures;
+  {
+    ScopedFakeTestPartResultReporter gtest_reporter(&gtest_failures);
+    DoExpectNoFatalFailureOnFails();
+  }
+  ASSERT_EQ(3, gtest_failures.size());
+  EXPECT_EQ(TestPartResult::kFatalFailure,
+            gtest_failures.GetTestPartResult(0).type());
+  EXPECT_EQ(TestPartResult::kNonFatalFailure,
+            gtest_failures.GetTestPartResult(1).type());
+  EXPECT_EQ(TestPartResult::kNonFatalFailure,
+            gtest_failures.GetTestPartResult(2).type());
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, "some fatal failure",
+                      gtest_failures.GetTestPartResult(0).message());
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, "it does",
+                      gtest_failures.GetTestPartResult(1).message());
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, "other failure",
+                      gtest_failures.GetTestPartResult(2).message());
+}
+
+TEST_F(NoFatalFailureTest, MessageIsStreamable) {
+  TestPartResultArray gtest_failures;
+  {
+    ScopedFakeTestPartResultReporter gtest_reporter(&gtest_failures);
+    EXPECT_NO_FATAL_FAILURE(FAIL() << "foo") << "my message";
+  }
+  ASSERT_EQ(2, gtest_failures.size());
+  EXPECT_EQ(TestPartResult::kNonFatalFailure,
+            gtest_failures.GetTestPartResult(0).type());
+  EXPECT_EQ(TestPartResult::kNonFatalFailure,
+            gtest_failures.GetTestPartResult(1).type());
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, "foo",
+                      gtest_failures.GetTestPartResult(0).message());
+  EXPECT_PRED_FORMAT2(testing::IsSubstring, "my message",
+                      gtest_failures.GetTestPartResult(1).message());
+}
+
+// Tests non-string assertions.
+
+std::string EditsToString(const std::vector<EditType>& edits) {
+  std::string out;
+  for (size_t i = 0; i < edits.size(); ++i) {
+    static const char kEdits[] = " +-/";
+    out.append(1, kEdits[edits[i]]);
+  }
+  return out;
+}
+
+std::vector<size_t> CharsToIndices(const std::string& str) {
+  std::vector<size_t> out;
+  for (size_t i = 0; i < str.size(); ++i) {
+    out.push_back(static_cast<size_t>(str[i]));
+  }
+  return out;
+}
+
+std::vector<std::string> CharsToLines(const std::string& str) {
+  std::vector<std::string> out;
+  for (size_t i = 0; i < str.size(); ++i) {
+    out.push_back(str.substr(i, 1));
+  }
+  return out;
+}
+
+TEST(EditDistance, TestSuites) {
+  struct Case {
+    int line;
+    const char* left;
+    const char* right;
+    const char* expected_edits;
+    const char* expected_diff;
+  };
+  static const Case kCases[] = {
+      // No change.
+      {__LINE__, "A", "A", " ", ""},
+      {__LINE__, "ABCDE", "ABCDE", "     ", ""},
+      // Simple adds.
+      {__LINE__, "X", "XA", " +", "@@ +1,2 @@\n X\n+A\n"},
+      {__LINE__, "X", "XABCD", " ++++", "@@ +1,5 @@\n X\n+A\n+B\n+C\n+D\n"},
+      // Simple removes.
+      {__LINE__, "XA", "X", " -", "@@ -1,2 @@\n X\n-A\n"},
+      {__LINE__, "XABCD", "X", " ----", "@@ -1,5 @@\n X\n-A\n-B\n-C\n-D\n"},
+      // Simple replaces.
+      {__LINE__, "A", "a", "/", "@@ -1,1 +1,1 @@\n-A\n+a\n"},
+      {__LINE__, "ABCD", "abcd", "////",
+       "@@ -1,4 +1,4 @@\n-A\n-B\n-C\n-D\n+a\n+b\n+c\n+d\n"},
+      // Path finding.
+      {__LINE__, "ABCDEFGH", "ABXEGH1", "  -/ -  +",
+       "@@ -1,8 +1,7 @@\n A\n B\n-C\n-D\n+X\n E\n-F\n G\n H\n+1\n"},
+      {__LINE__, "AAAABCCCC", "ABABCDCDC", "- /   + / ",
+       "@@ -1,9 +1,9 @@\n-A\n A\n-A\n+B\n A\n B\n C\n+D\n C\n-C\n+D\n C\n"},
+      {__LINE__, "ABCDE", "BCDCD", "-   +/",
+       "@@ -1,5 +1,5 @@\n-A\n B\n C\n D\n-E\n+C\n+D\n"},
+      {__LINE__, "ABCDEFGHIJKL", "BCDCDEFGJKLJK", "- ++     --   ++",
+       "@@ -1,4 +1,5 @@\n-A\n B\n+C\n+D\n C\n D\n"
+       "@@ -6,7 +7,7 @@\n F\n G\n-H\n-I\n J\n K\n L\n+J\n+K\n"},
+      {}};
+  for (const Case* c = kCases; c->left; ++c) {
+    EXPECT_TRUE(c->expected_edits ==
+                EditsToString(CalculateOptimalEdits(CharsToIndices(c->left),
+                                                    CharsToIndices(c->right))))
+        << "Left <" << c->left << "> Right <" << c->right << "> Edits <"
+        << EditsToString(CalculateOptimalEdits(
+               CharsToIndices(c->left), CharsToIndices(c->right))) << ">";
+    EXPECT_TRUE(c->expected_diff == CreateUnifiedDiff(CharsToLines(c->left),
+                                                      CharsToLines(c->right)))
+        << "Left <" << c->left << "> Right <" << c->right << "> Diff <"
+        << CreateUnifiedDiff(CharsToLines(c->left), CharsToLines(c->right))
+        << ">";
+  }
+}
+
+// Tests EqFailure(), used for implementing *EQ* assertions.
+TEST(AssertionTest, EqFailure) {
+  const std::string foo_val("5"), bar_val("6");
+  const std::string msg1(
+      EqFailure("foo", "bar", foo_val, bar_val, false)
+      .failure_message());
+  EXPECT_STREQ(
+      "Expected equality of these values:\n"
+      "  foo\n"
+      "    Which is: 5\n"
+      "  bar\n"
+      "    Which is: 6",
+      msg1.c_str());
+
+  const std::string msg2(
+      EqFailure("foo", "6", foo_val, bar_val, false)
+      .failure_message());
+  EXPECT_STREQ(
+      "Expected equality of these values:\n"
+      "  foo\n"
+      "    Which is: 5\n"
+      "  6",
+      msg2.c_str());
+
+  const std::string msg3(
+      EqFailure("5", "bar", foo_val, bar_val, false)
+      .failure_message());
+  EXPECT_STREQ(
+      "Expected equality of these values:\n"
+      "  5\n"
+      "  bar\n"
+      "    Which is: 6",
+      msg3.c_str());
+
+  const std::string msg4(
+      EqFailure("5", "6", foo_val, bar_val, false).failure_message());
+  EXPECT_STREQ(
+      "Expected equality of these values:\n"
+      "  5\n"
+      "  6",
+      msg4.c_str());
+
+  const std::string msg5(
+      EqFailure("foo", "bar",
+                std::string("\"x\""), std::string("\"y\""),
+                true).failure_message());
+  EXPECT_STREQ(
+      "Expected equality of these values:\n"
+      "  foo\n"
+      "    Which is: \"x\"\n"
+      "  bar\n"
+      "    Which is: \"y\"\n"
+      "Ignoring case",
+      msg5.c_str());
+}
+
+TEST(AssertionTest, EqFailureWithDiff) {
+  const std::string left(
+      "1\\n2XXX\\n3\\n5\\n6\\n7\\n8\\n9\\n10\\n11\\n12XXX\\n13\\n14\\n15");
+  const std::string right(
+      "1\\n2\\n3\\n4\\n5\\n6\\n7\\n8\\n9\\n11\\n12\\n13\\n14");
+  const std::string msg1(
+      EqFailure("left", "right", left, right, false).failure_message());
+  EXPECT_STREQ(
+      "Expected equality of these values:\n"
+      "  left\n"
+      "    Which is: "
+      "1\\n2XXX\\n3\\n5\\n6\\n7\\n8\\n9\\n10\\n11\\n12XXX\\n13\\n14\\n15\n"
+      "  right\n"
+      "    Which is: 1\\n2\\n3\\n4\\n5\\n6\\n7\\n8\\n9\\n11\\n12\\n13\\n14\n"
+      "With diff:\n@@ -1,5 +1,6 @@\n 1\n-2XXX\n+2\n 3\n+4\n 5\n 6\n"
+      "@@ -7,8 +8,6 @@\n 8\n 9\n-10\n 11\n-12XXX\n+12\n 13\n 14\n-15\n",
+      msg1.c_str());
+}
+
+// Tests AppendUserMessage(), used for implementing the *EQ* macros.
+TEST(AssertionTest, AppendUserMessage) {
+  const std::string foo("foo");
+
+  Message msg;
+  EXPECT_STREQ("foo",
+               AppendUserMessage(foo, msg).c_str());
+
+  msg << "bar";
+  EXPECT_STREQ("foo\nbar",
+               AppendUserMessage(foo, msg).c_str());
+}
+
+#ifdef __BORLANDC__
+// Silences warnings: "Condition is always true", "Unreachable code"
+# pragma option push -w-ccc -w-rch
+#endif
+
+// Tests ASSERT_TRUE.
+TEST(AssertionTest, ASSERT_TRUE) {
+  ASSERT_TRUE(2 > 1);  // NOLINT
+  EXPECT_FATAL_FAILURE(ASSERT_TRUE(2 < 1),
+                       "2 < 1");
+}
+
+// Tests ASSERT_TRUE(predicate) for predicates returning AssertionResult.
+TEST(AssertionTest, AssertTrueWithAssertionResult) {
+  ASSERT_TRUE(ResultIsEven(2));
+#ifndef __BORLANDC__
+  // ICE's in C++Builder.
+  EXPECT_FATAL_FAILURE(ASSERT_TRUE(ResultIsEven(3)),
+                       "Value of: ResultIsEven(3)\n"
+                       "  Actual: false (3 is odd)\n"
+                       "Expected: true");
+#endif
+  ASSERT_TRUE(ResultIsEvenNoExplanation(2));
+  EXPECT_FATAL_FAILURE(ASSERT_TRUE(ResultIsEvenNoExplanation(3)),
+                       "Value of: ResultIsEvenNoExplanation(3)\n"
+                       "  Actual: false (3 is odd)\n"
+                       "Expected: true");
+}
+
+// Tests ASSERT_FALSE.
+TEST(AssertionTest, ASSERT_FALSE) {
+  ASSERT_FALSE(2 < 1);  // NOLINT
+  EXPECT_FATAL_FAILURE(ASSERT_FALSE(2 > 1),
+                       "Value of: 2 > 1\n"
+                       "  Actual: true\n"
+                       "Expected: false");
+}
+
+// Tests ASSERT_FALSE(predicate) for predicates returning AssertionResult.
+TEST(AssertionTest, AssertFalseWithAssertionResult) {
+  ASSERT_FALSE(ResultIsEven(3));
+#ifndef __BORLANDC__
+  // ICE's in C++Builder.
+  EXPECT_FATAL_FAILURE(ASSERT_FALSE(ResultIsEven(2)),
+                       "Value of: ResultIsEven(2)\n"
+                       "  Actual: true (2 is even)\n"
+                       "Expected: false");
+#endif
+  ASSERT_FALSE(ResultIsEvenNoExplanation(3));
+  EXPECT_FATAL_FAILURE(ASSERT_FALSE(ResultIsEvenNoExplanation(2)),
+                       "Value of: ResultIsEvenNoExplanation(2)\n"
+                       "  Actual: true\n"
+                       "Expected: false");
+}
+
+#ifdef __BORLANDC__
+// Restores warnings after previous "#pragma option push" suppressed them
+# pragma option pop
+#endif
+
+// Tests using ASSERT_EQ on double values.  The purpose is to make
+// sure that the specialization we did for integer and anonymous enums
+// isn't used for double arguments.
+TEST(ExpectTest, ASSERT_EQ_Double) {
+  // A success.
+  ASSERT_EQ(5.6, 5.6);
+
+  // A failure.
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(5.1, 5.2),
+                       "5.1");
+}
+
+// Tests ASSERT_EQ.
+TEST(AssertionTest, ASSERT_EQ) {
+  ASSERT_EQ(5, 2 + 3);
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(5, 2*3),
+                       "Expected equality of these values:\n"
+                       "  5\n"
+                       "  2*3\n"
+                       "    Which is: 6");
+}
+
+// Tests ASSERT_EQ(NULL, pointer).
+TEST(AssertionTest, ASSERT_EQ_NULL) {
+  // A success.
+  const char* p = nullptr;
+  // Some older GCC versions may issue a spurious warning in this or the next
+  // assertion statement. This warning should not be suppressed with
+  // static_cast since the test verifies the ability to use bare NULL as the
+  // expected parameter to the macro.
+  ASSERT_EQ(nullptr, p);
+
+  // A failure.
+  static int n = 0;
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(nullptr, &n), "  &n\n    Which is:");
+}
+
+// Tests ASSERT_EQ(0, non_pointer).  Since the literal 0 can be
+// treated as a null pointer by the compiler, we need to make sure
+// that ASSERT_EQ(0, non_pointer) isn't interpreted by Google Test as
+// ASSERT_EQ(static_cast<void*>(NULL), non_pointer).
+TEST(ExpectTest, ASSERT_EQ_0) {
+  int n = 0;
+
+  // A success.
+  ASSERT_EQ(0, n);
+
+  // A failure.
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(0, 5.6),
+                       "  0\n  5.6");
+}
+
+// Tests ASSERT_NE.
+TEST(AssertionTest, ASSERT_NE) {
+  ASSERT_NE(6, 7);
+  EXPECT_FATAL_FAILURE(ASSERT_NE('a', 'a'),
+                       "Expected: ('a') != ('a'), "
+                       "actual: 'a' (97, 0x61) vs 'a' (97, 0x61)");
+}
+
+// Tests ASSERT_LE.
+TEST(AssertionTest, ASSERT_LE) {
+  ASSERT_LE(2, 3);
+  ASSERT_LE(2, 2);
+  EXPECT_FATAL_FAILURE(ASSERT_LE(2, 0),
+                       "Expected: (2) <= (0), actual: 2 vs 0");
+}
+
+// Tests ASSERT_LT.
+TEST(AssertionTest, ASSERT_LT) {
+  ASSERT_LT(2, 3);
+  EXPECT_FATAL_FAILURE(ASSERT_LT(2, 2),
+                       "Expected: (2) < (2), actual: 2 vs 2");
+}
+
+// Tests ASSERT_GE.
+TEST(AssertionTest, ASSERT_GE) {
+  ASSERT_GE(2, 1);
+  ASSERT_GE(2, 2);
+  EXPECT_FATAL_FAILURE(ASSERT_GE(2, 3),
+                       "Expected: (2) >= (3), actual: 2 vs 3");
+}
+
+// Tests ASSERT_GT.
+TEST(AssertionTest, ASSERT_GT) {
+  ASSERT_GT(2, 1);
+  EXPECT_FATAL_FAILURE(ASSERT_GT(2, 2),
+                       "Expected: (2) > (2), actual: 2 vs 2");
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+void ThrowNothing() {}
+
+// Tests ASSERT_THROW.
+TEST(AssertionTest, ASSERT_THROW) {
+  ASSERT_THROW(ThrowAnInteger(), int);
+
+# ifndef __BORLANDC__
+
+  // ICE's in C++Builder 2007 and 2009.
+  EXPECT_FATAL_FAILURE(
+      ASSERT_THROW(ThrowAnInteger(), bool),
+      "Expected: ThrowAnInteger() throws an exception of type bool.\n"
+      "  Actual: it throws a different type.");
+# endif
+
+  EXPECT_FATAL_FAILURE(
+      ASSERT_THROW(ThrowNothing(), bool),
+      "Expected: ThrowNothing() throws an exception of type bool.\n"
+      "  Actual: it throws nothing.");
+}
+
+// Tests ASSERT_NO_THROW.
+TEST(AssertionTest, ASSERT_NO_THROW) {
+  ASSERT_NO_THROW(ThrowNothing());
+  EXPECT_FATAL_FAILURE(ASSERT_NO_THROW(ThrowAnInteger()),
+                       "Expected: ThrowAnInteger() doesn't throw an exception."
+                       "\n  Actual: it throws.");
+}
+
+// Tests ASSERT_ANY_THROW.
+TEST(AssertionTest, ASSERT_ANY_THROW) {
+  ASSERT_ANY_THROW(ThrowAnInteger());
+  EXPECT_FATAL_FAILURE(
+      ASSERT_ANY_THROW(ThrowNothing()),
+      "Expected: ThrowNothing() throws an exception.\n"
+      "  Actual: it doesn't.");
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// Makes sure we deal with the precedence of <<.  This test should
+// compile.
+TEST(AssertionTest, AssertPrecedence) {
+  ASSERT_EQ(1 < 2, true);
+  bool false_value = false;
+  ASSERT_EQ(true && false_value, false);
+}
+
+// A subroutine used by the following test.
+void TestEq1(int x) {
+  ASSERT_EQ(1, x);
+}
+
+// Tests calling a test subroutine that's not part of a fixture.
+TEST(AssertionTest, NonFixtureSubroutine) {
+  EXPECT_FATAL_FAILURE(TestEq1(2),
+                       "  x\n    Which is: 2");
+}
+
+// An uncopyable class.
+class Uncopyable {
+ public:
+  explicit Uncopyable(int a_value) : value_(a_value) {}
+
+  int value() const { return value_; }
+  bool operator==(const Uncopyable& rhs) const {
+    return value() == rhs.value();
+  }
+ private:
+  // This constructor deliberately has no implementation, as we don't
+  // want this class to be copyable.
+  Uncopyable(const Uncopyable&);  // NOLINT
+
+  int value_;
+};
+
+::std::ostream& operator<<(::std::ostream& os, const Uncopyable& value) {
+  return os << value.value();
+}
+
+
+bool IsPositiveUncopyable(const Uncopyable& x) {
+  return x.value() > 0;
+}
+
+// A subroutine used by the following test.
+void TestAssertNonPositive() {
+  Uncopyable y(-1);
+  ASSERT_PRED1(IsPositiveUncopyable, y);
+}
+// A subroutine used by the following test.
+void TestAssertEqualsUncopyable() {
+  Uncopyable x(5);
+  Uncopyable y(-1);
+  ASSERT_EQ(x, y);
+}
+
+// Tests that uncopyable objects can be used in assertions.
+TEST(AssertionTest, AssertWorksWithUncopyableObject) {
+  Uncopyable x(5);
+  ASSERT_PRED1(IsPositiveUncopyable, x);
+  ASSERT_EQ(x, x);
+  EXPECT_FATAL_FAILURE(TestAssertNonPositive(),
+    "IsPositiveUncopyable(y) evaluates to false, where\ny evaluates to -1");
+  EXPECT_FATAL_FAILURE(TestAssertEqualsUncopyable(),
+                       "Expected equality of these values:\n"
+                       "  x\n    Which is: 5\n  y\n    Which is: -1");
+}
+
+// Tests that uncopyable objects can be used in expects.
+TEST(AssertionTest, ExpectWorksWithUncopyableObject) {
+  Uncopyable x(5);
+  EXPECT_PRED1(IsPositiveUncopyable, x);
+  Uncopyable y(-1);
+  EXPECT_NONFATAL_FAILURE(EXPECT_PRED1(IsPositiveUncopyable, y),
+    "IsPositiveUncopyable(y) evaluates to false, where\ny evaluates to -1");
+  EXPECT_EQ(x, x);
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(x, y),
+                          "Expected equality of these values:\n"
+                          "  x\n    Which is: 5\n  y\n    Which is: -1");
+}
+
+enum NamedEnum {
+  kE1 = 0,
+  kE2 = 1
+};
+
+TEST(AssertionTest, NamedEnum) {
+  EXPECT_EQ(kE1, kE1);
+  EXPECT_LT(kE1, kE2);
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(kE1, kE2), "Which is: 0");
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(kE1, kE2), "Which is: 1");
+}
+
+// Sun Studio and HP aCC2reject this code.
+#if !defined(__SUNPRO_CC) && !defined(__HP_aCC)
+
+// Tests using assertions with anonymous enums.
+enum {
+  kCaseA = -1,
+
+# if GTEST_OS_LINUX
+
+  // We want to test the case where the size of the anonymous enum is
+  // larger than sizeof(int), to make sure our implementation of the
+  // assertions doesn't truncate the enums.  However, MSVC
+  // (incorrectly) doesn't allow an enum value to exceed the range of
+  // an int, so this has to be conditionally compiled.
+  //
+  // On Linux, kCaseB and kCaseA have the same value when truncated to
+  // int size.  We want to test whether this will confuse the
+  // assertions.
+  kCaseB = testing::internal::kMaxBiggestInt,
+
+# else
+
+  kCaseB = INT_MAX,
+
+# endif  // GTEST_OS_LINUX
+
+  kCaseC = 42
+};
+
+TEST(AssertionTest, AnonymousEnum) {
+# if GTEST_OS_LINUX
+
+  EXPECT_EQ(static_cast<int>(kCaseA), static_cast<int>(kCaseB));
+
+# endif  // GTEST_OS_LINUX
+
+  EXPECT_EQ(kCaseA, kCaseA);
+  EXPECT_NE(kCaseA, kCaseB);
+  EXPECT_LT(kCaseA, kCaseB);
+  EXPECT_LE(kCaseA, kCaseB);
+  EXPECT_GT(kCaseB, kCaseA);
+  EXPECT_GE(kCaseA, kCaseA);
+  EXPECT_NONFATAL_FAILURE(EXPECT_GE(kCaseA, kCaseB),
+                          "(kCaseA) >= (kCaseB)");
+  EXPECT_NONFATAL_FAILURE(EXPECT_GE(kCaseA, kCaseC),
+                          "-1 vs 42");
+
+  ASSERT_EQ(kCaseA, kCaseA);
+  ASSERT_NE(kCaseA, kCaseB);
+  ASSERT_LT(kCaseA, kCaseB);
+  ASSERT_LE(kCaseA, kCaseB);
+  ASSERT_GT(kCaseB, kCaseA);
+  ASSERT_GE(kCaseA, kCaseA);
+
+# ifndef __BORLANDC__
+
+  // ICE's in C++Builder.
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(kCaseA, kCaseB),
+                       "  kCaseB\n    Which is: ");
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(kCaseA, kCaseC),
+                       "\n    Which is: 42");
+# endif
+
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(kCaseA, kCaseC),
+                       "\n    Which is: -1");
+}
+
+#endif  // !GTEST_OS_MAC && !defined(__SUNPRO_CC)
+
+#if GTEST_OS_WINDOWS
+
+static HRESULT UnexpectedHRESULTFailure() {
+  return E_UNEXPECTED;
+}
+
+static HRESULT OkHRESULTSuccess() {
+  return S_OK;
+}
+
+static HRESULT FalseHRESULTSuccess() {
+  return S_FALSE;
+}
+
+// HRESULT assertion tests test both zero and non-zero
+// success codes as well as failure message for each.
+//
+// Windows CE doesn't support message texts.
+TEST(HRESULTAssertionTest, EXPECT_HRESULT_SUCCEEDED) {
+  EXPECT_HRESULT_SUCCEEDED(S_OK);
+  EXPECT_HRESULT_SUCCEEDED(S_FALSE);
+
+  EXPECT_NONFATAL_FAILURE(EXPECT_HRESULT_SUCCEEDED(UnexpectedHRESULTFailure()),
+    "Expected: (UnexpectedHRESULTFailure()) succeeds.\n"
+    "  Actual: 0x8000FFFF");
+}
+
+TEST(HRESULTAssertionTest, ASSERT_HRESULT_SUCCEEDED) {
+  ASSERT_HRESULT_SUCCEEDED(S_OK);
+  ASSERT_HRESULT_SUCCEEDED(S_FALSE);
+
+  EXPECT_FATAL_FAILURE(ASSERT_HRESULT_SUCCEEDED(UnexpectedHRESULTFailure()),
+    "Expected: (UnexpectedHRESULTFailure()) succeeds.\n"
+    "  Actual: 0x8000FFFF");
+}
+
+TEST(HRESULTAssertionTest, EXPECT_HRESULT_FAILED) {
+  EXPECT_HRESULT_FAILED(E_UNEXPECTED);
+
+  EXPECT_NONFATAL_FAILURE(EXPECT_HRESULT_FAILED(OkHRESULTSuccess()),
+    "Expected: (OkHRESULTSuccess()) fails.\n"
+    "  Actual: 0x0");
+  EXPECT_NONFATAL_FAILURE(EXPECT_HRESULT_FAILED(FalseHRESULTSuccess()),
+    "Expected: (FalseHRESULTSuccess()) fails.\n"
+    "  Actual: 0x1");
+}
+
+TEST(HRESULTAssertionTest, ASSERT_HRESULT_FAILED) {
+  ASSERT_HRESULT_FAILED(E_UNEXPECTED);
+
+# ifndef __BORLANDC__
+
+  // ICE's in C++Builder 2007 and 2009.
+  EXPECT_FATAL_FAILURE(ASSERT_HRESULT_FAILED(OkHRESULTSuccess()),
+    "Expected: (OkHRESULTSuccess()) fails.\n"
+    "  Actual: 0x0");
+# endif
+
+  EXPECT_FATAL_FAILURE(ASSERT_HRESULT_FAILED(FalseHRESULTSuccess()),
+    "Expected: (FalseHRESULTSuccess()) fails.\n"
+    "  Actual: 0x1");
+}
+
+// Tests that streaming to the HRESULT macros works.
+TEST(HRESULTAssertionTest, Streaming) {
+  EXPECT_HRESULT_SUCCEEDED(S_OK) << "unexpected failure";
+  ASSERT_HRESULT_SUCCEEDED(S_OK) << "unexpected failure";
+  EXPECT_HRESULT_FAILED(E_UNEXPECTED) << "unexpected failure";
+  ASSERT_HRESULT_FAILED(E_UNEXPECTED) << "unexpected failure";
+
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_HRESULT_SUCCEEDED(E_UNEXPECTED) << "expected failure",
+      "expected failure");
+
+# ifndef __BORLANDC__
+
+  // ICE's in C++Builder 2007 and 2009.
+  EXPECT_FATAL_FAILURE(
+      ASSERT_HRESULT_SUCCEEDED(E_UNEXPECTED) << "expected failure",
+      "expected failure");
+# endif
+
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_HRESULT_FAILED(S_OK) << "expected failure",
+      "expected failure");
+
+  EXPECT_FATAL_FAILURE(
+      ASSERT_HRESULT_FAILED(S_OK) << "expected failure",
+      "expected failure");
+}
+
+#endif  // GTEST_OS_WINDOWS
+
+#ifdef __BORLANDC__
+// Silences warnings: "Condition is always true", "Unreachable code"
+# pragma option push -w-ccc -w-rch
+#endif
+
+// Tests that the assertion macros behave like single statements.
+TEST(AssertionSyntaxTest, BasicAssertionsBehavesLikeSingleStatement) {
+  if (AlwaysFalse())
+    ASSERT_TRUE(false) << "This should never be executed; "
+                          "It's a compilation test only.";
+
+  if (AlwaysTrue())
+    EXPECT_FALSE(false);
+  else
+    ;  // NOLINT
+
+  if (AlwaysFalse())
+    ASSERT_LT(1, 3);
+
+  if (AlwaysFalse())
+    ;  // NOLINT
+  else
+    EXPECT_GT(3, 2) << "";
+}
+
+#if GTEST_HAS_EXCEPTIONS
+// Tests that the compiler will not complain about unreachable code in the
+// EXPECT_THROW/EXPECT_ANY_THROW/EXPECT_NO_THROW macros.
+TEST(ExpectThrowTest, DoesNotGenerateUnreachableCodeWarning) {
+  int n = 0;
+
+  EXPECT_THROW(throw 1, int);
+  EXPECT_NONFATAL_FAILURE(EXPECT_THROW(n++, int), "");
+  EXPECT_NONFATAL_FAILURE(EXPECT_THROW(throw 1, const char*), "");
+  EXPECT_NO_THROW(n++);
+  EXPECT_NONFATAL_FAILURE(EXPECT_NO_THROW(throw 1), "");
+  EXPECT_ANY_THROW(throw 1);
+  EXPECT_NONFATAL_FAILURE(EXPECT_ANY_THROW(n++), "");
+}
+
+TEST(AssertionSyntaxTest, ExceptionAssertionsBehavesLikeSingleStatement) {
+  if (AlwaysFalse())
+    EXPECT_THROW(ThrowNothing(), bool);
+
+  if (AlwaysTrue())
+    EXPECT_THROW(ThrowAnInteger(), int);
+  else
+    ;  // NOLINT
+
+  if (AlwaysFalse())
+    EXPECT_NO_THROW(ThrowAnInteger());
+
+  if (AlwaysTrue())
+    EXPECT_NO_THROW(ThrowNothing());
+  else
+    ;  // NOLINT
+
+  if (AlwaysFalse())
+    EXPECT_ANY_THROW(ThrowNothing());
+
+  if (AlwaysTrue())
+    EXPECT_ANY_THROW(ThrowAnInteger());
+  else
+    ;  // NOLINT
+}
+#endif  // GTEST_HAS_EXCEPTIONS
+
+TEST(AssertionSyntaxTest, NoFatalFailureAssertionsBehavesLikeSingleStatement) {
+  if (AlwaysFalse())
+    EXPECT_NO_FATAL_FAILURE(FAIL()) << "This should never be executed. "
+                                    << "It's a compilation test only.";
+  else
+    ;  // NOLINT
+
+  if (AlwaysFalse())
+    ASSERT_NO_FATAL_FAILURE(FAIL()) << "";
+  else
+    ;  // NOLINT
+
+  if (AlwaysTrue())
+    EXPECT_NO_FATAL_FAILURE(SUCCEED());
+  else
+    ;  // NOLINT
+
+  if (AlwaysFalse())
+    ;  // NOLINT
+  else
+    ASSERT_NO_FATAL_FAILURE(SUCCEED());
+}
+
+// Tests that the assertion macros work well with switch statements.
+TEST(AssertionSyntaxTest, WorksWithSwitch) {
+  switch (0) {
+    case 1:
+      break;
+    default:
+      ASSERT_TRUE(true);
+  }
+
+  switch (0)
+    case 0:
+      EXPECT_FALSE(false) << "EXPECT_FALSE failed in switch case";
+
+  // Binary assertions are implemented using a different code path
+  // than the Boolean assertions.  Hence we test them separately.
+  switch (0) {
+    case 1:
+    default:
+      ASSERT_EQ(1, 1) << "ASSERT_EQ failed in default switch handler";
+  }
+
+  switch (0)
+    case 0:
+      EXPECT_NE(1, 2);
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+void ThrowAString() {
+    throw "std::string";
+}
+
+// Test that the exception assertion macros compile and work with const
+// type qualifier.
+TEST(AssertionSyntaxTest, WorksWithConst) {
+    ASSERT_THROW(ThrowAString(), const char*);
+
+    EXPECT_THROW(ThrowAString(), const char*);
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+}  // namespace
+
+namespace testing {
+
+// Tests that Google Test tracks SUCCEED*.
+TEST(SuccessfulAssertionTest, SUCCEED) {
+  SUCCEED();
+  SUCCEED() << "OK";
+  EXPECT_EQ(2, GetUnitTestImpl()->current_test_result()->total_part_count());
+}
+
+// Tests that Google Test doesn't track successful EXPECT_*.
+TEST(SuccessfulAssertionTest, EXPECT) {
+  EXPECT_TRUE(true);
+  EXPECT_EQ(0, GetUnitTestImpl()->current_test_result()->total_part_count());
+}
+
+// Tests that Google Test doesn't track successful EXPECT_STR*.
+TEST(SuccessfulAssertionTest, EXPECT_STR) {
+  EXPECT_STREQ("", "");
+  EXPECT_EQ(0, GetUnitTestImpl()->current_test_result()->total_part_count());
+}
+
+// Tests that Google Test doesn't track successful ASSERT_*.
+TEST(SuccessfulAssertionTest, ASSERT) {
+  ASSERT_TRUE(true);
+  EXPECT_EQ(0, GetUnitTestImpl()->current_test_result()->total_part_count());
+}
+
+// Tests that Google Test doesn't track successful ASSERT_STR*.
+TEST(SuccessfulAssertionTest, ASSERT_STR) {
+  ASSERT_STREQ("", "");
+  EXPECT_EQ(0, GetUnitTestImpl()->current_test_result()->total_part_count());
+}
+
+}  // namespace testing
+
+namespace {
+
+// Tests the message streaming variation of assertions.
+
+TEST(AssertionWithMessageTest, EXPECT) {
+  EXPECT_EQ(1, 1) << "This should succeed.";
+  EXPECT_NONFATAL_FAILURE(EXPECT_NE(1, 1) << "Expected failure #1.",
+                          "Expected failure #1");
+  EXPECT_LE(1, 2) << "This should succeed.";
+  EXPECT_NONFATAL_FAILURE(EXPECT_LT(1, 0) << "Expected failure #2.",
+                          "Expected failure #2.");
+  EXPECT_GE(1, 0) << "This should succeed.";
+  EXPECT_NONFATAL_FAILURE(EXPECT_GT(1, 2) << "Expected failure #3.",
+                          "Expected failure #3.");
+
+  EXPECT_STREQ("1", "1") << "This should succeed.";
+  EXPECT_NONFATAL_FAILURE(EXPECT_STRNE("1", "1") << "Expected failure #4.",
+                          "Expected failure #4.");
+  EXPECT_STRCASEEQ("a", "A") << "This should succeed.";
+  EXPECT_NONFATAL_FAILURE(EXPECT_STRCASENE("a", "A") << "Expected failure #5.",
+                          "Expected failure #5.");
+
+  EXPECT_FLOAT_EQ(1, 1) << "This should succeed.";
+  EXPECT_NONFATAL_FAILURE(EXPECT_DOUBLE_EQ(1, 1.2) << "Expected failure #6.",
+                          "Expected failure #6.");
+  EXPECT_NEAR(1, 1.1, 0.2) << "This should succeed.";
+}
+
+TEST(AssertionWithMessageTest, ASSERT) {
+  ASSERT_EQ(1, 1) << "This should succeed.";
+  ASSERT_NE(1, 2) << "This should succeed.";
+  ASSERT_LE(1, 2) << "This should succeed.";
+  ASSERT_LT(1, 2) << "This should succeed.";
+  ASSERT_GE(1, 0) << "This should succeed.";
+  EXPECT_FATAL_FAILURE(ASSERT_GT(1, 2) << "Expected failure.",
+                       "Expected failure.");
+}
+
+TEST(AssertionWithMessageTest, ASSERT_STR) {
+  ASSERT_STREQ("1", "1") << "This should succeed.";
+  ASSERT_STRNE("1", "2") << "This should succeed.";
+  ASSERT_STRCASEEQ("a", "A") << "This should succeed.";
+  EXPECT_FATAL_FAILURE(ASSERT_STRCASENE("a", "A") << "Expected failure.",
+                       "Expected failure.");
+}
+
+TEST(AssertionWithMessageTest, ASSERT_FLOATING) {
+  ASSERT_FLOAT_EQ(1, 1) << "This should succeed.";
+  ASSERT_DOUBLE_EQ(1, 1) << "This should succeed.";
+  EXPECT_FATAL_FAILURE(ASSERT_NEAR(1,1.2, 0.1) << "Expect failure.",  // NOLINT
+                       "Expect failure.");
+  // To work around a bug in gcc 2.95.0, there is intentionally no
+  // space after the first comma in the previous statement.
+}
+
+// Tests using ASSERT_FALSE with a streamed message.
+TEST(AssertionWithMessageTest, ASSERT_FALSE) {
+  ASSERT_FALSE(false) << "This shouldn't fail.";
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_FALSE(true) << "Expected failure: " << 2 << " > " << 1
+                       << " evaluates to " << true;
+  }, "Expected failure");
+}
+
+// Tests using FAIL with a streamed message.
+TEST(AssertionWithMessageTest, FAIL) {
+  EXPECT_FATAL_FAILURE(FAIL() << 0,
+                       "0");
+}
+
+// Tests using SUCCEED with a streamed message.
+TEST(AssertionWithMessageTest, SUCCEED) {
+  SUCCEED() << "Success == " << 1;
+}
+
+// Tests using ASSERT_TRUE with a streamed message.
+TEST(AssertionWithMessageTest, ASSERT_TRUE) {
+  ASSERT_TRUE(true) << "This should succeed.";
+  ASSERT_TRUE(true) << true;
+  EXPECT_FATAL_FAILURE(
+      {  // NOLINT
+        ASSERT_TRUE(false) << static_cast<const char*>(nullptr)
+                           << static_cast<char*>(nullptr);
+      },
+      "(null)(null)");
+}
+
+#if GTEST_OS_WINDOWS
+// Tests using wide strings in assertion messages.
+TEST(AssertionWithMessageTest, WideStringMessage) {
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_TRUE(false) << L"This failure is expected.\x8119";
+  }, "This failure is expected.");
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_EQ(1, 2) << "This failure is "
+                    << L"expected too.\x8120";
+  }, "This failure is expected too.");
+}
+#endif  // GTEST_OS_WINDOWS
+
+// Tests EXPECT_TRUE.
+TEST(ExpectTest, EXPECT_TRUE) {
+  EXPECT_TRUE(true) << "Intentional success";
+  EXPECT_NONFATAL_FAILURE(EXPECT_TRUE(false) << "Intentional failure #1.",
+                          "Intentional failure #1.");
+  EXPECT_NONFATAL_FAILURE(EXPECT_TRUE(false) << "Intentional failure #2.",
+                          "Intentional failure #2.");
+  EXPECT_TRUE(2 > 1);  // NOLINT
+  EXPECT_NONFATAL_FAILURE(EXPECT_TRUE(2 < 1),
+                          "Value of: 2 < 1\n"
+                          "  Actual: false\n"
+                          "Expected: true");
+  EXPECT_NONFATAL_FAILURE(EXPECT_TRUE(2 > 3),
+                          "2 > 3");
+}
+
+// Tests EXPECT_TRUE(predicate) for predicates returning AssertionResult.
+TEST(ExpectTest, ExpectTrueWithAssertionResult) {
+  EXPECT_TRUE(ResultIsEven(2));
+  EXPECT_NONFATAL_FAILURE(EXPECT_TRUE(ResultIsEven(3)),
+                          "Value of: ResultIsEven(3)\n"
+                          "  Actual: false (3 is odd)\n"
+                          "Expected: true");
+  EXPECT_TRUE(ResultIsEvenNoExplanation(2));
+  EXPECT_NONFATAL_FAILURE(EXPECT_TRUE(ResultIsEvenNoExplanation(3)),
+                          "Value of: ResultIsEvenNoExplanation(3)\n"
+                          "  Actual: false (3 is odd)\n"
+                          "Expected: true");
+}
+
+// Tests EXPECT_FALSE with a streamed message.
+TEST(ExpectTest, EXPECT_FALSE) {
+  EXPECT_FALSE(2 < 1);  // NOLINT
+  EXPECT_FALSE(false) << "Intentional success";
+  EXPECT_NONFATAL_FAILURE(EXPECT_FALSE(true) << "Intentional failure #1.",
+                          "Intentional failure #1.");
+  EXPECT_NONFATAL_FAILURE(EXPECT_FALSE(true) << "Intentional failure #2.",
+                          "Intentional failure #2.");
+  EXPECT_NONFATAL_FAILURE(EXPECT_FALSE(2 > 1),
+                          "Value of: 2 > 1\n"
+                          "  Actual: true\n"
+                          "Expected: false");
+  EXPECT_NONFATAL_FAILURE(EXPECT_FALSE(2 < 3),
+                          "2 < 3");
+}
+
+// Tests EXPECT_FALSE(predicate) for predicates returning AssertionResult.
+TEST(ExpectTest, ExpectFalseWithAssertionResult) {
+  EXPECT_FALSE(ResultIsEven(3));
+  EXPECT_NONFATAL_FAILURE(EXPECT_FALSE(ResultIsEven(2)),
+                          "Value of: ResultIsEven(2)\n"
+                          "  Actual: true (2 is even)\n"
+                          "Expected: false");
+  EXPECT_FALSE(ResultIsEvenNoExplanation(3));
+  EXPECT_NONFATAL_FAILURE(EXPECT_FALSE(ResultIsEvenNoExplanation(2)),
+                          "Value of: ResultIsEvenNoExplanation(2)\n"
+                          "  Actual: true\n"
+                          "Expected: false");
+}
+
+#ifdef __BORLANDC__
+// Restores warnings after previous "#pragma option push" suppressed them
+# pragma option pop
+#endif
+
+// Tests EXPECT_EQ.
+TEST(ExpectTest, EXPECT_EQ) {
+  EXPECT_EQ(5, 2 + 3);
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(5, 2*3),
+                          "Expected equality of these values:\n"
+                          "  5\n"
+                          "  2*3\n"
+                          "    Which is: 6");
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(5, 2 - 3),
+                          "2 - 3");
+}
+
+// Tests using EXPECT_EQ on double values.  The purpose is to make
+// sure that the specialization we did for integer and anonymous enums
+// isn't used for double arguments.
+TEST(ExpectTest, EXPECT_EQ_Double) {
+  // A success.
+  EXPECT_EQ(5.6, 5.6);
+
+  // A failure.
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(5.1, 5.2),
+                          "5.1");
+}
+
+// Tests EXPECT_EQ(NULL, pointer).
+TEST(ExpectTest, EXPECT_EQ_NULL) {
+  // A success.
+  const char* p = nullptr;
+  // Some older GCC versions may issue a spurious warning in this or the next
+  // assertion statement. This warning should not be suppressed with
+  // static_cast since the test verifies the ability to use bare NULL as the
+  // expected parameter to the macro.
+  EXPECT_EQ(nullptr, p);
+
+  // A failure.
+  int n = 0;
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(nullptr, &n), "  &n\n    Which is:");
+}
+
+// Tests EXPECT_EQ(0, non_pointer).  Since the literal 0 can be
+// treated as a null pointer by the compiler, we need to make sure
+// that EXPECT_EQ(0, non_pointer) isn't interpreted by Google Test as
+// EXPECT_EQ(static_cast<void*>(NULL), non_pointer).
+TEST(ExpectTest, EXPECT_EQ_0) {
+  int n = 0;
+
+  // A success.
+  EXPECT_EQ(0, n);
+
+  // A failure.
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(0, 5.6),
+                          "  0\n  5.6");
+}
+
+// Tests EXPECT_NE.
+TEST(ExpectTest, EXPECT_NE) {
+  EXPECT_NE(6, 7);
+
+  EXPECT_NONFATAL_FAILURE(EXPECT_NE('a', 'a'),
+                          "Expected: ('a') != ('a'), "
+                          "actual: 'a' (97, 0x61) vs 'a' (97, 0x61)");
+  EXPECT_NONFATAL_FAILURE(EXPECT_NE(2, 2),
+                          "2");
+  char* const p0 = nullptr;
+  EXPECT_NONFATAL_FAILURE(EXPECT_NE(p0, p0),
+                          "p0");
+  // Only way to get the Nokia compiler to compile the cast
+  // is to have a separate void* variable first. Putting
+  // the two casts on the same line doesn't work, neither does
+  // a direct C-style to char*.
+  void* pv1 = (void*)0x1234;  // NOLINT
+  char* const p1 = reinterpret_cast<char*>(pv1);
+  EXPECT_NONFATAL_FAILURE(EXPECT_NE(p1, p1),
+                          "p1");
+}
+
+// Tests EXPECT_LE.
+TEST(ExpectTest, EXPECT_LE) {
+  EXPECT_LE(2, 3);
+  EXPECT_LE(2, 2);
+  EXPECT_NONFATAL_FAILURE(EXPECT_LE(2, 0),
+                          "Expected: (2) <= (0), actual: 2 vs 0");
+  EXPECT_NONFATAL_FAILURE(EXPECT_LE(1.1, 0.9),
+                          "(1.1) <= (0.9)");
+}
+
+// Tests EXPECT_LT.
+TEST(ExpectTest, EXPECT_LT) {
+  EXPECT_LT(2, 3);
+  EXPECT_NONFATAL_FAILURE(EXPECT_LT(2, 2),
+                          "Expected: (2) < (2), actual: 2 vs 2");
+  EXPECT_NONFATAL_FAILURE(EXPECT_LT(2, 1),
+                          "(2) < (1)");
+}
+
+// Tests EXPECT_GE.
+TEST(ExpectTest, EXPECT_GE) {
+  EXPECT_GE(2, 1);
+  EXPECT_GE(2, 2);
+  EXPECT_NONFATAL_FAILURE(EXPECT_GE(2, 3),
+                          "Expected: (2) >= (3), actual: 2 vs 3");
+  EXPECT_NONFATAL_FAILURE(EXPECT_GE(0.9, 1.1),
+                          "(0.9) >= (1.1)");
+}
+
+// Tests EXPECT_GT.
+TEST(ExpectTest, EXPECT_GT) {
+  EXPECT_GT(2, 1);
+  EXPECT_NONFATAL_FAILURE(EXPECT_GT(2, 2),
+                          "Expected: (2) > (2), actual: 2 vs 2");
+  EXPECT_NONFATAL_FAILURE(EXPECT_GT(2, 3),
+                          "(2) > (3)");
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+// Tests EXPECT_THROW.
+TEST(ExpectTest, EXPECT_THROW) {
+  EXPECT_THROW(ThrowAnInteger(), int);
+  EXPECT_NONFATAL_FAILURE(EXPECT_THROW(ThrowAnInteger(), bool),
+                          "Expected: ThrowAnInteger() throws an exception of "
+                          "type bool.\n  Actual: it throws a different type.");
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_THROW(ThrowNothing(), bool),
+      "Expected: ThrowNothing() throws an exception of type bool.\n"
+      "  Actual: it throws nothing.");
+}
+
+// Tests EXPECT_NO_THROW.
+TEST(ExpectTest, EXPECT_NO_THROW) {
+  EXPECT_NO_THROW(ThrowNothing());
+  EXPECT_NONFATAL_FAILURE(EXPECT_NO_THROW(ThrowAnInteger()),
+                          "Expected: ThrowAnInteger() doesn't throw an "
+                          "exception.\n  Actual: it throws.");
+}
+
+// Tests EXPECT_ANY_THROW.
+TEST(ExpectTest, EXPECT_ANY_THROW) {
+  EXPECT_ANY_THROW(ThrowAnInteger());
+  EXPECT_NONFATAL_FAILURE(
+      EXPECT_ANY_THROW(ThrowNothing()),
+      "Expected: ThrowNothing() throws an exception.\n"
+      "  Actual: it doesn't.");
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// Make sure we deal with the precedence of <<.
+TEST(ExpectTest, ExpectPrecedence) {
+  EXPECT_EQ(1 < 2, true);
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(true, true && false),
+                          "  true && false\n    Which is: false");
+}
+
+
+// Tests the StreamableToString() function.
+
+// Tests using StreamableToString() on a scalar.
+TEST(StreamableToStringTest, Scalar) {
+  EXPECT_STREQ("5", StreamableToString(5).c_str());
+}
+
+// Tests using StreamableToString() on a non-char pointer.
+TEST(StreamableToStringTest, Pointer) {
+  int n = 0;
+  int* p = &n;
+  EXPECT_STRNE("(null)", StreamableToString(p).c_str());
+}
+
+// Tests using StreamableToString() on a NULL non-char pointer.
+TEST(StreamableToStringTest, NullPointer) {
+  int* p = nullptr;
+  EXPECT_STREQ("(null)", StreamableToString(p).c_str());
+}
+
+// Tests using StreamableToString() on a C string.
+TEST(StreamableToStringTest, CString) {
+  EXPECT_STREQ("Foo", StreamableToString("Foo").c_str());
+}
+
+// Tests using StreamableToString() on a NULL C string.
+TEST(StreamableToStringTest, NullCString) {
+  char* p = nullptr;
+  EXPECT_STREQ("(null)", StreamableToString(p).c_str());
+}
+
+// Tests using streamable values as assertion messages.
+
+// Tests using std::string as an assertion message.
+TEST(StreamableTest, string) {
+  static const std::string str(
+      "This failure message is a std::string, and is expected.");
+  EXPECT_FATAL_FAILURE(FAIL() << str,
+                       str.c_str());
+}
+
+// Tests that we can output strings containing embedded NULs.
+// Limited to Linux because we can only do this with std::string's.
+TEST(StreamableTest, stringWithEmbeddedNUL) {
+  static const char char_array_with_nul[] =
+      "Here's a NUL\0 and some more string";
+  static const std::string string_with_nul(char_array_with_nul,
+                                           sizeof(char_array_with_nul)
+                                           - 1);  // drops the trailing NUL
+  EXPECT_FATAL_FAILURE(FAIL() << string_with_nul,
+                       "Here's a NUL\\0 and some more string");
+}
+
+// Tests that we can output a NUL char.
+TEST(StreamableTest, NULChar) {
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    FAIL() << "A NUL" << '\0' << " and some more string";
+  }, "A NUL\\0 and some more string");
+}
+
+// Tests using int as an assertion message.
+TEST(StreamableTest, int) {
+  EXPECT_FATAL_FAILURE(FAIL() << 900913,
+                       "900913");
+}
+
+// Tests using NULL char pointer as an assertion message.
+//
+// In MSVC, streaming a NULL char * causes access violation.  Google Test
+// implemented a workaround (substituting "(null)" for NULL).  This
+// tests whether the workaround works.
+TEST(StreamableTest, NullCharPtr) {
+  EXPECT_FATAL_FAILURE(FAIL() << static_cast<const char*>(nullptr), "(null)");
+}
+
+// Tests that basic IO manipulators (endl, ends, and flush) can be
+// streamed to testing::Message.
+TEST(StreamableTest, BasicIoManip) {
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    FAIL() << "Line 1." << std::endl
+           << "A NUL char " << std::ends << std::flush << " in line 2.";
+  }, "Line 1.\nA NUL char \\0 in line 2.");
+}
+
+// Tests the macros that haven't been covered so far.
+
+void AddFailureHelper(bool* aborted) {
+  *aborted = true;
+  ADD_FAILURE() << "Intentional failure.";
+  *aborted = false;
+}
+
+// Tests ADD_FAILURE.
+TEST(MacroTest, ADD_FAILURE) {
+  bool aborted = true;
+  EXPECT_NONFATAL_FAILURE(AddFailureHelper(&aborted),
+                          "Intentional failure.");
+  EXPECT_FALSE(aborted);
+}
+
+// Tests ADD_FAILURE_AT.
+TEST(MacroTest, ADD_FAILURE_AT) {
+  // Verifies that ADD_FAILURE_AT does generate a nonfatal failure and
+  // the failure message contains the user-streamed part.
+  EXPECT_NONFATAL_FAILURE(ADD_FAILURE_AT("foo.cc", 42) << "Wrong!", "Wrong!");
+
+  // Verifies that the user-streamed part is optional.
+  EXPECT_NONFATAL_FAILURE(ADD_FAILURE_AT("foo.cc", 42), "Failed");
+
+  // Unfortunately, we cannot verify that the failure message contains
+  // the right file path and line number the same way, as
+  // EXPECT_NONFATAL_FAILURE() doesn't get to see the file path and
+  // line number.  Instead, we do that in googletest-output-test_.cc.
+}
+
+// Tests FAIL.
+TEST(MacroTest, FAIL) {
+  EXPECT_FATAL_FAILURE(FAIL(),
+                       "Failed");
+  EXPECT_FATAL_FAILURE(FAIL() << "Intentional failure.",
+                       "Intentional failure.");
+}
+
+// Tests GTEST_FAIL_AT.
+TEST(MacroTest, GTEST_FAIL_AT) {
+  // Verifies that GTEST_FAIL_AT does generate a fatal failure and
+  // the failure message contains the user-streamed part.
+  EXPECT_FATAL_FAILURE(GTEST_FAIL_AT("foo.cc", 42) << "Wrong!", "Wrong!");
+
+  // Verifies that the user-streamed part is optional.
+  EXPECT_FATAL_FAILURE(GTEST_FAIL_AT("foo.cc", 42), "Failed");
+
+  // See the ADD_FAIL_AT test above to see how we test that the failure message
+  // contains the right filename and line number -- the same applies here.
+}
+
+// Tests SUCCEED
+TEST(MacroTest, SUCCEED) {
+  SUCCEED();
+  SUCCEED() << "Explicit success.";
+}
+
+// Tests for EXPECT_EQ() and ASSERT_EQ().
+//
+// These tests fail *intentionally*, s.t. the failure messages can be
+// generated and tested.
+//
+// We have different tests for different argument types.
+
+// Tests using bool values in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, Bool) {
+  EXPECT_EQ(true,  true);
+  EXPECT_FATAL_FAILURE({
+      bool false_value = false;
+      ASSERT_EQ(false_value, true);
+    }, "  false_value\n    Which is: false\n  true");
+}
+
+// Tests using int values in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, Int) {
+  ASSERT_EQ(32, 32);
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(32, 33),
+                          "  32\n  33");
+}
+
+// Tests using time_t values in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, Time_T) {
+  EXPECT_EQ(static_cast<time_t>(0),
+            static_cast<time_t>(0));
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(static_cast<time_t>(0),
+                                 static_cast<time_t>(1234)),
+                       "1234");
+}
+
+// Tests using char values in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, Char) {
+  ASSERT_EQ('z', 'z');
+  const char ch = 'b';
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ('\0', ch),
+                          "  ch\n    Which is: 'b'");
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ('a', ch),
+                          "  ch\n    Which is: 'b'");
+}
+
+// Tests using wchar_t values in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, WideChar) {
+  EXPECT_EQ(L'b', L'b');
+
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(L'\0', L'x'),
+                          "Expected equality of these values:\n"
+                          "  L'\0'\n"
+                          "    Which is: L'\0' (0, 0x0)\n"
+                          "  L'x'\n"
+                          "    Which is: L'x' (120, 0x78)");
+
+  static wchar_t wchar;
+  wchar = L'b';
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(L'a', wchar),
+                          "wchar");
+  wchar = 0x8119;
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(static_cast<wchar_t>(0x8120), wchar),
+                       "  wchar\n    Which is: L'");
+}
+
+// Tests using ::std::string values in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, StdString) {
+  // Compares a const char* to an std::string that has identical
+  // content.
+  ASSERT_EQ("Test", ::std::string("Test"));
+
+  // Compares two identical std::strings.
+  static const ::std::string str1("A * in the middle");
+  static const ::std::string str2(str1);
+  EXPECT_EQ(str1, str2);
+
+  // Compares a const char* to an std::string that has different
+  // content
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ("Test", ::std::string("test")),
+                          "\"test\"");
+
+  // Compares an std::string to a char* that has different content.
+  char* const p1 = const_cast<char*>("foo");
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(::std::string("bar"), p1),
+                          "p1");
+
+  // Compares two std::strings that have different contents, one of
+  // which having a NUL character in the middle.  This should fail.
+  static ::std::string str3(str1);
+  str3.at(2) = '\0';
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(str1, str3),
+                       "  str3\n    Which is: \"A \\0 in the middle\"");
+}
+
+#if GTEST_HAS_STD_WSTRING
+
+// Tests using ::std::wstring values in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, StdWideString) {
+  // Compares two identical std::wstrings.
+  const ::std::wstring wstr1(L"A * in the middle");
+  const ::std::wstring wstr2(wstr1);
+  ASSERT_EQ(wstr1, wstr2);
+
+  // Compares an std::wstring to a const wchar_t* that has identical
+  // content.
+  const wchar_t kTestX8119[] = { 'T', 'e', 's', 't', 0x8119, '\0' };
+  EXPECT_EQ(::std::wstring(kTestX8119), kTestX8119);
+
+  // Compares an std::wstring to a const wchar_t* that has different
+  // content.
+  const wchar_t kTestX8120[] = { 'T', 'e', 's', 't', 0x8120, '\0' };
+  EXPECT_NONFATAL_FAILURE({  // NOLINT
+    EXPECT_EQ(::std::wstring(kTestX8119), kTestX8120);
+  }, "kTestX8120");
+
+  // Compares two std::wstrings that have different contents, one of
+  // which having a NUL character in the middle.
+  ::std::wstring wstr3(wstr1);
+  wstr3.at(2) = L'\0';
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(wstr1, wstr3),
+                          "wstr3");
+
+  // Compares a wchar_t* to an std::wstring that has different
+  // content.
+  EXPECT_FATAL_FAILURE({  // NOLINT
+    ASSERT_EQ(const_cast<wchar_t*>(L"foo"), ::std::wstring(L"bar"));
+  }, "");
+}
+
+#endif  // GTEST_HAS_STD_WSTRING
+
+// Tests using char pointers in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, CharPointer) {
+  char* const p0 = nullptr;
+  // Only way to get the Nokia compiler to compile the cast
+  // is to have a separate void* variable first. Putting
+  // the two casts on the same line doesn't work, neither does
+  // a direct C-style to char*.
+  void* pv1 = (void*)0x1234;  // NOLINT
+  void* pv2 = (void*)0xABC0;  // NOLINT
+  char* const p1 = reinterpret_cast<char*>(pv1);
+  char* const p2 = reinterpret_cast<char*>(pv2);
+  ASSERT_EQ(p1, p1);
+
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(p0, p2),
+                          "  p2\n    Which is:");
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(p1, p2),
+                          "  p2\n    Which is:");
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(reinterpret_cast<char*>(0x1234),
+                                 reinterpret_cast<char*>(0xABC0)),
+                       "ABC0");
+}
+
+// Tests using wchar_t pointers in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, WideCharPointer) {
+  wchar_t* const p0 = nullptr;
+  // Only way to get the Nokia compiler to compile the cast
+  // is to have a separate void* variable first. Putting
+  // the two casts on the same line doesn't work, neither does
+  // a direct C-style to char*.
+  void* pv1 = (void*)0x1234;  // NOLINT
+  void* pv2 = (void*)0xABC0;  // NOLINT
+  wchar_t* const p1 = reinterpret_cast<wchar_t*>(pv1);
+  wchar_t* const p2 = reinterpret_cast<wchar_t*>(pv2);
+  EXPECT_EQ(p0, p0);
+
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(p0, p2),
+                          "  p2\n    Which is:");
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(p1, p2),
+                          "  p2\n    Which is:");
+  void* pv3 = (void*)0x1234;  // NOLINT
+  void* pv4 = (void*)0xABC0;  // NOLINT
+  const wchar_t* p3 = reinterpret_cast<const wchar_t*>(pv3);
+  const wchar_t* p4 = reinterpret_cast<const wchar_t*>(pv4);
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(p3, p4),
+                          "p4");
+}
+
+// Tests using other types of pointers in {EXPECT|ASSERT}_EQ.
+TEST(EqAssertionTest, OtherPointer) {
+  ASSERT_EQ(static_cast<const int*>(nullptr), static_cast<const int*>(nullptr));
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(static_cast<const int*>(nullptr),
+                                 reinterpret_cast<const int*>(0x1234)),
+                       "0x1234");
+}
+
+// A class that supports binary comparison operators but not streaming.
+class UnprintableChar {
+ public:
+  explicit UnprintableChar(char ch) : char_(ch) {}
+
+  bool operator==(const UnprintableChar& rhs) const {
+    return char_ == rhs.char_;
+  }
+  bool operator!=(const UnprintableChar& rhs) const {
+    return char_ != rhs.char_;
+  }
+  bool operator<(const UnprintableChar& rhs) const {
+    return char_ < rhs.char_;
+  }
+  bool operator<=(const UnprintableChar& rhs) const {
+    return char_ <= rhs.char_;
+  }
+  bool operator>(const UnprintableChar& rhs) const {
+    return char_ > rhs.char_;
+  }
+  bool operator>=(const UnprintableChar& rhs) const {
+    return char_ >= rhs.char_;
+  }
+
+ private:
+  char char_;
+};
+
+// Tests that ASSERT_EQ() and friends don't require the arguments to
+// be printable.
+TEST(ComparisonAssertionTest, AcceptsUnprintableArgs) {
+  const UnprintableChar x('x'), y('y');
+  ASSERT_EQ(x, x);
+  EXPECT_NE(x, y);
+  ASSERT_LT(x, y);
+  EXPECT_LE(x, y);
+  ASSERT_GT(y, x);
+  EXPECT_GE(x, x);
+
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(x, y), "1-byte object <78>");
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(x, y), "1-byte object <79>");
+  EXPECT_NONFATAL_FAILURE(EXPECT_LT(y, y), "1-byte object <79>");
+  EXPECT_NONFATAL_FAILURE(EXPECT_GT(x, y), "1-byte object <78>");
+  EXPECT_NONFATAL_FAILURE(EXPECT_GT(x, y), "1-byte object <79>");
+
+  // Code tested by EXPECT_FATAL_FAILURE cannot reference local
+  // variables, so we have to write UnprintableChar('x') instead of x.
+#ifndef __BORLANDC__
+  // ICE's in C++Builder.
+  EXPECT_FATAL_FAILURE(ASSERT_NE(UnprintableChar('x'), UnprintableChar('x')),
+                       "1-byte object <78>");
+  EXPECT_FATAL_FAILURE(ASSERT_LE(UnprintableChar('y'), UnprintableChar('x')),
+                       "1-byte object <78>");
+#endif
+  EXPECT_FATAL_FAILURE(ASSERT_LE(UnprintableChar('y'), UnprintableChar('x')),
+                       "1-byte object <79>");
+  EXPECT_FATAL_FAILURE(ASSERT_GE(UnprintableChar('x'), UnprintableChar('y')),
+                       "1-byte object <78>");
+  EXPECT_FATAL_FAILURE(ASSERT_GE(UnprintableChar('x'), UnprintableChar('y')),
+                       "1-byte object <79>");
+}
+
+// Tests the FRIEND_TEST macro.
+
+// This class has a private member we want to test.  We will test it
+// both in a TEST and in a TEST_F.
+class Foo {
+ public:
+  Foo() {}
+
+ private:
+  int Bar() const { return 1; }
+
+  // Declares the friend tests that can access the private member
+  // Bar().
+  FRIEND_TEST(FRIEND_TEST_Test, TEST);
+  FRIEND_TEST(FRIEND_TEST_Test2, TEST_F);
+};
+
+// Tests that the FRIEND_TEST declaration allows a TEST to access a
+// class's private members.  This should compile.
+TEST(FRIEND_TEST_Test, TEST) {
+  ASSERT_EQ(1, Foo().Bar());
+}
+
+// The fixture needed to test using FRIEND_TEST with TEST_F.
+class FRIEND_TEST_Test2 : public Test {
+ protected:
+  Foo foo;
+};
+
+// Tests that the FRIEND_TEST declaration allows a TEST_F to access a
+// class's private members.  This should compile.
+TEST_F(FRIEND_TEST_Test2, TEST_F) {
+  ASSERT_EQ(1, foo.Bar());
+}
+
+// Tests the life cycle of Test objects.
+
+// The test fixture for testing the life cycle of Test objects.
+//
+// This class counts the number of live test objects that uses this
+// fixture.
+class TestLifeCycleTest : public Test {
+ protected:
+  // Constructor.  Increments the number of test objects that uses
+  // this fixture.
+  TestLifeCycleTest() { count_++; }
+
+  // Destructor.  Decrements the number of test objects that uses this
+  // fixture.
+  ~TestLifeCycleTest() override { count_--; }
+
+  // Returns the number of live test objects that uses this fixture.
+  int count() const { return count_; }
+
+ private:
+  static int count_;
+};
+
+int TestLifeCycleTest::count_ = 0;
+
+// Tests the life cycle of test objects.
+TEST_F(TestLifeCycleTest, Test1) {
+  // There should be only one test object in this test case that's
+  // currently alive.
+  ASSERT_EQ(1, count());
+}
+
+// Tests the life cycle of test objects.
+TEST_F(TestLifeCycleTest, Test2) {
+  // After Test1 is done and Test2 is started, there should still be
+  // only one live test object, as the object for Test1 should've been
+  // deleted.
+  ASSERT_EQ(1, count());
+}
+
+}  // namespace
+
+// Tests that the copy constructor works when it is NOT optimized away by
+// the compiler.
+TEST(AssertionResultTest, CopyConstructorWorksWhenNotOptimied) {
+  // Checks that the copy constructor doesn't try to dereference NULL pointers
+  // in the source object.
+  AssertionResult r1 = AssertionSuccess();
+  AssertionResult r2 = r1;
+  // The following line is added to prevent the compiler from optimizing
+  // away the constructor call.
+  r1 << "abc";
+
+  AssertionResult r3 = r1;
+  EXPECT_EQ(static_cast<bool>(r3), static_cast<bool>(r1));
+  EXPECT_STREQ("abc", r1.message());
+}
+
+// Tests that AssertionSuccess and AssertionFailure construct
+// AssertionResult objects as expected.
+TEST(AssertionResultTest, ConstructionWorks) {
+  AssertionResult r1 = AssertionSuccess();
+  EXPECT_TRUE(r1);
+  EXPECT_STREQ("", r1.message());
+
+  AssertionResult r2 = AssertionSuccess() << "abc";
+  EXPECT_TRUE(r2);
+  EXPECT_STREQ("abc", r2.message());
+
+  AssertionResult r3 = AssertionFailure();
+  EXPECT_FALSE(r3);
+  EXPECT_STREQ("", r3.message());
+
+  AssertionResult r4 = AssertionFailure() << "def";
+  EXPECT_FALSE(r4);
+  EXPECT_STREQ("def", r4.message());
+
+  AssertionResult r5 = AssertionFailure(Message() << "ghi");
+  EXPECT_FALSE(r5);
+  EXPECT_STREQ("ghi", r5.message());
+}
+
+// Tests that the negation flips the predicate result but keeps the message.
+TEST(AssertionResultTest, NegationWorks) {
+  AssertionResult r1 = AssertionSuccess() << "abc";
+  EXPECT_FALSE(!r1);
+  EXPECT_STREQ("abc", (!r1).message());
+
+  AssertionResult r2 = AssertionFailure() << "def";
+  EXPECT_TRUE(!r2);
+  EXPECT_STREQ("def", (!r2).message());
+}
+
+TEST(AssertionResultTest, StreamingWorks) {
+  AssertionResult r = AssertionSuccess();
+  r << "abc" << 'd' << 0 << true;
+  EXPECT_STREQ("abcd0true", r.message());
+}
+
+TEST(AssertionResultTest, CanStreamOstreamManipulators) {
+  AssertionResult r = AssertionSuccess();
+  r << "Data" << std::endl << std::flush << std::ends << "Will be visible";
+  EXPECT_STREQ("Data\n\\0Will be visible", r.message());
+}
+
+// The next test uses explicit conversion operators
+
+TEST(AssertionResultTest, ConstructibleFromContextuallyConvertibleToBool) {
+  struct ExplicitlyConvertibleToBool {
+    explicit operator bool() const { return value; }
+    bool value;
+  };
+  ExplicitlyConvertibleToBool v1 = {false};
+  ExplicitlyConvertibleToBool v2 = {true};
+  EXPECT_FALSE(v1);
+  EXPECT_TRUE(v2);
+}
+
+struct ConvertibleToAssertionResult {
+  operator AssertionResult() const { return AssertionResult(true); }
+};
+
+TEST(AssertionResultTest, ConstructibleFromImplicitlyConvertible) {
+  ConvertibleToAssertionResult obj;
+  EXPECT_TRUE(obj);
+}
+
+// Tests streaming a user type whose definition and operator << are
+// both in the global namespace.
+class Base {
+ public:
+  explicit Base(int an_x) : x_(an_x) {}
+  int x() const { return x_; }
+ private:
+  int x_;
+};
+std::ostream& operator<<(std::ostream& os,
+                         const Base& val) {
+  return os << val.x();
+}
+std::ostream& operator<<(std::ostream& os,
+                         const Base* pointer) {
+  return os << "(" << pointer->x() << ")";
+}
+
+TEST(MessageTest, CanStreamUserTypeInGlobalNameSpace) {
+  Message msg;
+  Base a(1);
+
+  msg << a << &a;  // Uses ::operator<<.
+  EXPECT_STREQ("1(1)", msg.GetString().c_str());
+}
+
+// Tests streaming a user type whose definition and operator<< are
+// both in an unnamed namespace.
+namespace {
+class MyTypeInUnnamedNameSpace : public Base {
+ public:
+  explicit MyTypeInUnnamedNameSpace(int an_x): Base(an_x) {}
+};
+std::ostream& operator<<(std::ostream& os,
+                         const MyTypeInUnnamedNameSpace& val) {
+  return os << val.x();
+}
+std::ostream& operator<<(std::ostream& os,
+                         const MyTypeInUnnamedNameSpace* pointer) {
+  return os << "(" << pointer->x() << ")";
+}
+}  // namespace
+
+TEST(MessageTest, CanStreamUserTypeInUnnamedNameSpace) {
+  Message msg;
+  MyTypeInUnnamedNameSpace a(1);
+
+  msg << a << &a;  // Uses <unnamed_namespace>::operator<<.
+  EXPECT_STREQ("1(1)", msg.GetString().c_str());
+}
+
+// Tests streaming a user type whose definition and operator<< are
+// both in a user namespace.
+namespace namespace1 {
+class MyTypeInNameSpace1 : public Base {
+ public:
+  explicit MyTypeInNameSpace1(int an_x): Base(an_x) {}
+};
+std::ostream& operator<<(std::ostream& os,
+                         const MyTypeInNameSpace1& val) {
+  return os << val.x();
+}
+std::ostream& operator<<(std::ostream& os,
+                         const MyTypeInNameSpace1* pointer) {
+  return os << "(" << pointer->x() << ")";
+}
+}  // namespace namespace1
+
+TEST(MessageTest, CanStreamUserTypeInUserNameSpace) {
+  Message msg;
+  namespace1::MyTypeInNameSpace1 a(1);
+
+  msg << a << &a;  // Uses namespace1::operator<<.
+  EXPECT_STREQ("1(1)", msg.GetString().c_str());
+}
+
+// Tests streaming a user type whose definition is in a user namespace
+// but whose operator<< is in the global namespace.
+namespace namespace2 {
+class MyTypeInNameSpace2 : public ::Base {
+ public:
+  explicit MyTypeInNameSpace2(int an_x): Base(an_x) {}
+};
+}  // namespace namespace2
+std::ostream& operator<<(std::ostream& os,
+                         const namespace2::MyTypeInNameSpace2& val) {
+  return os << val.x();
+}
+std::ostream& operator<<(std::ostream& os,
+                         const namespace2::MyTypeInNameSpace2* pointer) {
+  return os << "(" << pointer->x() << ")";
+}
+
+TEST(MessageTest, CanStreamUserTypeInUserNameSpaceWithStreamOperatorInGlobal) {
+  Message msg;
+  namespace2::MyTypeInNameSpace2 a(1);
+
+  msg << a << &a;  // Uses ::operator<<.
+  EXPECT_STREQ("1(1)", msg.GetString().c_str());
+}
+
+// Tests streaming NULL pointers to testing::Message.
+TEST(MessageTest, NullPointers) {
+  Message msg;
+  char* const p1 = nullptr;
+  unsigned char* const p2 = nullptr;
+  int* p3 = nullptr;
+  double* p4 = nullptr;
+  bool* p5 = nullptr;
+  Message* p6 = nullptr;
+
+  msg << p1 << p2 << p3 << p4 << p5 << p6;
+  ASSERT_STREQ("(null)(null)(null)(null)(null)(null)",
+               msg.GetString().c_str());
+}
+
+// Tests streaming wide strings to testing::Message.
+TEST(MessageTest, WideStrings) {
+  // Streams a NULL of type const wchar_t*.
+  const wchar_t* const_wstr = nullptr;
+  EXPECT_STREQ("(null)",
+               (Message() << const_wstr).GetString().c_str());
+
+  // Streams a NULL of type wchar_t*.
+  wchar_t* wstr = nullptr;
+  EXPECT_STREQ("(null)",
+               (Message() << wstr).GetString().c_str());
+
+  // Streams a non-NULL of type const wchar_t*.
+  const_wstr = L"abc\x8119";
+  EXPECT_STREQ("abc\xe8\x84\x99",
+               (Message() << const_wstr).GetString().c_str());
+
+  // Streams a non-NULL of type wchar_t*.
+  wstr = const_cast<wchar_t*>(const_wstr);
+  EXPECT_STREQ("abc\xe8\x84\x99",
+               (Message() << wstr).GetString().c_str());
+}
+
+
+// This line tests that we can define tests in the testing namespace.
+namespace testing {
+
+// Tests the TestInfo class.
+
+class TestInfoTest : public Test {
+ protected:
+  static const TestInfo* GetTestInfo(const char* test_name) {
+    const TestSuite* const test_suite =
+        GetUnitTestImpl()->GetTestSuite("TestInfoTest", "", nullptr, nullptr);
+
+    for (int i = 0; i < test_suite->total_test_count(); ++i) {
+      const TestInfo* const test_info = test_suite->GetTestInfo(i);
+      if (strcmp(test_name, test_info->name()) == 0)
+        return test_info;
+    }
+    return nullptr;
+  }
+
+  static const TestResult* GetTestResult(
+      const TestInfo* test_info) {
+    return test_info->result();
+  }
+};
+
+// Tests TestInfo::test_case_name() and TestInfo::name().
+TEST_F(TestInfoTest, Names) {
+  const TestInfo* const test_info = GetTestInfo("Names");
+
+  ASSERT_STREQ("TestInfoTest", test_info->test_case_name());
+  ASSERT_STREQ("Names", test_info->name());
+}
+
+// Tests TestInfo::result().
+TEST_F(TestInfoTest, result) {
+  const TestInfo* const test_info = GetTestInfo("result");
+
+  // Initially, there is no TestPartResult for this test.
+  ASSERT_EQ(0, GetTestResult(test_info)->total_part_count());
+
+  // After the previous assertion, there is still none.
+  ASSERT_EQ(0, GetTestResult(test_info)->total_part_count());
+}
+
+#define VERIFY_CODE_LOCATION \
+  const int expected_line = __LINE__ - 1; \
+  const TestInfo* const test_info = GetUnitTestImpl()->current_test_info(); \
+  ASSERT_TRUE(test_info); \
+  EXPECT_STREQ(__FILE__, test_info->file()); \
+  EXPECT_EQ(expected_line, test_info->line())
+
+TEST(CodeLocationForTEST, Verify) {
+  VERIFY_CODE_LOCATION;
+}
+
+class CodeLocationForTESTF : public Test {
+};
+
+TEST_F(CodeLocationForTESTF, Verify) {
+  VERIFY_CODE_LOCATION;
+}
+
+class CodeLocationForTESTP : public TestWithParam<int> {
+};
+
+TEST_P(CodeLocationForTESTP, Verify) {
+  VERIFY_CODE_LOCATION;
+}
+
+INSTANTIATE_TEST_SUITE_P(, CodeLocationForTESTP, Values(0));
+
+template <typename T>
+class CodeLocationForTYPEDTEST : public Test {
+};
+
+TYPED_TEST_SUITE(CodeLocationForTYPEDTEST, int);
+
+TYPED_TEST(CodeLocationForTYPEDTEST, Verify) {
+  VERIFY_CODE_LOCATION;
+}
+
+template <typename T>
+class CodeLocationForTYPEDTESTP : public Test {
+};
+
+TYPED_TEST_SUITE_P(CodeLocationForTYPEDTESTP);
+
+TYPED_TEST_P(CodeLocationForTYPEDTESTP, Verify) {
+  VERIFY_CODE_LOCATION;
+}
+
+REGISTER_TYPED_TEST_SUITE_P(CodeLocationForTYPEDTESTP, Verify);
+
+INSTANTIATE_TYPED_TEST_SUITE_P(My, CodeLocationForTYPEDTESTP, int);
+
+#undef VERIFY_CODE_LOCATION
+
+// Tests setting up and tearing down a test case.
+// Legacy API is deprecated but still available
+#ifndef REMOVE_LEGACY_TEST_CASEAPI
+class SetUpTestCaseTest : public Test {
+ protected:
+  // This will be called once before the first test in this test case
+  // is run.
+  static void SetUpTestCase() {
+    printf("Setting up the test case . . .\n");
+
+    // Initializes some shared resource.  In this simple example, we
+    // just create a C string.  More complex stuff can be done if
+    // desired.
+    shared_resource_ = "123";
+
+    // Increments the number of test cases that have been set up.
+    counter_++;
+
+    // SetUpTestCase() should be called only once.
+    EXPECT_EQ(1, counter_);
+  }
+
+  // This will be called once after the last test in this test case is
+  // run.
+  static void TearDownTestCase() {
+    printf("Tearing down the test case . . .\n");
+
+    // Decrements the number of test cases that have been set up.
+    counter_--;
+
+    // TearDownTestCase() should be called only once.
+    EXPECT_EQ(0, counter_);
+
+    // Cleans up the shared resource.
+    shared_resource_ = nullptr;
+  }
+
+  // This will be called before each test in this test case.
+  void SetUp() override {
+    // SetUpTestCase() should be called only once, so counter_ should
+    // always be 1.
+    EXPECT_EQ(1, counter_);
+  }
+
+  // Number of test cases that have been set up.
+  static int counter_;
+
+  // Some resource to be shared by all tests in this test case.
+  static const char* shared_resource_;
+};
+
+int SetUpTestCaseTest::counter_ = 0;
+const char* SetUpTestCaseTest::shared_resource_ = nullptr;
+
+// A test that uses the shared resource.
+TEST_F(SetUpTestCaseTest, Test1) { EXPECT_STRNE(nullptr, shared_resource_); }
+
+// Another test that uses the shared resource.
+TEST_F(SetUpTestCaseTest, Test2) {
+  EXPECT_STREQ("123", shared_resource_);
+}
+#endif  //  REMOVE_LEGACY_TEST_CASEAPI
+
+// Tests SetupTestSuite/TearDown TestSuite
+class SetUpTestSuiteTest : public Test {
+ protected:
+  // This will be called once before the first test in this test case
+  // is run.
+  static void SetUpTestSuite() {
+    printf("Setting up the test suite . . .\n");
+
+    // Initializes some shared resource.  In this simple example, we
+    // just create a C string.  More complex stuff can be done if
+    // desired.
+    shared_resource_ = "123";
+
+    // Increments the number of test cases that have been set up.
+    counter_++;
+
+    // SetUpTestSuite() should be called only once.
+    EXPECT_EQ(1, counter_);
+  }
+
+  // This will be called once after the last test in this test case is
+  // run.
+  static void TearDownTestSuite() {
+    printf("Tearing down the test suite . . .\n");
+
+    // Decrements the number of test suites that have been set up.
+    counter_--;
+
+    // TearDownTestSuite() should be called only once.
+    EXPECT_EQ(0, counter_);
+
+    // Cleans up the shared resource.
+    shared_resource_ = nullptr;
+  }
+
+  // This will be called before each test in this test case.
+  void SetUp() override {
+    // SetUpTestSuite() should be called only once, so counter_ should
+    // always be 1.
+    EXPECT_EQ(1, counter_);
+  }
+
+  // Number of test suites that have been set up.
+  static int counter_;
+
+  // Some resource to be shared by all tests in this test case.
+  static const char* shared_resource_;
+};
+
+int SetUpTestSuiteTest::counter_ = 0;
+const char* SetUpTestSuiteTest::shared_resource_ = nullptr;
+
+// A test that uses the shared resource.
+TEST_F(SetUpTestSuiteTest, TestSetupTestSuite1) {
+  EXPECT_STRNE(nullptr, shared_resource_);
+}
+
+// Another test that uses the shared resource.
+TEST_F(SetUpTestSuiteTest, TestSetupTestSuite2) {
+  EXPECT_STREQ("123", shared_resource_);
+}
+
+// The ParseFlagsTest test case tests ParseGoogleTestFlagsOnly.
+
+// The Flags struct stores a copy of all Google Test flags.
+struct Flags {
+  // Constructs a Flags struct where each flag has its default value.
+  Flags() : also_run_disabled_tests(false),
+            break_on_failure(false),
+            catch_exceptions(false),
+            death_test_use_fork(false),
+            filter(""),
+            list_tests(false),
+            output(""),
+            print_time(true),
+            random_seed(0),
+            repeat(1),
+            shuffle(false),
+            stack_trace_depth(kMaxStackTraceDepth),
+            stream_result_to(""),
+            throw_on_failure(false) {}
+
+  // Factory methods.
+
+  // Creates a Flags struct where the gtest_also_run_disabled_tests flag has
+  // the given value.
+  static Flags AlsoRunDisabledTests(bool also_run_disabled_tests) {
+    Flags flags;
+    flags.also_run_disabled_tests = also_run_disabled_tests;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_break_on_failure flag has
+  // the given value.
+  static Flags BreakOnFailure(bool break_on_failure) {
+    Flags flags;
+    flags.break_on_failure = break_on_failure;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_catch_exceptions flag has
+  // the given value.
+  static Flags CatchExceptions(bool catch_exceptions) {
+    Flags flags;
+    flags.catch_exceptions = catch_exceptions;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_death_test_use_fork flag has
+  // the given value.
+  static Flags DeathTestUseFork(bool death_test_use_fork) {
+    Flags flags;
+    flags.death_test_use_fork = death_test_use_fork;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_filter flag has the given
+  // value.
+  static Flags Filter(const char* filter) {
+    Flags flags;
+    flags.filter = filter;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_list_tests flag has the
+  // given value.
+  static Flags ListTests(bool list_tests) {
+    Flags flags;
+    flags.list_tests = list_tests;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_output flag has the given
+  // value.
+  static Flags Output(const char* output) {
+    Flags flags;
+    flags.output = output;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_print_time flag has the given
+  // value.
+  static Flags PrintTime(bool print_time) {
+    Flags flags;
+    flags.print_time = print_time;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_random_seed flag has the given
+  // value.
+  static Flags RandomSeed(Int32 random_seed) {
+    Flags flags;
+    flags.random_seed = random_seed;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_repeat flag has the given
+  // value.
+  static Flags Repeat(Int32 repeat) {
+    Flags flags;
+    flags.repeat = repeat;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_shuffle flag has the given
+  // value.
+  static Flags Shuffle(bool shuffle) {
+    Flags flags;
+    flags.shuffle = shuffle;
+    return flags;
+  }
+
+  // Creates a Flags struct where the GTEST_FLAG(stack_trace_depth) flag has
+  // the given value.
+  static Flags StackTraceDepth(Int32 stack_trace_depth) {
+    Flags flags;
+    flags.stack_trace_depth = stack_trace_depth;
+    return flags;
+  }
+
+  // Creates a Flags struct where the GTEST_FLAG(stream_result_to) flag has
+  // the given value.
+  static Flags StreamResultTo(const char* stream_result_to) {
+    Flags flags;
+    flags.stream_result_to = stream_result_to;
+    return flags;
+  }
+
+  // Creates a Flags struct where the gtest_throw_on_failure flag has
+  // the given value.
+  static Flags ThrowOnFailure(bool throw_on_failure) {
+    Flags flags;
+    flags.throw_on_failure = throw_on_failure;
+    return flags;
+  }
+
+  // These fields store the flag values.
+  bool also_run_disabled_tests;
+  bool break_on_failure;
+  bool catch_exceptions;
+  bool death_test_use_fork;
+  const char* filter;
+  bool list_tests;
+  const char* output;
+  bool print_time;
+  Int32 random_seed;
+  Int32 repeat;
+  bool shuffle;
+  Int32 stack_trace_depth;
+  const char* stream_result_to;
+  bool throw_on_failure;
+};
+
+// Fixture for testing ParseGoogleTestFlagsOnly().
+class ParseFlagsTest : public Test {
+ protected:
+  // Clears the flags before each test.
+  void SetUp() override {
+    GTEST_FLAG(also_run_disabled_tests) = false;
+    GTEST_FLAG(break_on_failure) = false;
+    GTEST_FLAG(catch_exceptions) = false;
+    GTEST_FLAG(death_test_use_fork) = false;
+    GTEST_FLAG(filter) = "";
+    GTEST_FLAG(list_tests) = false;
+    GTEST_FLAG(output) = "";
+    GTEST_FLAG(print_time) = true;
+    GTEST_FLAG(random_seed) = 0;
+    GTEST_FLAG(repeat) = 1;
+    GTEST_FLAG(shuffle) = false;
+    GTEST_FLAG(stack_trace_depth) = kMaxStackTraceDepth;
+    GTEST_FLAG(stream_result_to) = "";
+    GTEST_FLAG(throw_on_failure) = false;
+  }
+
+  // Asserts that two narrow or wide string arrays are equal.
+  template <typename CharType>
+  static void AssertStringArrayEq(int size1, CharType** array1, int size2,
+                                  CharType** array2) {
+    ASSERT_EQ(size1, size2) << " Array sizes different.";
+
+    for (int i = 0; i != size1; i++) {
+      ASSERT_STREQ(array1[i], array2[i]) << " where i == " << i;
+    }
+  }
+
+  // Verifies that the flag values match the expected values.
+  static void CheckFlags(const Flags& expected) {
+    EXPECT_EQ(expected.also_run_disabled_tests,
+              GTEST_FLAG(also_run_disabled_tests));
+    EXPECT_EQ(expected.break_on_failure, GTEST_FLAG(break_on_failure));
+    EXPECT_EQ(expected.catch_exceptions, GTEST_FLAG(catch_exceptions));
+    EXPECT_EQ(expected.death_test_use_fork, GTEST_FLAG(death_test_use_fork));
+    EXPECT_STREQ(expected.filter, GTEST_FLAG(filter).c_str());
+    EXPECT_EQ(expected.list_tests, GTEST_FLAG(list_tests));
+    EXPECT_STREQ(expected.output, GTEST_FLAG(output).c_str());
+    EXPECT_EQ(expected.print_time, GTEST_FLAG(print_time));
+    EXPECT_EQ(expected.random_seed, GTEST_FLAG(random_seed));
+    EXPECT_EQ(expected.repeat, GTEST_FLAG(repeat));
+    EXPECT_EQ(expected.shuffle, GTEST_FLAG(shuffle));
+    EXPECT_EQ(expected.stack_trace_depth, GTEST_FLAG(stack_trace_depth));
+    EXPECT_STREQ(expected.stream_result_to,
+                 GTEST_FLAG(stream_result_to).c_str());
+    EXPECT_EQ(expected.throw_on_failure, GTEST_FLAG(throw_on_failure));
+  }
+
+  // Parses a command line (specified by argc1 and argv1), then
+  // verifies that the flag values are expected and that the
+  // recognized flags are removed from the command line.
+  template <typename CharType>
+  static void TestParsingFlags(int argc1, const CharType** argv1,
+                               int argc2, const CharType** argv2,
+                               const Flags& expected, bool should_print_help) {
+    const bool saved_help_flag = ::testing::internal::g_help_flag;
+    ::testing::internal::g_help_flag = false;
+
+# if GTEST_HAS_STREAM_REDIRECTION
+    CaptureStdout();
+# endif
+
+    // Parses the command line.
+    internal::ParseGoogleTestFlagsOnly(&argc1, const_cast<CharType**>(argv1));
+
+# if GTEST_HAS_STREAM_REDIRECTION
+    const std::string captured_stdout = GetCapturedStdout();
+# endif
+
+    // Verifies the flag values.
+    CheckFlags(expected);
+
+    // Verifies that the recognized flags are removed from the command
+    // line.
+    AssertStringArrayEq(argc1 + 1, argv1, argc2 + 1, argv2);
+
+    // ParseGoogleTestFlagsOnly should neither set g_help_flag nor print the
+    // help message for the flags it recognizes.
+    EXPECT_EQ(should_print_help, ::testing::internal::g_help_flag);
+
+# if GTEST_HAS_STREAM_REDIRECTION
+    const char* const expected_help_fragment =
+        "This program contains tests written using";
+    if (should_print_help) {
+      EXPECT_PRED_FORMAT2(IsSubstring, expected_help_fragment, captured_stdout);
+    } else {
+      EXPECT_PRED_FORMAT2(IsNotSubstring,
+                          expected_help_fragment, captured_stdout);
+    }
+# endif  // GTEST_HAS_STREAM_REDIRECTION
+
+    ::testing::internal::g_help_flag = saved_help_flag;
+  }
+
+  // This macro wraps TestParsingFlags s.t. the user doesn't need
+  // to specify the array sizes.
+
+# define GTEST_TEST_PARSING_FLAGS_(argv1, argv2, expected, should_print_help) \
+  TestParsingFlags(sizeof(argv1)/sizeof(*argv1) - 1, argv1, \
+                   sizeof(argv2)/sizeof(*argv2) - 1, argv2, \
+                   expected, should_print_help)
+};
+
+// Tests parsing an empty command line.
+TEST_F(ParseFlagsTest, Empty) {
+  const char* argv[] = {nullptr};
+
+  const char* argv2[] = {nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags(), false);
+}
+
+// Tests parsing a command line that has no flag.
+TEST_F(ParseFlagsTest, NoFlag) {
+  const char* argv[] = {"foo.exe", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags(), false);
+}
+
+// Tests parsing a bad --gtest_filter flag.
+TEST_F(ParseFlagsTest, FilterBad) {
+  const char* argv[] = {"foo.exe", "--gtest_filter", nullptr};
+
+  const char* argv2[] = {"foo.exe", "--gtest_filter", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Filter(""), true);
+}
+
+// Tests parsing an empty --gtest_filter flag.
+TEST_F(ParseFlagsTest, FilterEmpty) {
+  const char* argv[] = {"foo.exe", "--gtest_filter=", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Filter(""), false);
+}
+
+// Tests parsing a non-empty --gtest_filter flag.
+TEST_F(ParseFlagsTest, FilterNonEmpty) {
+  const char* argv[] = {"foo.exe", "--gtest_filter=abc", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Filter("abc"), false);
+}
+
+// Tests parsing --gtest_break_on_failure.
+TEST_F(ParseFlagsTest, BreakOnFailureWithoutValue) {
+  const char* argv[] = {"foo.exe", "--gtest_break_on_failure", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::BreakOnFailure(true), false);
+}
+
+// Tests parsing --gtest_break_on_failure=0.
+TEST_F(ParseFlagsTest, BreakOnFailureFalse_0) {
+  const char* argv[] = {"foo.exe", "--gtest_break_on_failure=0", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::BreakOnFailure(false), false);
+}
+
+// Tests parsing --gtest_break_on_failure=f.
+TEST_F(ParseFlagsTest, BreakOnFailureFalse_f) {
+  const char* argv[] = {"foo.exe", "--gtest_break_on_failure=f", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::BreakOnFailure(false), false);
+}
+
+// Tests parsing --gtest_break_on_failure=F.
+TEST_F(ParseFlagsTest, BreakOnFailureFalse_F) {
+  const char* argv[] = {"foo.exe", "--gtest_break_on_failure=F", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::BreakOnFailure(false), false);
+}
+
+// Tests parsing a --gtest_break_on_failure flag that has a "true"
+// definition.
+TEST_F(ParseFlagsTest, BreakOnFailureTrue) {
+  const char* argv[] = {"foo.exe", "--gtest_break_on_failure=1", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::BreakOnFailure(true), false);
+}
+
+// Tests parsing --gtest_catch_exceptions.
+TEST_F(ParseFlagsTest, CatchExceptions) {
+  const char* argv[] = {"foo.exe", "--gtest_catch_exceptions", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::CatchExceptions(true), false);
+}
+
+// Tests parsing --gtest_death_test_use_fork.
+TEST_F(ParseFlagsTest, DeathTestUseFork) {
+  const char* argv[] = {"foo.exe", "--gtest_death_test_use_fork", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::DeathTestUseFork(true), false);
+}
+
+// Tests having the same flag twice with different values.  The
+// expected behavior is that the one coming last takes precedence.
+TEST_F(ParseFlagsTest, DuplicatedFlags) {
+  const char* argv[] = {"foo.exe", "--gtest_filter=a", "--gtest_filter=b",
+                        nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Filter("b"), false);
+}
+
+// Tests having an unrecognized flag on the command line.
+TEST_F(ParseFlagsTest, UnrecognizedFlag) {
+  const char* argv[] = {"foo.exe", "--gtest_break_on_failure",
+                        "bar",  // Unrecognized by Google Test.
+                        "--gtest_filter=b", nullptr};
+
+  const char* argv2[] = {"foo.exe", "bar", nullptr};
+
+  Flags flags;
+  flags.break_on_failure = true;
+  flags.filter = "b";
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, flags, false);
+}
+
+// Tests having a --gtest_list_tests flag
+TEST_F(ParseFlagsTest, ListTestsFlag) {
+  const char* argv[] = {"foo.exe", "--gtest_list_tests", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::ListTests(true), false);
+}
+
+// Tests having a --gtest_list_tests flag with a "true" value
+TEST_F(ParseFlagsTest, ListTestsTrue) {
+  const char* argv[] = {"foo.exe", "--gtest_list_tests=1", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::ListTests(true), false);
+}
+
+// Tests having a --gtest_list_tests flag with a "false" value
+TEST_F(ParseFlagsTest, ListTestsFalse) {
+  const char* argv[] = {"foo.exe", "--gtest_list_tests=0", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::ListTests(false), false);
+}
+
+// Tests parsing --gtest_list_tests=f.
+TEST_F(ParseFlagsTest, ListTestsFalse_f) {
+  const char* argv[] = {"foo.exe", "--gtest_list_tests=f", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::ListTests(false), false);
+}
+
+// Tests parsing --gtest_list_tests=F.
+TEST_F(ParseFlagsTest, ListTestsFalse_F) {
+  const char* argv[] = {"foo.exe", "--gtest_list_tests=F", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::ListTests(false), false);
+}
+
+// Tests parsing --gtest_output (invalid).
+TEST_F(ParseFlagsTest, OutputEmpty) {
+  const char* argv[] = {"foo.exe", "--gtest_output", nullptr};
+
+  const char* argv2[] = {"foo.exe", "--gtest_output", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags(), true);
+}
+
+// Tests parsing --gtest_output=xml
+TEST_F(ParseFlagsTest, OutputXml) {
+  const char* argv[] = {"foo.exe", "--gtest_output=xml", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Output("xml"), false);
+}
+
+// Tests parsing --gtest_output=xml:file
+TEST_F(ParseFlagsTest, OutputXmlFile) {
+  const char* argv[] = {"foo.exe", "--gtest_output=xml:file", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Output("xml:file"), false);
+}
+
+// Tests parsing --gtest_output=xml:directory/path/
+TEST_F(ParseFlagsTest, OutputXmlDirectory) {
+  const char* argv[] = {"foo.exe", "--gtest_output=xml:directory/path/",
+                        nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2,
+                            Flags::Output("xml:directory/path/"), false);
+}
+
+// Tests having a --gtest_print_time flag
+TEST_F(ParseFlagsTest, PrintTimeFlag) {
+  const char* argv[] = {"foo.exe", "--gtest_print_time", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::PrintTime(true), false);
+}
+
+// Tests having a --gtest_print_time flag with a "true" value
+TEST_F(ParseFlagsTest, PrintTimeTrue) {
+  const char* argv[] = {"foo.exe", "--gtest_print_time=1", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::PrintTime(true), false);
+}
+
+// Tests having a --gtest_print_time flag with a "false" value
+TEST_F(ParseFlagsTest, PrintTimeFalse) {
+  const char* argv[] = {"foo.exe", "--gtest_print_time=0", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::PrintTime(false), false);
+}
+
+// Tests parsing --gtest_print_time=f.
+TEST_F(ParseFlagsTest, PrintTimeFalse_f) {
+  const char* argv[] = {"foo.exe", "--gtest_print_time=f", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::PrintTime(false), false);
+}
+
+// Tests parsing --gtest_print_time=F.
+TEST_F(ParseFlagsTest, PrintTimeFalse_F) {
+  const char* argv[] = {"foo.exe", "--gtest_print_time=F", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::PrintTime(false), false);
+}
+
+// Tests parsing --gtest_random_seed=number
+TEST_F(ParseFlagsTest, RandomSeed) {
+  const char* argv[] = {"foo.exe", "--gtest_random_seed=1000", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::RandomSeed(1000), false);
+}
+
+// Tests parsing --gtest_repeat=number
+TEST_F(ParseFlagsTest, Repeat) {
+  const char* argv[] = {"foo.exe", "--gtest_repeat=1000", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Repeat(1000), false);
+}
+
+// Tests having a --gtest_also_run_disabled_tests flag
+TEST_F(ParseFlagsTest, AlsoRunDisabledTestsFlag) {
+  const char* argv[] = {"foo.exe", "--gtest_also_run_disabled_tests", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::AlsoRunDisabledTests(true),
+                            false);
+}
+
+// Tests having a --gtest_also_run_disabled_tests flag with a "true" value
+TEST_F(ParseFlagsTest, AlsoRunDisabledTestsTrue) {
+  const char* argv[] = {"foo.exe", "--gtest_also_run_disabled_tests=1",
+                        nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::AlsoRunDisabledTests(true),
+                            false);
+}
+
+// Tests having a --gtest_also_run_disabled_tests flag with a "false" value
+TEST_F(ParseFlagsTest, AlsoRunDisabledTestsFalse) {
+  const char* argv[] = {"foo.exe", "--gtest_also_run_disabled_tests=0",
+                        nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::AlsoRunDisabledTests(false),
+                            false);
+}
+
+// Tests parsing --gtest_shuffle.
+TEST_F(ParseFlagsTest, ShuffleWithoutValue) {
+  const char* argv[] = {"foo.exe", "--gtest_shuffle", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Shuffle(true), false);
+}
+
+// Tests parsing --gtest_shuffle=0.
+TEST_F(ParseFlagsTest, ShuffleFalse_0) {
+  const char* argv[] = {"foo.exe", "--gtest_shuffle=0", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Shuffle(false), false);
+}
+
+// Tests parsing a --gtest_shuffle flag that has a "true" definition.
+TEST_F(ParseFlagsTest, ShuffleTrue) {
+  const char* argv[] = {"foo.exe", "--gtest_shuffle=1", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Shuffle(true), false);
+}
+
+// Tests parsing --gtest_stack_trace_depth=number.
+TEST_F(ParseFlagsTest, StackTraceDepth) {
+  const char* argv[] = {"foo.exe", "--gtest_stack_trace_depth=5", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::StackTraceDepth(5), false);
+}
+
+TEST_F(ParseFlagsTest, StreamResultTo) {
+  const char* argv[] = {"foo.exe", "--gtest_stream_result_to=localhost:1234",
+                        nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(
+      argv, argv2, Flags::StreamResultTo("localhost:1234"), false);
+}
+
+// Tests parsing --gtest_throw_on_failure.
+TEST_F(ParseFlagsTest, ThrowOnFailureWithoutValue) {
+  const char* argv[] = {"foo.exe", "--gtest_throw_on_failure", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::ThrowOnFailure(true), false);
+}
+
+// Tests parsing --gtest_throw_on_failure=0.
+TEST_F(ParseFlagsTest, ThrowOnFailureFalse_0) {
+  const char* argv[] = {"foo.exe", "--gtest_throw_on_failure=0", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::ThrowOnFailure(false), false);
+}
+
+// Tests parsing a --gtest_throw_on_failure flag that has a "true"
+// definition.
+TEST_F(ParseFlagsTest, ThrowOnFailureTrue) {
+  const char* argv[] = {"foo.exe", "--gtest_throw_on_failure=1", nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::ThrowOnFailure(true), false);
+}
+
+# if GTEST_OS_WINDOWS
+// Tests parsing wide strings.
+TEST_F(ParseFlagsTest, WideStrings) {
+  const wchar_t* argv[] = {
+    L"foo.exe",
+    L"--gtest_filter=Foo*",
+    L"--gtest_list_tests=1",
+    L"--gtest_break_on_failure",
+    L"--non_gtest_flag",
+    NULL
+  };
+
+  const wchar_t* argv2[] = {
+    L"foo.exe",
+    L"--non_gtest_flag",
+    NULL
+  };
+
+  Flags expected_flags;
+  expected_flags.break_on_failure = true;
+  expected_flags.filter = "Foo*";
+  expected_flags.list_tests = true;
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, expected_flags, false);
+}
+# endif  // GTEST_OS_WINDOWS
+
+#if GTEST_USE_OWN_FLAGFILE_FLAG_
+class FlagfileTest : public ParseFlagsTest {
+ public:
+  virtual void SetUp() {
+    ParseFlagsTest::SetUp();
+
+    testdata_path_.Set(internal::FilePath(
+        testing::TempDir() + internal::GetCurrentExecutableName().string() +
+        "_flagfile_test"));
+    testing::internal::posix::RmDir(testdata_path_.c_str());
+    EXPECT_TRUE(testdata_path_.CreateFolder());
+  }
+
+  virtual void TearDown() {
+    testing::internal::posix::RmDir(testdata_path_.c_str());
+    ParseFlagsTest::TearDown();
+  }
+
+  internal::FilePath CreateFlagfile(const char* contents) {
+    internal::FilePath file_path(internal::FilePath::GenerateUniqueFileName(
+        testdata_path_, internal::FilePath("unique"), "txt"));
+    FILE* f = testing::internal::posix::FOpen(file_path.c_str(), "w");
+    fprintf(f, "%s", contents);
+    fclose(f);
+    return file_path;
+  }
+
+ private:
+  internal::FilePath testdata_path_;
+};
+
+// Tests an empty flagfile.
+TEST_F(FlagfileTest, Empty) {
+  internal::FilePath flagfile_path(CreateFlagfile(""));
+  std::string flagfile_flag =
+      std::string("--" GTEST_FLAG_PREFIX_ "flagfile=") + flagfile_path.c_str();
+
+  const char* argv[] = {"foo.exe", flagfile_flag.c_str(), nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags(), false);
+}
+
+// Tests passing a non-empty --gtest_filter flag via --gtest_flagfile.
+TEST_F(FlagfileTest, FilterNonEmpty) {
+  internal::FilePath flagfile_path(CreateFlagfile(
+      "--"  GTEST_FLAG_PREFIX_  "filter=abc"));
+  std::string flagfile_flag =
+      std::string("--" GTEST_FLAG_PREFIX_ "flagfile=") + flagfile_path.c_str();
+
+  const char* argv[] = {"foo.exe", flagfile_flag.c_str(), nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, Flags::Filter("abc"), false);
+}
+
+// Tests passing several flags via --gtest_flagfile.
+TEST_F(FlagfileTest, SeveralFlags) {
+  internal::FilePath flagfile_path(CreateFlagfile(
+      "--"  GTEST_FLAG_PREFIX_  "filter=abc\n"
+      "--"  GTEST_FLAG_PREFIX_  "break_on_failure\n"
+      "--"  GTEST_FLAG_PREFIX_  "list_tests"));
+  std::string flagfile_flag =
+      std::string("--" GTEST_FLAG_PREFIX_ "flagfile=") + flagfile_path.c_str();
+
+  const char* argv[] = {"foo.exe", flagfile_flag.c_str(), nullptr};
+
+  const char* argv2[] = {"foo.exe", nullptr};
+
+  Flags expected_flags;
+  expected_flags.break_on_failure = true;
+  expected_flags.filter = "abc";
+  expected_flags.list_tests = true;
+
+  GTEST_TEST_PARSING_FLAGS_(argv, argv2, expected_flags, false);
+}
+#endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
+
+// Tests current_test_info() in UnitTest.
+class CurrentTestInfoTest : public Test {
+ protected:
+  // Tests that current_test_info() returns NULL before the first test in
+  // the test case is run.
+  static void SetUpTestSuite() {
+    // There should be no tests running at this point.
+    const TestInfo* test_info =
+      UnitTest::GetInstance()->current_test_info();
+    EXPECT_TRUE(test_info == nullptr)
+        << "There should be no tests running at this point.";
+  }
+
+  // Tests that current_test_info() returns NULL after the last test in
+  // the test case has run.
+  static void TearDownTestSuite() {
+    const TestInfo* test_info =
+      UnitTest::GetInstance()->current_test_info();
+    EXPECT_TRUE(test_info == nullptr)
+        << "There should be no tests running at this point.";
+  }
+};
+
+// Tests that current_test_info() returns TestInfo for currently running
+// test by checking the expected test name against the actual one.
+TEST_F(CurrentTestInfoTest, WorksForFirstTestInATestSuite) {
+  const TestInfo* test_info =
+    UnitTest::GetInstance()->current_test_info();
+  ASSERT_TRUE(nullptr != test_info)
+      << "There is a test running so we should have a valid TestInfo.";
+  EXPECT_STREQ("CurrentTestInfoTest", test_info->test_case_name())
+      << "Expected the name of the currently running test case.";
+  EXPECT_STREQ("WorksForFirstTestInATestSuite", test_info->name())
+      << "Expected the name of the currently running test.";
+}
+
+// Tests that current_test_info() returns TestInfo for currently running
+// test by checking the expected test name against the actual one.  We
+// use this test to see that the TestInfo object actually changed from
+// the previous invocation.
+TEST_F(CurrentTestInfoTest, WorksForSecondTestInATestSuite) {
+  const TestInfo* test_info =
+    UnitTest::GetInstance()->current_test_info();
+  ASSERT_TRUE(nullptr != test_info)
+      << "There is a test running so we should have a valid TestInfo.";
+  EXPECT_STREQ("CurrentTestInfoTest", test_info->test_case_name())
+      << "Expected the name of the currently running test case.";
+  EXPECT_STREQ("WorksForSecondTestInATestSuite", test_info->name())
+      << "Expected the name of the currently running test.";
+}
+
+}  // namespace testing
+
+
+// These two lines test that we can define tests in a namespace that
+// has the name "testing" and is nested in another namespace.
+namespace my_namespace {
+namespace testing {
+
+// Makes sure that TEST knows to use ::testing::Test instead of
+// ::my_namespace::testing::Test.
+class Test {};
+
+// Makes sure that an assertion knows to use ::testing::Message instead of
+// ::my_namespace::testing::Message.
+class Message {};
+
+// Makes sure that an assertion knows to use
+// ::testing::AssertionResult instead of
+// ::my_namespace::testing::AssertionResult.
+class AssertionResult {};
+
+// Tests that an assertion that should succeed works as expected.
+TEST(NestedTestingNamespaceTest, Success) {
+  EXPECT_EQ(1, 1) << "This shouldn't fail.";
+}
+
+// Tests that an assertion that should fail works as expected.
+TEST(NestedTestingNamespaceTest, Failure) {
+  EXPECT_FATAL_FAILURE(FAIL() << "This failure is expected.",
+                       "This failure is expected.");
+}
+
+}  // namespace testing
+}  // namespace my_namespace
+
+// Tests that one can call superclass SetUp and TearDown methods--
+// that is, that they are not private.
+// No tests are based on this fixture; the test "passes" if it compiles
+// successfully.
+class ProtectedFixtureMethodsTest : public Test {
+ protected:
+  void SetUp() override { Test::SetUp(); }
+  void TearDown() override { Test::TearDown(); }
+};
+
+// StreamingAssertionsTest tests the streaming versions of a representative
+// sample of assertions.
+TEST(StreamingAssertionsTest, Unconditional) {
+  SUCCEED() << "expected success";
+  EXPECT_NONFATAL_FAILURE(ADD_FAILURE() << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(FAIL() << "expected failure",
+                       "expected failure");
+}
+
+#ifdef __BORLANDC__
+// Silences warnings: "Condition is always true", "Unreachable code"
+# pragma option push -w-ccc -w-rch
+#endif
+
+TEST(StreamingAssertionsTest, Truth) {
+  EXPECT_TRUE(true) << "unexpected failure";
+  ASSERT_TRUE(true) << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_TRUE(false) << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_TRUE(false) << "expected failure",
+                       "expected failure");
+}
+
+TEST(StreamingAssertionsTest, Truth2) {
+  EXPECT_FALSE(false) << "unexpected failure";
+  ASSERT_FALSE(false) << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_FALSE(true) << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_FALSE(true) << "expected failure",
+                       "expected failure");
+}
+
+#ifdef __BORLANDC__
+// Restores warnings after previous "#pragma option push" suppressed them
+# pragma option pop
+#endif
+
+TEST(StreamingAssertionsTest, IntegerEquals) {
+  EXPECT_EQ(1, 1) << "unexpected failure";
+  ASSERT_EQ(1, 1) << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_EQ(1, 2) << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_EQ(1, 2) << "expected failure",
+                       "expected failure");
+}
+
+TEST(StreamingAssertionsTest, IntegerLessThan) {
+  EXPECT_LT(1, 2) << "unexpected failure";
+  ASSERT_LT(1, 2) << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_LT(2, 1) << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_LT(2, 1) << "expected failure",
+                       "expected failure");
+}
+
+TEST(StreamingAssertionsTest, StringsEqual) {
+  EXPECT_STREQ("foo", "foo") << "unexpected failure";
+  ASSERT_STREQ("foo", "foo") << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_STREQ("foo", "bar") << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_STREQ("foo", "bar") << "expected failure",
+                       "expected failure");
+}
+
+TEST(StreamingAssertionsTest, StringsNotEqual) {
+  EXPECT_STRNE("foo", "bar") << "unexpected failure";
+  ASSERT_STRNE("foo", "bar") << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_STRNE("foo", "foo") << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_STRNE("foo", "foo") << "expected failure",
+                       "expected failure");
+}
+
+TEST(StreamingAssertionsTest, StringsEqualIgnoringCase) {
+  EXPECT_STRCASEEQ("foo", "FOO") << "unexpected failure";
+  ASSERT_STRCASEEQ("foo", "FOO") << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_STRCASEEQ("foo", "bar") << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_STRCASEEQ("foo", "bar") << "expected failure",
+                       "expected failure");
+}
+
+TEST(StreamingAssertionsTest, StringNotEqualIgnoringCase) {
+  EXPECT_STRCASENE("foo", "bar") << "unexpected failure";
+  ASSERT_STRCASENE("foo", "bar") << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_STRCASENE("foo", "FOO") << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_STRCASENE("bar", "BAR") << "expected failure",
+                       "expected failure");
+}
+
+TEST(StreamingAssertionsTest, FloatingPointEquals) {
+  EXPECT_FLOAT_EQ(1.0, 1.0) << "unexpected failure";
+  ASSERT_FLOAT_EQ(1.0, 1.0) << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_FLOAT_EQ(0.0, 1.0) << "expected failure",
+                          "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_FLOAT_EQ(0.0, 1.0) << "expected failure",
+                       "expected failure");
+}
+
+#if GTEST_HAS_EXCEPTIONS
+
+TEST(StreamingAssertionsTest, Throw) {
+  EXPECT_THROW(ThrowAnInteger(), int) << "unexpected failure";
+  ASSERT_THROW(ThrowAnInteger(), int) << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_THROW(ThrowAnInteger(), bool) <<
+                          "expected failure", "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_THROW(ThrowAnInteger(), bool) <<
+                       "expected failure", "expected failure");
+}
+
+TEST(StreamingAssertionsTest, NoThrow) {
+  EXPECT_NO_THROW(ThrowNothing()) << "unexpected failure";
+  ASSERT_NO_THROW(ThrowNothing()) << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_NO_THROW(ThrowAnInteger()) <<
+                          "expected failure", "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_NO_THROW(ThrowAnInteger()) <<
+                       "expected failure", "expected failure");
+}
+
+TEST(StreamingAssertionsTest, AnyThrow) {
+  EXPECT_ANY_THROW(ThrowAnInteger()) << "unexpected failure";
+  ASSERT_ANY_THROW(ThrowAnInteger()) << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_ANY_THROW(ThrowNothing()) <<
+                          "expected failure", "expected failure");
+  EXPECT_FATAL_FAILURE(ASSERT_ANY_THROW(ThrowNothing()) <<
+                       "expected failure", "expected failure");
+}
+
+#endif  // GTEST_HAS_EXCEPTIONS
+
+// Tests that Google Test correctly decides whether to use colors in the output.
+
+TEST(ColoredOutputTest, UsesColorsWhenGTestColorFlagIsYes) {
+  GTEST_FLAG(color) = "yes";
+
+  SetEnv("TERM", "xterm");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+  EXPECT_TRUE(ShouldUseColor(false));  // Stdout is not a TTY.
+
+  SetEnv("TERM", "dumb");  // TERM doesn't support colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+  EXPECT_TRUE(ShouldUseColor(false));  // Stdout is not a TTY.
+}
+
+TEST(ColoredOutputTest, UsesColorsWhenGTestColorFlagIsAliasOfYes) {
+  SetEnv("TERM", "dumb");  // TERM doesn't support colors.
+
+  GTEST_FLAG(color) = "True";
+  EXPECT_TRUE(ShouldUseColor(false));  // Stdout is not a TTY.
+
+  GTEST_FLAG(color) = "t";
+  EXPECT_TRUE(ShouldUseColor(false));  // Stdout is not a TTY.
+
+  GTEST_FLAG(color) = "1";
+  EXPECT_TRUE(ShouldUseColor(false));  // Stdout is not a TTY.
+}
+
+TEST(ColoredOutputTest, UsesNoColorWhenGTestColorFlagIsNo) {
+  GTEST_FLAG(color) = "no";
+
+  SetEnv("TERM", "xterm");  // TERM supports colors.
+  EXPECT_FALSE(ShouldUseColor(true));  // Stdout is a TTY.
+  EXPECT_FALSE(ShouldUseColor(false));  // Stdout is not a TTY.
+
+  SetEnv("TERM", "dumb");  // TERM doesn't support colors.
+  EXPECT_FALSE(ShouldUseColor(true));  // Stdout is a TTY.
+  EXPECT_FALSE(ShouldUseColor(false));  // Stdout is not a TTY.
+}
+
+TEST(ColoredOutputTest, UsesNoColorWhenGTestColorFlagIsInvalid) {
+  SetEnv("TERM", "xterm");  // TERM supports colors.
+
+  GTEST_FLAG(color) = "F";
+  EXPECT_FALSE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  GTEST_FLAG(color) = "0";
+  EXPECT_FALSE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  GTEST_FLAG(color) = "unknown";
+  EXPECT_FALSE(ShouldUseColor(true));  // Stdout is a TTY.
+}
+
+TEST(ColoredOutputTest, UsesColorsWhenStdoutIsTty) {
+  GTEST_FLAG(color) = "auto";
+
+  SetEnv("TERM", "xterm");  // TERM supports colors.
+  EXPECT_FALSE(ShouldUseColor(false));  // Stdout is not a TTY.
+  EXPECT_TRUE(ShouldUseColor(true));    // Stdout is a TTY.
+}
+
+TEST(ColoredOutputTest, UsesColorsWhenTermSupportsColors) {
+  GTEST_FLAG(color) = "auto";
+
+#if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
+  // On Windows, we ignore the TERM variable as it's usually not set.
+
+  SetEnv("TERM", "dumb");
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "");
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "xterm");
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+#else
+  // On non-Windows platforms, we rely on TERM to determine if the
+  // terminal supports colors.
+
+  SetEnv("TERM", "dumb");  // TERM doesn't support colors.
+  EXPECT_FALSE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "emacs");  // TERM doesn't support colors.
+  EXPECT_FALSE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "vt100");  // TERM doesn't support colors.
+  EXPECT_FALSE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "xterm-mono");  // TERM doesn't support colors.
+  EXPECT_FALSE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "xterm");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "xterm-color");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "xterm-256color");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "screen");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "screen-256color");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "tmux");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "tmux-256color");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "rxvt-unicode");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "rxvt-unicode-256color");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "linux");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "cygwin");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+#endif  // GTEST_OS_WINDOWS
+}
+
+// Verifies that StaticAssertTypeEq works in a namespace scope.
+
+static bool dummy1 GTEST_ATTRIBUTE_UNUSED_ = StaticAssertTypeEq<bool, bool>();
+static bool dummy2 GTEST_ATTRIBUTE_UNUSED_ =
+    StaticAssertTypeEq<const int, const int>();
+
+// Verifies that StaticAssertTypeEq works in a class.
+
+template <typename T>
+class StaticAssertTypeEqTestHelper {
+ public:
+  StaticAssertTypeEqTestHelper() { StaticAssertTypeEq<bool, T>(); }
+};
+
+TEST(StaticAssertTypeEqTest, WorksInClass) {
+  StaticAssertTypeEqTestHelper<bool>();
+}
+
+// Verifies that StaticAssertTypeEq works inside a function.
+
+typedef int IntAlias;
+
+TEST(StaticAssertTypeEqTest, CompilesForEqualTypes) {
+  StaticAssertTypeEq<int, IntAlias>();
+  StaticAssertTypeEq<int*, IntAlias*>();
+}
+
+TEST(HasNonfatalFailureTest, ReturnsFalseWhenThereIsNoFailure) {
+  EXPECT_FALSE(HasNonfatalFailure());
+}
+
+static void FailFatally() { FAIL(); }
+
+TEST(HasNonfatalFailureTest, ReturnsFalseWhenThereIsOnlyFatalFailure) {
+  FailFatally();
+  const bool has_nonfatal_failure = HasNonfatalFailure();
+  ClearCurrentTestPartResults();
+  EXPECT_FALSE(has_nonfatal_failure);
+}
+
+TEST(HasNonfatalFailureTest, ReturnsTrueWhenThereIsNonfatalFailure) {
+  ADD_FAILURE();
+  const bool has_nonfatal_failure = HasNonfatalFailure();
+  ClearCurrentTestPartResults();
+  EXPECT_TRUE(has_nonfatal_failure);
+}
+
+TEST(HasNonfatalFailureTest, ReturnsTrueWhenThereAreFatalAndNonfatalFailures) {
+  FailFatally();
+  ADD_FAILURE();
+  const bool has_nonfatal_failure = HasNonfatalFailure();
+  ClearCurrentTestPartResults();
+  EXPECT_TRUE(has_nonfatal_failure);
+}
+
+// A wrapper for calling HasNonfatalFailure outside of a test body.
+static bool HasNonfatalFailureHelper() {
+  return testing::Test::HasNonfatalFailure();
+}
+
+TEST(HasNonfatalFailureTest, WorksOutsideOfTestBody) {
+  EXPECT_FALSE(HasNonfatalFailureHelper());
+}
+
+TEST(HasNonfatalFailureTest, WorksOutsideOfTestBody2) {
+  ADD_FAILURE();
+  const bool has_nonfatal_failure = HasNonfatalFailureHelper();
+  ClearCurrentTestPartResults();
+  EXPECT_TRUE(has_nonfatal_failure);
+}
+
+TEST(HasFailureTest, ReturnsFalseWhenThereIsNoFailure) {
+  EXPECT_FALSE(HasFailure());
+}
+
+TEST(HasFailureTest, ReturnsTrueWhenThereIsFatalFailure) {
+  FailFatally();
+  const bool has_failure = HasFailure();
+  ClearCurrentTestPartResults();
+  EXPECT_TRUE(has_failure);
+}
+
+TEST(HasFailureTest, ReturnsTrueWhenThereIsNonfatalFailure) {
+  ADD_FAILURE();
+  const bool has_failure = HasFailure();
+  ClearCurrentTestPartResults();
+  EXPECT_TRUE(has_failure);
+}
+
+TEST(HasFailureTest, ReturnsTrueWhenThereAreFatalAndNonfatalFailures) {
+  FailFatally();
+  ADD_FAILURE();
+  const bool has_failure = HasFailure();
+  ClearCurrentTestPartResults();
+  EXPECT_TRUE(has_failure);
+}
+
+// A wrapper for calling HasFailure outside of a test body.
+static bool HasFailureHelper() { return testing::Test::HasFailure(); }
+
+TEST(HasFailureTest, WorksOutsideOfTestBody) {
+  EXPECT_FALSE(HasFailureHelper());
+}
+
+TEST(HasFailureTest, WorksOutsideOfTestBody2) {
+  ADD_FAILURE();
+  const bool has_failure = HasFailureHelper();
+  ClearCurrentTestPartResults();
+  EXPECT_TRUE(has_failure);
+}
+
+class TestListener : public EmptyTestEventListener {
+ public:
+  TestListener() : on_start_counter_(nullptr), is_destroyed_(nullptr) {}
+  TestListener(int* on_start_counter, bool* is_destroyed)
+      : on_start_counter_(on_start_counter),
+        is_destroyed_(is_destroyed) {}
+
+  ~TestListener() override {
+    if (is_destroyed_)
+      *is_destroyed_ = true;
+  }
+
+ protected:
+  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {
+    if (on_start_counter_ != nullptr) (*on_start_counter_)++;
+  }
+
+ private:
+  int* on_start_counter_;
+  bool* is_destroyed_;
+};
+
+// Tests the constructor.
+TEST(TestEventListenersTest, ConstructionWorks) {
+  TestEventListeners listeners;
+
+  EXPECT_TRUE(TestEventListenersAccessor::GetRepeater(&listeners) != nullptr);
+  EXPECT_TRUE(listeners.default_result_printer() == nullptr);
+  EXPECT_TRUE(listeners.default_xml_generator() == nullptr);
+}
+
+// Tests that the TestEventListeners destructor deletes all the listeners it
+// owns.
+TEST(TestEventListenersTest, DestructionWorks) {
+  bool default_result_printer_is_destroyed = false;
+  bool default_xml_printer_is_destroyed = false;
+  bool extra_listener_is_destroyed = false;
+  TestListener* default_result_printer =
+      new TestListener(nullptr, &default_result_printer_is_destroyed);
+  TestListener* default_xml_printer =
+      new TestListener(nullptr, &default_xml_printer_is_destroyed);
+  TestListener* extra_listener =
+      new TestListener(nullptr, &extra_listener_is_destroyed);
+
+  {
+    TestEventListeners listeners;
+    TestEventListenersAccessor::SetDefaultResultPrinter(&listeners,
+                                                        default_result_printer);
+    TestEventListenersAccessor::SetDefaultXmlGenerator(&listeners,
+                                                       default_xml_printer);
+    listeners.Append(extra_listener);
+  }
+  EXPECT_TRUE(default_result_printer_is_destroyed);
+  EXPECT_TRUE(default_xml_printer_is_destroyed);
+  EXPECT_TRUE(extra_listener_is_destroyed);
+}
+
+// Tests that a listener Append'ed to a TestEventListeners list starts
+// receiving events.
+TEST(TestEventListenersTest, Append) {
+  int on_start_counter = 0;
+  bool is_destroyed = false;
+  TestListener* listener = new TestListener(&on_start_counter, &is_destroyed);
+  {
+    TestEventListeners listeners;
+    listeners.Append(listener);
+    TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+        *UnitTest::GetInstance());
+    EXPECT_EQ(1, on_start_counter);
+  }
+  EXPECT_TRUE(is_destroyed);
+}
+
+// Tests that listeners receive events in the order they were appended to
+// the list, except for *End requests, which must be received in the reverse
+// order.
+class SequenceTestingListener : public EmptyTestEventListener {
+ public:
+  SequenceTestingListener(std::vector<std::string>* vector, const char* id)
+      : vector_(vector), id_(id) {}
+
+ protected:
+  void OnTestProgramStart(const UnitTest& /*unit_test*/) override {
+    vector_->push_back(GetEventDescription("OnTestProgramStart"));
+  }
+
+  void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {
+    vector_->push_back(GetEventDescription("OnTestProgramEnd"));
+  }
+
+  void OnTestIterationStart(const UnitTest& /*unit_test*/,
+                            int /*iteration*/) override {
+    vector_->push_back(GetEventDescription("OnTestIterationStart"));
+  }
+
+  void OnTestIterationEnd(const UnitTest& /*unit_test*/,
+                          int /*iteration*/) override {
+    vector_->push_back(GetEventDescription("OnTestIterationEnd"));
+  }
+
+ private:
+  std::string GetEventDescription(const char* method) {
+    Message message;
+    message << id_ << "." << method;
+    return message.GetString();
+  }
+
+  std::vector<std::string>* vector_;
+  const char* const id_;
+
+  GTEST_DISALLOW_COPY_AND_ASSIGN_(SequenceTestingListener);
+};
+
+TEST(EventListenerTest, AppendKeepsOrder) {
+  std::vector<std::string> vec;
+  TestEventListeners listeners;
+  listeners.Append(new SequenceTestingListener(&vec, "1st"));
+  listeners.Append(new SequenceTestingListener(&vec, "2nd"));
+  listeners.Append(new SequenceTestingListener(&vec, "3rd"));
+
+  TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+      *UnitTest::GetInstance());
+  ASSERT_EQ(3U, vec.size());
+  EXPECT_STREQ("1st.OnTestProgramStart", vec[0].c_str());
+  EXPECT_STREQ("2nd.OnTestProgramStart", vec[1].c_str());
+  EXPECT_STREQ("3rd.OnTestProgramStart", vec[2].c_str());
+
+  vec.clear();
+  TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramEnd(
+      *UnitTest::GetInstance());
+  ASSERT_EQ(3U, vec.size());
+  EXPECT_STREQ("3rd.OnTestProgramEnd", vec[0].c_str());
+  EXPECT_STREQ("2nd.OnTestProgramEnd", vec[1].c_str());
+  EXPECT_STREQ("1st.OnTestProgramEnd", vec[2].c_str());
+
+  vec.clear();
+  TestEventListenersAccessor::GetRepeater(&listeners)->OnTestIterationStart(
+      *UnitTest::GetInstance(), 0);
+  ASSERT_EQ(3U, vec.size());
+  EXPECT_STREQ("1st.OnTestIterationStart", vec[0].c_str());
+  EXPECT_STREQ("2nd.OnTestIterationStart", vec[1].c_str());
+  EXPECT_STREQ("3rd.OnTestIterationStart", vec[2].c_str());
+
+  vec.clear();
+  TestEventListenersAccessor::GetRepeater(&listeners)->OnTestIterationEnd(
+      *UnitTest::GetInstance(), 0);
+  ASSERT_EQ(3U, vec.size());
+  EXPECT_STREQ("3rd.OnTestIterationEnd", vec[0].c_str());
+  EXPECT_STREQ("2nd.OnTestIterationEnd", vec[1].c_str());
+  EXPECT_STREQ("1st.OnTestIterationEnd", vec[2].c_str());
+}
+
+// Tests that a listener removed from a TestEventListeners list stops receiving
+// events and is not deleted when the list is destroyed.
+TEST(TestEventListenersTest, Release) {
+  int on_start_counter = 0;
+  bool is_destroyed = false;
+  // Although Append passes the ownership of this object to the list,
+  // the following calls release it, and we need to delete it before the
+  // test ends.
+  TestListener* listener = new TestListener(&on_start_counter, &is_destroyed);
+  {
+    TestEventListeners listeners;
+    listeners.Append(listener);
+    EXPECT_EQ(listener, listeners.Release(listener));
+    TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+        *UnitTest::GetInstance());
+    EXPECT_TRUE(listeners.Release(listener) == nullptr);
+  }
+  EXPECT_EQ(0, on_start_counter);
+  EXPECT_FALSE(is_destroyed);
+  delete listener;
+}
+
+// Tests that no events are forwarded when event forwarding is disabled.
+TEST(EventListenerTest, SuppressEventForwarding) {
+  int on_start_counter = 0;
+  TestListener* listener = new TestListener(&on_start_counter, nullptr);
+
+  TestEventListeners listeners;
+  listeners.Append(listener);
+  ASSERT_TRUE(TestEventListenersAccessor::EventForwardingEnabled(listeners));
+  TestEventListenersAccessor::SuppressEventForwarding(&listeners);
+  ASSERT_FALSE(TestEventListenersAccessor::EventForwardingEnabled(listeners));
+  TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+      *UnitTest::GetInstance());
+  EXPECT_EQ(0, on_start_counter);
+}
+
+// Tests that events generated by Google Test are not forwarded in
+// death test subprocesses.
+TEST(EventListenerDeathTest, EventsNotForwardedInDeathTestSubprecesses) {
+  EXPECT_DEATH_IF_SUPPORTED({
+      GTEST_CHECK_(TestEventListenersAccessor::EventForwardingEnabled(
+          *GetUnitTestImpl()->listeners())) << "expected failure";},
+      "expected failure");
+}
+
+// Tests that a listener installed via SetDefaultResultPrinter() starts
+// receiving events and is returned via default_result_printer() and that
+// the previous default_result_printer is removed from the list and deleted.
+TEST(EventListenerTest, default_result_printer) {
+  int on_start_counter = 0;
+  bool is_destroyed = false;
+  TestListener* listener = new TestListener(&on_start_counter, &is_destroyed);
+
+  TestEventListeners listeners;
+  TestEventListenersAccessor::SetDefaultResultPrinter(&listeners, listener);
+
+  EXPECT_EQ(listener, listeners.default_result_printer());
+
+  TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+      *UnitTest::GetInstance());
+
+  EXPECT_EQ(1, on_start_counter);
+
+  // Replacing default_result_printer with something else should remove it
+  // from the list and destroy it.
+  TestEventListenersAccessor::SetDefaultResultPrinter(&listeners, nullptr);
+
+  EXPECT_TRUE(listeners.default_result_printer() == nullptr);
+  EXPECT_TRUE(is_destroyed);
+
+  // After broadcasting an event the counter is still the same, indicating
+  // the listener is not in the list anymore.
+  TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+      *UnitTest::GetInstance());
+  EXPECT_EQ(1, on_start_counter);
+}
+
+// Tests that the default_result_printer listener stops receiving events
+// when removed via Release and that is not owned by the list anymore.
+TEST(EventListenerTest, RemovingDefaultResultPrinterWorks) {
+  int on_start_counter = 0;
+  bool is_destroyed = false;
+  // Although Append passes the ownership of this object to the list,
+  // the following calls release it, and we need to delete it before the
+  // test ends.
+  TestListener* listener = new TestListener(&on_start_counter, &is_destroyed);
+  {
+    TestEventListeners listeners;
+    TestEventListenersAccessor::SetDefaultResultPrinter(&listeners, listener);
+
+    EXPECT_EQ(listener, listeners.Release(listener));
+    EXPECT_TRUE(listeners.default_result_printer() == nullptr);
+    EXPECT_FALSE(is_destroyed);
+
+    // Broadcasting events now should not affect default_result_printer.
+    TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+        *UnitTest::GetInstance());
+    EXPECT_EQ(0, on_start_counter);
+  }
+  // Destroying the list should not affect the listener now, too.
+  EXPECT_FALSE(is_destroyed);
+  delete listener;
+}
+
+// Tests that a listener installed via SetDefaultXmlGenerator() starts
+// receiving events and is returned via default_xml_generator() and that
+// the previous default_xml_generator is removed from the list and deleted.
+TEST(EventListenerTest, default_xml_generator) {
+  int on_start_counter = 0;
+  bool is_destroyed = false;
+  TestListener* listener = new TestListener(&on_start_counter, &is_destroyed);
+
+  TestEventListeners listeners;
+  TestEventListenersAccessor::SetDefaultXmlGenerator(&listeners, listener);
+
+  EXPECT_EQ(listener, listeners.default_xml_generator());
+
+  TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+      *UnitTest::GetInstance());
+
+  EXPECT_EQ(1, on_start_counter);
+
+  // Replacing default_xml_generator with something else should remove it
+  // from the list and destroy it.
+  TestEventListenersAccessor::SetDefaultXmlGenerator(&listeners, nullptr);
+
+  EXPECT_TRUE(listeners.default_xml_generator() == nullptr);
+  EXPECT_TRUE(is_destroyed);
+
+  // After broadcasting an event the counter is still the same, indicating
+  // the listener is not in the list anymore.
+  TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+      *UnitTest::GetInstance());
+  EXPECT_EQ(1, on_start_counter);
+}
+
+// Tests that the default_xml_generator listener stops receiving events
+// when removed via Release and that is not owned by the list anymore.
+TEST(EventListenerTest, RemovingDefaultXmlGeneratorWorks) {
+  int on_start_counter = 0;
+  bool is_destroyed = false;
+  // Although Append passes the ownership of this object to the list,
+  // the following calls release it, and we need to delete it before the
+  // test ends.
+  TestListener* listener = new TestListener(&on_start_counter, &is_destroyed);
+  {
+    TestEventListeners listeners;
+    TestEventListenersAccessor::SetDefaultXmlGenerator(&listeners, listener);
+
+    EXPECT_EQ(listener, listeners.Release(listener));
+    EXPECT_TRUE(listeners.default_xml_generator() == nullptr);
+    EXPECT_FALSE(is_destroyed);
+
+    // Broadcasting events now should not affect default_xml_generator.
+    TestEventListenersAccessor::GetRepeater(&listeners)->OnTestProgramStart(
+        *UnitTest::GetInstance());
+    EXPECT_EQ(0, on_start_counter);
+  }
+  // Destroying the list should not affect the listener now, too.
+  EXPECT_FALSE(is_destroyed);
+  delete listener;
+}
+
+// Sanity tests to ensure that the alternative, verbose spellings of
+// some of the macros work.  We don't test them thoroughly as that
+// would be quite involved.  Since their implementations are
+// straightforward, and they are rarely used, we'll just rely on the
+// users to tell us when they are broken.
+GTEST_TEST(AlternativeNameTest, Works) {  // GTEST_TEST is the same as TEST.
+  GTEST_SUCCEED() << "OK";  // GTEST_SUCCEED is the same as SUCCEED.
+
+  // GTEST_FAIL is the same as FAIL.
+  EXPECT_FATAL_FAILURE(GTEST_FAIL() << "An expected failure",
+                       "An expected failure");
+
+  // GTEST_ASSERT_XY is the same as ASSERT_XY.
+
+  GTEST_ASSERT_EQ(0, 0);
+  EXPECT_FATAL_FAILURE(GTEST_ASSERT_EQ(0, 1) << "An expected failure",
+                       "An expected failure");
+  EXPECT_FATAL_FAILURE(GTEST_ASSERT_EQ(1, 0) << "An expected failure",
+                       "An expected failure");
+
+  GTEST_ASSERT_NE(0, 1);
+  GTEST_ASSERT_NE(1, 0);
+  EXPECT_FATAL_FAILURE(GTEST_ASSERT_NE(0, 0) << "An expected failure",
+                       "An expected failure");
+
+  GTEST_ASSERT_LE(0, 0);
+  GTEST_ASSERT_LE(0, 1);
+  EXPECT_FATAL_FAILURE(GTEST_ASSERT_LE(1, 0) << "An expected failure",
+                       "An expected failure");
+
+  GTEST_ASSERT_LT(0, 1);
+  EXPECT_FATAL_FAILURE(GTEST_ASSERT_LT(0, 0) << "An expected failure",
+                       "An expected failure");
+  EXPECT_FATAL_FAILURE(GTEST_ASSERT_LT(1, 0) << "An expected failure",
+                       "An expected failure");
+
+  GTEST_ASSERT_GE(0, 0);
+  GTEST_ASSERT_GE(1, 0);
+  EXPECT_FATAL_FAILURE(GTEST_ASSERT_GE(0, 1) << "An expected failure",
+                       "An expected failure");
+
+  GTEST_ASSERT_GT(1, 0);
+  EXPECT_FATAL_FAILURE(GTEST_ASSERT_GT(0, 1) << "An expected failure",
+                       "An expected failure");
+  EXPECT_FATAL_FAILURE(GTEST_ASSERT_GT(1, 1) << "An expected failure",
+                       "An expected failure");
+}
+
+// Tests for internal utilities necessary for implementation of the universal
+// printing.
+
+class ConversionHelperBase {};
+class ConversionHelperDerived : public ConversionHelperBase {};
+
+// Tests that IsAProtocolMessage<T>::value is a compile-time constant.
+TEST(IsAProtocolMessageTest, ValueIsCompileTimeConstant) {
+  GTEST_COMPILE_ASSERT_(IsAProtocolMessage<::proto2::Message>::value,
+                        const_true);
+  GTEST_COMPILE_ASSERT_(!IsAProtocolMessage<int>::value, const_false);
+}
+
+// Tests that IsAProtocolMessage<T>::value is true when T is
+// proto2::Message or a sub-class of it.
+TEST(IsAProtocolMessageTest, ValueIsTrueWhenTypeIsAProtocolMessage) {
+  EXPECT_TRUE(IsAProtocolMessage< ::proto2::Message>::value);
+}
+
+// Tests that IsAProtocolMessage<T>::value is false when T is neither
+// ::proto2::Message nor a sub-class of it.
+TEST(IsAProtocolMessageTest, ValueIsFalseWhenTypeIsNotAProtocolMessage) {
+  EXPECT_FALSE(IsAProtocolMessage<int>::value);
+  EXPECT_FALSE(IsAProtocolMessage<const ConversionHelperBase>::value);
+}
+
+// Tests GTEST_REMOVE_REFERENCE_AND_CONST_.
+
+template <typename T1, typename T2>
+void TestGTestRemoveReferenceAndConst() {
+  static_assert(std::is_same<T1, GTEST_REMOVE_REFERENCE_AND_CONST_(T2)>::value,
+                "GTEST_REMOVE_REFERENCE_AND_CONST_ failed.");
+}
+
+TEST(RemoveReferenceToConstTest, Works) {
+  TestGTestRemoveReferenceAndConst<int, int>();
+  TestGTestRemoveReferenceAndConst<double, double&>();
+  TestGTestRemoveReferenceAndConst<char, const char>();
+  TestGTestRemoveReferenceAndConst<char, const char&>();
+  TestGTestRemoveReferenceAndConst<const char*, const char*>();
+}
+
+// Tests GTEST_REFERENCE_TO_CONST_.
+
+template <typename T1, typename T2>
+void TestGTestReferenceToConst() {
+  static_assert(std::is_same<T1, GTEST_REFERENCE_TO_CONST_(T2)>::value,
+                "GTEST_REFERENCE_TO_CONST_ failed.");
+}
+
+TEST(GTestReferenceToConstTest, Works) {
+  TestGTestReferenceToConst<const char&, char>();
+  TestGTestReferenceToConst<const int&, const int>();
+  TestGTestReferenceToConst<const double&, double>();
+  TestGTestReferenceToConst<const std::string&, const std::string&>();
+}
+
+
+// Tests IsContainerTest.
+
+class NonContainer {};
+
+TEST(IsContainerTestTest, WorksForNonContainer) {
+  EXPECT_EQ(sizeof(IsNotContainer), sizeof(IsContainerTest<int>(0)));
+  EXPECT_EQ(sizeof(IsNotContainer), sizeof(IsContainerTest<char[5]>(0)));
+  EXPECT_EQ(sizeof(IsNotContainer), sizeof(IsContainerTest<NonContainer>(0)));
+}
+
+TEST(IsContainerTestTest, WorksForContainer) {
+  EXPECT_EQ(sizeof(IsContainer),
+            sizeof(IsContainerTest<std::vector<bool> >(0)));
+  EXPECT_EQ(sizeof(IsContainer),
+            sizeof(IsContainerTest<std::map<int, double> >(0)));
+}
+
+struct ConstOnlyContainerWithPointerIterator {
+  using const_iterator = int*;
+  const_iterator begin() const;
+  const_iterator end() const;
+};
+
+struct ConstOnlyContainerWithClassIterator {
+  struct const_iterator {
+    const int& operator*() const;
+    const_iterator& operator++(/* pre-increment */);
+  };
+  const_iterator begin() const;
+  const_iterator end() const;
+};
+
+TEST(IsContainerTestTest, ConstOnlyContainer) {
+  EXPECT_EQ(sizeof(IsContainer),
+            sizeof(IsContainerTest<ConstOnlyContainerWithPointerIterator>(0)));
+  EXPECT_EQ(sizeof(IsContainer),
+            sizeof(IsContainerTest<ConstOnlyContainerWithClassIterator>(0)));
+}
+
+// Tests IsHashTable.
+struct AHashTable {
+  typedef void hasher;
+};
+struct NotReallyAHashTable {
+  typedef void hasher;
+  typedef void reverse_iterator;
+};
+TEST(IsHashTable, Basic) {
+  EXPECT_TRUE(testing::internal::IsHashTable<AHashTable>::value);
+  EXPECT_FALSE(testing::internal::IsHashTable<NotReallyAHashTable>::value);
+  EXPECT_FALSE(testing::internal::IsHashTable<std::vector<int>>::value);
+  EXPECT_TRUE(testing::internal::IsHashTable<std::unordered_set<int>>::value);
+}
+
+// Tests ArrayEq().
+
+TEST(ArrayEqTest, WorksForDegeneratedArrays) {
+  EXPECT_TRUE(ArrayEq(5, 5L));
+  EXPECT_FALSE(ArrayEq('a', 0));
+}
+
+TEST(ArrayEqTest, WorksForOneDimensionalArrays) {
+  // Note that a and b are distinct but compatible types.
+  const int a[] = { 0, 1 };
+  long b[] = { 0, 1 };
+  EXPECT_TRUE(ArrayEq(a, b));
+  EXPECT_TRUE(ArrayEq(a, 2, b));
+
+  b[0] = 2;
+  EXPECT_FALSE(ArrayEq(a, b));
+  EXPECT_FALSE(ArrayEq(a, 1, b));
+}
+
+TEST(ArrayEqTest, WorksForTwoDimensionalArrays) {
+  const char a[][3] = { "hi", "lo" };
+  const char b[][3] = { "hi", "lo" };
+  const char c[][3] = { "hi", "li" };
+
+  EXPECT_TRUE(ArrayEq(a, b));
+  EXPECT_TRUE(ArrayEq(a, 2, b));
+
+  EXPECT_FALSE(ArrayEq(a, c));
+  EXPECT_FALSE(ArrayEq(a, 2, c));
+}
+
+// Tests ArrayAwareFind().
+
+TEST(ArrayAwareFindTest, WorksForOneDimensionalArray) {
+  const char a[] = "hello";
+  EXPECT_EQ(a + 4, ArrayAwareFind(a, a + 5, 'o'));
+  EXPECT_EQ(a + 5, ArrayAwareFind(a, a + 5, 'x'));
+}
+
+TEST(ArrayAwareFindTest, WorksForTwoDimensionalArray) {
+  int a[][2] = { { 0, 1 }, { 2, 3 }, { 4, 5 } };
+  const int b[2] = { 2, 3 };
+  EXPECT_EQ(a + 1, ArrayAwareFind(a, a + 3, b));
+
+  const int c[2] = { 6, 7 };
+  EXPECT_EQ(a + 3, ArrayAwareFind(a, a + 3, c));
+}
+
+// Tests CopyArray().
+
+TEST(CopyArrayTest, WorksForDegeneratedArrays) {
+  int n = 0;
+  CopyArray('a', &n);
+  EXPECT_EQ('a', n);
+}
+
+TEST(CopyArrayTest, WorksForOneDimensionalArrays) {
+  const char a[3] = "hi";
+  int b[3];
+#ifndef __BORLANDC__  // C++Builder cannot compile some array size deductions.
+  CopyArray(a, &b);
+  EXPECT_TRUE(ArrayEq(a, b));
+#endif
+
+  int c[3];
+  CopyArray(a, 3, c);
+  EXPECT_TRUE(ArrayEq(a, c));
+}
+
+TEST(CopyArrayTest, WorksForTwoDimensionalArrays) {
+  const int a[2][3] = { { 0, 1, 2 }, { 3, 4, 5 } };
+  int b[2][3];
+#ifndef __BORLANDC__  // C++Builder cannot compile some array size deductions.
+  CopyArray(a, &b);
+  EXPECT_TRUE(ArrayEq(a, b));
+#endif
+
+  int c[2][3];
+  CopyArray(a, 2, c);
+  EXPECT_TRUE(ArrayEq(a, c));
+}
+
+// Tests NativeArray.
+
+TEST(NativeArrayTest, ConstructorFromArrayWorks) {
+  const int a[3] = { 0, 1, 2 };
+  NativeArray<int> na(a, 3, RelationToSourceReference());
+  EXPECT_EQ(3U, na.size());
+  EXPECT_EQ(a, na.begin());
+}
+
+TEST(NativeArrayTest, CreatesAndDeletesCopyOfArrayWhenAskedTo) {
+  typedef int Array[2];
+  Array* a = new Array[1];
+  (*a)[0] = 0;
+  (*a)[1] = 1;
+  NativeArray<int> na(*a, 2, RelationToSourceCopy());
+  EXPECT_NE(*a, na.begin());
+  delete[] a;
+  EXPECT_EQ(0, na.begin()[0]);
+  EXPECT_EQ(1, na.begin()[1]);
+
+  // We rely on the heap checker to verify that na deletes the copy of
+  // array.
+}
+
+TEST(NativeArrayTest, TypeMembersAreCorrect) {
+  StaticAssertTypeEq<char, NativeArray<char>::value_type>();
+  StaticAssertTypeEq<int[2], NativeArray<int[2]>::value_type>();
+
+  StaticAssertTypeEq<const char*, NativeArray<char>::const_iterator>();
+  StaticAssertTypeEq<const bool(*)[2], NativeArray<bool[2]>::const_iterator>();
+}
+
+TEST(NativeArrayTest, MethodsWork) {
+  const int a[3] = { 0, 1, 2 };
+  NativeArray<int> na(a, 3, RelationToSourceCopy());
+  ASSERT_EQ(3U, na.size());
+  EXPECT_EQ(3, na.end() - na.begin());
+
+  NativeArray<int>::const_iterator it = na.begin();
+  EXPECT_EQ(0, *it);
+  ++it;
+  EXPECT_EQ(1, *it);
+  it++;
+  EXPECT_EQ(2, *it);
+  ++it;
+  EXPECT_EQ(na.end(), it);
+
+  EXPECT_TRUE(na == na);
+
+  NativeArray<int> na2(a, 3, RelationToSourceReference());
+  EXPECT_TRUE(na == na2);
+
+  const int b1[3] = { 0, 1, 1 };
+  const int b2[4] = { 0, 1, 2, 3 };
+  EXPECT_FALSE(na == NativeArray<int>(b1, 3, RelationToSourceReference()));
+  EXPECT_FALSE(na == NativeArray<int>(b2, 4, RelationToSourceCopy()));
+}
+
+TEST(NativeArrayTest, WorksForTwoDimensionalArray) {
+  const char a[2][3] = { "hi", "lo" };
+  NativeArray<char[3]> na(a, 2, RelationToSourceReference());
+  ASSERT_EQ(2U, na.size());
+  EXPECT_EQ(a, na.begin());
+}
+
+// IndexSequence
+TEST(IndexSequence, MakeIndexSequence) {
+  using testing::internal::IndexSequence;
+  using testing::internal::MakeIndexSequence;
+  EXPECT_TRUE(
+      (std::is_same<IndexSequence<>, MakeIndexSequence<0>::type>::value));
+  EXPECT_TRUE(
+      (std::is_same<IndexSequence<0>, MakeIndexSequence<1>::type>::value));
+  EXPECT_TRUE(
+      (std::is_same<IndexSequence<0, 1>, MakeIndexSequence<2>::type>::value));
+  EXPECT_TRUE((
+      std::is_same<IndexSequence<0, 1, 2>, MakeIndexSequence<3>::type>::value));
+  EXPECT_TRUE(
+      (std::is_base_of<IndexSequence<0, 1, 2>, MakeIndexSequence<3>>::value));
+}
+
+// ElemFromList
+TEST(ElemFromList, Basic) {
+  using testing::internal::ElemFromList;
+  using Idx = testing::internal::MakeIndexSequence<3>::type;
+  EXPECT_TRUE((
+      std::is_same<int, ElemFromList<0, Idx, int, double, char>::type>::value));
+  EXPECT_TRUE(
+      (std::is_same<double,
+                    ElemFromList<1, Idx, int, double, char>::type>::value));
+  EXPECT_TRUE(
+      (std::is_same<char,
+                    ElemFromList<2, Idx, int, double, char>::type>::value));
+  EXPECT_TRUE(
+      (std::is_same<
+          char, ElemFromList<7, testing::internal::MakeIndexSequence<12>::type,
+                             int, int, int, int, int, int, int, char, int, int,
+                             int, int>::type>::value));
+}
+
+// FlatTuple
+TEST(FlatTuple, Basic) {
+  using testing::internal::FlatTuple;
+
+  FlatTuple<int, double, const char*> tuple = {};
+  EXPECT_EQ(0, tuple.Get<0>());
+  EXPECT_EQ(0.0, tuple.Get<1>());
+  EXPECT_EQ(nullptr, tuple.Get<2>());
+
+  tuple = FlatTuple<int, double, const char*>(7, 3.2, "Foo");
+  EXPECT_EQ(7, tuple.Get<0>());
+  EXPECT_EQ(3.2, tuple.Get<1>());
+  EXPECT_EQ(std::string("Foo"), tuple.Get<2>());
+
+  tuple.Get<1>() = 5.1;
+  EXPECT_EQ(5.1, tuple.Get<1>());
+}
+
+TEST(FlatTuple, ManyTypes) {
+  using testing::internal::FlatTuple;
+
+  // Instantiate FlatTuple with 257 ints.
+  // Tests show that we can do it with thousands of elements, but very long
+  // compile times makes it unusuitable for this test.
+#define GTEST_FLAT_TUPLE_INT8 int, int, int, int, int, int, int, int,
+#define GTEST_FLAT_TUPLE_INT16 GTEST_FLAT_TUPLE_INT8 GTEST_FLAT_TUPLE_INT8
+#define GTEST_FLAT_TUPLE_INT32 GTEST_FLAT_TUPLE_INT16 GTEST_FLAT_TUPLE_INT16
+#define GTEST_FLAT_TUPLE_INT64 GTEST_FLAT_TUPLE_INT32 GTEST_FLAT_TUPLE_INT32
+#define GTEST_FLAT_TUPLE_INT128 GTEST_FLAT_TUPLE_INT64 GTEST_FLAT_TUPLE_INT64
+#define GTEST_FLAT_TUPLE_INT256 GTEST_FLAT_TUPLE_INT128 GTEST_FLAT_TUPLE_INT128
+
+  // Let's make sure that we can have a very long list of types without blowing
+  // up the template instantiation depth.
+  FlatTuple<GTEST_FLAT_TUPLE_INT256 int> tuple;
+
+  tuple.Get<0>() = 7;
+  tuple.Get<99>() = 17;
+  tuple.Get<256>() = 1000;
+  EXPECT_EQ(7, tuple.Get<0>());
+  EXPECT_EQ(17, tuple.Get<99>());
+  EXPECT_EQ(1000, tuple.Get<256>());
+}
+
+// Tests SkipPrefix().
+
+TEST(SkipPrefixTest, SkipsWhenPrefixMatches) {
+  const char* const str = "hello";
+
+  const char* p = str;
+  EXPECT_TRUE(SkipPrefix("", &p));
+  EXPECT_EQ(str, p);
+
+  p = str;
+  EXPECT_TRUE(SkipPrefix("hell", &p));
+  EXPECT_EQ(str + 4, p);
+}
+
+TEST(SkipPrefixTest, DoesNotSkipWhenPrefixDoesNotMatch) {
+  const char* const str = "world";
+
+  const char* p = str;
+  EXPECT_FALSE(SkipPrefix("W", &p));
+  EXPECT_EQ(str, p);
+
+  p = str;
+  EXPECT_FALSE(SkipPrefix("world!", &p));
+  EXPECT_EQ(str, p);
+}
+
+// Tests ad_hoc_test_result().
+
+class AdHocTestResultTest : public testing::Test {
+ protected:
+  static void SetUpTestSuite() {
+    FAIL() << "A failure happened inside SetUpTestSuite().";
+  }
+};
+
+TEST_F(AdHocTestResultTest, AdHocTestResultForTestSuiteShowsFailure) {
+  const testing::TestResult& test_result = testing::UnitTest::GetInstance()
+                                               ->current_test_suite()
+                                               ->ad_hoc_test_result();
+  EXPECT_TRUE(test_result.Failed());
+}
+
+TEST_F(AdHocTestResultTest, AdHocTestResultTestForUnitTestDoesNotShowFailure) {
+  const testing::TestResult& test_result =
+      testing::UnitTest::GetInstance()->ad_hoc_test_result();
+  EXPECT_FALSE(test_result.Failed());
+}
+
+class DynamicUnitTestFixture : public testing::Test {};
+
+class DynamicTest : public DynamicUnitTestFixture {
+  void TestBody() override { EXPECT_TRUE(true); }
+};
+
+auto* dynamic_test = testing::RegisterTest(
+    "DynamicUnitTestFixture", "DynamicTest", "TYPE", "VALUE", __FILE__,
+    __LINE__, []() -> DynamicUnitTestFixture* { return new DynamicTest; });
+
+TEST(RegisterTest, WasRegistered) {
+  auto* unittest = testing::UnitTest::GetInstance();
+  for (int i = 0; i < unittest->total_test_suite_count(); ++i) {
+    auto* tests = unittest->GetTestSuite(i);
+    if (tests->name() != std::string("DynamicUnitTestFixture")) continue;
+    for (int j = 0; j < tests->total_test_count(); ++j) {
+      if (tests->GetTestInfo(j)->name() != std::string("DynamicTest")) continue;
+      // Found it.
+      EXPECT_STREQ(tests->GetTestInfo(j)->value_param(), "VALUE");
+      EXPECT_STREQ(tests->GetTestInfo(j)->type_param(), "TYPE");
+      return;
+    }
+  }
+
+  FAIL() << "Didn't find the test!";
+}
diff --git a/3rdparty/gtest/test/gtest_xml_outfile1_test_.cc b/3rdparty/gtest/test/gtest_xml_outfile1_test_.cc
new file mode 100644
index 0000000..19aa252
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_xml_outfile1_test_.cc
@@ -0,0 +1,43 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// gtest_xml_outfile1_test_ writes some xml via TestProperty used by
+// gtest_xml_outfiles_test.py
+
+#include "gtest/gtest.h"
+
+class PropertyOne : public testing::Test {
+ protected:
+  void SetUp() override { RecordProperty("SetUpProp", 1); }
+  void TearDown() override { RecordProperty("TearDownProp", 1); }
+};
+
+TEST_F(PropertyOne, TestSomeProperties) {
+  RecordProperty("TestSomeProperty", 1);
+}
diff --git a/3rdparty/gtest/test/gtest_xml_outfile2_test_.cc b/3rdparty/gtest/test/gtest_xml_outfile2_test_.cc
new file mode 100644
index 0000000..f9a2a6e
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_xml_outfile2_test_.cc
@@ -0,0 +1,43 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// gtest_xml_outfile2_test_ writes some xml via TestProperty used by
+// gtest_xml_outfiles_test.py
+
+#include "gtest/gtest.h"
+
+class PropertyTwo : public testing::Test {
+ protected:
+  void SetUp() override { RecordProperty("SetUpProp", 2); }
+  void TearDown() override { RecordProperty("TearDownProp", 2); }
+};
+
+TEST_F(PropertyTwo, TestSomeProperties) {
+  RecordProperty("TestSomeProperty", 2);
+}
diff --git a/3rdparty/gtest/test/gtest_xml_outfiles_test.py b/3rdparty/gtest/test/gtest_xml_outfiles_test.py
new file mode 100644
index 0000000..e093f6f
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_xml_outfiles_test.py
@@ -0,0 +1,135 @@
+#!/usr/bin/env python
+#
+# Copyright 2008, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test for the gtest_xml_output module."""
+
+import os
+from xml.dom import minidom, Node
+import gtest_test_utils
+import gtest_xml_test_utils
+
+GTEST_OUTPUT_SUBDIR = "xml_outfiles"
+GTEST_OUTPUT_1_TEST = "gtest_xml_outfile1_test_"
+GTEST_OUTPUT_2_TEST = "gtest_xml_outfile2_test_"
+
+EXPECTED_XML_1 = """<?xml version="1.0" encoding="UTF-8"?>
+<testsuites tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*" name="AllTests">
+  <testsuite name="PropertyOne" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="TestSomeProperties" status="run" result="completed" time="*" timestamp="*" classname="PropertyOne">
+      <properties>
+        <property name="SetUpProp" value="1"/>
+        <property name="TestSomeProperty" value="1"/>
+        <property name="TearDownProp" value="1"/>
+      </properties>
+    </testcase>
+  </testsuite>
+</testsuites>
+"""
+
+EXPECTED_XML_2 = """<?xml version="1.0" encoding="UTF-8"?>
+<testsuites tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*" name="AllTests">
+  <testsuite name="PropertyTwo" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="TestSomeProperties" status="run" result="completed" time="*" timestamp="*" classname="PropertyTwo">
+      <properties>
+        <property name="SetUpProp" value="2"/>
+        <property name="TestSomeProperty" value="2"/>
+        <property name="TearDownProp" value="2"/>
+      </properties>
+    </testcase>
+  </testsuite>
+</testsuites>
+"""
+
+
+class GTestXMLOutFilesTest(gtest_xml_test_utils.GTestXMLTestCase):
+  """Unit test for Google Test's XML output functionality."""
+
+  def setUp(self):
+    # We want the trailing '/' that the last "" provides in os.path.join, for
+    # telling Google Test to create an output directory instead of a single file
+    # for xml output.
+    self.output_dir_ = os.path.join(gtest_test_utils.GetTempDir(),
+                                    GTEST_OUTPUT_SUBDIR, "")
+    self.DeleteFilesAndDir()
+
+  def tearDown(self):
+    self.DeleteFilesAndDir()
+
+  def DeleteFilesAndDir(self):
+    try:
+      os.remove(os.path.join(self.output_dir_, GTEST_OUTPUT_1_TEST + ".xml"))
+    except os.error:
+      pass
+    try:
+      os.remove(os.path.join(self.output_dir_, GTEST_OUTPUT_2_TEST + ".xml"))
+    except os.error:
+      pass
+    try:
+      os.rmdir(self.output_dir_)
+    except os.error:
+      pass
+
+  def testOutfile1(self):
+    self._TestOutFile(GTEST_OUTPUT_1_TEST, EXPECTED_XML_1)
+
+  def testOutfile2(self):
+    self._TestOutFile(GTEST_OUTPUT_2_TEST, EXPECTED_XML_2)
+
+  def _TestOutFile(self, test_name, expected_xml):
+    gtest_prog_path = gtest_test_utils.GetTestExecutablePath(test_name)
+    command = [gtest_prog_path, "--gtest_output=xml:%s" % self.output_dir_]
+    p = gtest_test_utils.Subprocess(command,
+                                    working_dir=gtest_test_utils.GetTempDir())
+    self.assert_(p.exited)
+    self.assertEquals(0, p.exit_code)
+
+    output_file_name1 = test_name + ".xml"
+    output_file1 = os.path.join(self.output_dir_, output_file_name1)
+    output_file_name2 = 'lt-' + output_file_name1
+    output_file2 = os.path.join(self.output_dir_, output_file_name2)
+    self.assert_(os.path.isfile(output_file1) or os.path.isfile(output_file2),
+                 output_file1)
+
+    expected = minidom.parseString(expected_xml)
+    if os.path.isfile(output_file1):
+      actual = minidom.parse(output_file1)
+    else:
+      actual = minidom.parse(output_file2)
+    self.NormalizeXml(actual.documentElement)
+    self.AssertEquivalentNodes(expected.documentElement,
+                               actual.documentElement)
+    expected.unlink()
+    actual.unlink()
+
+
+if __name__ == "__main__":
+  os.environ["GTEST_STACK_TRACE_DEPTH"] = "0"
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/gtest_xml_output_unittest.py b/3rdparty/gtest/test/gtest_xml_output_unittest.py
new file mode 100644
index 0000000..63b1af0
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_xml_output_unittest.py
@@ -0,0 +1,389 @@
+#!/usr/bin/env python
+#
+# Copyright 2006, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test for the gtest_xml_output module"""
+
+import datetime
+import errno
+import os
+import re
+import sys
+from xml.dom import minidom, Node
+
+import gtest_test_utils
+import gtest_xml_test_utils
+
+GTEST_FILTER_FLAG = '--gtest_filter'
+GTEST_LIST_TESTS_FLAG = '--gtest_list_tests'
+GTEST_OUTPUT_FLAG = '--gtest_output'
+GTEST_DEFAULT_OUTPUT_FILE = 'test_detail.xml'
+GTEST_PROGRAM_NAME = 'gtest_xml_output_unittest_'
+
+# The flag indicating stacktraces are not supported
+NO_STACKTRACE_SUPPORT_FLAG = '--no_stacktrace_support'
+
+# The environment variables for test sharding.
+TOTAL_SHARDS_ENV_VAR = 'GTEST_TOTAL_SHARDS'
+SHARD_INDEX_ENV_VAR = 'GTEST_SHARD_INDEX'
+SHARD_STATUS_FILE_ENV_VAR = 'GTEST_SHARD_STATUS_FILE'
+
+SUPPORTS_STACK_TRACES = NO_STACKTRACE_SUPPORT_FLAG not in sys.argv
+
+if SUPPORTS_STACK_TRACES:
+  STACK_TRACE_TEMPLATE = '\nStack trace:\n*'
+else:
+  STACK_TRACE_TEMPLATE = ''
+  # unittest.main() can't handle unknown flags
+  sys.argv.remove(NO_STACKTRACE_SUPPORT_FLAG)
+
+EXPECTED_NON_EMPTY_XML = """<?xml version="1.0" encoding="UTF-8"?>
+<testsuites tests="24" failures="4" disabled="2" errors="0" time="*" timestamp="*" name="AllTests" ad_hoc_property="42">
+  <testsuite name="SuccessfulTest" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="Succeeds" status="run" result="completed" time="*" timestamp="*" classname="SuccessfulTest"/>
+  </testsuite>
+  <testsuite name="FailedTest" tests="1" failures="1" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="Fails" status="run" result="completed" time="*" timestamp="*" classname="FailedTest">
+      <failure message="gtest_xml_output_unittest_.cc:*&#x0A;Expected equality of these values:&#x0A;  1&#x0A;  2" type=""><![CDATA[gtest_xml_output_unittest_.cc:*
+Expected equality of these values:
+  1
+  2%(stack)s]]></failure>
+    </testcase>
+  </testsuite>
+  <testsuite name="MixedResultTest" tests="3" failures="1" disabled="1" errors="0" time="*" timestamp="*">
+    <testcase name="Succeeds" status="run" result="completed" time="*" timestamp="*" classname="MixedResultTest"/>
+    <testcase name="Fails" status="run" result="completed" time="*" timestamp="*" classname="MixedResultTest">
+      <failure message="gtest_xml_output_unittest_.cc:*&#x0A;Expected equality of these values:&#x0A;  1&#x0A;  2" type=""><![CDATA[gtest_xml_output_unittest_.cc:*
+Expected equality of these values:
+  1
+  2%(stack)s]]></failure>
+      <failure message="gtest_xml_output_unittest_.cc:*&#x0A;Expected equality of these values:&#x0A;  2&#x0A;  3" type=""><![CDATA[gtest_xml_output_unittest_.cc:*
+Expected equality of these values:
+  2
+  3%(stack)s]]></failure>
+    </testcase>
+    <testcase name="DISABLED_test" status="notrun" result="suppressed" time="*" timestamp="*" classname="MixedResultTest"/>
+  </testsuite>
+  <testsuite name="XmlQuotingTest" tests="1" failures="1" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="OutputsCData" status="run" result="completed" time="*" timestamp="*" classname="XmlQuotingTest">
+      <failure message="gtest_xml_output_unittest_.cc:*&#x0A;Failed&#x0A;XML output: &lt;?xml encoding=&quot;utf-8&quot;&gt;&lt;top&gt;&lt;![CDATA[cdata text]]&gt;&lt;/top&gt;" type=""><![CDATA[gtest_xml_output_unittest_.cc:*
+Failed
+XML output: <?xml encoding="utf-8"><top><![CDATA[cdata text]]>]]&gt;<![CDATA[</top>%(stack)s]]></failure>
+    </testcase>
+  </testsuite>
+  <testsuite name="InvalidCharactersTest" tests="1" failures="1" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="InvalidCharactersInMessage" status="run" result="completed" time="*" timestamp="*" classname="InvalidCharactersTest">
+      <failure message="gtest_xml_output_unittest_.cc:*&#x0A;Failed&#x0A;Invalid characters in brackets []" type=""><![CDATA[gtest_xml_output_unittest_.cc:*
+Failed
+Invalid characters in brackets []%(stack)s]]></failure>
+    </testcase>
+  </testsuite>
+  <testsuite name="DisabledTest" tests="1" failures="0" disabled="1" errors="0" time="*" timestamp="*">
+    <testcase name="DISABLED_test_not_run" status="notrun" result="suppressed" time="*" timestamp="*" classname="DisabledTest"/>
+  </testsuite>
+  <testsuite name="SkippedTest" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="Skipped" status="run" result="skipped" time="*" timestamp="*" classname="SkippedTest"/>
+  </testsuite>
+  <testsuite name="PropertyRecordingTest" tests="4" failures="0" disabled="0" errors="0" time="*" timestamp="*" SetUpTestSuite="yes" TearDownTestSuite="aye">
+    <testcase name="OneProperty" status="run" result="completed" time="*" timestamp="*" classname="PropertyRecordingTest">
+      <properties>
+        <property name="key_1" value="1"/>
+      </properties>
+    </testcase>
+    <testcase name="IntValuedProperty" status="run" result="completed" time="*" timestamp="*" classname="PropertyRecordingTest">
+      <properties>
+        <property name="key_int" value="1"/>
+      </properties>
+    </testcase>
+    <testcase name="ThreeProperties" status="run" result="completed" time="*" timestamp="*" classname="PropertyRecordingTest">
+      <properties>
+        <property name="key_1" value="1"/>
+        <property name="key_2" value="2"/>
+        <property name="key_3" value="3"/>
+      </properties>
+    </testcase>
+    <testcase name="TwoValuesForOneKeyUsesLastValue" status="run" result="completed" time="*" timestamp="*" classname="PropertyRecordingTest">
+      <properties>
+        <property name="key_1" value="2"/>
+      </properties>
+    </testcase>
+  </testsuite>
+  <testsuite name="NoFixtureTest" tests="3" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+     <testcase name="RecordProperty" status="run" result="completed" time="*" timestamp="*" classname="NoFixtureTest">
+       <properties>
+         <property name="key" value="1"/>
+       </properties>
+     </testcase>
+     <testcase name="ExternalUtilityThatCallsRecordIntValuedProperty" status="run" result="completed" time="*" timestamp="*" classname="NoFixtureTest">
+       <properties>
+         <property name="key_for_utility_int" value="1"/>
+       </properties>
+     </testcase>
+     <testcase name="ExternalUtilityThatCallsRecordStringValuedProperty" status="run" result="completed" time="*" timestamp="*" classname="NoFixtureTest">
+       <properties>
+         <property name="key_for_utility_string" value="1"/>
+       </properties>
+     </testcase>
+  </testsuite>
+  <testsuite name="Single/ValueParamTest" tests="4" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="HasValueParamAttribute/0" value_param="33" status="run" result="completed" time="*" timestamp="*" classname="Single/ValueParamTest" />
+    <testcase name="HasValueParamAttribute/1" value_param="42" status="run" result="completed" time="*" timestamp="*" classname="Single/ValueParamTest" />
+    <testcase name="AnotherTestThatHasValueParamAttribute/0" value_param="33" status="run" result="completed" time="*" timestamp="*" classname="Single/ValueParamTest" />
+    <testcase name="AnotherTestThatHasValueParamAttribute/1" value_param="42" status="run" result="completed" time="*" timestamp="*" classname="Single/ValueParamTest" />
+  </testsuite>
+  <testsuite name="TypedTest/0" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="HasTypeParamAttribute" type_param="*" status="run" result="completed" time="*" timestamp="*" classname="TypedTest/0" />
+  </testsuite>
+  <testsuite name="TypedTest/1" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="HasTypeParamAttribute" type_param="*" status="run" result="completed" time="*" timestamp="*" classname="TypedTest/1" />
+  </testsuite>
+  <testsuite name="Single/TypeParameterizedTestSuite/0" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="HasTypeParamAttribute" type_param="*" status="run" result="completed" time="*" timestamp="*" classname="Single/TypeParameterizedTestSuite/0" />
+  </testsuite>
+  <testsuite name="Single/TypeParameterizedTestSuite/1" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="HasTypeParamAttribute" type_param="*" status="run" result="completed" time="*" timestamp="*" classname="Single/TypeParameterizedTestSuite/1" />
+  </testsuite>
+</testsuites>""" % {
+    'stack': STACK_TRACE_TEMPLATE
+}
+
+EXPECTED_FILTERED_TEST_XML = """<?xml version="1.0" encoding="UTF-8"?>
+<testsuites tests="1" failures="0" disabled="0" errors="0" time="*"
+            timestamp="*" name="AllTests" ad_hoc_property="42">
+  <testsuite name="SuccessfulTest" tests="1" failures="0" disabled="0"
+             errors="0" time="*" timestamp="*">
+    <testcase name="Succeeds" status="run" result="completed" time="*" timestamp="*" classname="SuccessfulTest"/>
+  </testsuite>
+</testsuites>"""
+
+EXPECTED_SHARDED_TEST_XML = """<?xml version="1.0" encoding="UTF-8"?>
+<testsuites tests="3" failures="0" disabled="0" errors="0" time="*" timestamp="*" name="AllTests" ad_hoc_property="42">
+  <testsuite name="SuccessfulTest" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="Succeeds" status="run" result="completed" time="*" timestamp="*" classname="SuccessfulTest"/>
+  </testsuite>
+  <testsuite name="PropertyRecordingTest" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*" SetUpTestSuite="yes" TearDownTestSuite="aye">
+    <testcase name="TwoValuesForOneKeyUsesLastValue" status="run" result="completed" time="*" timestamp="*" classname="PropertyRecordingTest">
+      <properties>
+        <property name="key_1" value="2"/>
+      </properties>
+    </testcase>
+  </testsuite>
+  <testsuite name="Single/ValueParamTest" tests="1" failures="0" disabled="0" errors="0" time="*" timestamp="*">
+    <testcase name="AnotherTestThatHasValueParamAttribute/0" value_param="33" status="run" result="completed" time="*" timestamp="*" classname="Single/ValueParamTest" />
+  </testsuite>
+</testsuites>"""
+
+EXPECTED_EMPTY_XML = """<?xml version="1.0" encoding="UTF-8"?>
+<testsuites tests="0" failures="0" disabled="0" errors="0" time="*"
+            timestamp="*" name="AllTests">
+</testsuites>"""
+
+GTEST_PROGRAM_PATH = gtest_test_utils.GetTestExecutablePath(GTEST_PROGRAM_NAME)
+
+SUPPORTS_TYPED_TESTS = 'TypedTest' in gtest_test_utils.Subprocess(
+    [GTEST_PROGRAM_PATH, GTEST_LIST_TESTS_FLAG], capture_stderr=False).output
+
+
+class GTestXMLOutputUnitTest(gtest_xml_test_utils.GTestXMLTestCase):
+  """
+  Unit test for Google Test's XML output functionality.
+  """
+
+  # This test currently breaks on platforms that do not support typed and
+  # type-parameterized tests, so we don't run it under them.
+  if SUPPORTS_TYPED_TESTS:
+    def testNonEmptyXmlOutput(self):
+      """
+      Runs a test program that generates a non-empty XML output, and
+      tests that the XML output is expected.
+      """
+      self._TestXmlOutput(GTEST_PROGRAM_NAME, EXPECTED_NON_EMPTY_XML, 1)
+
+  def testEmptyXmlOutput(self):
+    """Verifies XML output for a Google Test binary without actual tests.
+
+    Runs a test program that generates an empty XML output, and
+    tests that the XML output is expected.
+    """
+
+    self._TestXmlOutput('gtest_no_test_unittest', EXPECTED_EMPTY_XML, 0)
+
+  def testTimestampValue(self):
+    """Checks whether the timestamp attribute in the XML output is valid.
+
+    Runs a test program that generates an empty XML output, and checks if
+    the timestamp attribute in the testsuites tag is valid.
+    """
+    actual = self._GetXmlOutput('gtest_no_test_unittest', [], {}, 0)
+    date_time_str = actual.documentElement.getAttributeNode('timestamp').value
+    # datetime.strptime() is only available in Python 2.5+ so we have to
+    # parse the expected datetime manually.
+    match = re.match(r'(\d+)-(\d\d)-(\d\d)T(\d\d):(\d\d):(\d\d)', date_time_str)
+    self.assertTrue(
+        re.match,
+        'XML datettime string %s has incorrect format' % date_time_str)
+    date_time_from_xml = datetime.datetime(
+        year=int(match.group(1)), month=int(match.group(2)),
+        day=int(match.group(3)), hour=int(match.group(4)),
+        minute=int(match.group(5)), second=int(match.group(6)))
+
+    time_delta = abs(datetime.datetime.now() - date_time_from_xml)
+    # timestamp value should be near the current local time
+    self.assertTrue(time_delta < datetime.timedelta(seconds=600),
+                    'time_delta is %s' % time_delta)
+    actual.unlink()
+
+  def testDefaultOutputFile(self):
+    """
+    Confirms that Google Test produces an XML output file with the expected
+    default name if no name is explicitly specified.
+    """
+    output_file = os.path.join(gtest_test_utils.GetTempDir(),
+                               GTEST_DEFAULT_OUTPUT_FILE)
+    gtest_prog_path = gtest_test_utils.GetTestExecutablePath(
+        'gtest_no_test_unittest')
+    try:
+      os.remove(output_file)
+    except OSError:
+      e = sys.exc_info()[1]
+      if e.errno != errno.ENOENT:
+        raise
+
+    p = gtest_test_utils.Subprocess(
+        [gtest_prog_path, '%s=xml' % GTEST_OUTPUT_FLAG],
+        working_dir=gtest_test_utils.GetTempDir())
+    self.assert_(p.exited)
+    self.assertEquals(0, p.exit_code)
+    self.assert_(os.path.isfile(output_file))
+
+  def testSuppressedXmlOutput(self):
+    """
+    Tests that no XML file is generated if the default XML listener is
+    shut down before RUN_ALL_TESTS is invoked.
+    """
+
+    xml_path = os.path.join(gtest_test_utils.GetTempDir(),
+                            GTEST_PROGRAM_NAME + 'out.xml')
+    if os.path.isfile(xml_path):
+      os.remove(xml_path)
+
+    command = [GTEST_PROGRAM_PATH,
+               '%s=xml:%s' % (GTEST_OUTPUT_FLAG, xml_path),
+               '--shut_down_xml']
+    p = gtest_test_utils.Subprocess(command)
+    if p.terminated_by_signal:
+      # p.signal is available only if p.terminated_by_signal is True.
+      self.assertFalse(
+          p.terminated_by_signal,
+          '%s was killed by signal %d' % (GTEST_PROGRAM_NAME, p.signal))
+    else:
+      self.assert_(p.exited)
+      self.assertEquals(1, p.exit_code,
+                        "'%s' exited with code %s, which doesn't match "
+                        'the expected exit code %s.'
+                        % (command, p.exit_code, 1))
+
+    self.assert_(not os.path.isfile(xml_path))
+
+  def testFilteredTestXmlOutput(self):
+    """Verifies XML output when a filter is applied.
+
+    Runs a test program that executes only some tests and verifies that
+    non-selected tests do not show up in the XML output.
+    """
+
+    self._TestXmlOutput(GTEST_PROGRAM_NAME, EXPECTED_FILTERED_TEST_XML, 0,
+                        extra_args=['%s=SuccessfulTest.*' % GTEST_FILTER_FLAG])
+
+  def testShardedTestXmlOutput(self):
+    """Verifies XML output when run using multiple shards.
+
+    Runs a test program that executes only one shard and verifies that tests
+    from other shards do not show up in the XML output.
+    """
+
+    self._TestXmlOutput(
+        GTEST_PROGRAM_NAME,
+        EXPECTED_SHARDED_TEST_XML,
+        0,
+        extra_env={SHARD_INDEX_ENV_VAR: '0',
+                   TOTAL_SHARDS_ENV_VAR: '10'})
+
+  def _GetXmlOutput(self, gtest_prog_name, extra_args, extra_env,
+                    expected_exit_code):
+    """
+    Returns the xml output generated by running the program gtest_prog_name.
+    Furthermore, the program's exit code must be expected_exit_code.
+    """
+    xml_path = os.path.join(gtest_test_utils.GetTempDir(),
+                            gtest_prog_name + 'out.xml')
+    gtest_prog_path = gtest_test_utils.GetTestExecutablePath(gtest_prog_name)
+
+    command = ([gtest_prog_path, '%s=xml:%s' % (GTEST_OUTPUT_FLAG, xml_path)] +
+               extra_args)
+    environ_copy = os.environ.copy()
+    if extra_env:
+      environ_copy.update(extra_env)
+    p = gtest_test_utils.Subprocess(command, env=environ_copy)
+
+    if p.terminated_by_signal:
+      self.assert_(False,
+                   '%s was killed by signal %d' % (gtest_prog_name, p.signal))
+    else:
+      self.assert_(p.exited)
+      self.assertEquals(expected_exit_code, p.exit_code,
+                        "'%s' exited with code %s, which doesn't match "
+                        'the expected exit code %s.'
+                        % (command, p.exit_code, expected_exit_code))
+    actual = minidom.parse(xml_path)
+    return actual
+
+  def _TestXmlOutput(self, gtest_prog_name, expected_xml,
+                     expected_exit_code, extra_args=None, extra_env=None):
+    """
+    Asserts that the XML document generated by running the program
+    gtest_prog_name matches expected_xml, a string containing another
+    XML document.  Furthermore, the program's exit code must be
+    expected_exit_code.
+    """
+
+    actual = self._GetXmlOutput(gtest_prog_name, extra_args or [],
+                                extra_env or {}, expected_exit_code)
+    expected = minidom.parseString(expected_xml)
+    self.NormalizeXml(actual.documentElement)
+    self.AssertEquivalentNodes(expected.documentElement,
+                               actual.documentElement)
+    expected.unlink()
+    actual.unlink()
+
+
+if __name__ == '__main__':
+  os.environ['GTEST_STACK_TRACE_DEPTH'] = '1'
+  gtest_test_utils.Main()
diff --git a/3rdparty/gtest/test/gtest_xml_output_unittest_.cc b/3rdparty/gtest/test/gtest_xml_output_unittest_.cc
new file mode 100644
index 0000000..c95fd66
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_xml_output_unittest_.cc
@@ -0,0 +1,188 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Unit test for Google Test XML output.
+//
+// A user can specify XML output in a Google Test program to run via
+// either the GTEST_OUTPUT environment variable or the --gtest_output
+// flag.  This is used for testing such functionality.
+//
+// This program will be invoked from a Python unit test.  Don't run it
+// directly.
+
+#include "gtest/gtest.h"
+
+using ::testing::InitGoogleTest;
+using ::testing::TestEventListeners;
+using ::testing::TestWithParam;
+using ::testing::UnitTest;
+using ::testing::Test;
+using ::testing::Values;
+
+class SuccessfulTest : public Test {
+};
+
+TEST_F(SuccessfulTest, Succeeds) {
+  SUCCEED() << "This is a success.";
+  ASSERT_EQ(1, 1);
+}
+
+class FailedTest : public Test {
+};
+
+TEST_F(FailedTest, Fails) {
+  ASSERT_EQ(1, 2);
+}
+
+class DisabledTest : public Test {
+};
+
+TEST_F(DisabledTest, DISABLED_test_not_run) {
+  FAIL() << "Unexpected failure: Disabled test should not be run";
+}
+
+class SkippedTest : public Test {
+};
+
+TEST_F(SkippedTest, Skipped) {
+  GTEST_SKIP();
+}
+
+TEST(MixedResultTest, Succeeds) {
+  EXPECT_EQ(1, 1);
+  ASSERT_EQ(1, 1);
+}
+
+TEST(MixedResultTest, Fails) {
+  EXPECT_EQ(1, 2);
+  ASSERT_EQ(2, 3);
+}
+
+TEST(MixedResultTest, DISABLED_test) {
+  FAIL() << "Unexpected failure: Disabled test should not be run";
+}
+
+TEST(XmlQuotingTest, OutputsCData) {
+  FAIL() << "XML output: "
+            "<?xml encoding=\"utf-8\"><top><![CDATA[cdata text]]></top>";
+}
+
+// Helps to test that invalid characters produced by test code do not make
+// it into the XML file.
+TEST(InvalidCharactersTest, InvalidCharactersInMessage) {
+  FAIL() << "Invalid characters in brackets [\x1\x2]";
+}
+
+class PropertyRecordingTest : public Test {
+ public:
+  static void SetUpTestSuite() { RecordProperty("SetUpTestSuite", "yes"); }
+  static void TearDownTestSuite() {
+    RecordProperty("TearDownTestSuite", "aye");
+  }
+};
+
+TEST_F(PropertyRecordingTest, OneProperty) {
+  RecordProperty("key_1", "1");
+}
+
+TEST_F(PropertyRecordingTest, IntValuedProperty) {
+  RecordProperty("key_int", 1);
+}
+
+TEST_F(PropertyRecordingTest, ThreeProperties) {
+  RecordProperty("key_1", "1");
+  RecordProperty("key_2", "2");
+  RecordProperty("key_3", "3");
+}
+
+TEST_F(PropertyRecordingTest, TwoValuesForOneKeyUsesLastValue) {
+  RecordProperty("key_1", "1");
+  RecordProperty("key_1", "2");
+}
+
+TEST(NoFixtureTest, RecordProperty) {
+  RecordProperty("key", "1");
+}
+
+void ExternalUtilityThatCallsRecordProperty(const std::string& key, int value) {
+  testing::Test::RecordProperty(key, value);
+}
+
+void ExternalUtilityThatCallsRecordProperty(const std::string& key,
+                                            const std::string& value) {
+  testing::Test::RecordProperty(key, value);
+}
+
+TEST(NoFixtureTest, ExternalUtilityThatCallsRecordIntValuedProperty) {
+  ExternalUtilityThatCallsRecordProperty("key_for_utility_int", 1);
+}
+
+TEST(NoFixtureTest, ExternalUtilityThatCallsRecordStringValuedProperty) {
+  ExternalUtilityThatCallsRecordProperty("key_for_utility_string", "1");
+}
+
+// Verifies that the test parameter value is output in the 'value_param'
+// XML attribute for value-parameterized tests.
+class ValueParamTest : public TestWithParam<int> {};
+TEST_P(ValueParamTest, HasValueParamAttribute) {}
+TEST_P(ValueParamTest, AnotherTestThatHasValueParamAttribute) {}
+INSTANTIATE_TEST_SUITE_P(Single, ValueParamTest, Values(33, 42));
+
+#if GTEST_HAS_TYPED_TEST
+// Verifies that the type parameter name is output in the 'type_param'
+// XML attribute for typed tests.
+template <typename T> class TypedTest : public Test {};
+typedef testing::Types<int, long> TypedTestTypes;
+TYPED_TEST_SUITE(TypedTest, TypedTestTypes);
+TYPED_TEST(TypedTest, HasTypeParamAttribute) {}
+#endif
+
+#if GTEST_HAS_TYPED_TEST_P
+// Verifies that the type parameter name is output in the 'type_param'
+// XML attribute for type-parameterized tests.
+template <typename T>
+class TypeParameterizedTestSuite : public Test {};
+TYPED_TEST_SUITE_P(TypeParameterizedTestSuite);
+TYPED_TEST_P(TypeParameterizedTestSuite, HasTypeParamAttribute) {}
+REGISTER_TYPED_TEST_SUITE_P(TypeParameterizedTestSuite, HasTypeParamAttribute);
+typedef testing::Types<int, long> TypeParameterizedTestSuiteTypes;  // NOLINT
+INSTANTIATE_TYPED_TEST_SUITE_P(Single, TypeParameterizedTestSuite,
+                               TypeParameterizedTestSuiteTypes);
+#endif
+
+int main(int argc, char** argv) {
+  InitGoogleTest(&argc, argv);
+
+  if (argc > 1 && strcmp(argv[1], "--shut_down_xml") == 0) {
+    TestEventListeners& listeners = UnitTest::GetInstance()->listeners();
+    delete listeners.Release(listeners.default_xml_generator());
+  }
+  testing::Test::RecordProperty("ad_hoc_property", "42");
+  return RUN_ALL_TESTS();
+}
diff --git a/3rdparty/gtest/test/gtest_xml_test_utils.py b/3rdparty/gtest/test/gtest_xml_test_utils.py
new file mode 100644
index 0000000..9914a49
--- /dev/null
+++ b/3rdparty/gtest/test/gtest_xml_test_utils.py
@@ -0,0 +1,196 @@
+# Copyright 2006, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Unit test utilities for gtest_xml_output"""
+
+import re
+from xml.dom import minidom, Node
+import gtest_test_utils
+
+GTEST_DEFAULT_OUTPUT_FILE = 'test_detail.xml'
+
+class GTestXMLTestCase(gtest_test_utils.TestCase):
+  """
+  Base class for tests of Google Test's XML output functionality.
+  """
+
+
+  def AssertEquivalentNodes(self, expected_node, actual_node):
+    """
+    Asserts that actual_node (a DOM node object) is equivalent to
+    expected_node (another DOM node object), in that either both of
+    them are CDATA nodes and have the same value, or both are DOM
+    elements and actual_node meets all of the following conditions:
+
+    *  It has the same tag name as expected_node.
+    *  It has the same set of attributes as expected_node, each with
+       the same value as the corresponding attribute of expected_node.
+       Exceptions are any attribute named "time", which needs only be
+       convertible to a floating-point number and any attribute named
+       "type_param" which only has to be non-empty.
+    *  It has an equivalent set of child nodes (including elements and
+       CDATA sections) as expected_node.  Note that we ignore the
+       order of the children as they are not guaranteed to be in any
+       particular order.
+    """
+
+    if expected_node.nodeType == Node.CDATA_SECTION_NODE:
+      self.assertEquals(Node.CDATA_SECTION_NODE, actual_node.nodeType)
+      self.assertEquals(expected_node.nodeValue, actual_node.nodeValue)
+      return
+
+    self.assertEquals(Node.ELEMENT_NODE, actual_node.nodeType)
+    self.assertEquals(Node.ELEMENT_NODE, expected_node.nodeType)
+    self.assertEquals(expected_node.tagName, actual_node.tagName)
+
+    expected_attributes = expected_node.attributes
+    actual_attributes   = actual_node  .attributes
+    self.assertEquals(
+        expected_attributes.length, actual_attributes.length,
+        'attribute numbers differ in element %s:\nExpected: %r\nActual: %r' % (
+            actual_node.tagName, expected_attributes.keys(),
+            actual_attributes.keys()))
+    for i in range(expected_attributes.length):
+      expected_attr = expected_attributes.item(i)
+      actual_attr   = actual_attributes.get(expected_attr.name)
+      self.assert_(
+          actual_attr is not None,
+          'expected attribute %s not found in element %s' %
+          (expected_attr.name, actual_node.tagName))
+      self.assertEquals(
+          expected_attr.value, actual_attr.value,
+          ' values of attribute %s in element %s differ: %s vs %s' %
+          (expected_attr.name, actual_node.tagName,
+           expected_attr.value, actual_attr.value))
+
+    expected_children = self._GetChildren(expected_node)
+    actual_children = self._GetChildren(actual_node)
+    self.assertEquals(
+        len(expected_children), len(actual_children),
+        'number of child elements differ in element ' + actual_node.tagName)
+    for child_id, child in expected_children.items():
+      self.assert_(child_id in actual_children,
+                   '<%s> is not in <%s> (in element %s)' %
+                   (child_id, actual_children, actual_node.tagName))
+      self.AssertEquivalentNodes(child, actual_children[child_id])
+
+  identifying_attribute = {
+      'testsuites': 'name',
+      'testsuite': 'name',
+      'testcase': 'name',
+      'failure': 'message',
+      'property': 'name',
+  }
+
+  def _GetChildren(self, element):
+    """
+    Fetches all of the child nodes of element, a DOM Element object.
+    Returns them as the values of a dictionary keyed by the IDs of the
+    children.  For <testsuites>, <testsuite>, <testcase>, and <property>
+    elements, the ID is the value of their "name" attribute; for <failure>
+    elements, it is the value of the "message" attribute; for <properties>
+    elements, it is the value of their parent's "name" attribute plus the
+    literal string "properties"; CDATA sections and non-whitespace
+    text nodes are concatenated into a single CDATA section with ID
+    "detail".  An exception is raised if any element other than the above
+    four is encountered, if two child elements with the same identifying
+    attributes are encountered, or if any other type of node is encountered.
+    """
+
+    children = {}
+    for child in element.childNodes:
+      if child.nodeType == Node.ELEMENT_NODE:
+        if child.tagName == 'properties':
+          self.assert_(child.parentNode is not None,
+                       'Encountered <properties> element without a parent')
+          child_id = child.parentNode.getAttribute('name') + '-properties'
+        else:
+          self.assert_(child.tagName in self.identifying_attribute,
+                       'Encountered unknown element <%s>' % child.tagName)
+          child_id = child.getAttribute(
+              self.identifying_attribute[child.tagName])
+        self.assert_(child_id not in children)
+        children[child_id] = child
+      elif child.nodeType in [Node.TEXT_NODE, Node.CDATA_SECTION_NODE]:
+        if 'detail' not in children:
+          if (child.nodeType == Node.CDATA_SECTION_NODE or
+              not child.nodeValue.isspace()):
+            children['detail'] = child.ownerDocument.createCDATASection(
+                child.nodeValue)
+        else:
+          children['detail'].nodeValue += child.nodeValue
+      else:
+        self.fail('Encountered unexpected node type %d' % child.nodeType)
+    return children
+
+  def NormalizeXml(self, element):
+    """
+    Normalizes Google Test's XML output to eliminate references to transient
+    information that may change from run to run.
+
+    *  The "time" attribute of <testsuites>, <testsuite> and <testcase>
+       elements is replaced with a single asterisk, if it contains
+       only digit characters.
+    *  The "timestamp" attribute of <testsuites> elements is replaced with a
+       single asterisk, if it contains a valid ISO8601 datetime value.
+    *  The "type_param" attribute of <testcase> elements is replaced with a
+       single asterisk (if it sn non-empty) as it is the type name returned
+       by the compiler and is platform dependent.
+    *  The line info reported in the first line of the "message"
+       attribute and CDATA section of <failure> elements is replaced with the
+       file's basename and a single asterisk for the line number.
+    *  The directory names in file paths are removed.
+    *  The stack traces are removed.
+    """
+
+    if element.tagName in ('testsuites', 'testsuite', 'testcase'):
+      timestamp = element.getAttributeNode('timestamp')
+      timestamp.value = re.sub(r'^\d{4}-\d\d-\d\dT\d\d:\d\d:\d\d$',
+                               '*', timestamp.value)
+    if element.tagName in ('testsuites', 'testsuite', 'testcase'):
+      time = element.getAttributeNode('time')
+      time.value = re.sub(r'^\d+(\.\d+)?$', '*', time.value)
+      type_param = element.getAttributeNode('type_param')
+      if type_param and type_param.value:
+        type_param.value = '*'
+    elif element.tagName == 'failure':
+      source_line_pat = r'^.*[/\\](.*:)\d+\n'
+      # Replaces the source line information with a normalized form.
+      message = element.getAttributeNode('message')
+      message.value = re.sub(source_line_pat, '\\1*\n', message.value)
+      for child in element.childNodes:
+        if child.nodeType == Node.CDATA_SECTION_NODE:
+          # Replaces the source line information with a normalized form.
+          cdata = re.sub(source_line_pat, '\\1*\n', child.nodeValue)
+          # Removes the actual stack trace.
+          child.nodeValue = re.sub(r'Stack trace:\n(.|\n)*',
+                                   'Stack trace:\n*', cdata)
+    for child in element.childNodes:
+      if child.nodeType == Node.ELEMENT_NODE:
+        self.NormalizeXml(child)
diff --git a/3rdparty/gtest/test/production.cc b/3rdparty/gtest/test/production.cc
new file mode 100644
index 0000000..0f69f6d
--- /dev/null
+++ b/3rdparty/gtest/test/production.cc
@@ -0,0 +1,35 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// This is part of the unit test for gtest_prod.h.
+
+#include "production.h"
+
+PrivateCode::PrivateCode() : x_(0) {}
diff --git a/3rdparty/gtest/test/production.h b/3rdparty/gtest/test/production.h
new file mode 100644
index 0000000..542723b
--- /dev/null
+++ b/3rdparty/gtest/test/production.h
@@ -0,0 +1,54 @@
+// Copyright 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//
+// This is part of the unit test for gtest_prod.h.
+
+#ifndef GTEST_TEST_PRODUCTION_H_
+#define GTEST_TEST_PRODUCTION_H_
+
+#include "gtest/gtest_prod.h"
+
+class PrivateCode {
+ public:
+  // Declares a friend test that does not use a fixture.
+  FRIEND_TEST(PrivateCodeTest, CanAccessPrivateMembers);
+
+  // Declares a friend test that uses a fixture.
+  FRIEND_TEST(PrivateCodeFixtureTest, CanAccessPrivateMembers);
+
+  PrivateCode();
+
+  int x() const { return x_; }
+ private:
+  void set_x(int an_x) { x_ = an_x; }
+  int x_;
+};
+
+#endif  // GTEST_TEST_PRODUCTION_H_
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..7e07dd3
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,74 @@
+cmake_minimum_required(VERSION 3.10)
+project(cpp-ipc)
+
+option(LIBIPC_BUILD_TESTS       "Build all of libipc's own tests."                      OFF)
+option(LIBIPC_BUILD_DEMOS       "Build all of libipc's own demos."                      OFF)
+option(LIBIPC_BUILD_SHARED_LIBS "Build shared libraries (DLLs)."                        OFF)
+option(LIBIPC_USE_STATIC_CRT    "Set to ON to build with static CRT on Windows (/MT)."  OFF)
+
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -DNDEBUG")
+if(NOT MSVC)
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2")
+endif()
+
+if (MSVC)
+    set(CompilerFlags
+        CMAKE_CXX_FLAGS
+        CMAKE_CXX_FLAGS_DEBUG
+        CMAKE_CXX_FLAGS_RELEASE
+        CMAKE_C_FLAGS
+        CMAKE_C_FLAGS_DEBUG
+        CMAKE_C_FLAGS_RELEASE
+        )
+    if (LIBIPC_USE_STATIC_CRT)
+        foreach(CompilerFlag ${CompilerFlags})
+            string(REPLACE "/MD" "/MT" ${CompilerFlag} "${${CompilerFlag}}")
+            string(REPLACE "/MDd" "/MTd" ${CompilerFlag} "${${CompilerFlag}}")
+        endforeach()
+    else()
+        foreach(CompilerFlag ${CompilerFlags})
+            string(REPLACE "/MT" "/MD" ${CompilerFlag} "${${CompilerFlag}}")
+            string(REPLACE "/MTd" "/MDd" ${CompilerFlag} "${${CompilerFlag}}")
+        endforeach()
+    endif()
+endif()
+
+set(LIBRARY_OUTPUT_PATH    ${CMAKE_BINARY_DIR}/bin)
+set(EXECUTABLE_OUTPUT_PATH ${CMAKE_BINARY_DIR}/bin)
+set(LIBIPC_PROJECT_DIR     ${PROJECT_SOURCE_DIR})
+
+# Unicode Support
+add_definitions(-DUNICODE -D_UNICODE)
+
+add_subdirectory(src)
+
+if (LIBIPC_BUILD_TESTS)
+    set(GOOGLETEST_VERSION 1.10.0)
+    if (LIBIPC_USE_STATIC_CRT)
+        set(gtest_force_shared_crt OFF)
+    else()
+        set(gtest_force_shared_crt ON)
+    endif()
+    add_subdirectory(3rdparty/gtest)
+    add_subdirectory(test)
+endif()
+
+if (LIBIPC_BUILD_DEMOS)
+    add_subdirectory(demo/chat)
+    add_subdirectory(demo/msg_que)
+    add_subdirectory(demo/send_recv)
+    if (MSVC)
+        add_subdirectory(demo/win_service/service)
+        add_subdirectory(demo/win_service/client)
+    else()
+        add_subdirectory(demo/linux_service/service)
+        add_subdirectory(demo/linux_service/client)
+    endif()
+endif()
+
+install(
+    DIRECTORY "include/"
+    DESTINATION "include"
+)
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..cf01f90
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+cpp-ipc(libipc) - A high-performance inter-process communication using shared memory on Linux/Windows.
+
+Copyright (c) 2018 mutouyun (http://orzz.org)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/demo/chat/CMakeLists.txt b/demo/chat/CMakeLists.txt
new file mode 100644
index 0000000..c5bcea8
--- /dev/null
+++ b/demo/chat/CMakeLists.txt
@@ -0,0 +1,8 @@
+project(chat)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)
diff --git a/demo/chat/main.cpp b/demo/chat/main.cpp
new file mode 100644
index 0000000..ec9c3be
--- /dev/null
+++ b/demo/chat/main.cpp
@@ -0,0 +1,62 @@
+
+#include <iostream>
+#include <string>
+#include <thread>
+#include <regex>
+#include <atomic>
+
+#include "libipc/ipc.h"
+
+namespace {
+
+constexpr char const name__[] = "ipc-chat";
+constexpr char const quit__[] = "q";
+constexpr char const id__  [] = "c";
+
+inline std::size_t calc_unique_id() {
+    static ipc::shm::handle g_shm { "__CHAT_ACC_STORAGE__", sizeof(std::atomic<std::size_t>) };
+    return static_cast<std::atomic<std::size_t>*>(g_shm.get())->fetch_add(1, std::memory_order_relaxed);
+}
+
+ipc::channel sender__   { name__, ipc::sender   };
+ipc::channel receiver__ { name__, ipc::receiver };
+
+} // namespace
+
+int main() {
+    std::string buf, id = id__ + std::to_string(calc_unique_id());
+    std::regex  reg { "(c\\d+)> (.*)" };
+
+    std::thread r {[&id, &reg] {
+        std::cout << id << " is ready." << std::endl;
+        while (1) {
+            ipc::buff_t buf = receiver__.recv();
+            if (buf.empty()) break; // quit
+            std::string dat { buf.get<char const *>(), buf.size() - 1 };
+            std::smatch mid;
+            if (std::regex_match(dat, mid, reg)) {
+                if (mid.str(1) == id) {
+                    if (mid.str(2) == quit__) {
+                        break;
+                    }
+                    continue;
+                }
+            }
+            std::cout << dat << std::endl;
+        }
+        std::cout << id << " receiver is quit..." << std::endl;
+    }};
+
+    for (/*int i = 1*/;; /*++i*/) {
+        std::cin >> buf;
+        if (buf.empty() || (buf == quit__)) break;
+//        std::cout << "[" << i << "]" << std::endl;
+        sender__.send(id + "> " + buf);
+        buf.clear();
+    }
+
+    receiver__.disconnect();
+    r.join();
+    std::cout << id << " sender is quit..." << std::endl;
+    return 0;
+}
diff --git a/demo/linux_service/client/CMakeLists.txt b/demo/linux_service/client/CMakeLists.txt
new file mode 100644
index 0000000..b7d8392
--- /dev/null
+++ b/demo/linux_service/client/CMakeLists.txt
@@ -0,0 +1,8 @@
+project(linux_client)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)
diff --git a/demo/linux_service/client/main.cpp b/demo/linux_service/client/main.cpp
new file mode 100644
index 0000000..9839be9
--- /dev/null
+++ b/demo/linux_service/client/main.cpp
@@ -0,0 +1,28 @@
+/// \brief To create a basic command line program.
+
+#include <stdio.h>
+#include <thread>
+#include <chrono>
+
+#include "libipc/ipc.h"
+
+int main(int argc, char *argv[]) {
+    printf("My Sample Client: Entry\n");
+    ipc::channel ipc_r{"service ipc r", ipc::receiver};
+    ipc::channel ipc_w{"service ipc w", ipc::sender};
+    while (1) {
+        auto msg = ipc_r.recv();
+        if (msg.empty()) {
+            printf("My Sample Client: message recv error\n");
+            return -1;
+        }
+        printf("My Sample Client: message recv: [%s]\n", (char const *)msg.data());
+        while (!ipc_w.send("Copy.")) {
+            printf("My Sample Client: message send error\n");
+            std::this_thread::sleep_for(std::chrono::seconds(1));
+        }
+        printf("My Sample Client: message send [Copy]\n");
+    }
+    printf("My Sample Client: Exit\n");
+    return 0;
+}
diff --git a/demo/linux_service/service/CMakeLists.txt b/demo/linux_service/service/CMakeLists.txt
new file mode 100644
index 0000000..a877337
--- /dev/null
+++ b/demo/linux_service/service/CMakeLists.txt
@@ -0,0 +1,8 @@
+project(linux_service)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)
diff --git a/demo/linux_service/service/main.cpp b/demo/linux_service/service/main.cpp
new file mode 100644
index 0000000..cf8dec3
--- /dev/null
+++ b/demo/linux_service/service/main.cpp
@@ -0,0 +1,34 @@
+/// \brief To create a basic command line program.
+
+#include <stdio.h>
+#include <string>
+#include <thread>
+#include <chrono>
+
+#include "libipc/ipc.h"
+
+int main(int argc, char *argv[]) {
+    printf("My Sample Service: Main: Entry\n");
+
+    ipc::channel ipc_r{"service ipc r", ipc::sender};
+    ipc::channel ipc_w{"service ipc w", ipc::receiver};
+
+    while (1) {
+        if (!ipc_r.send("Hello, World!")) {
+            printf("My Sample Service: send failed.\n");
+        }
+        else {
+            printf("My Sample Service: send [Hello, World!]\n");
+            auto msg = ipc_w.recv(1000);
+            if (msg.empty()) {
+                printf("My Sample Service: recv error\n");
+            } else {
+                printf("%s\n", (std::string{"My Sample Service: recv ["} + msg.get<char const *>() + "]").c_str());
+            }
+        }
+        std::this_thread::sleep_for(std::chrono::seconds(3));
+    }
+
+    printf("My Sample Service: Main: Exit\n");
+    return 0;
+}
diff --git a/demo/msg_que/CMakeLists.txt b/demo/msg_que/CMakeLists.txt
new file mode 100644
index 0000000..da0de71
--- /dev/null
+++ b/demo/msg_que/CMakeLists.txt
@@ -0,0 +1,11 @@
+project(msg_que)
+
+include_directories(
+    ${LIBIPC_PROJECT_DIR}/3rdparty)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)
diff --git a/demo/msg_que/main.cpp b/demo/msg_que/main.cpp
new file mode 100644
index 0000000..eda7f51
--- /dev/null
+++ b/demo/msg_que/main.cpp
@@ -0,0 +1,137 @@
+
+#include <signal.h>
+
+#include <iostream>
+#include <string>
+#include <atomic>
+#include <thread>
+#include <chrono>
+#include <cstddef>
+
+#include "libipc/ipc.h"
+#include "capo/random.hpp"
+
+namespace {
+
+constexpr char const name__  [] = "ipc-msg-que";
+constexpr char const mode_s__[] = "s";
+constexpr char const mode_r__[] = "r";
+
+constexpr std::size_t const min_sz = 128;
+constexpr std::size_t const max_sz = 1024 * 16;
+
+std::atomic<bool> is_quit__ {false};
+std::atomic<std::size_t> size_counter__ {0};
+
+using msg_que_t = ipc::chan<ipc::relat::single, ipc::relat::multi, ipc::trans::broadcast>;
+
+msg_que_t que__{ name__ };
+ipc::byte_t buff__[max_sz];
+capo::random<> rand__{ 
+    static_cast<int>(min_sz), 
+    static_cast<int>(max_sz)
+};
+
+inline std::string str_of_size(std::size_t sz) noexcept {
+    if (sz > 1024 * 1024) {
+        return std::to_string(sz / (1024 * 1024)) + " MB";
+    }
+    if (sz > 1024) {
+        return std::to_string(sz / 1024) + " KB";
+    }
+    return std::to_string(sz) + " bytes";
+}
+
+inline std::string speed_of(std::size_t sz) noexcept {
+    return str_of_size(sz) + "/s";
+}
+
+void do_counting() {
+    for (int i = 1; !is_quit__.load(std::memory_order_acquire); ++i) {
+        std::this_thread::sleep_for(std::chrono::milliseconds(100)); // 100 ms
+        if (i % 10) continue;
+        i = 0;
+        std::cout
+            << speed_of(size_counter__.exchange(0, std::memory_order_relaxed))
+            << std::endl;
+    }
+}
+
+void do_send() {
+    std::cout 
+        << __func__ << ": start [" 
+        << str_of_size(min_sz) << " - " << str_of_size(max_sz) 
+        << "]...\n";
+    if (!que__.reconnect(ipc::sender)) {
+        std::cerr << __func__ << ": connect failed.\n";
+    }
+    else {
+        std::thread counting{ do_counting };
+        while (!is_quit__.load(std::memory_order_acquire)) {
+            std::size_t sz = static_cast<std::size_t>(rand__());
+            if (!que__.send(ipc::buff_t(buff__, sz))) {
+                std::cerr << __func__ << ": send failed.\n";
+                std::cout << __func__ << ": waiting for receiver...\n";
+                if (!que__.wait_for_recv(1)) {
+                    std::cerr << __func__ << ": wait receiver failed.\n";
+                    is_quit__.store(true, std::memory_order_release);
+                    break;
+                }
+            }
+            size_counter__.fetch_add(sz, std::memory_order_relaxed);
+            std::this_thread::yield();
+        }
+        counting.join();
+    }
+    std::cout << __func__ << ": quit...\n";
+}
+
+void do_recv() {
+    std::cout
+        << __func__ << ": start ["
+        << str_of_size(min_sz) << " - " << str_of_size(max_sz)
+        << "]...\n";
+    if (!que__.reconnect(ipc::receiver)) {
+        std::cerr << __func__ << ": connect failed.\n";
+    }
+    else {
+        std::thread counting{ do_counting };
+        while (!is_quit__.load(std::memory_order_acquire)) {
+            auto msg = que__.recv();
+            if (msg.empty()) break;
+            size_counter__.fetch_add(msg.size(), std::memory_order_relaxed);
+        }
+        counting.join();
+    }
+    std::cout << __func__ << ": quit...\n";
+}
+
+} // namespace
+
+int main(int argc, char ** argv) {
+    if (argc < 2) return 0;
+
+    auto exit = [](int) {
+        is_quit__.store(true, std::memory_order_release);
+        que__.disconnect();
+    };
+    ::signal(SIGINT  , exit);
+    ::signal(SIGABRT , exit);
+    ::signal(SIGSEGV , exit);
+    ::signal(SIGTERM , exit);
+#if defined(WIN64) || defined(_WIN64) || defined(__WIN64__) || \
+    defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || \
+    defined(WINCE) || defined(_WIN32_WCE)
+    ::signal(SIGBREAK, exit);
+#else
+    ::signal(SIGHUP  , exit);
+#endif
+
+    std::string mode {argv[1]};
+    if (mode == mode_s__) {
+        do_send();
+    } else if (mode == mode_r__) {
+        do_recv();
+    }
+    return 0;
+}
diff --git a/demo/send_recv/CMakeLists.txt b/demo/send_recv/CMakeLists.txt
new file mode 100644
index 0000000..9d3f0fb
--- /dev/null
+++ b/demo/send_recv/CMakeLists.txt
@@ -0,0 +1,11 @@
+project(send_recv)
+
+include_directories(
+    ${LIBIPC_PROJECT_DIR}/3rdparty)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)
diff --git a/demo/send_recv/main.cpp b/demo/send_recv/main.cpp
new file mode 100644
index 0000000..52287c2
--- /dev/null
+++ b/demo/send_recv/main.cpp
@@ -0,0 +1,72 @@
+
+#include <signal.h>
+
+#include <iostream>
+#include <string>
+#include <thread>
+#include <chrono>
+#include <atomic>
+
+#include "libipc/ipc.h"
+
+namespace {
+
+std::atomic<bool> is_quit__ {false};
+ipc::channel *ipc__ = nullptr;
+
+void do_send(int size, int interval) {
+    ipc::channel ipc {"ipc", ipc::sender};
+    ipc__ = &ipc;
+    std::string buffer(size, 'A');
+    while (!is_quit__.load(std::memory_order_acquire)) {
+        std::cout << "send size: " << buffer.size() + 1 << "\n";
+        ipc.send(buffer, 0/*tm*/);
+        std::this_thread::sleep_for(std::chrono::milliseconds(interval));
+    }
+}
+
+void do_recv(int interval) {
+    ipc::channel ipc {"ipc", ipc::receiver};
+    ipc__ = &ipc;
+    while (!is_quit__.load(std::memory_order_acquire)) {
+        ipc::buff_t recv;
+        for (int k = 1; recv.empty(); ++k) {
+            std::cout << "recv waiting... " << k << "\n";
+            recv = ipc.recv(interval);
+            if (is_quit__.load(std::memory_order_acquire)) return;
+        }
+        std::cout << "recv size: " << recv.size() << "\n";
+    }
+}
+
+} // namespace
+
+int main(int argc, char ** argv) {
+    if (argc < 3) return -1;
+
+    auto exit = [](int) {
+        is_quit__.store(true, std::memory_order_release);
+        if (ipc__ != nullptr) ipc__->disconnect();
+    };
+    ::signal(SIGINT  , exit);
+    ::signal(SIGABRT , exit);
+    ::signal(SIGSEGV , exit);
+    ::signal(SIGTERM , exit);
+#if defined(WIN64) || defined(_WIN64) || defined(__WIN64__) || \
+    defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || \
+    defined(WINCE) || defined(_WIN32_WCE)
+    ::signal(SIGBREAK, exit);
+#else
+    ::signal(SIGHUP  , exit);
+#endif
+
+    std::string mode {argv[1]};
+    if (mode == "send") {
+        if (argc < 4) return -1;
+        do_send(std::stoi(argv[2]) /*size*/, 
+                std::stoi(argv[3]) /*interval*/);
+    } else if (mode == "recv") {
+        do_recv(std::stoi(argv[2]) /*interval*/);
+    }
+    return 0;
+}
diff --git a/demo/win_service/client/CMakeLists.txt b/demo/win_service/client/CMakeLists.txt
new file mode 100644
index 0000000..2dc03d5
--- /dev/null
+++ b/demo/win_service/client/CMakeLists.txt
@@ -0,0 +1,8 @@
+project(win_client)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)
diff --git a/demo/win_service/client/main.cpp b/demo/win_service/client/main.cpp
new file mode 100644
index 0000000..44a9ba6
--- /dev/null
+++ b/demo/win_service/client/main.cpp
@@ -0,0 +1,41 @@
+/// \brief To create a basic Windows command line program.
+
+#include <Windows.h>
+#include <tchar.h>
+#include <stdio.h>
+
+#include "libipc/ipc.h"
+
+int _tmain (int argc, TCHAR *argv[]) {
+    _tprintf(_T("My Sample Client: Entry\n"));
+    ipc::channel ipc_r{ipc::prefix{"Global\\"}, "service ipc r", ipc::receiver};
+    ipc::channel ipc_w{ipc::prefix{"Global\\"}, "service ipc w", ipc::sender};
+    while (1) {
+        if (!ipc_r.reconnect(ipc::receiver)) {
+            Sleep(1000);
+            continue;
+        }
+        auto msg = ipc_r.recv();
+        if (msg.empty()) {
+            _tprintf(_T("My Sample Client: message recv error\n"));
+            ipc_r.disconnect();
+            continue;
+        }
+        printf("My Sample Client: message recv: [%s]\n", (char const *)msg.data());
+        for (;;) {
+            if (!ipc_w.reconnect(ipc::sender)) {
+                Sleep(1000);
+                continue;
+            }
+            if (ipc_w.send("Copy.")) {
+                break;
+            }
+            _tprintf(_T("My Sample Client: message send error\n"));
+            ipc_w.disconnect();
+            Sleep(1000);
+        }
+        _tprintf(_T("My Sample Client: message send [Copy]\n"));
+    }
+    _tprintf(_T("My Sample Client: Exit\n"));
+    return 0;
+}
diff --git a/demo/win_service/service/CMakeLists.txt b/demo/win_service/service/CMakeLists.txt
new file mode 100644
index 0000000..b7bb357
--- /dev/null
+++ b/demo/win_service/service/CMakeLists.txt
@@ -0,0 +1,8 @@
+project(win_service)
+
+file(GLOB SRC_FILES ./*.cpp)
+file(GLOB HEAD_FILES ./*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+target_link_libraries(${PROJECT_NAME} ipc)
diff --git a/demo/win_service/service/main.cpp b/demo/win_service/service/main.cpp
new file mode 100644
index 0000000..ce52228
--- /dev/null
+++ b/demo/win_service/service/main.cpp
@@ -0,0 +1,189 @@
+/// \brief To create a basic Windows Service in C++.
+/// \see https://www.codeproject.com/Articles/499465/Simple-Windows-Service-in-Cplusplus
+
+#include <Windows.h>
+#include <tchar.h>
+#include <string>
+
+#include "libipc/ipc.h"
+
+SERVICE_STATUS        g_ServiceStatus = {0};
+SERVICE_STATUS_HANDLE g_StatusHandle = NULL;
+HANDLE                g_ServiceStopEvent = INVALID_HANDLE_VALUE;
+
+VOID WINAPI ServiceMain (DWORD argc, LPTSTR *argv);
+VOID WINAPI ServiceCtrlHandler (DWORD);
+DWORD WINAPI ServiceWorkerThread (LPVOID lpParam);
+
+#define SERVICE_NAME  _T("My Sample Service")
+
+int _tmain (int argc, TCHAR *argv[]) {
+    OutputDebugString(_T("My Sample Service: Main: Entry"));
+
+    SERVICE_TABLE_ENTRY ServiceTable[] = {
+        {SERVICE_NAME, (LPSERVICE_MAIN_FUNCTION) ServiceMain},
+        {NULL, NULL}
+    };
+
+    if (StartServiceCtrlDispatcher (ServiceTable) == FALSE) {
+        OutputDebugString(_T("My Sample Service: Main: StartServiceCtrlDispatcher returned error"));
+        return GetLastError ();
+    }
+
+    OutputDebugString(_T("My Sample Service: Main: Exit"));
+    return 0;
+}
+
+VOID WINAPI ServiceMain (DWORD argc, LPTSTR *argv) {
+    DWORD Status = E_FAIL;
+
+    OutputDebugString(_T("My Sample Service: ServiceMain: Entry"));
+
+    g_StatusHandle = RegisterServiceCtrlHandler (SERVICE_NAME, ServiceCtrlHandler);
+
+    if (g_StatusHandle == NULL) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: RegisterServiceCtrlHandler returned error"));
+        goto EXIT;
+    }
+
+    // Tell the service controller we are starting
+    ZeroMemory (&g_ServiceStatus, sizeof (g_ServiceStatus));
+    g_ServiceStatus.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
+    g_ServiceStatus.dwControlsAccepted = 0;
+    g_ServiceStatus.dwCurrentState = SERVICE_START_PENDING;
+    g_ServiceStatus.dwWin32ExitCode = 0;
+    g_ServiceStatus.dwServiceSpecificExitCode = 0;
+    g_ServiceStatus.dwCheckPoint = 0;
+
+    if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: SetServiceStatus returned error"));
+    }
+
+    /* 
+     * Perform tasks neccesary to start the service here
+     */
+    OutputDebugString(_T("My Sample Service: ServiceMain: Performing Service Start Operations"));
+
+    // Create stop event to wait on later.
+    g_ServiceStopEvent = CreateEvent (NULL, TRUE, FALSE, NULL);
+    if (g_ServiceStopEvent == NULL) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: CreateEvent(g_ServiceStopEvent) returned error"));
+
+        g_ServiceStatus.dwControlsAccepted = 0;
+        g_ServiceStatus.dwCurrentState = SERVICE_STOPPED;
+        g_ServiceStatus.dwWin32ExitCode = GetLastError();
+        g_ServiceStatus.dwCheckPoint = 1;
+
+        if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+            OutputDebugString(_T("My Sample Service: ServiceMain: SetServiceStatus returned error"));
+        }
+        goto EXIT; 
+    }    
+
+    // Tell the service controller we are started
+    g_ServiceStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP;
+    g_ServiceStatus.dwCurrentState = SERVICE_RUNNING;
+    g_ServiceStatus.dwWin32ExitCode = 0;
+    g_ServiceStatus.dwCheckPoint = 0;
+
+    if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: SetServiceStatus returned error"));
+    }
+
+    // Start the thread that will perform the main task of the service
+    HANDLE hThread = CreateThread (NULL, 0, ServiceWorkerThread, NULL, 0, NULL);
+
+    OutputDebugString(_T("My Sample Service: ServiceMain: Waiting for Worker Thread to complete"));
+
+    // Wait until our worker thread exits effectively signaling that the service needs to stop
+    WaitForSingleObject (hThread, INFINITE);
+    
+    OutputDebugString(_T("My Sample Service: ServiceMain: Worker Thread Stop Event signaled"));
+    
+    
+    /* 
+     * Perform any cleanup tasks
+     */
+    OutputDebugString(_T("My Sample Service: ServiceMain: Performing Cleanup Operations"));
+
+    CloseHandle (g_ServiceStopEvent);
+
+    g_ServiceStatus.dwControlsAccepted = 0;
+    g_ServiceStatus.dwCurrentState = SERVICE_STOPPED;
+    g_ServiceStatus.dwWin32ExitCode = 0;
+    g_ServiceStatus.dwCheckPoint = 3;
+
+    if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+        OutputDebugString(_T("My Sample Service: ServiceMain: SetServiceStatus returned error"));
+    }
+    
+EXIT:
+    OutputDebugString(_T("My Sample Service: ServiceMain: Exit"));
+    return;
+}
+
+VOID WINAPI ServiceCtrlHandler (DWORD CtrlCode) {
+    OutputDebugString(_T("My Sample Service: ServiceCtrlHandler: Entry"));
+
+    switch (CtrlCode) {
+    case SERVICE_CONTROL_STOP :
+
+        OutputDebugString(_T("My Sample Service: ServiceCtrlHandler: SERVICE_CONTROL_STOP Request"));
+
+        if (g_ServiceStatus.dwCurrentState != SERVICE_RUNNING)
+           break;
+
+        /* 
+         * Perform tasks neccesary to stop the service here 
+         */
+        
+        g_ServiceStatus.dwControlsAccepted = 0;
+        g_ServiceStatus.dwCurrentState = SERVICE_STOP_PENDING;
+        g_ServiceStatus.dwWin32ExitCode = 0;
+        g_ServiceStatus.dwCheckPoint = 4;
+
+        if (SetServiceStatus (g_StatusHandle, &g_ServiceStatus) == FALSE) {
+            OutputDebugString(_T("My Sample Service: ServiceCtrlHandler: SetServiceStatus returned error"));
+        }
+
+        // This will signal the worker thread to start shutting down
+        SetEvent (g_ServiceStopEvent);
+
+        break;
+
+    default:
+        break;
+    }
+
+    OutputDebugString(_T("My Sample Service: ServiceCtrlHandler: Exit"));
+}
+
+DWORD WINAPI ServiceWorkerThread (LPVOID lpParam) {
+    OutputDebugString(_T("My Sample Service: ServiceWorkerThread: Entry"));
+    ipc::channel ipc_r{ipc::prefix{"Global\\"}, "service ipc r", ipc::sender};
+    ipc::channel ipc_w{ipc::prefix{"Global\\"}, "service ipc w", ipc::receiver};
+
+    //  Periodically check if the service has been requested to stop
+    while (WaitForSingleObject(g_ServiceStopEvent, 0) != WAIT_OBJECT_0) {        
+        /* 
+         * Perform main service function here
+         */
+        if (!ipc_r.send("Hello, World!")) {
+            OutputDebugString(_T("My Sample Service: send failed."));
+        }
+        else {
+            OutputDebugString(_T("My Sample Service: send [Hello, World!]"));
+            auto msg = ipc_w.recv(1000);
+            if (msg.empty()) {
+                OutputDebugString(_T("My Sample Service: recv error"));
+            } else {
+                OutputDebugStringA((std::string{"My Sample Service: recv ["} + msg.get<char const *>() + "]").c_str());
+            }
+        }
+        Sleep(3000);
+    }
+
+    OutputDebugString(_T("My Sample Service: ServiceWorkerThread: Exit"));
+
+    return ERROR_SUCCESS;
+}
diff --git a/include/libipc/buffer.h b/include/libipc/buffer.h
new file mode 100644
index 0000000..3f8c229
--- /dev/null
+++ b/include/libipc/buffer.h
@@ -0,0 +1,68 @@
+#pragma once
+
+#include <cstddef>
+#include <tuple>
+#include <vector>
+#include <type_traits>
+
+#include "libipc/export.h"
+#include "libipc/def.h"
+
+namespace ipc {
+
+class IPC_EXPORT buffer {
+public:
+    using destructor_t = void (*)(void*, std::size_t);
+
+    buffer();
+
+    buffer(void* p, std::size_t s, destructor_t d);
+    buffer(void* p, std::size_t s, destructor_t d, void* additional);
+    buffer(void* p, std::size_t s);
+
+    template <std::size_t N>
+    explicit buffer(byte_t const (& data)[N])
+        : buffer(data, sizeof(data)) {
+    }
+    explicit buffer(char const & c);
+
+    buffer(buffer&& rhs);
+    ~buffer();
+
+    void swap(buffer& rhs);
+    buffer& operator=(buffer rhs);
+
+    bool empty() const noexcept;
+
+    void *       data()       noexcept;
+    void const * data() const noexcept;
+
+    template <typename T>
+    T get() const { return T(data()); }
+
+    std::size_t size() const noexcept;
+
+    std::tuple<void*, std::size_t> to_tuple() {
+        return std::make_tuple(data(), size());
+    }
+
+    std::tuple<void const *, std::size_t> to_tuple() const {
+        return std::make_tuple(data(), size());
+    }
+
+    std::vector<byte_t> to_vector() const {
+        return {
+            get<byte_t const *>(),
+            get<byte_t const *>() + size()
+        };
+    }
+
+    friend IPC_EXPORT bool operator==(buffer const & b1, buffer const & b2);
+    friend IPC_EXPORT bool operator!=(buffer const & b1, buffer const & b2);
+
+private:
+    class buffer_;
+    buffer_* p_;
+};
+
+} // namespace ipc
diff --git a/include/libipc/condition.h b/include/libipc/condition.h
new file mode 100644
index 0000000..a4e2ac3
--- /dev/null
+++ b/include/libipc/condition.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <cstdint>  // std::uint64_t
+
+#include "libipc/export.h"
+#include "libipc/def.h"
+#include "libipc/mutex.h"
+
+namespace ipc {
+namespace sync {
+
+class IPC_EXPORT condition {
+    condition(condition const &) = delete;
+    condition &operator=(condition const &) = delete;
+
+public:
+    condition();
+    explicit condition(char const *name);
+    ~condition();
+
+    void const *native() const noexcept;
+    void *native() noexcept;
+
+    bool valid() const noexcept;
+
+    bool open(char const *name) noexcept;
+    void close() noexcept;
+
+    bool wait(ipc::sync::mutex &mtx, std::uint64_t tm = ipc::invalid_value) noexcept;
+    bool notify(ipc::sync::mutex &mtx) noexcept;
+    bool broadcast(ipc::sync::mutex &mtx) noexcept;
+
+private:
+    class condition_;
+    condition_* p_;
+};
+
+} // namespace sync
+} // namespace ipc
diff --git a/include/libipc/def.h b/include/libipc/def.h
new file mode 100644
index 0000000..45cd780
--- /dev/null
+++ b/include/libipc/def.h
@@ -0,0 +1,73 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <limits>       // std::numeric_limits
+#include <new>
+#include <utility>
+
+namespace ipc {
+
+// types
+
+using byte_t = std::uint8_t;
+
+template <std::size_t N>
+struct uint;
+
+template <> struct uint<8 > { using type = std::uint8_t ; };
+template <> struct uint<16> { using type = std::uint16_t; };
+template <> struct uint<32> { using type = std::uint32_t; };
+template <> struct uint<64> { using type = std::uint64_t; };
+
+template <std::size_t N>
+using uint_t = typename uint<N>::type;
+
+// constants
+
+enum : std::uint32_t {
+    invalid_value   = (std::numeric_limits<std::uint32_t>::max)(),
+    default_timeout = 100, // ms
+};
+
+enum : std::size_t {
+    data_length     = 64,
+    large_msg_limit = data_length,
+    large_msg_align = 1024,
+    large_msg_cache = 32,
+};
+
+enum class relat { // multiplicity of the relationship
+    single,
+    multi
+};
+
+enum class trans { // transmission
+    unicast,
+    broadcast
+};
+
+// producer-consumer policy flag
+
+template <relat Rp, relat Rc, trans Ts>
+struct wr {};
+
+template <typename WR>
+struct relat_trait;
+
+template <relat Rp, relat Rc, trans Ts>
+struct relat_trait<wr<Rp, Rc, Ts>> {
+    constexpr static bool is_multi_producer = (Rp == relat::multi);
+    constexpr static bool is_multi_consumer = (Rc == relat::multi);
+    constexpr static bool is_broadcast      = (Ts == trans::broadcast);
+};
+
+template <template <typename> class Policy, typename Flag>
+struct relat_trait<Policy<Flag>> : relat_trait<Flag> {};
+
+// the prefix tag of a channel
+struct prefix {
+    char const *str;
+};
+
+} // namespace ipc
diff --git a/include/libipc/export.h b/include/libipc/export.h
new file mode 100644
index 0000000..884f2fc
--- /dev/null
+++ b/include/libipc/export.h
@@ -0,0 +1,54 @@
+#pragma once
+
+#if defined(Q_DECL_EXPORT) && defined(Q_DECL_IMPORT)
+
+#   define IPC_DECL_EXPORT Q_DECL_EXPORT
+#   define IPC_DECL_IMPORT Q_DECL_IMPORT
+
+#else // defined(Q_DECL_EXPORT) && defined(Q_DECL_IMPORT)
+
+/*
+ * Compiler & system detection for IPC_DECL_EXPORT & IPC_DECL_IMPORT.
+ * Not using QtCore cause it shouldn't depend on Qt.
+*/
+
+#if defined(_MSC_VER)
+#   define IPC_DECL_EXPORT      __declspec(dllexport)
+#   define IPC_DECL_IMPORT      __declspec(dllimport)
+#elif defined(__ARMCC__) || defined(__CC_ARM)
+#   if defined(ANDROID) || defined(__linux__) || defined(__linux)
+#       define IPC_DECL_EXPORT  __attribute__((visibility("default")))
+#       define IPC_DECL_IMPORT  __attribute__((visibility("default")))
+#   else
+#       define IPC_DECL_EXPORT  __declspec(dllexport)
+#       define IPC_DECL_IMPORT  __declspec(dllimport)
+#   endif
+#elif defined(__GNUC__)
+#   if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || \
+       defined(WIN64) || defined(_WIN64) || defined(__WIN64__)
+#       define IPC_DECL_EXPORT  __declspec(dllexport)
+#       define IPC_DECL_IMPORT  __declspec(dllimport)
+#   else
+#       define IPC_DECL_EXPORT  __attribute__((visibility("default")))
+#       define IPC_DECL_IMPORT  __attribute__((visibility("default")))
+#   endif
+#else
+#   define IPC_DECL_EXPORT      __attribute__((visibility("default")))
+#   define IPC_DECL_IMPORT      __attribute__((visibility("default")))
+#endif
+
+#endif // defined(Q_DECL_EXPORT) && defined(Q_DECL_IMPORT)
+
+/*
+ * Define IPC_EXPORT for exporting function & class.
+*/
+
+#ifndef IPC_EXPORT
+#if defined(LIBIPC_LIBRARY_SHARED_BUILDING__)
+#  define IPC_EXPORT IPC_DECL_EXPORT
+#elif defined(LIBIPC_LIBRARY_SHARED_USING__)
+#  define IPC_EXPORT IPC_DECL_IMPORT
+#else
+#  define IPC_EXPORT
+#endif
+#endif /*IPC_EXPORT*/
diff --git a/include/libipc/ipc.h b/include/libipc/ipc.h
new file mode 100644
index 0000000..3175094
--- /dev/null
+++ b/include/libipc/ipc.h
@@ -0,0 +1,200 @@
+#pragma once
+
+#include <string>
+
+#include "libipc/export.h"
+#include "libipc/def.h"
+#include "libipc/buffer.h"
+#include "libipc/shm.h"
+
+namespace ipc {
+
+using handle_t = void*;
+using buff_t   = buffer;
+
+enum : unsigned {
+    sender,
+    receiver
+};
+
+template <typename Flag>
+struct IPC_EXPORT chan_impl {
+    static ipc::handle_t inited();
+
+    static bool connect   (ipc::handle_t * ph, char const * name, unsigned mode);
+    static bool connect   (ipc::handle_t * ph, prefix, char const * name, unsigned mode);
+    static bool reconnect (ipc::handle_t * ph, unsigned mode);
+    static void disconnect(ipc::handle_t h);
+    static void destroy   (ipc::handle_t h);
+
+    static char const * name(ipc::handle_t h);
+
+    static std::size_t recv_count(ipc::handle_t h);
+    static bool wait_for_recv(ipc::handle_t h, std::size_t r_count, std::uint64_t tm);
+
+    static bool   send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm);
+    static buff_t recv(ipc::handle_t h, std::uint64_t tm);
+
+    static bool   try_send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm);
+    static buff_t try_recv(ipc::handle_t h);
+};
+
+template <typename Flag>
+class chan_wrapper {
+private:
+    using detail_t = chan_impl<Flag>;
+
+    ipc::handle_t h_ = detail_t::inited();
+    unsigned mode_   = ipc::sender;
+    bool connected_  = false;
+
+public:
+    chan_wrapper() noexcept = default;
+
+    explicit chan_wrapper(char const * name, unsigned mode = ipc::sender)
+        : connected_{this->connect(name, mode)} {
+    }
+
+    chan_wrapper(prefix pref, char const * name, unsigned mode = ipc::sender)
+        : connected_{this->connect(pref, name, mode)} {
+    }
+
+    chan_wrapper(chan_wrapper&& rhs) noexcept
+        : chan_wrapper{} {
+        swap(rhs);
+    }
+
+    ~chan_wrapper() {
+        detail_t::destroy(h_);
+    }
+
+    void swap(chan_wrapper& rhs) noexcept {
+        std::swap(h_        , rhs.h_);
+        std::swap(mode_     , rhs.mode_);
+        std::swap(connected_, rhs.connected_);
+    }
+
+    chan_wrapper& operator=(chan_wrapper rhs) noexcept {
+        swap(rhs);
+        return *this;
+    }
+
+    char const * name() const noexcept {
+        return detail_t::name(h_);
+    }
+
+    ipc::handle_t handle() const noexcept {
+        return h_;
+    }
+
+    bool valid() const noexcept {
+        return (handle() != nullptr);
+    }
+
+    unsigned mode() const noexcept {
+        return mode_;
+    }
+
+    chan_wrapper clone() const {
+        return chan_wrapper { name(), mode_ };
+    }
+
+    /**
+     * Building handle, then try connecting with name & mode flags.
+    */
+    bool connect(char const * name, unsigned mode = ipc::sender | ipc::receiver) {
+        if (name == nullptr || name[0] == '\0') return false;
+        detail_t::disconnect(h_); // clear old connection
+        return connected_ = detail_t::connect(&h_, name, mode_ = mode);
+    }
+    bool connect(prefix pref, char const * name, unsigned mode = ipc::sender | ipc::receiver) {
+        if (name == nullptr || name[0] == '\0') return false;
+        detail_t::disconnect(h_); // clear old connection
+        return connected_ = detail_t::connect(&h_, pref, name, mode_ = mode);
+    }
+
+    /**
+     * Try connecting with new mode flags.
+    */
+    bool reconnect(unsigned mode) {
+        if (!valid()) return false;
+        if (connected_ && (mode_ == mode)) return true;
+        return connected_ = detail_t::reconnect(&h_, mode_ = mode);
+    }
+
+    void disconnect() {
+        if (!valid()) return;
+        detail_t::disconnect(h_);
+        connected_ = false;
+    }
+
+    std::size_t recv_count() const {
+        return detail_t::recv_count(h_);
+    }
+
+    bool wait_for_recv(std::size_t r_count, std::uint64_t tm = invalid_value) const {
+        return detail_t::wait_for_recv(h_, r_count, tm);
+    }
+
+    static bool wait_for_recv(char const * name, std::size_t r_count, std::uint64_t tm = invalid_value) {
+        return chan_wrapper(name).wait_for_recv(r_count, tm);
+    }
+
+    /**
+     * If timeout, this function would call 'force_push' to send the data forcibly.
+    */
+    bool send(void const * data, std::size_t size, std::uint64_t tm = default_timeout) {
+        return detail_t::send(h_, data, size, tm);
+    }
+    bool send(buff_t const & buff, std::uint64_t tm = default_timeout) {
+        return this->send(buff.data(), buff.size(), tm);
+    }
+    bool send(std::string const & str, std::uint64_t tm = default_timeout) {
+        return this->send(str.c_str(), str.size() + 1, tm);
+    }
+
+    /**
+     * If timeout, this function would just return false.
+    */
+    bool try_send(void const * data, std::size_t size, std::uint64_t tm = default_timeout) {
+        return detail_t::try_send(h_, data, size, tm);
+    }
+    bool try_send(buff_t const & buff, std::uint64_t tm = default_timeout) {
+        return this->try_send(buff.data(), buff.size(), tm);
+    }
+    bool try_send(std::string const & str, std::uint64_t tm = default_timeout) {
+        return this->try_send(str.c_str(), str.size() + 1, tm);
+    }
+
+    buff_t recv(std::uint64_t tm = invalid_value) {
+        return detail_t::recv(h_, tm);
+    }
+
+    buff_t try_recv() {
+        return detail_t::try_recv(h_);
+    }
+};
+
+template <relat Rp, relat Rc, trans Ts>
+using chan = chan_wrapper<ipc::wr<Rp, Rc, Ts>>;
+
+/**
+ * \class route
+ *
+ * \note You could use one producer/server/sender for sending messages to a route,
+ *       then all the consumers/clients/receivers which are receiving with this route,
+ *       would receive your sent messages.
+ *       A route could only be used in 1 to N (one producer/writer to multi consumers/readers).
+*/
+using route = chan<relat::single, relat::multi, trans::broadcast>;
+
+/**
+ * \class channel
+ *
+ * \note You could use multi producers/writers for sending messages to a channel,
+ *       then all the consumers/readers which are receiving with this channel,
+ *       would receive your sent messages.
+*/
+using channel = chan<relat::multi, relat::multi, trans::broadcast>;
+
+} // namespace ipc
diff --git a/include/libipc/mutex.h b/include/libipc/mutex.h
new file mode 100644
index 0000000..2d4781f
--- /dev/null
+++ b/include/libipc/mutex.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <cstdint>  // std::uint64_t
+#include <system_error>
+
+#include "libipc/export.h"
+#include "libipc/def.h"
+
+namespace ipc {
+namespace sync {
+
+class IPC_EXPORT mutex {
+    mutex(mutex const &) = delete;
+    mutex &operator=(mutex const &) = delete;
+
+public:
+    mutex();
+    explicit mutex(char const *name);
+    ~mutex();
+
+    void const *native() const noexcept;
+    void *native() noexcept;
+
+    bool valid() const noexcept;
+
+    bool open(char const *name) noexcept;
+    void close() noexcept;
+
+    bool lock(std::uint64_t tm = ipc::invalid_value) noexcept;
+    bool try_lock() noexcept(false); // std::system_error
+    bool unlock() noexcept;
+
+private:
+    class mutex_;
+    mutex_* p_;
+};
+
+} // namespace sync
+} // namespace ipc
diff --git a/include/libipc/pool_alloc.h b/include/libipc/pool_alloc.h
new file mode 100644
index 0000000..999bee9
--- /dev/null
+++ b/include/libipc/pool_alloc.h
@@ -0,0 +1,103 @@
+#pragma once
+
+#include <new>
+#include <utility>
+
+#include "libipc/export.h"
+#include "libipc/def.h"
+
+namespace ipc {
+namespace mem {
+
+class IPC_EXPORT pool_alloc {
+public:
+    static void* alloc(std::size_t size);
+    static void  free (void* p, std::size_t size);
+};
+
+////////////////////////////////////////////////////////////////
+/// construct/destruct an object
+////////////////////////////////////////////////////////////////
+
+namespace detail {
+
+template <typename T>
+struct impl {
+    template <typename... P>
+    static T* construct(T* p, P&&... params) {
+        ::new (p) T(std::forward<P>(params)...);
+        return p;
+    }
+
+    static void destruct(T* p) {
+        reinterpret_cast<T*>(p)->~T();
+    }
+};
+
+template <typename T, size_t N>
+struct impl<T[N]> {
+    using type = T[N];
+
+    template <typename... P>
+    static type* construct(type* p, P&&... params) {
+        for (size_t i = 0; i < N; ++i) {
+            impl<T>::construct(&((*p)[i]), std::forward<P>(params)...);
+        }
+        return p;
+    }
+
+    static void destruct(type* p) {
+        for (size_t i = 0; i < N; ++i) {
+            impl<T>::destruct(&((*p)[i]));
+        }
+    }
+};
+
+} // namespace detail
+
+template <typename T, typename... P>
+T* construct(T* p, P&&... params) {
+    return detail::impl<T>::construct(p, std::forward<P>(params)...);
+}
+
+template <typename T, typename... P>
+T* construct(void* p, P&&... params) {
+    return construct(static_cast<T*>(p), std::forward<P>(params)...);
+}
+
+template <typename T>
+void destruct(T* p) {
+    return detail::impl<T>::destruct(p);
+}
+
+template <typename T>
+void destruct(void* p) {
+    destruct(static_cast<T*>(p));
+}
+
+////////////////////////////////////////////////////////////////
+/// general alloc/free
+////////////////////////////////////////////////////////////////
+
+inline void* alloc(std::size_t size) {
+    return pool_alloc::alloc(size);
+}
+
+template <typename T, typename... P>
+T* alloc(P&&... params) {
+    return construct<T>(pool_alloc::alloc(sizeof(T)), std::forward<P>(params)...);
+}
+
+inline void free(void* p, std::size_t size) {
+    pool_alloc::free(p, size);
+}
+
+template <typename T>
+void free(T* p) {
+    if (p == nullptr) return;
+    destruct(p);
+    pool_alloc::free(p, sizeof(T));
+}
+
+} // namespace mem
+} // namespace ipc
diff --git a/include/libipc/rw_lock.h b/include/libipc/rw_lock.h
new file mode 100644
index 0000000..76cd2bd
--- /dev/null
+++ b/include/libipc/rw_lock.h
@@ -0,0 +1,171 @@
+#pragma once
+
+#include <atomic>
+#include <thread>
+#include <chrono>
+#include <limits>
+#include <type_traits>
+#include <utility>
+
+////////////////////////////////////////////////////////////////
+/// Gives hint to processor that improves performance of spin-wait loops.
+////////////////////////////////////////////////////////////////
+
+#pragma push_macro("IPC_LOCK_PAUSE_")
+#undef  IPC_LOCK_PAUSE_
+
+#if defined(_MSC_VER)
+#include <windows.h>    // YieldProcessor
+/*
+    See: http://msdn.microsoft.com/en-us/library/windows/desktop/ms687419(v=vs.85).aspx
+    Not for intel c++ compiler, so ignore http://software.intel.com/en-us/forums/topic/296168
+*/
+#   define IPC_LOCK_PAUSE_() YieldProcessor()
+#elif defined(__GNUC__)
+#if defined(__i386__) || defined(__x86_64__)
+/*
+    See: Intel(R) 64 and IA-32 Architectures Software Developer's Manual V2
+         PAUSE-Spin Loop Hint, 4-57
+         http://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-instruction-set-reference-manual-325383.html?wapkw=instruction+set+reference
+*/
+#   define IPC_LOCK_PAUSE_() __asm__ __volatile__("pause")
+#elif defined(__ia64__) || defined(__ia64)
+/*
+    See: Intel(R) Itanium(R) Architecture Developer's Manual, Vol.3
+         hint - Performance Hint, 3:145
+         http://www.intel.com/content/www/us/en/processors/itanium/itanium-architecture-vol-3-manual.html
+*/
+#   define IPC_LOCK_PAUSE_() __asm__ __volatile__ ("hint @pause")
+#elif defined(__arm__)
+/*
+    See: ARM Architecture Reference Manuals (YIELD)
+         http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.subset.architecture.reference/index.html
+*/
+#   define IPC_LOCK_PAUSE_() __asm__ __volatile__ ("yield")
+#endif
+#endif/*compilers*/
+
+#if !defined(IPC_LOCK_PAUSE_)
+/*
+    Just use a compiler fence, prevent compiler from optimizing loop
+*/
+#   define IPC_LOCK_PAUSE_() std::atomic_signal_fence(std::memory_order_seq_cst)
+#endif/*!defined(IPC_LOCK_PAUSE_)*/
+
+////////////////////////////////////////////////////////////////
+/// Yield to other threads
+////////////////////////////////////////////////////////////////
+
+namespace ipc {
+
+template <typename K>
+inline void yield(K& k) noexcept {
+    if (k < 4)  { /* Do nothing */ }
+    else
+    if (k < 16) { IPC_LOCK_PAUSE_(); }
+    else
+    if (k < 32) { std::this_thread::yield(); }
+    else {
+        std::this_thread::sleep_for(std::chrono::milliseconds(1));
+        return;
+    }
+    ++k;
+}
+
+template <std::size_t N = 32, typename K, typename F>
+inline void sleep(K& k, F&& f) {
+    if (k < static_cast<K>(N)) {
+        std::this_thread::yield();
+    }
+    else {
+        static_cast<void>(std::forward<F>(f)());
+        return;
+    }
+    ++k;
+}
+
+template <std::size_t N = 32, typename K>
+inline void sleep(K& k) {
+    sleep<N>(k, [] {
+        std::this_thread::sleep_for(std::chrono::milliseconds(1));
+    });
+}
+
+} // namespace ipc
+
+#pragma pop_macro("IPC_LOCK_PAUSE_")
+
+namespace ipc {
+
+class spin_lock {
+    std::atomic<unsigned> lc_ { 0 };
+
+public:
+    void lock(void) noexcept {
+        for (unsigned k = 0;
+             lc_.exchange(1, std::memory_order_acquire);
+             yield(k)) ;
+    }
+
+    void unlock(void) noexcept {
+        lc_.store(0, std::memory_order_release);
+    }
+};
+
+class rw_lock {
+    using lc_ui_t = unsigned;
+
+    std::atomic<lc_ui_t> lc_ { 0 };
+
+    enum : lc_ui_t {
+        w_mask = (std::numeric_limits<std::make_signed_t<lc_ui_t>>::max)(), // b 0111 1111
+        w_flag = w_mask + 1                                                 // b 1000 0000
+    };
+
+public:
+    rw_lock() = default;
+
+    rw_lock(const rw_lock&) = delete;
+    rw_lock& operator=(const rw_lock&) = delete;
+    rw_lock(rw_lock&&) = delete;
+    rw_lock& operator=(rw_lock&&) = delete;
+
+    void lock() noexcept {
+        for (unsigned k = 0;;) {
+            auto old = lc_.fetch_or(w_flag, std::memory_order_acq_rel);
+            if (!old) return;           // got w-lock
+            if (!(old & w_flag)) break; // other thread having r-lock
+            yield(k);                   // other thread having w-lock
+        }
+        // wait for reading finished
+        for (unsigned k = 0;
+             lc_.load(std::memory_order_acquire) & w_mask;
+             yield(k)) ;
+    }
+
+    void unlock() noexcept {
+        lc_.store(0, std::memory_order_release);
+    }
+
+    void lock_shared() noexcept {
+        auto old = lc_.load(std::memory_order_acquire);
+        for (unsigned k = 0;;) {
+            // if w_flag set, just continue
+            if (old & w_flag) {
+                yield(k);
+                old = lc_.load(std::memory_order_acquire);
+            }
+            // otherwise try cas lc + 1 (set r-lock)
+            else if (lc_.compare_exchange_weak(old, old + 1, std::memory_order_release)) {
+                return;
+            }
+            // set r-lock failed, old has been updated
+        }
+    }
+
+    void unlock_shared() noexcept {
+        lc_.fetch_sub(1, std::memory_order_release);
+    }
+};
+
+} // namespace ipc
diff --git a/include/libipc/semaphore.h b/include/libipc/semaphore.h
new file mode 100644
index 0000000..7f557e2
--- /dev/null
+++ b/include/libipc/semaphore.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#include <cstdint>  // std::uint64_t
+
+#include "libipc/export.h"
+#include "libipc/def.h"
+
+namespace ipc {
+namespace sync {
+
+class IPC_EXPORT semaphore {
+    semaphore(semaphore const &) = delete;
+    semaphore &operator=(semaphore const &) = delete;
+
+public:
+    semaphore();
+    explicit semaphore(char const *name, std::uint32_t count = 0);
+    ~semaphore();
+
+    void const *native() const noexcept;
+    void *native() noexcept;
+
+    bool valid() const noexcept;
+
+    bool open(char const *name, std::uint32_t count = 0) noexcept;
+    void close() noexcept;
+
+    bool wait(std::uint64_t tm = ipc::invalid_value) noexcept;
+    bool post(std::uint32_t count = 1) noexcept;
+
+private:
+    class semaphore_;
+    semaphore_* p_;
+};
+
+} // namespace sync
+} // namespace ipc
diff --git a/include/libipc/shm.h b/include/libipc/shm.h
new file mode 100644
index 0000000..03433ec
--- /dev/null
+++ b/include/libipc/shm.h
@@ -0,0 +1,59 @@
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+
+#include "libipc/export.h"
+
+namespace ipc {
+namespace shm {
+
+using id_t = void*;
+
+enum : unsigned {
+    create = 0x01,
+    open   = 0x02
+};
+
+IPC_EXPORT id_t         acquire(char const * name, std::size_t size, unsigned mode = create | open);
+IPC_EXPORT void *       get_mem(id_t id, std::size_t * size);
+IPC_EXPORT std::int32_t release(id_t id);
+IPC_EXPORT void         remove (id_t id);
+IPC_EXPORT void         remove (char const * name);
+
+IPC_EXPORT std::int32_t get_ref(id_t id);
+IPC_EXPORT void sub_ref(id_t id);
+
+class IPC_EXPORT handle {
+public:
+    handle();
+    handle(char const * name, std::size_t size, unsigned mode = create | open);
+    handle(handle&& rhs);
+
+    ~handle();
+
+    void swap(handle& rhs);
+    handle& operator=(handle rhs);
+
+    bool         valid() const noexcept;
+    std::size_t  size () const noexcept;
+    char const * name () const noexcept;
+
+    std::int32_t ref() const noexcept;
+    void sub_ref() noexcept;
+
+    bool acquire(char const * name, std::size_t size, unsigned mode = create | open);
+    std::int32_t release();
+
+    void* get() const;
+
+    void attach(id_t);
+    id_t detach();
+
+private:
+    class handle_;
+    handle_* p_;
+};
+
+} // namespace shm
+} // namespace ipc
diff --git a/performance.xlsx b/performance.xlsx
new file mode 100644
index 0000000..ac085e1
Binary files /dev/null and b/performance.xlsx differ
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
new file mode 100644
index 0000000..0d16732
--- /dev/null
+++ b/src/CMakeLists.txt
@@ -0,0 +1,81 @@
+project(ipc)
+
+set (PACKAGE_VERSION 1.3.0)
+
+aux_source_directory(${LIBIPC_PROJECT_DIR}/src/libipc SRC_FILES)
+aux_source_directory(${LIBIPC_PROJECT_DIR}/src/libipc/sync SRC_FILES)
+aux_source_directory(${LIBIPC_PROJECT_DIR}/src/libipc/platform SRC_FILES)
+
+file(GLOB HEAD_FILES
+  ${LIBIPC_PROJECT_DIR}/include/libipc/*.h
+  ${LIBIPC_PROJECT_DIR}/src/libipc/*.h
+  ${LIBIPC_PROJECT_DIR}/src/libipc/*.inc
+  ${LIBIPC_PROJECT_DIR}/src/libipc/circ/*.h
+  ${LIBIPC_PROJECT_DIR}/src/libipc/memory/*.h
+  ${LIBIPC_PROJECT_DIR}/src/libipc/platform/*.h
+  ${LIBIPC_PROJECT_DIR}/src/libipc/utility/*.h)
+
+if (LIBIPC_BUILD_SHARED_LIBS)
+  add_library(${PROJECT_NAME} SHARED ${SRC_FILES} ${HEAD_FILES})
+  target_compile_definitions(${PROJECT_NAME}
+    INTERFACE
+      LIBIPC_LIBRARY_SHARED_USING__
+    PRIVATE
+      LIBIPC_LIBRARY_SHARED_BUILDING__)
+else()
+  add_library(${PROJECT_NAME} STATIC ${SRC_FILES} ${HEAD_FILES})
+endif()
+
+# set output directory
+set_target_properties(${PROJECT_NAME}
+	PROPERTIES
+	ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+	LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
+	RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin")
+
+# set version
+set_target_properties(${PROJECT_NAME}
+    PROPERTIES
+    VERSION ${PACKAGE_VERSION}
+    SOVERSION 3)
+
+target_include_directories(${PROJECT_NAME}
+  PUBLIC  
+    "$<BUILD_INTERFACE:${LIBIPC_PROJECT_DIR}/include>"
+    "$<INSTALL_INTERFACE:include>"
+  PRIVATE ${LIBIPC_PROJECT_DIR}/src
+          $<$<BOOL:UNIX>:${LIBIPC_PROJECT_DIR}/src/libipc/platform/linux>)
+
+if(NOT MSVC)
+  target_link_libraries(${PROJECT_NAME} PUBLIC
+    $<$<NOT:$<STREQUAL:${CMAKE_SYSTEM_NAME},QNX>>:pthread>
+    $<$<NOT:$<OR:$<STREQUAL:${CMAKE_SYSTEM_NAME},Windows>,$<STREQUAL:${CMAKE_SYSTEM_NAME},QNX>>>:rt>)
+endif()
+
+install(
+  TARGETS ${PROJECT_NAME}
+  EXPORT cpp-ipc-targets
+  RUNTIME DESTINATION bin
+  LIBRARY DESTINATION lib
+  ARCHIVE DESTINATION lib)
+
+install(EXPORT cpp-ipc-targets
+	FILE cpp-ipc-targets.cmake
+	NAMESPACE cpp-ipc::
+	DESTINATION share/cpp-ipc
+)
+
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/cpp-ipc-config.cmake.in"
+[[include(CMakeFindDependencyMacro)
+include("${CMAKE_CURRENT_LIST_DIR}/cpp-ipc-targets.cmake")
+]])
+configure_file("${CMAKE_CURRENT_BINARY_DIR}/cpp-ipc-config.cmake.in" "${CMAKE_CURRENT_BINARY_DIR}/cpp-ipc-config.cmake" @ONLY)
+install(FILES ${CMAKE_CURRENT_BINARY_DIR}/cpp-ipc-config.cmake DESTINATION share/cpp-ipc)
+
+include(CMakePackageConfigHelpers)
+write_basic_package_version_file(
+	cppIpcConfigVersion.cmake
+	VERSION ${PACKAGE_VERSION}
+	COMPATIBILITY AnyNewerVersion
+)
+install(FILES ${CMAKE_CURRENT_BINARY_DIR}/cppIpcConfigVersion.cmake DESTINATION share/cpp-ipc)
\ No newline at end of file
diff --git a/src/libipc/buffer.cpp b/src/libipc/buffer.cpp
new file mode 100644
index 0000000..0ac0fa7
--- /dev/null
+++ b/src/libipc/buffer.cpp
@@ -0,0 +1,87 @@
+#include "libipc/buffer.h"
+#include "libipc/utility/pimpl.h"
+
+#include <cstring>
+
+namespace ipc {
+
+bool operator==(buffer const & b1, buffer const & b2) {
+    return (b1.size() == b2.size()) && (std::memcmp(b1.data(), b2.data(), b1.size()) == 0);
+}
+
+bool operator!=(buffer const & b1, buffer const & b2) {
+    return !(b1 == b2);
+}
+
+class buffer::buffer_ : public pimpl<buffer_> {
+public:
+    void*       p_;
+    std::size_t s_;
+    void*       a_;
+    buffer::destructor_t d_;
+
+    buffer_(void* p, std::size_t s, buffer::destructor_t d, void* a)
+        : p_(p), s_(s), a_(a), d_(d) {
+    }
+
+    ~buffer_() {
+        if (d_ == nullptr) return;
+        d_((a_ == nullptr) ? p_ : a_, s_);
+    }
+};
+
+buffer::buffer()
+    : buffer(nullptr, 0, nullptr, nullptr) {
+}
+
+buffer::buffer(void* p, std::size_t s, destructor_t d)
+    : p_(p_->make(p, s, d, nullptr)) {
+}
+
+buffer::buffer(void* p, std::size_t s, destructor_t d, void* additional)
+    : p_(p_->make(p, s, d, additional)) {
+}
+
+buffer::buffer(void* p, std::size_t s)
+    : buffer(p, s, nullptr) {
+}
+
+buffer::buffer(char const & c)
+    : buffer(const_cast<char*>(&c), 1) {
+}
+
+buffer::buffer(buffer&& rhs)
+    : buffer() {
+    swap(rhs);
+}
+
+buffer::~buffer() {
+    p_->clear();
+}
+
+void buffer::swap(buffer& rhs) {
+    std::swap(p_, rhs.p_);
+}
+
+buffer& buffer::operator=(buffer rhs) {
+    swap(rhs);
+    return *this;
+}
+
+bool buffer::empty() const noexcept {
+    return (impl(p_)->p_ == nullptr) || (impl(p_)->s_ == 0);
+}
+
+void* buffer::data() noexcept {
+    return impl(p_)->p_;
+}
+
+void const * buffer::data() const noexcept {
+    return impl(p_)->p_;
+}
+
+std::size_t buffer::size() const noexcept {
+    return impl(p_)->s_;
+}
+
+} // namespace ipc
diff --git a/src/libipc/circ/elem_array.h b/src/libipc/circ/elem_array.h
new file mode 100644
index 0000000..0759613
--- /dev/null
+++ b/src/libipc/circ/elem_array.h
@@ -0,0 +1,141 @@
+#pragma once
+
+#include <atomic>   // std::atomic<?>
+#include <limits>
+#include <utility>
+#include <type_traits>
+
+#include "libipc/def.h"
+#include "libipc/rw_lock.h"
+
+#include "libipc/circ/elem_def.h"
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+namespace circ {
+
+template <typename Policy,
+          std::size_t DataSize,
+          std::size_t AlignSize = (ipc::detail::min)(DataSize, alignof(std::max_align_t))>
+class elem_array : public ipc::circ::conn_head<Policy> {
+public:
+    using base_t   = ipc::circ::conn_head<Policy>;
+    using policy_t = Policy;
+    using cursor_t = decltype(std::declval<policy_t>().cursor());
+    using elem_t   = typename policy_t::template elem_t<DataSize, AlignSize>;
+
+    enum : std::size_t {
+        head_size  = sizeof(base_t) + sizeof(policy_t),
+        data_size  = DataSize,
+        elem_max   = (std::numeric_limits<uint_t<8>>::max)() + 1, // default is 255 + 1
+        elem_size  = sizeof(elem_t),
+        block_size = elem_size * elem_max
+    };
+
+private:
+    policy_t head_;
+    elem_t   block_[elem_max] {};
+
+    /**
+     * \remarks 'warning C4348: redefinition of default parameter' with MSVC.
+     * \see
+     *  - https://stackoverflow.com/questions/12656239/redefinition-of-default-template-parameter
+     *  - https://developercommunity.visualstudio.com/content/problem/425978/incorrect-c4348-warning-in-nested-template-declara.html
+    */
+    template <typename P, bool/* = relat_trait<P>::is_multi_producer*/>
+    struct sender_checker;
+
+    template <typename P>
+    struct sender_checker<P, true> {
+        constexpr static bool connect() noexcept {
+            // always return true
+            return true;
+        }
+        constexpr static void disconnect() noexcept {}
+    };
+
+    template <typename P>
+    struct sender_checker<P, false> {
+        bool connect() noexcept {
+            return !flag_.test_and_set(std::memory_order_acq_rel);
+        }
+        void disconnect() noexcept {
+            flag_.clear();
+        }
+
+    private:
+        // in shm, it should be 0 whether it's initialized or not.
+        std::atomic_flag flag_ = ATOMIC_FLAG_INIT;
+    };
+
+    template <typename P, bool/* = relat_trait<P>::is_multi_consumer*/>
+    struct receiver_checker;
+
+    template <typename P>
+    struct receiver_checker<P, true> {
+        constexpr static cc_t connect(base_t &conn) noexcept {
+            return conn.connect();
+        }
+        constexpr static cc_t disconnect(base_t &conn, cc_t cc_id) noexcept {
+            return conn.disconnect(cc_id);
+        }
+    };
+
+    template <typename P>
+    struct receiver_checker<P, false> : protected sender_checker<P, false> {
+        cc_t connect(base_t &conn) noexcept {
+            return sender_checker<P, false>::connect() ? conn.connect() : 0;
+        }
+        cc_t disconnect(base_t &conn, cc_t cc_id) noexcept {
+            sender_checker<P, false>::disconnect();
+            return conn.disconnect(cc_id);
+        }
+    };
+
+    sender_checker  <policy_t, relat_trait<policy_t>::is_multi_producer> s_ckr_;
+    receiver_checker<policy_t, relat_trait<policy_t>::is_multi_consumer> r_ckr_;
+
+    // make these be private
+    using base_t::connect;
+    using base_t::disconnect;
+
+public:
+    bool connect_sender() noexcept {
+        return s_ckr_.connect();
+    }
+
+    void disconnect_sender() noexcept {
+        return s_ckr_.disconnect();
+    }
+
+    cc_t connect_receiver() noexcept {
+        return r_ckr_.connect(*this);
+    }
+
+    cc_t disconnect_receiver(cc_t cc_id) noexcept {
+        return r_ckr_.disconnect(*this, cc_id);
+    }
+
+    cursor_t cursor() const noexcept {
+        return head_.cursor();
+    }
+
+    template <typename Q, typename F>
+    bool push(Q* que, F&& f) {
+        return head_.push(que, std::forward<F>(f), block_);
+    }
+
+    template <typename Q, typename F>
+    bool force_push(Q* que, F&& f) {
+        return head_.force_push(que, std::forward<F>(f), block_);
+    }
+
+    template <typename Q, typename F, typename R>
+    bool pop(Q* que, cursor_t* cur, F&& f, R&& out) {
+        if (cur == nullptr) return false;
+        return head_.pop(que, *cur, std::forward<F>(f), std::forward<R>(out), block_);
+    }
+};
+
+} // namespace circ
+} // namespace ipc
diff --git a/src/libipc/circ/elem_def.h b/src/libipc/circ/elem_def.h
new file mode 100644
index 0000000..4fd5797
--- /dev/null
+++ b/src/libipc/circ/elem_def.h
@@ -0,0 +1,109 @@
+#pragma once
+
+#include <atomic>
+#include <cstddef>
+#include <cstdint>
+#include <new>
+
+#include "libipc/def.h"
+#include "libipc/rw_lock.h"
+
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+namespace circ {
+
+using u1_t = ipc::uint_t<8>;
+using u2_t = ipc::uint_t<32>;
+
+/** only supports max 32 connections in broadcast mode */
+using cc_t = u2_t;
+
+constexpr u1_t index_of(u2_t c) noexcept {
+    return static_cast<u1_t>(c);
+}
+
+class conn_head_base {
+protected:
+    std::atomic<cc_t> cc_{0}; // connections
+    ipc::spin_lock lc_;
+    std::atomic<bool> constructed_{false};
+
+public:
+    void init() {
+        /* DCLP */
+        if (!constructed_.load(std::memory_order_acquire)) {
+            IPC_UNUSED_ auto guard = ipc::detail::unique_lock(lc_);
+            if (!constructed_.load(std::memory_order_relaxed)) {
+                ::new (this) conn_head_base;
+                constructed_.store(true, std::memory_order_release);
+            }
+        }
+    }
+
+    conn_head_base() = default;
+    conn_head_base(conn_head_base const &) = delete;
+    conn_head_base &operator=(conn_head_base const &) = delete;
+
+    cc_t connections(std::memory_order order = std::memory_order_acquire) const noexcept {
+        return this->cc_.load(order);
+    }
+};
+
+template <typename P, bool = relat_trait<P>::is_broadcast>
+class conn_head;
+
+template <typename P>
+class conn_head<P, true> : public conn_head_base {
+public:
+    cc_t connect() noexcept {
+        for (unsigned k = 0;; ipc::yield(k)) {
+            cc_t curr = this->cc_.load(std::memory_order_acquire);
+            cc_t next = curr | (curr + 1); // find the first 0, and set it to 1.
+            if (next == 0) {
+                // connection-slot is full.
+                return 0;
+            }
+            if (this->cc_.compare_exchange_weak(curr, next, std::memory_order_release)) {
+                return next ^ curr; // return connected id
+            }
+        }
+    }
+
+    cc_t disconnect(cc_t cc_id) noexcept {
+        return this->cc_.fetch_and(~cc_id, std::memory_order_acq_rel) & ~cc_id;
+    }
+
+    std::size_t conn_count(std::memory_order order = std::memory_order_acquire) const noexcept {
+        cc_t cur = this->cc_.load(order);
+        cc_t cnt; // accumulates the total bits set in cc
+        for (cnt = 0; cur; ++cnt) cur &= cur - 1;
+        return cnt;
+    }
+};
+
+template <typename P>
+class conn_head<P, false> : public conn_head_base {
+public:
+    cc_t connect() noexcept {
+        return this->cc_.fetch_add(1, std::memory_order_relaxed) + 1;
+    }
+
+    cc_t disconnect(cc_t cc_id) noexcept {
+        if (cc_id == ~static_cast<circ::cc_t>(0u)) {
+            // clear all connections
+            this->cc_.store(0, std::memory_order_relaxed);
+            return 0u;
+        }
+        else {
+            return this->cc_.fetch_sub(1, std::memory_order_relaxed) - 1;
+        }
+    }
+
+    std::size_t conn_count(std::memory_order order = std::memory_order_acquire) const noexcept {
+        return this->connections(order);
+    }
+};
+
+} // namespace circ
+} // namespace ipc
diff --git a/src/libipc/ipc.cpp b/src/libipc/ipc.cpp
new file mode 100644
index 0000000..5b086fb
--- /dev/null
+++ b/src/libipc/ipc.cpp
@@ -0,0 +1,778 @@
+
+#include <type_traits>
+#include <cstring>
+#include <algorithm>
+#include <utility>          // std::pair, std::move, std::forward
+#include <atomic>
+#include <type_traits>      // aligned_storage_t
+#include <string>
+#include <vector>
+#include <array>
+#include <cassert>
+#include <mutex>
+
+#include "libipc/ipc.h"
+#include "libipc/def.h"
+#include "libipc/shm.h"
+#include "libipc/pool_alloc.h"
+#include "libipc/queue.h"
+#include "libipc/policy.h"
+#include "libipc/rw_lock.h"
+#include "libipc/waiter.h"
+
+#include "libipc/utility/log.h"
+#include "libipc/utility/id_pool.h"
+#include "libipc/utility/scope_guard.h"
+#include "libipc/utility/utility.h"
+
+#include "libipc/memory/resource.h"
+#include "libipc/platform/detail.h"
+#include "libipc/circ/elem_array.h"
+
+namespace {
+
+using msg_id_t = std::uint32_t;
+using acc_t    = std::atomic<msg_id_t>;
+
+template <std::size_t DataSize, std::size_t AlignSize>
+struct msg_t;
+
+template <std::size_t AlignSize>
+struct msg_t<0, AlignSize> {
+    msg_id_t     cc_id_;
+    msg_id_t     id_;
+    std::int32_t remain_;
+    bool         storage_;
+};
+
+template <std::size_t DataSize, std::size_t AlignSize>
+struct msg_t : msg_t<0, AlignSize> {
+    std::aligned_storage_t<DataSize, AlignSize> data_ {};
+
+    msg_t() = default;
+    msg_t(msg_id_t cc_id, msg_id_t id, std::int32_t remain, void const * data, std::size_t size)
+        : msg_t<0, AlignSize> {cc_id, id, remain, (data == nullptr) || (size == 0)} {
+        if (this->storage_) {
+            if (data != nullptr) {
+                // copy storage-id
+                *reinterpret_cast<ipc::storage_id_t*>(&data_) =
+                     *static_cast<ipc::storage_id_t const *>(data);
+            }
+        }
+        else std::memcpy(&data_, data, size);
+    }
+};
+
+template <typename T>
+ipc::buff_t make_cache(T& data, std::size_t size) {
+    auto ptr = ipc::mem::alloc(size);
+    std::memcpy(ptr, &data, (ipc::detail::min)(sizeof(data), size));
+    return { ptr, size, ipc::mem::free };
+}
+
+acc_t *cc_acc(ipc::string const &pref) {
+    static ipc::unordered_map<ipc::string, ipc::shm::handle> handles;
+    static std::mutex lock;
+    std::lock_guard<std::mutex> guard {lock};
+    auto it = handles.find(pref);
+    if (it == handles.end()) {
+        ipc::string shm_name {ipc::make_prefix(pref, {"CA_CONN__"})};
+        ipc::shm::handle h;
+        if (!h.acquire(shm_name.c_str(), sizeof(acc_t))) {
+            ipc::error("[cc_acc] acquire failed: %s\n", shm_name.c_str());
+            return nullptr;
+        }
+        it = handles.emplace(pref, std::move(h)).first;
+    }
+    return static_cast<acc_t *>(it->second.get());
+}
+
+struct cache_t {
+    std::size_t fill_;
+    ipc::buff_t buff_;
+
+    cache_t(std::size_t f, ipc::buff_t && b)
+        : fill_(f), buff_(std::move(b))
+    {}
+
+    void append(void const * data, std::size_t size) {
+        if (fill_ >= buff_.size() || data == nullptr || size == 0) return;
+        auto new_fill = (ipc::detail::min)(fill_ + size, buff_.size());
+        std::memcpy(static_cast<ipc::byte_t*>(buff_.data()) + fill_, data, new_fill - fill_);
+        fill_ = new_fill;
+    }
+};
+
+struct conn_info_head {
+
+    ipc::string prefix_;
+    ipc::string name_;
+    msg_id_t    cc_id_; // connection-info id
+    ipc::detail::waiter cc_waiter_, wt_waiter_, rd_waiter_;
+    ipc::shm::handle acc_h_;
+
+    conn_info_head(char const * prefix, char const * name)
+        : prefix_{ipc::make_string(prefix)}
+        , name_  {ipc::make_string(name)}
+        , cc_id_ {} {}
+
+    void init() {
+        if (!cc_waiter_.valid()) cc_waiter_.open(ipc::make_prefix(prefix_, {"CC_CONN__", name_}).c_str());
+        if (!wt_waiter_.valid()) wt_waiter_.open(ipc::make_prefix(prefix_, {"WT_CONN__", name_}).c_str());
+        if (!rd_waiter_.valid()) rd_waiter_.open(ipc::make_prefix(prefix_, {"RD_CONN__", name_}).c_str());
+        if (!acc_h_.valid()) acc_h_.acquire(ipc::make_prefix(prefix_, {"AC_CONN__", name_}).c_str(), sizeof(acc_t));
+        if (cc_id_ != 0) {
+            return;
+        }
+        acc_t *pacc = cc_acc(prefix_);
+        if (pacc == nullptr) {
+            // Failed to obtain the global accumulator.
+            return;
+        }
+        cc_id_ = pacc->fetch_add(1, std::memory_order_relaxed) + 1;
+        if (cc_id_ == 0) {
+            // The identity cannot be 0.
+            cc_id_ = pacc->fetch_add(1, std::memory_order_relaxed) + 1;
+        }
+    }
+
+    void quit_waiting() {
+        cc_waiter_.quit_waiting();
+        wt_waiter_.quit_waiting();
+        rd_waiter_.quit_waiting();
+    }
+
+    auto acc() {
+        return static_cast<acc_t*>(acc_h_.get());
+    }
+
+    auto& recv_cache() {
+        thread_local ipc::unordered_map<msg_id_t, cache_t> tls;
+        return tls;
+    }
+};
+
+IPC_CONSTEXPR_ std::size_t align_chunk_size(std::size_t size) noexcept {
+    return (((size - 1) / ipc::large_msg_align) + 1) * ipc::large_msg_align;
+}
+
+IPC_CONSTEXPR_ std::size_t calc_chunk_size(std::size_t size) noexcept {
+    return ipc::make_align(alignof(std::max_align_t), align_chunk_size(
+           ipc::make_align(alignof(std::max_align_t), sizeof(std::atomic<ipc::circ::cc_t>)) + size));
+}
+
+struct chunk_t {
+    std::atomic<ipc::circ::cc_t> &conns() noexcept {
+        return *reinterpret_cast<std::atomic<ipc::circ::cc_t> *>(this);
+    }
+
+    void *data() noexcept {
+        return reinterpret_cast<ipc::byte_t *>(this)
+             + ipc::make_align(alignof(std::max_align_t), sizeof(std::atomic<ipc::circ::cc_t>));
+    }
+};
+
+struct chunk_info_t {
+    ipc::id_pool<> pool_;
+    ipc::spin_lock lock_;
+
+    IPC_CONSTEXPR_ static std::size_t chunks_mem_size(std::size_t chunk_size) noexcept {
+        return ipc::id_pool<>::max_count * chunk_size;
+    }
+
+    ipc::byte_t *chunks_mem() noexcept {
+        return reinterpret_cast<ipc::byte_t *>(this + 1);
+    }
+
+    chunk_t *at(std::size_t chunk_size, ipc::storage_id_t id) noexcept {
+        if (id < 0) return nullptr;
+        return reinterpret_cast<chunk_t *>(chunks_mem() + (chunk_size * id));
+    }
+};
+
+auto& chunk_storages() {
+    class chunk_handle_t {
+        ipc::unordered_map<ipc::string, ipc::shm::handle> handles_;
+        std::mutex lock_;
+
+        static bool make_handle(ipc::shm::handle &h, ipc::string const &shm_name, std::size_t chunk_size) {
+            if (!h.valid() &&
+                !h.acquire( shm_name.c_str(), 
+                            sizeof(chunk_info_t) + chunk_info_t::chunks_mem_size(chunk_size) )) {
+                ipc::error("[chunk_storages] chunk_shm.id_info_.acquire failed: chunk_size = %zd\n", chunk_size);
+                return false;
+            }
+            return true;
+        }
+
+    public:
+        chunk_info_t *get_info(conn_info_head *inf, std::size_t chunk_size) {
+            ipc::string pref {(inf == nullptr) ? ipc::string{} : inf->prefix_};
+            ipc::string shm_name {ipc::make_prefix(pref, {"CHUNK_INFO__", ipc::to_string(chunk_size)})};
+            ipc::shm::handle *h;
+            {
+                std::lock_guard<std::mutex> guard {lock_};
+                h = &(handles_[pref]);
+                if (!make_handle(*h, shm_name, chunk_size)) {
+                    return nullptr;
+                }
+            }
+            auto *info = static_cast<chunk_info_t*>(h->get());
+            if (info == nullptr) {
+                ipc::error("[chunk_storages] chunk_shm.id_info_.get failed: chunk_size = %zd\n", chunk_size);
+                return nullptr;
+            }
+            return info;
+        }
+    };
+    using deleter_t = void (*)(chunk_handle_t*);
+    using chunk_handle_ptr_t = std::unique_ptr<chunk_handle_t, deleter_t>;
+    static ipc::map<std::size_t, chunk_handle_ptr_t> chunk_hs;
+    return chunk_hs;
+}
+
+chunk_info_t *chunk_storage_info(conn_info_head *inf, std::size_t chunk_size) {
+    auto &storages = chunk_storages();
+    std::decay_t<decltype(storages)>::iterator it;
+    {
+        static ipc::rw_lock lock;
+        IPC_UNUSED_ std::shared_lock<ipc::rw_lock> guard {lock};
+        if ((it = storages.find(chunk_size)) == storages.end()) {
+            using chunk_handle_ptr_t = std::decay_t<decltype(storages)>::value_type::second_type;
+            using chunk_handle_t     = chunk_handle_ptr_t::element_type;
+            guard.unlock();
+            IPC_UNUSED_ std::lock_guard<ipc::rw_lock> guard {lock};
+            it = storages.emplace(chunk_size, chunk_handle_ptr_t{
+                ipc::mem::alloc<chunk_handle_t>(), [](chunk_handle_t *p) {
+                    ipc::mem::destruct(p);
+                }}).first;
+        }
+    }
+    return it->second->get_info(inf, chunk_size);
+}
+
+std::pair<ipc::storage_id_t, void*> acquire_storage(conn_info_head *inf, std::size_t size, ipc::circ::cc_t conns) {
+    std::size_t chunk_size = calc_chunk_size(size);
+    auto info = chunk_storage_info(inf, chunk_size);
+    if (info == nullptr) return {};
+
+    info->lock_.lock();
+    info->pool_.prepare();
+    // got an unique id
+    auto id = info->pool_.acquire();
+    info->lock_.unlock();
+
+    auto chunk = info->at(chunk_size, id);
+    if (chunk == nullptr) return {};
+    chunk->conns().store(conns, std::memory_order_relaxed);
+    return { id, chunk->data() };
+}
+
+void *find_storage(ipc::storage_id_t id, conn_info_head *inf, std::size_t size) {
+    if (id < 0) {
+        ipc::error("[find_storage] id is invalid: id = %ld, size = %zd\n", (long)id, size);
+        return nullptr;
+    }
+    std::size_t chunk_size = calc_chunk_size(size);
+    auto info = chunk_storage_info(inf, chunk_size);
+    if (info == nullptr) return nullptr;
+    return info->at(chunk_size, id)->data();
+}
+
+void release_storage(ipc::storage_id_t id, conn_info_head *inf, std::size_t size) {
+    if (id < 0) {
+        ipc::error("[release_storage] id is invalid: id = %ld, size = %zd\n", (long)id, size);
+        return;
+    }
+    std::size_t chunk_size = calc_chunk_size(size);
+    auto info = chunk_storage_info(inf, chunk_size);
+    if (info == nullptr) return;
+    info->lock_.lock();
+    info->pool_.release(id);
+    info->lock_.unlock();
+}
+
+template <ipc::relat Rp, ipc::relat Rc>
+bool sub_rc(ipc::wr<Rp, Rc, ipc::trans::unicast>, 
+            std::atomic<ipc::circ::cc_t> &/*conns*/, ipc::circ::cc_t /*curr_conns*/, ipc::circ::cc_t /*conn_id*/) noexcept {
+    return true;
+}
+
+template <ipc::relat Rp, ipc::relat Rc>
+bool sub_rc(ipc::wr<Rp, Rc, ipc::trans::broadcast>, 
+            std::atomic<ipc::circ::cc_t> &conns, ipc::circ::cc_t curr_conns, ipc::circ::cc_t conn_id) noexcept {
+    auto last_conns = curr_conns & ~conn_id;
+    for (unsigned k = 0;;) {
+        auto chunk_conns  = conns.load(std::memory_order_acquire);
+        if (conns.compare_exchange_weak(chunk_conns, chunk_conns & last_conns, std::memory_order_release)) {
+            return (chunk_conns & last_conns) == 0;
+        }
+        ipc::yield(k);
+    }
+}
+
+template <typename Flag>
+void recycle_storage(ipc::storage_id_t id, conn_info_head *inf, std::size_t size, ipc::circ::cc_t curr_conns, ipc::circ::cc_t conn_id) {
+    if (id < 0) {
+        ipc::error("[recycle_storage] id is invalid: id = %ld, size = %zd\n", (long)id, size);
+        return;
+    }
+    std::size_t chunk_size = calc_chunk_size(size);
+    auto info = chunk_storage_info(inf, chunk_size);
+    if (info == nullptr) return;
+
+    auto chunk = info->at(chunk_size, id);
+    if (chunk == nullptr) return;
+
+    if (!sub_rc(Flag{}, chunk->conns(), curr_conns, conn_id)) {
+        return;
+    }
+    info->lock_.lock();
+    info->pool_.release(id);
+    info->lock_.unlock();
+}
+
+template <typename MsgT>
+bool clear_message(conn_info_head *inf, void* p) {
+    auto msg = static_cast<MsgT*>(p);
+    if (msg->storage_) {
+        std::int32_t r_size = static_cast<std::int32_t>(ipc::data_length) + msg->remain_;
+        if (r_size <= 0) {
+            ipc::error("[clear_message] invalid msg size: %d\n", (int)r_size);
+            return true;
+        }
+        release_storage(*reinterpret_cast<ipc::storage_id_t*>(&msg->data_),
+                        inf, static_cast<std::size_t>(r_size));
+    }
+    return true;
+}
+
+template <typename W, typename F>
+bool wait_for(W& waiter, F&& pred, std::uint64_t tm) {
+    if (tm == 0) return !pred();
+    for (unsigned k = 0; pred();) {
+        bool ret = true;
+        ipc::sleep(k, [&k, &ret, &waiter, &pred, tm] {
+            ret = waiter.wait_if(std::forward<F>(pred), tm);
+            k   = 0;
+        });
+        if (!ret) return false; // timeout or fail
+        if (k == 0) break; // k has been reset
+    }
+    return true;
+}
+
+template <typename Policy,
+          std::size_t DataSize  = ipc::data_length,
+          std::size_t AlignSize = (ipc::detail::min)(DataSize, alignof(std::max_align_t))>
+struct queue_generator {
+
+    using queue_t = ipc::queue<msg_t<DataSize, AlignSize>, Policy>;
+
+    struct conn_info_t : conn_info_head {
+        queue_t que_;
+
+        conn_info_t(char const * pref, char const * name)
+            : conn_info_head{pref, name} { init(); }
+
+        void init() {
+            conn_info_head::init();
+            if (!que_.valid()) {
+                que_.open(ipc::make_prefix(prefix_, {
+                          "QU_CONN__",
+                          ipc::to_string(DataSize), "__",
+                          ipc::to_string(AlignSize), "__", 
+                          this->name_}).c_str());
+            }
+        }
+
+        void disconnect_receiver() {
+            bool dis = que_.disconnect();
+            this->quit_waiting();
+            if (dis) {
+                this->recv_cache().clear();
+            }
+        }
+    };
+};
+
+template <typename Policy>
+struct detail_impl {
+
+using policy_t    = Policy;
+using flag_t      = typename policy_t::flag_t;
+using queue_t     = typename queue_generator<policy_t>::queue_t;
+using conn_info_t = typename queue_generator<policy_t>::conn_info_t;
+
+constexpr static conn_info_t* info_of(ipc::handle_t h) noexcept {
+    return static_cast<conn_info_t*>(h);
+}
+
+constexpr static queue_t* queue_of(ipc::handle_t h) noexcept {
+    return (info_of(h) == nullptr) ? nullptr : &(info_of(h)->que_);
+}
+
+/* API implementations */
+
+static bool connect(ipc::handle_t * ph, ipc::prefix pref, char const * name, bool start_to_recv) {
+    assert(ph != nullptr);
+    if (*ph == nullptr) {
+        *ph = ipc::mem::alloc<conn_info_t>(pref.str, name);
+    }
+    return reconnect(ph, start_to_recv);
+}
+
+static bool connect(ipc::handle_t * ph, char const * name, bool start_to_recv) {
+    return connect(ph, {nullptr}, name, start_to_recv);
+}
+
+static void disconnect(ipc::handle_t h) {
+    auto que = queue_of(h);
+    if (que == nullptr) {
+        return;
+    }
+    que->shut_sending();
+    assert(info_of(h) != nullptr);
+    info_of(h)->disconnect_receiver();
+}
+
+static bool reconnect(ipc::handle_t * ph, bool start_to_recv) {
+    assert(ph != nullptr);
+    assert(*ph != nullptr);
+    auto que = queue_of(*ph);
+    if (que == nullptr) {
+        return false;
+    }
+    info_of(*ph)->init();
+    if (start_to_recv) {
+        que->shut_sending();
+        if (que->connect()) { // wouldn't connect twice
+            info_of(*ph)->cc_waiter_.broadcast();
+            return true;
+        }
+        return false;
+    }
+    // start_to_recv == false
+    if (que->connected()) {
+        info_of(*ph)->disconnect_receiver();
+    }
+    return que->ready_sending();
+}
+
+static void destroy(ipc::handle_t h) {
+    disconnect(h);
+    ipc::mem::free(info_of(h));
+}
+
+static std::size_t recv_count(ipc::handle_t h) noexcept {
+    auto que = queue_of(h);
+    if (que == nullptr) {
+        return ipc::invalid_value;
+    }
+    return que->conn_count();
+}
+
+static bool wait_for_recv(ipc::handle_t h, std::size_t r_count, std::uint64_t tm) {
+    auto que = queue_of(h);
+    if (que == nullptr) {
+        return false;
+    }
+    return wait_for(info_of(h)->cc_waiter_, [que, r_count] {
+        return que->conn_count() < r_count;
+    }, tm);
+}
+
+template <typename F>
+static bool send(F&& gen_push, ipc::handle_t h, void const * data, std::size_t size) {
+    if (data == nullptr || size == 0) {
+        ipc::error("fail: send(%p, %zd)\n", data, size);
+        return false;
+    }
+    auto que = queue_of(h);
+    if (que == nullptr) {
+        ipc::error("fail: send, queue_of(h) == nullptr\n");
+        return false;
+    }
+    if (que->elems() == nullptr) {
+        ipc::error("fail: send, queue_of(h)->elems() == nullptr\n");
+        return false;
+    }
+    if (!que->ready_sending()) {
+        ipc::error("fail: send, que->ready_sending() == false\n");
+        return false;
+    }
+    ipc::circ::cc_t conns = que->elems()->connections(std::memory_order_relaxed);
+    if (conns == 0) {
+        ipc::error("fail: send, there is no receiver on this connection.\n");
+        return false;
+    }
+    // calc a new message id
+    conn_info_t *inf = info_of(h);
+    auto acc = inf->acc();
+    if (acc == nullptr) {
+        ipc::error("fail: send, info_of(h)->acc() == nullptr\n");
+        return false;
+    }
+    auto msg_id   = acc->fetch_add(1, std::memory_order_relaxed);
+    auto try_push = std::forward<F>(gen_push)(inf, que, msg_id);
+    if (size > ipc::large_msg_limit) {
+        auto   dat = acquire_storage(inf, size, conns);
+        void * buf = dat.second;
+        if (buf != nullptr) {
+            std::memcpy(buf, data, size);
+            return try_push(static_cast<std::int32_t>(size) - 
+                            static_cast<std::int32_t>(ipc::data_length), &(dat.first), 0);
+        }
+        // try using message fragment
+        //ipc::log("fail: shm::handle for big message. msg_id: %zd, size: %zd\n", msg_id, size);
+    }
+    // push message fragment
+    std::int32_t offset = 0;
+    for (std::int32_t i = 0; i < static_cast<std::int32_t>(size / ipc::data_length); ++i, offset += ipc::data_length) {
+        if (!try_push(static_cast<std::int32_t>(size) - offset - static_cast<std::int32_t>(ipc::data_length),
+                      static_cast<ipc::byte_t const *>(data) + offset, ipc::data_length)) {
+            return false;
+        }
+    }
+    // if remain > 0, this is the last message fragment
+    std::int32_t remain = static_cast<std::int32_t>(size) - offset;
+    if (remain > 0) {
+        if (!try_push(remain - static_cast<std::int32_t>(ipc::data_length),
+                      static_cast<ipc::byte_t const *>(data) + offset, 
+                      static_cast<std::size_t>(remain))) {
+            return false;
+        }
+    }
+    return true;
+}
+
+static bool send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm) {
+    return send([tm](auto *info, auto *que, auto msg_id) {
+        return [tm, info, que, msg_id](std::int32_t remain, void const * data, std::size_t size) {
+            if (!wait_for(info->wt_waiter_, [&] {
+                    return !que->push(
+                        [](void*) { return true; },
+                        info->cc_id_, msg_id, remain, data, size);
+                }, tm)) {
+                ipc::log("force_push: msg_id = %zd, remain = %d, size = %zd\n", msg_id, remain, size);
+                if (!que->force_push(
+                        [info](void* p) { return clear_message<typename queue_t::value_t>(info, p); },
+                        info->cc_id_, msg_id, remain, data, size)) {
+                    return false;
+                }
+            }
+            info->rd_waiter_.broadcast();
+            return true;
+        };
+    }, h, data, size);
+}
+
+static bool try_send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm) {
+    return send([tm](auto *info, auto *que, auto msg_id) {
+        return [tm, info, que, msg_id](std::int32_t remain, void const * data, std::size_t size) {
+            if (!wait_for(info->wt_waiter_, [&] {
+                    return !que->push(
+                        [](void*) { return true; },
+                        info->cc_id_, msg_id, remain, data, size);
+                }, tm)) {
+                return false;
+            }
+            info->rd_waiter_.broadcast();
+            return true;
+        };
+    }, h, data, size);
+}
+
+static ipc::buff_t recv(ipc::handle_t h, std::uint64_t tm) {
+    auto que = queue_of(h);
+    if (que == nullptr) {
+        ipc::error("fail: recv, queue_of(h) == nullptr\n");
+        return {};
+    }
+    if (!que->connected()) {
+        // hasn't connected yet, just return.
+        return {};
+    }
+    conn_info_t *inf = info_of(h);
+    auto& rc = inf->recv_cache();
+    for (;;) {
+        // pop a new message
+        typename queue_t::value_t msg {};
+        if (!wait_for(inf->rd_waiter_, [que, &msg] {
+                return !que->pop(msg);
+            }, tm)) {
+            // pop failed, just return.
+            return {};
+        }
+        inf->wt_waiter_.broadcast();
+        if ((inf->acc() != nullptr) && (msg.cc_id_ == inf->cc_id_)) {
+            continue; // ignore message to self
+        }
+        // msg.remain_ may minus & abs(msg.remain_) < data_length
+        std::int32_t r_size = static_cast<std::int32_t>(ipc::data_length) + msg.remain_;
+        if (r_size <= 0) {
+            ipc::error("fail: recv, r_size = %d\n", (int)r_size);
+            return {};
+        }
+        std::size_t msg_size = static_cast<std::size_t>(r_size);
+        // large message
+        if (msg.storage_) {
+            ipc::storage_id_t buf_id = *reinterpret_cast<ipc::storage_id_t*>(&msg.data_);
+            void* buf = find_storage(buf_id, inf, msg_size);
+            if (buf != nullptr) {
+                struct recycle_t {
+                    ipc::storage_id_t storage_id;
+                    conn_info_t *     inf;
+                    ipc::circ::cc_t   curr_conns;
+                    ipc::circ::cc_t   conn_id;
+                } *r_info = ipc::mem::alloc<recycle_t>(recycle_t{
+                    buf_id, 
+                    inf, 
+                    que->elems()->connections(std::memory_order_relaxed), 
+                    que->connected_id()
+                });
+                if (r_info == nullptr) {
+                    ipc::log("fail: ipc::mem::alloc<recycle_t>.\n");
+                    return ipc::buff_t{buf, msg_size}; // no recycle
+                } else {
+                    return ipc::buff_t{buf, msg_size, [](void* p_info, std::size_t size) {
+                        auto r_info = static_cast<recycle_t *>(p_info);
+                        IPC_UNUSED_ auto finally = ipc::guard([r_info] {
+                            ipc::mem::free(r_info);
+                        });
+                        recycle_storage<flag_t>(r_info->storage_id, 
+                                                r_info->inf, 
+                                                size, 
+                                                r_info->curr_conns, 
+                                                r_info->conn_id);
+                    }, r_info};
+                }
+            } else {
+                ipc::log("fail: shm::handle for large message. msg_id: %zd, buf_id: %zd, size: %zd\n", msg.id_, buf_id, msg_size);
+                continue;
+            }
+        }
+        // find cache with msg.id_
+        auto cac_it = rc.find(msg.id_);
+        if (cac_it == rc.end()) {
+            if (msg_size <= ipc::data_length) {
+                return make_cache(msg.data_, msg_size);
+            }
+            // gc
+            if (rc.size() > 1024) {
+                std::vector<msg_id_t> need_del;
+                for (auto const & pair : rc) {
+                    auto cmp = std::minmax(msg.id_, pair.first);
+                    if (cmp.second - cmp.first > 8192) {
+                        need_del.push_back(pair.first);
+                    }
+                }
+                for (auto id : need_del) rc.erase(id);
+            }
+            // cache the first message fragment
+            rc.emplace(msg.id_, cache_t { ipc::data_length, make_cache(msg.data_, msg_size) });
+        }
+        // has cached before this message
+        else {
+            auto& cac = cac_it->second;
+            // this is the last message fragment
+            if (msg.remain_ <= 0) {
+                cac.append(&(msg.data_), msg_size);
+                // finish this message, erase it from cache
+                auto buff = std::move(cac.buff_);
+                rc.erase(cac_it);
+                return buff;
+            }
+            // there are remain datas after this message
+            cac.append(&(msg.data_), ipc::data_length);
+        }
+    }
+}
+
+static ipc::buff_t try_recv(ipc::handle_t h) {
+    return recv(h, 0);
+}
+
+}; // detail_impl<Policy>
+
+template <typename Flag>
+using policy_t = ipc::policy::choose<ipc::circ::elem_array, Flag>;
+
+} // internal-linkage
+
+namespace ipc {
+
+template <typename Flag>
+ipc::handle_t chan_impl<Flag>::inited() {
+    ipc::detail::waiter::init();
+    return nullptr;
+}
+
+template <typename Flag>
+bool chan_impl<Flag>::connect(ipc::handle_t * ph, char const * name, unsigned mode) {
+    return detail_impl<policy_t<Flag>>::connect(ph, name, mode & receiver);
+}
+
+template <typename Flag>
+bool chan_impl<Flag>::connect(ipc::handle_t * ph, prefix pref, char const * name, unsigned mode) {
+    return detail_impl<policy_t<Flag>>::connect(ph, pref, name, mode & receiver);
+}
+
+template <typename Flag>
+bool chan_impl<Flag>::reconnect(ipc::handle_t * ph, unsigned mode) {
+    return detail_impl<policy_t<Flag>>::reconnect(ph, mode & receiver);
+}
+
+template <typename Flag>
+void chan_impl<Flag>::disconnect(ipc::handle_t h) {
+    detail_impl<policy_t<Flag>>::disconnect(h);
+}
+
+template <typename Flag>
+void chan_impl<Flag>::destroy(ipc::handle_t h) {
+    detail_impl<policy_t<Flag>>::destroy(h);
+}
+
+template <typename Flag>
+char const * chan_impl<Flag>::name(ipc::handle_t h) {
+    auto *info = detail_impl<policy_t<Flag>>::info_of(h);
+    return (info == nullptr) ? nullptr : info->name_.c_str();
+}
+
+template <typename Flag>
+std::size_t chan_impl<Flag>::recv_count(ipc::handle_t h) {
+    return detail_impl<policy_t<Flag>>::recv_count(h);
+}
+
+template <typename Flag>
+bool chan_impl<Flag>::wait_for_recv(ipc::handle_t h, std::size_t r_count, std::uint64_t tm) {
+    return detail_impl<policy_t<Flag>>::wait_for_recv(h, r_count, tm);
+}
+
+template <typename Flag>
+bool chan_impl<Flag>::send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm) {
+    return detail_impl<policy_t<Flag>>::send(h, data, size, tm);
+}
+
+template <typename Flag>
+buff_t chan_impl<Flag>::recv(ipc::handle_t h, std::uint64_t tm) {
+    return detail_impl<policy_t<Flag>>::recv(h, tm);
+}
+
+template <typename Flag>
+bool chan_impl<Flag>::try_send(ipc::handle_t h, void const * data, std::size_t size, std::uint64_t tm) {
+    return detail_impl<policy_t<Flag>>::try_send(h, data, size, tm);
+}
+
+template <typename Flag>
+buff_t chan_impl<Flag>::try_recv(ipc::handle_t h) {
+    return detail_impl<policy_t<Flag>>::try_recv(h);
+}
+
+template struct chan_impl<ipc::wr<relat::single, relat::single, trans::unicast  >>;
+// template struct chan_impl<ipc::wr<relat::single, relat::multi , trans::unicast  >>; // TBD
+// template struct chan_impl<ipc::wr<relat::multi , relat::multi , trans::unicast  >>; // TBD
+template struct chan_impl<ipc::wr<relat::single, relat::multi , trans::broadcast>>;
+template struct chan_impl<ipc::wr<relat::multi , relat::multi , trans::broadcast>>;
+
+} // namespace ipc
diff --git a/src/libipc/memory/alloc.h b/src/libipc/memory/alloc.h
new file mode 100644
index 0000000..a3e7430
--- /dev/null
+++ b/src/libipc/memory/alloc.h
@@ -0,0 +1,424 @@
+#pragma once
+
+#include <algorithm>
+#include <utility>
+#include <iterator>
+#include <limits>       // std::numeric_limits
+#include <cstdlib>
+#include <cassert>      // assert
+
+#include "libipc/def.h"
+#include "libipc/rw_lock.h"
+
+#include "libipc/utility/concept.h"
+#include "libipc/memory/allocator_wrapper.h"
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+namespace mem {
+
+class static_alloc {
+public:
+    static void swap(static_alloc&) {}
+
+    static void* alloc(std::size_t size) {
+        return size ? std::malloc(size) : nullptr;
+    }
+
+    static void free(void* p) {
+        std::free(p);
+    }
+
+    static void free(void* p, std::size_t /*size*/) {
+        free(p);
+    }
+};
+
+////////////////////////////////////////////////////////////////
+/// Scope allocation -- The destructor will release all allocated blocks.
+////////////////////////////////////////////////////////////////
+
+namespace detail {
+
+constexpr std::size_t aligned(std::size_t size, size_t alignment) noexcept {
+    return ( (size - 1) & ~(alignment - 1) ) + alignment;
+}
+
+IPC_CONCEPT_(has_take, take(std::move(std::declval<Type>())));
+
+class scope_alloc_base {
+protected:
+    struct block_t {
+        std::size_t size_;
+        block_t   * next_;
+    } * head_ = nullptr, * tail_ = nullptr;
+
+    enum : std::size_t {
+        aligned_block_size = aligned(sizeof(block_t), alignof(std::max_align_t))
+    };
+
+public:
+    void swap(scope_alloc_base & rhs) {
+        std::swap(head_, rhs.head_);
+        std::swap(tail_, rhs.tail_);
+    }
+
+    bool empty() const noexcept {
+        return head_ == nullptr;
+    }
+
+    void take(scope_alloc_base && rhs) {
+        if (rhs.empty()) return;
+        if (empty()) swap(rhs);
+        else {
+            std::swap(tail_->next_, rhs.head_);
+            // rhs.head_ should be nullptr here
+            tail_ = rhs.tail_;
+            rhs.tail_ = nullptr;
+        }
+    }
+
+    void free(void* /*p*/) {}
+    void free(void* /*p*/, std::size_t) {}
+};
+
+} // namespace detail
+
+template <typename AllocP = static_alloc>
+class scope_alloc : public detail::scope_alloc_base {
+public:
+    using base_t = detail::scope_alloc_base;
+    using alloc_policy = AllocP;
+
+private:
+    alloc_policy alloc_;
+
+    void free_all() {
+        while (!empty()) {
+            auto curr = head_;
+            head_ = head_->next_;
+            alloc_.free(curr, curr->size_);
+        }
+        // now head_ is nullptr
+    }
+
+public:
+    scope_alloc() = default;
+
+    scope_alloc(scope_alloc && rhs)         { swap(rhs); }
+    scope_alloc& operator=(scope_alloc rhs) { swap(rhs); return (*this); }
+
+    ~scope_alloc() { free_all(); }
+
+    void swap(scope_alloc& rhs) {
+        alloc_.swap(rhs.alloc_);
+        base_t::swap(rhs);
+    }
+
+    template <typename A = AllocP>
+    auto take(scope_alloc && rhs) -> ipc::require<detail::has_take<A>::value> {
+        base_t::take(std::move(rhs));
+        alloc_.take(std::move(rhs.alloc_));
+    }
+
+    template <typename A = AllocP>
+    auto take(scope_alloc && rhs) -> ipc::require<!detail::has_take<A>::value> {
+        base_t::take(std::move(rhs));
+    }
+
+    void* alloc(std::size_t size) {
+        std::size_t real_size = aligned_block_size + size;
+        auto curr = static_cast<block_t*>(alloc_.alloc(real_size));
+        curr->size_ = real_size;
+        curr->next_ = head_;
+        head_ = curr;
+        if (tail_ == nullptr) {
+            tail_ = curr;
+        }
+        return (reinterpret_cast<byte_t*>(curr) + aligned_block_size);
+    }
+};
+
+////////////////////////////////////////////////////////////////
+/// Fixed-size blocks allocation
+////////////////////////////////////////////////////////////////
+
+namespace detail {
+
+class fixed_alloc_base {
+protected:
+    std::size_t block_size_;
+    std::size_t init_expand_;
+    void      * cursor_;
+
+    void init(std::size_t block_size, std::size_t init_expand) {
+        block_size_  = block_size;
+        init_expand_ = init_expand;
+        cursor_      = nullptr;
+    }
+
+    static void** node_p(void* node) {
+        return reinterpret_cast<void**>(node);
+    }
+
+    static auto& next(void* node) {
+        return *node_p(node);
+    }
+
+public:
+    bool operator<(fixed_alloc_base const & right) const {
+        return init_expand_ < right.init_expand_;
+    }
+
+    void set_block_size(std::size_t block_size) {
+        block_size_ = block_size;
+    }
+
+    void swap(fixed_alloc_base& rhs) {
+        std::swap(block_size_ , rhs.block_size_);
+        std::swap(init_expand_, rhs.init_expand_);
+        std::swap(cursor_     , rhs.cursor_);
+    }
+
+    bool empty() const noexcept {
+        return cursor_ == nullptr;
+    }
+
+    void take(fixed_alloc_base && rhs) {
+        assert(block_size_ == rhs.block_size_);
+        init_expand_ = (ipc::detail::max)(init_expand_, rhs.init_expand_);
+        if (rhs.empty()) return;
+        auto curr = cursor_;
+        if (curr != nullptr) while (1) {
+            auto next_cur = next(curr);
+            if (next_cur == nullptr) {
+                std::swap(next(curr), rhs.cursor_);
+                return;
+            }
+            // next_cur != nullptr
+            else curr = next_cur;
+        }
+        // curr == nullptr, means cursor_ == nullptr
+        else std::swap(cursor_, rhs.cursor_);
+        // rhs.cursor_ must be nullptr
+    }
+
+    void free(void* p) {
+        if (p == nullptr) return;
+        next(p) = cursor_;
+        cursor_ = p;
+    }
+
+    void free(void* p, std::size_t) {
+        free(p);
+    }
+};
+
+template <typename AllocP, typename ExpandP>
+class fixed_alloc : public detail::fixed_alloc_base {
+public:
+    using base_t = detail::fixed_alloc_base;
+    using alloc_policy = AllocP;
+
+private:
+    alloc_policy alloc_;
+
+    void* try_expand() {
+        if (empty()) {
+            auto size = ExpandP::next(block_size_, init_expand_);
+            auto p = node_p(cursor_ = alloc_.alloc(size));
+            for (std::size_t i = 0; i < (size / block_size_) - 1; ++i)
+                p = node_p((*p) = reinterpret_cast<byte_t*>(p) + block_size_);
+            (*p) = nullptr;
+        }
+        return cursor_;
+    }
+
+public:
+    explicit fixed_alloc(std::size_t block_size, std::size_t init_expand = 1) {
+        init(block_size, init_expand);
+    }
+
+    fixed_alloc(fixed_alloc && rhs) {
+        init(0, 0);
+        swap(rhs);
+    }
+
+    fixed_alloc& operator=(fixed_alloc rhs) {
+        swap(rhs);
+        return (*this);
+    }
+
+    void swap(fixed_alloc& rhs) {
+        alloc_.swap(rhs.alloc_);
+        base_t::swap(rhs);
+    }
+
+    template <typename A = AllocP>
+    auto take(fixed_alloc && rhs) -> ipc::require<detail::has_take<A>::value> {
+        base_t::take(std::move(rhs));
+        alloc_.take(std::move(rhs.alloc_));
+    }
+
+    void* alloc() {
+        void* p = try_expand();
+        cursor_ = next(p);
+        return p;
+    }
+
+    void* alloc(std::size_t) {
+        return alloc();
+    }
+};
+
+} // namespace detail
+
+template <std::size_t BaseSize  = sizeof(void*) * 1024, 
+          std::size_t LimitSize = (std::numeric_limits<std::uint32_t>::max)()>
+struct fixed_expand_policy {
+
+    enum : std::size_t {
+        base_size  = BaseSize,
+        limit_size = LimitSize
+    };
+
+    constexpr static std::size_t prev(std::size_t e) noexcept {
+        return ((e / 2) == 0) ? 1 : (e / 2);
+    }
+
+    constexpr static std::size_t next(std::size_t e) noexcept {
+        return e * 2;
+    }
+
+    static std::size_t next(std::size_t block_size, std::size_t & e) {
+        auto n = ipc::detail::max<std::size_t>(block_size, base_size) * e;
+             e = ipc::detail::min<std::size_t>(limit_size, next(e));
+        return n;
+    }
+};
+
+template <std::size_t BlockSize,
+          typename AllocP  = scope_alloc<>,
+          typename ExpandP = fixed_expand_policy<>>
+class fixed_alloc : public detail::fixed_alloc<AllocP, ExpandP> {
+public:
+    using base_t = detail::fixed_alloc<AllocP, ExpandP>;
+
+    enum : std::size_t {
+        block_size = ipc::detail::max<std::size_t>(BlockSize, sizeof(void*))
+    };
+
+public:
+    explicit fixed_alloc(std::size_t init_expand)
+        : base_t(block_size, init_expand) {
+    }
+
+    fixed_alloc() : fixed_alloc(1) {}
+
+    fixed_alloc(fixed_alloc && rhs)
+        : base_t(std::move(rhs)) {
+    }
+
+    fixed_alloc& operator=(fixed_alloc rhs) {
+        swap(rhs);
+        return (*this);
+    }
+
+    void swap(fixed_alloc& rhs) {
+        base_t::swap(rhs);
+    }
+};
+
+////////////////////////////////////////////////////////////////
+/// Variable-size blocks allocation (without alignment)
+////////////////////////////////////////////////////////////////
+
+namespace detail {
+
+class variable_alloc_base {
+protected:
+    byte_t * head_ = nullptr, * tail_ = nullptr;
+
+public:
+    void swap(variable_alloc_base & rhs) {
+        std::swap(head_, rhs.head_);
+        std::swap(tail_, rhs.tail_);
+    }
+
+    std::size_t remain() const noexcept {
+        return static_cast<std::size_t>(tail_ - head_);
+    }
+
+    bool empty() const noexcept {
+        return remain() == 0;
+    }
+
+    void take(variable_alloc_base && rhs) {
+        if (remain() < rhs.remain()) {
+            // replace this by rhs
+            head_ = rhs.head_;
+            tail_ = rhs.tail_;
+        }
+        // discard rhs
+        rhs.head_ = rhs.tail_ = nullptr;
+    }
+
+    void free(void* /*p*/) {}
+    void free(void* /*p*/, std::size_t) {}
+};
+
+} // namespace detail
+
+template <std::size_t ChunkSize = (sizeof(void*) * 1024), typename AllocP = scope_alloc<>>
+class variable_alloc : public detail::variable_alloc_base {
+public:
+    using base_t       = detail::variable_alloc_base;
+    using alloc_policy = AllocP;
+
+    enum : std::size_t {
+        aligned_chunk_size = detail::aligned(ChunkSize, alignof(std::max_align_t))
+    };
+
+private:
+    alloc_policy alloc_;
+
+public:
+    variable_alloc() = default;
+
+    variable_alloc(variable_alloc && rhs)         { swap(rhs); }
+    variable_alloc& operator=(variable_alloc rhs) { swap(rhs); return (*this); }
+
+    void swap(variable_alloc& rhs) {
+        alloc_.swap(rhs.alloc_);
+        base_t::swap(rhs);
+    }
+
+    template <typename A = AllocP>
+    auto take(variable_alloc && rhs) -> ipc::require<detail::has_take<A>::value> {
+        base_t::take(std::move(rhs));
+        alloc_.take(std::move(rhs.alloc_));
+    }
+
+    void* alloc(std::size_t size) {
+        /*
+         * byte alignment is always alignof(std::max_align_t).
+        */
+        size = detail::aligned(size, alignof(std::max_align_t));
+        void* ptr;
+        // size would never be 0 here
+        if (remain() < size) {
+            std::size_t chunk_size = ipc::detail::max<std::size_t>(aligned_chunk_size, size);
+            ptr   = alloc_.alloc(chunk_size);
+            tail_ = static_cast<byte_t*>(ptr) + chunk_size;
+            head_ = tail_ - (chunk_size - size);
+        }
+        else {
+            ptr   = head_;
+            head_ += size;
+        }
+        return ptr;
+    }
+};
+
+} // namespace mem
+} // namespace ipc
diff --git a/src/libipc/memory/allocator_wrapper.h b/src/libipc/memory/allocator_wrapper.h
new file mode 100644
index 0000000..a4da782
--- /dev/null
+++ b/src/libipc/memory/allocator_wrapper.h
@@ -0,0 +1,121 @@
+#pragma once
+
+#include <limits>   // std::numeric_limits
+#include <utility>  // std::forward
+#include <cstddef>
+
+#include "libipc/pool_alloc.h"
+
+namespace ipc {
+namespace mem {
+
+////////////////////////////////////////////////////////////////
+/// The allocator wrapper class for STL
+////////////////////////////////////////////////////////////////
+
+namespace detail {
+
+template <typename T, typename AllocP>
+struct rebind {
+    template <typename U>
+    using alloc_t = AllocP;
+};
+
+template <typename T, template <typename> class AllocT>
+struct rebind<T, AllocT<T>> {
+    template <typename U>
+    using alloc_t = AllocT<U>;
+};
+
+} // namespace detail
+
+template <typename T, typename AllocP>
+class allocator_wrapper {
+
+    template <typename U, typename AllocU>
+    friend class allocator_wrapper;
+
+public:
+    // type definitions
+    typedef T                 value_type;
+    typedef value_type*       pointer;
+    typedef const value_type* const_pointer;
+    typedef value_type&       reference;
+    typedef const value_type& const_reference;
+    typedef std::size_t       size_type;
+    typedef std::ptrdiff_t    difference_type;
+    typedef AllocP            alloc_policy;
+
+private:
+    alloc_policy alloc_;
+
+public:
+    allocator_wrapper() noexcept {}
+
+    // construct by copying (do nothing)
+    allocator_wrapper           (const allocator_wrapper<T, AllocP>&) noexcept {}
+    allocator_wrapper& operator=(const allocator_wrapper<T, AllocP>&) noexcept { return *this; }
+	
+    // construct from a related allocator (do nothing)
+    template <typename U, typename AllocU> allocator_wrapper           (const allocator_wrapper<U, AllocU>&) noexcept {}
+    template <typename U, typename AllocU> allocator_wrapper& operator=(const allocator_wrapper<U, AllocU>&) noexcept { return *this; }
+
+    allocator_wrapper           (allocator_wrapper && rhs) noexcept : alloc_ ( std::move(rhs.alloc_) ) {}
+    allocator_wrapper& operator=(allocator_wrapper && rhs) noexcept { alloc_ = std::move(rhs.alloc_); return *this; }
+
+public:
+    // the other type of std_allocator
+    template <typename U>
+    struct rebind { 
+        using other = allocator_wrapper< U, typename detail::rebind<T, AllocP>::template alloc_t<U> >;
+    };
+
+    constexpr size_type max_size(void) const noexcept {
+        return (std::numeric_limits<size_type>::max)() / sizeof(value_type);
+    }
+
+public:
+    pointer allocate(size_type count) noexcept {
+        if (count == 0) return nullptr;
+        if (count > this->max_size()) return nullptr;
+        return static_cast<pointer>(alloc_.alloc(count * sizeof(value_type)));
+    }
+
+    void deallocate(pointer p, size_type count) noexcept {
+        alloc_.free(p, count * sizeof(value_type));
+    }
+
+    template <typename... P>
+    static void construct(pointer p, P && ... params) {
+        ipc::mem::construct(p, std::forward<P>(params)...);
+    }
+
+    static void destroy(pointer p) {
+        ipc::mem::destruct(p);
+    }
+};
+
+template <class AllocP>
+class allocator_wrapper<void, AllocP> {
+public:
+    // type definitions
+    typedef void              value_type;
+    typedef value_type*       pointer;
+    typedef const value_type* const_pointer;
+    typedef std::size_t       size_type;
+    typedef std::ptrdiff_t    difference_type;
+    typedef AllocP            alloc_policy;
+};
+
+template <typename T, typename U, class AllocP>
+constexpr bool operator==(const allocator_wrapper<T, AllocP>&, const allocator_wrapper<U, AllocP>&) noexcept {
+    return true;
+}
+
+template <typename T, typename U, class AllocP>
+constexpr bool operator!=(const allocator_wrapper<T, AllocP>&, const allocator_wrapper<U, AllocP>&) noexcept {
+    return false;
+}
+
+} // namespace mem
+} // namespace ipc
diff --git a/src/libipc/memory/resource.h b/src/libipc/memory/resource.h
new file mode 100644
index 0000000..7c29dc1
--- /dev/null
+++ b/src/libipc/memory/resource.h
@@ -0,0 +1,110 @@
+#pragma once
+
+#include <type_traits>
+#include <limits>
+#include <utility>
+#include <functional>
+#include <unordered_map>
+#include <map>
+#include <string>
+#include <cstdio>
+
+#include "libipc/def.h"
+
+#include "libipc/memory/alloc.h"
+#include "libipc/memory/wrapper.h"
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+namespace mem {
+
+//using async_pool_alloc = static_wrapper<variable_wrapper<async_wrapper<
+//    detail::fixed_alloc<
+//        variable_alloc                           <sizeof(void*) * 1024 * 256>, 
+//        fixed_expand_policy<sizeof(void*) * 1024, sizeof(void*) * 1024 * 256>
+//    >, 
+//    default_recycler >>>;
+using async_pool_alloc = ipc::mem::static_alloc;
+
+template <typename T>
+using allocator = allocator_wrapper<T, async_pool_alloc>;
+
+} // namespace mem
+
+namespace {
+
+constexpr char const * pf(int)                { return "%d"  ; }
+constexpr char const * pf(long)               { return "%ld" ; }
+constexpr char const * pf(long long)          { return "%lld"; }
+constexpr char const * pf(unsigned int)       { return "%u"  ; }
+constexpr char const * pf(unsigned long)      { return "%lu" ; }
+constexpr char const * pf(unsigned long long) { return "%llu"; }
+constexpr char const * pf(float)              { return "%f"  ; }
+constexpr char const * pf(double)             { return "%f"  ; }
+constexpr char const * pf(long double)        { return "%Lf" ; }
+
+} // internal-linkage
+
+template <typename T>
+struct hash : public std::hash<T> {};
+
+template <typename Key, typename T>
+using unordered_map = std::unordered_map<
+    Key, T, ipc::hash<Key>, std::equal_to<Key>, ipc::mem::allocator<std::pair<Key const, T>>
+>;
+
+template <typename Key, typename T>
+using map = std::map<
+    Key, T, std::less<Key>, ipc::mem::allocator<std::pair<Key const, T>>
+>;
+
+template <typename Char>
+using basic_string = std::basic_string<
+    Char, std::char_traits<Char>, ipc::mem::allocator<Char>
+>;
+
+using string  = basic_string<char>;
+using wstring = basic_string<wchar_t>;
+
+template <> struct hash<string> {
+    std::size_t operator()(string const &val) const noexcept {
+        return std::hash<char const *>{}(val.c_str());
+    }
+};
+
+template <> struct hash<wstring> {
+    std::size_t operator()(wstring const &val) const noexcept {
+        return std::hash<wchar_t const *>{}(val.c_str());
+    }
+};
+
+template <typename T>
+ipc::string to_string(T val) {
+    char buf[std::numeric_limits<T>::digits10 + 1] {};
+    if (std::snprintf(buf, sizeof(buf), pf(val), val) > 0) {
+        return buf;
+    }
+    return {};
+}
+
+/// \brief Check string validity.
+constexpr bool is_valid_string(char const *str) noexcept {
+    return (str != nullptr) && (str[0] != '\0');
+}
+
+/// \brief Make a valid string.
+inline ipc::string make_string(char const *str) {
+    return is_valid_string(str) ? ipc::string{str} : ipc::string{};
+}
+
+/// \brief Combine prefix from a list of strings.
+inline ipc::string make_prefix(ipc::string prefix, std::initializer_list<ipc::string> args) {
+    prefix += "__IPC_SHM__";
+    for (auto const &txt: args) {
+        if (txt.empty()) continue;
+        prefix += txt;
+    }
+    return prefix;
+}
+
+} // namespace ipc
diff --git a/src/libipc/memory/wrapper.h b/src/libipc/memory/wrapper.h
new file mode 100644
index 0000000..bd98d46
--- /dev/null
+++ b/src/libipc/memory/wrapper.h
@@ -0,0 +1,327 @@
+#pragma once
+
+#include <tuple>
+#include <thread>
+#include <deque>        // std::deque
+#include <functional>   // std::function
+#include <utility>      // std::forward
+#include <cstddef>
+#include <cassert>      // assert
+#include <type_traits>  // std::aligned_storage_t
+
+#include "libipc/def.h"
+#include "libipc/rw_lock.h"
+#include "libipc/pool_alloc.h"
+
+#include "libipc/utility/concept.h"
+#include "libipc/memory/alloc.h"
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+namespace mem {
+
+////////////////////////////////////////////////////////////////
+/// Thread-safe allocation wrapper
+////////////////////////////////////////////////////////////////
+
+namespace detail {
+
+IPC_CONCEPT_(is_comparable, operator<(std::declval<Type>()));
+
+} // namespace detail
+
+template <typename AllocP, bool = detail::is_comparable<AllocP>::value>
+class limited_recycler;
+
+template <typename AllocP>
+class limited_recycler<AllocP, true> {
+public:
+    using alloc_policy = AllocP;
+
+protected:
+    std::deque<alloc_policy> master_allocs_;
+    ipc::spin_lock master_lock_;
+
+    template <typename F>
+    void take_first_do(F && pred) {
+        auto it = master_allocs_.begin();
+        pred(const_cast<alloc_policy&>(*it));
+        master_allocs_.erase(it);
+    }
+
+public:
+    void try_recover(alloc_policy & alc) {
+        IPC_UNUSED_ auto guard = ipc::detail::unique_lock(master_lock_);
+        if (master_allocs_.empty()) return;
+        take_first_do([&alc](alloc_policy & first) { alc.swap(first); });
+    }
+
+    void collect(alloc_policy && alc) {
+        IPC_UNUSED_ auto guard = ipc::detail::unique_lock(master_lock_);
+        if (master_allocs_.size() >= 32) {
+            take_first_do([](alloc_policy &) {}); // erase first
+        }
+        master_allocs_.emplace_back(std::move(alc));
+    }
+
+    IPC_CONSTEXPR_ auto try_replenish(alloc_policy&, std::size_t) noexcept {}
+};
+
+template <typename AllocP>
+class default_recycler : public limited_recycler<AllocP> {
+
+    IPC_CONCEPT_(has_remain, remain());
+    IPC_CONCEPT_(has_empty , empty());
+
+    template <typename A>
+    void try_fill(A & alc) {
+        IPC_UNUSED_ auto guard = ipc::detail::unique_lock(this->master_lock_);
+        if (this->master_allocs_.empty()) return;
+        this->take_first_do([&alc](alloc_policy & first) { alc.take(std::move(first)); });
+    }
+
+public:
+    using alloc_policy = typename limited_recycler<AllocP>::alloc_policy;
+
+    template <typename A = AllocP>
+    auto try_replenish(alloc_policy & alc, std::size_t size)
+        -> ipc::require<detail::has_take<A>::value && has_remain<A>::value> {
+        if (alc.remain() >= size) return;
+        this->try_fill(alc);
+    }
+
+    template <typename A = AllocP>
+    auto try_replenish(alloc_policy & alc, std::size_t /*size*/)
+        -> ipc::require<detail::has_take<A>::value && !has_remain<A>::value && has_empty<A>::value> {
+        if (!alc.empty()) return;
+        this->try_fill(alc);
+    }
+
+    template <typename A = AllocP>
+    auto try_replenish(alloc_policy & alc, std::size_t /*size*/)
+        -> ipc::require<!detail::has_take<A>::value && has_empty<A>::value> {
+        if (!alc.empty()) return;
+        this->try_recover(alc);
+    }
+
+    template <typename A = AllocP>
+    IPC_CONSTEXPR_ auto try_replenish(alloc_policy & /*alc*/, std::size_t /*size*/) noexcept
+        -> ipc::require<(!detail::has_take<A>::value || !has_remain<A>::value) && !has_empty<A>::value> {
+        // Do Nothing.
+    }
+};
+
+template <typename AllocP>
+class empty_recycler {
+public:
+    using alloc_policy = AllocP;
+
+    IPC_CONSTEXPR_ void try_recover(alloc_policy&)                noexcept {}
+    IPC_CONSTEXPR_ auto try_replenish(alloc_policy&, std::size_t) noexcept {}
+    IPC_CONSTEXPR_ void collect(alloc_policy&&)                   noexcept {}
+};
+
+template <typename AllocP,
+          template <typename> class RecyclerP = default_recycler>
+class async_wrapper {
+public:
+    using alloc_policy = AllocP;
+
+private:
+    RecyclerP<alloc_policy> recycler_;
+
+    class alloc_proxy : public AllocP {
+        async_wrapper * w_ = nullptr;
+
+    public:
+        alloc_proxy(alloc_proxy && rhs) = default;
+
+        template <typename ... P>
+        alloc_proxy(async_wrapper* w, P && ... pars)
+            : AllocP(std::forward<P>(pars) ...), w_(w) {
+            assert(w_ != nullptr);
+            w_->recycler_.try_recover(*this);
+        }
+
+        ~alloc_proxy() {
+            w_->recycler_.collect(std::move(*this));
+        }
+
+        auto alloc(std::size_t size) {
+            w_->recycler_.try_replenish(*this, size);
+            return AllocP::alloc(size);
+        }
+    };
+
+    friend class alloc_proxy;
+    using ref_t = alloc_proxy&;
+
+    std::function<ref_t()> get_alloc_;
+
+public:
+    template <typename ... P>
+    async_wrapper(P ... pars) {
+        get_alloc_ = [this, pars ...]()->ref_t {
+            thread_local alloc_proxy tls(pars ...);
+            return tls;
+        };
+    }
+
+    void* alloc(std::size_t size) {
+        return get_alloc_().alloc(size);
+    }
+
+    void free(void* p, std::size_t size) {
+        get_alloc_().free(p, size);
+    }
+};
+
+////////////////////////////////////////////////////////////////
+/// Thread-safe allocation wrapper (with spin_lock)
+////////////////////////////////////////////////////////////////
+
+template <typename AllocP, typename MutexT = ipc::spin_lock>
+class sync_wrapper {
+public:
+    using alloc_policy = AllocP;
+    using mutex_type   = MutexT;
+
+private:
+    mutex_type   lock_;
+    alloc_policy alloc_;
+
+public:
+    template <typename ... P>
+    sync_wrapper(P && ... pars)
+        : alloc_(std::forward<P>(pars) ...)
+    {}
+
+    void swap(sync_wrapper& rhs) {
+        IPC_UNUSED_ auto guard = ipc::detail::unique_lock(lock_);
+        alloc_.swap(rhs.alloc_);
+    }
+
+    void* alloc(std::size_t size) {
+        IPC_UNUSED_ auto guard = ipc::detail::unique_lock(lock_);
+        return alloc_.alloc(size);
+    }
+
+    void free(void* p, std::size_t size) {
+        IPC_UNUSED_ auto guard = ipc::detail::unique_lock(lock_);
+        alloc_.free(p, size);
+    }
+};
+
+////////////////////////////////////////////////////////////////
+/// Variable memory allocation wrapper
+////////////////////////////////////////////////////////////////
+
+template <std::size_t BaseSize = 0, std::size_t IterSize = sizeof(void*)>
+struct default_mapping_policy {
+
+    enum : std::size_t {
+        base_size    = BaseSize,
+        iter_size    = IterSize,
+        classes_size = 64
+    };
+
+    template <typename F, typename ... P>
+    IPC_CONSTEXPR_ static void foreach(F && f, P && ... params) {
+        for (std::size_t i = 0; i < classes_size; ++i) {
+            f(i, std::forward<P>(params)...);
+        }
+    }
+
+    IPC_CONSTEXPR_ static std::size_t block_size(std::size_t id) noexcept {
+        return (id < classes_size) ? (base_size + (id + 1) * iter_size) : 0;
+    }
+
+    template <typename F, typename D, typename ... P>
+    IPC_CONSTEXPR_ static auto classify(F && f, D && d, std::size_t size, P && ... params) {
+        std::size_t id = (size - base_size - 1) / iter_size;
+        return (id < classes_size) ? 
+            f(id, size, std::forward<P>(params)...) : 
+            d(size, std::forward<P>(params)...);
+    }
+};
+
+template <typename FixedAlloc,
+          typename DefaultAlloc = mem::static_alloc,
+          typename MappingP     = default_mapping_policy<>>
+class variable_wrapper {
+
+    struct initiator {
+
+        using falc_t = std::aligned_storage_t<sizeof(FixedAlloc), alignof(FixedAlloc)>;
+        falc_t arr_[MappingP::classes_size];
+
+        initiator() {
+            MappingP::foreach([](std::size_t id, falc_t * a) {
+                ipc::mem::construct(&initiator::at(a, id), MappingP::block_size(id));
+            }, arr_);
+        }
+
+        ~initiator() {
+            MappingP::foreach([](std::size_t id, falc_t * a) {
+                ipc::mem::destruct(&initiator::at(a, id));
+            }, arr_);
+        }
+
+        static FixedAlloc & at(falc_t * arr, std::size_t id) noexcept {
+            return reinterpret_cast<FixedAlloc&>(arr[id]);
+        }
+    } init_;
+
+    using falc_t = typename initiator::falc_t;
+
+public:
+    void swap(variable_wrapper & other) {
+        MappingP::foreach([](std::size_t id, falc_t * in, falc_t * ot) {
+            initiator::at(in, id).swap(initiator::at(ot, id));
+        }, init_.arr_, other.init_.arr_);
+    }
+
+    void* alloc(std::size_t size) {
+        return MappingP::classify([](std::size_t id, std::size_t size, falc_t * a) {
+            return initiator::at(a, id).alloc(size);
+        }, [](std::size_t size, falc_t *) {
+            return DefaultAlloc::alloc(size);
+        }, size, init_.arr_);
+    }
+
+    void free(void* p, std::size_t size) {
+        MappingP::classify([](std::size_t id, std::size_t size, void* p, falc_t * a) {
+            initiator::at(a, id).free(p, size);
+        }, [](std::size_t size, void* p, falc_t *) {
+            DefaultAlloc::free(p, size);
+        }, size, p, init_.arr_);
+    }
+};
+
+////////////////////////////////////////////////////////////////
+/// Static allocation wrapper
+////////////////////////////////////////////////////////////////
+
+template <typename AllocP>
+class static_wrapper {
+public:
+    using alloc_policy = AllocP;
+
+    static alloc_policy& instance() {
+        static alloc_policy alloc;
+        return alloc;
+    }
+
+    static void swap(static_wrapper&) {}
+
+    static void* alloc(std::size_t size) {
+        return instance().alloc(size);
+    }
+
+    static void free(void* p, std::size_t size) {
+        instance().free(p, size);
+    }
+};
+
+} // namespace mem
+} // namespace ipc
diff --git a/src/libipc/platform/detail.h b/src/libipc/platform/detail.h
new file mode 100644
index 0000000..d552969
--- /dev/null
+++ b/src/libipc/platform/detail.h
@@ -0,0 +1,136 @@
+#ifndef LIBIPC_SRC_PLATFORM_DETAIL_H_
+#define LIBIPC_SRC_PLATFORM_DETAIL_H_
+
+// detect platform
+
+#if defined(WIN64) || defined(_WIN64) || defined(__WIN64__) || \
+    defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || \
+    defined(WINCE) || defined(_WIN32_WCE)
+#   define IPC_OS_WINDOWS_
+#elif defined(__linux__) || defined(__linux)
+#   define IPC_OS_LINUX_
+#elif defined(__QNX__)
+#   define IPC_OS_QNX_
+#elif defined(__APPLE__)
+#elif defined(__ANDROID__)
+// TBD
+#endif
+
+#if defined(__cplusplus)
+
+#include <memory>
+#include <mutex>
+#include <shared_mutex>
+#include <type_traits>
+#include <tuple>
+#include <algorithm>
+
+// pre-defined
+
+#ifdef IPC_UNUSED_
+#   error "IPC_UNUSED_ has been defined."
+#endif
+#ifdef IPC_FALLTHROUGH_
+#   error "IPC_FALLTHROUGH_ has been defined."
+#endif
+#ifdef IPC_STBIND_
+#   error "IPC_STBIND_ has been defined."
+#endif
+#ifdef IPC_CONSTEXPR_
+#   error "IPC_CONSTEXPR_ has been defined."
+#endif
+
+#if __cplusplus >= 201703L
+
+#define IPC_UNUSED_      [[maybe_unused]]
+#define IPC_FALLTHROUGH_ [[fallthrough]]
+#define IPC_STBIND_(A, B, ...) auto [A, B] = __VA_ARGS__
+#define IPC_CONSTEXPR_   constexpr
+
+#else /*__cplusplus < 201703L*/
+
+#if defined(_MSC_VER)
+#   define IPC_UNUSED_ __pragma(warning(suppress: 4100 4101 4189))
+#elif defined(__GNUC__)
+#   define IPC_UNUSED_ __attribute__((__unused__))
+#else
+#   define IPC_UNUSED_
+#endif
+
+#define IPC_FALLTHROUGH_
+
+#define IPC_STBIND_(A, B, ...)       \
+    auto tp___ = __VA_ARGS__         \
+    auto A     = std::get<0>(tp___); \
+    auto B     = std::get<1>(tp___)
+
+#define IPC_CONSTEXPR_ inline
+
+#endif/*__cplusplus < 201703L*/
+
+#if __cplusplus >= 201703L
+
+namespace std {
+
+// deduction guides for std::unique_ptr
+template <typename T>
+unique_ptr(T* p) -> unique_ptr<T>;
+template <typename T, typename D>
+unique_ptr(T* p, D&& d) -> unique_ptr<T, std::decay_t<D>>;
+
+} // namespace std
+
+namespace ipc {
+namespace detail {
+
+using std::unique_ptr;
+using std::unique_lock;
+using std::shared_lock;
+using std::max;
+using std::min;
+
+#else /*__cplusplus < 201703L*/
+
+namespace ipc {
+namespace detail {
+
+// deduction guides for std::unique_ptr
+template <typename T>
+constexpr auto unique_ptr(T* p) noexcept {
+    return std::unique_ptr<T> { p };
+}
+
+template <typename T, typename D>
+constexpr auto unique_ptr(T* p, D&& d) noexcept {
+    return std::unique_ptr<T, std::decay_t<D>> { p, std::forward<D>(d) };
+}
+
+// deduction guides for std::unique_lock
+template <typename T>
+constexpr auto unique_lock(T&& lc) noexcept {
+    return std::unique_lock<std::decay_t<T>> { std::forward<T>(lc) };
+}
+
+// deduction guides for std::shared_lock
+template <typename T>
+constexpr auto shared_lock(T&& lc) noexcept {
+    return std::shared_lock<std::decay_t<T>> { std::forward<T>(lc) };
+}
+
+template <typename T>
+constexpr const T& (max)(const T& a, const T& b) {
+    return (a < b) ? b : a;
+}
+
+template <typename T>
+constexpr const T& (min)(const T& a, const T& b) {
+    return (b < a) ? b : a;
+}
+
+#endif/*__cplusplus < 201703L*/
+
+} // namespace detail
+} // namespace ipc
+
+#endif // defined(__cplusplus)
+#endif // LIBIPC_SRC_PLATFORM_DETAIL_H_
diff --git a/src/libipc/platform/linux/a0/LICENSE b/src/libipc/platform/linux/a0/LICENSE
new file mode 100644
index 0000000..cf1ab25
--- /dev/null
+++ b/src/libipc/platform/linux/a0/LICENSE
@@ -0,0 +1,24 @@
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+For more information, please refer to <http://unlicense.org>
diff --git a/src/libipc/platform/linux/a0/README.md b/src/libipc/platform/linux/a0/README.md
new file mode 100644
index 0000000..8aed9d7
--- /dev/null
+++ b/src/libipc/platform/linux/a0/README.md
@@ -0,0 +1,213 @@
+<h1 align="center">
+  <br>
+  <img src="https://raw.githubusercontent.com/alephzero/logo/master/rendered/alephzero.svg" width="256px">
+  <br>
+  AlephZero
+</h1>
+
+<h3 align="center">Simple, Robust, Fast IPC.</h3>
+
+<p align="center">
+  <a href="https://github.com/alephzero/alephzero/actions?query=workflow%3ACI"><img src="https://github.com/alephzero/alephzero/workflows/CI/badge.svg"></a>
+  <a href="https://codecov.io/gh/alephzero/alephzero"><img src="https://codecov.io/gh/alephzero/alephzero/branch/master/graph/badge.svg"></a>
+  <a href="https://alephzero.readthedocs.io/en/latest/?badge=latest"><img src="https://readthedocs.org/projects/alephzero/badge/?version=latest"></a>
+  <a href="http://unlicense.org"><img src="https://img.shields.io/badge/license-Unlicense-blue.svg"></a>
+</p>
+
+<p align="center">
+  <a href="#overview">Overview</a> •
+  <a href="#transport">Transport</a> •
+  <a href="#protocol">Protocol</a> •
+  <a href="#examples">Examples</a> •
+  <a href="#installation">Installation</a> •
+  <a href="#across-dockers">Across Dockers</a>
+</p>
+
+# Overview
+
+[Presentation from March 25, 2020](https://docs.google.com/presentation/d/12KE9UucjZPtpVnM1NljxOqBolBBKECWJdrCoE2yJaBw/edit#slide=id.p)
+
+AlephZero is a library for message based communication between programs running on the same machine.
+
+## Simple
+
+AlephZero's main goal is to be simple to use. Nothing is higher priority.
+
+There is no "master" process in between your nodes that is needed to do handshakes or exchanges of any kind. All you need is the topic name.
+
+See the <a href="#examples">Examples</a>.
+
+## Robust
+
+This is probably the main value of AlephZero, above similar libraries.
+
+AlephZero uses a lot of tricks to ensure the state of all channels is consistent, even when programs die. This includes double-buffering the state of the communication channel and [robustifying](https://man7.org/linux/man-pages/man3/pthread_mutexattr_setrobust.3.html) the locks and notification channels.
+
+## Fast
+
+AlephZero uses shared memory across multiple processes to read and write messages, minimizing the involvement of the kernel. The kernel only really gets involved in notifying a process that a new message exists, and for that we use futex (fast user-space mutex).
+
+TODO: Benchmarks
+
+# Transport
+
+AlephZero, at its core, is a simple allocator on top of a contiguous region of memory. Usually, shared-memory. The allocator of choice is a circular-linked-list, which is fast, simple, and sufficient for the protocol listed below. It also plays well with the robustness requirement.
+
+This has a number of implications. For one, this means that old messages are kept around until the space is needed. The oldest messages are always discarded before any more recent messages.
+
+# Protocol
+
+Rather than exposing the low-level transport directly, AlephZero provides a few higher level protocol:
+
+* <b>PubSub</b>: Broadcast published messages. Subscribers get notified.
+* <b>RPC</b>: Request-response.
+* <b>PRPC (Progressive RPC)</b>: Request-streaming response.
+* <b>Sessions</b>: Bi-directional channel of communication. Not yet implemented. Let me know if you want this.
+
+# Examples
+
+Many more example and an interactive experience can be found at: https://github.com/alephzero/playground
+
+For the curious, here are some simple snippets to get you started:
+
+To begin with, we need to include AlephZero:
+```cc
+#include <a0.h>
+```
+
+## PubSub
+
+You can have as many publisher and subscribers on the same topic as you wish. They just need to agree on the filename.
+
+```cc
+a0::Publisher p("my_pubsub_topic");
+p.pub("foo");
+```
+
+You just published `"foo"` to the `"my_pubsub_topic"`.
+
+To read those message, you can create a subscriber on the same topic:
+```cc
+a0::Subscriber sub(
+    "my_pubsub_topic",
+    A0_INIT_AWAIT_NEW,  // or MOST_RECENT or OLDEST
+    A0_ITER_NEWEST,     // or NEXT
+    [](a0::PacketView pkt_view) {
+      std::cout << "Got: " << pkt_view.payload() << std::endl;
+    });
+```
+The callback will trigger whenever a message is published.
+
+The `Subscriber` object spawns a thread that will read the topic and call the callback.
+
+The `A0_INIT` tells the subscriber where to start reading. 
+* `A0_INIT_AWAIT_NEW`: Start with messages published after the creation of the subscriber.
+* `A0_INIT_MOST_RECENT`: Start with the most recently published message. Useful for state and configuration. But be careful, this can be quite old!
+* `A0_INIT_OLDEST`: Topics keep a history of 16MB (unless configures otherwise). Start with the oldest thing still in there.
+
+The `A0_ITER` tells the subscriber how to continue reading messages. After each callback:
+* `A0_ITER_NEXT`: grab the sequentially next message. When you don't want to miss a thing.
+* `A0_ITER_NEWEST`: grab the newest available unread message. When you want to keep up with the firehose.
+
+```cc
+a0::SubscriberSync sub_sync(
+    "my_pubsub_topic",
+    A0_INIT_OLDEST, A0_ITER_NEXT);
+while (sub_sync.has_next()) {
+  auto pkt = sub_sync.next();
+  std::cout << "Got: " << pkt.payload() << std::endl;
+}
+```
+
+## RPC
+
+Create an `RpcServer`:
+
+```cc
+a0::RpcServer server(
+    "my_rpc_topic",
+    /* onrequest = */ [](a0::RpcRequest req) {
+        std::cout << "Got: " << req.pkt().payload() << std::endl;
+        req.reply("echo " + std::string(req.pkt().payload()));
+    },
+    /* oncancel = */ nullptr);
+```
+
+Create an `RpcClient`:
+
+```cc
+a0::RpcClient client("my_rpc_topic");
+client.send("client msg", [](a0::PacketView reply) {
+  std::cout << "Got: " << reply.payload() << std::endl;
+});
+```
+
+# Installation
+
+## Install From Source
+
+### Ubuntu Dependencies
+
+```sh
+apt install g++ make
+```
+
+### Alpine Dependencies
+
+```sh
+apk add g++ linux-headers make
+```
+
+### Download And Install
+
+```sh
+git clone https://github.com/alephzero/alephzero.git
+cd alephzero
+make install -j
+```
+
+## Install From Package
+
+Coming soon-ish. Let me know if you want this and I'll prioritize it. External support is much appreciated.
+
+## Integration
+
+### Command Line
+
+Add the following to g++ / clang commands.
+```sh
+-L${libdir} -lalephzero -lpthread
+```
+
+### Package-cfg
+
+```sh
+pkg-config --cflags --libs alephzero
+```
+
+### CMake
+
+Coming soon-ish. Let me know if you want this and I'll prioritize it. External support is much appreciated.
+
+### Bazel
+
+Coming soon-ish. Let me know if you want this and I'll prioritize it.
+
+# Across Dockers
+
+For programs running across different dockers to be able to communicate, we need to have them match up on two flags: `--ipc` and `--pid`.
+
+* `--ipc` shares the `/dev/shm` filesystem. This is necessary to open the same file topics.
+* `--pid` shares the process id namespace. This is necessary for the locking and notification systems.
+
+In the simplest case, you can set them both to `host` and talk through the system's global `/dev/shm` and process id namespace.
+```sh
+docker run --ipc=host --pid=host --name=foo foo_image
+docker run --ipc=host --pid=host --name=bar bar_image
+```
+
+Or, you can mark one as `shareable` and have the others connect to it:
+```sh
+docker run --ipc=shareable --pid=shareable --name=foo foo_image
+docker run --ipc=container:foo --pid=container:foo --name=bar bar_image
+```
diff --git a/src/libipc/platform/linux/a0/atomic.h b/src/libipc/platform/linux/a0/atomic.h
new file mode 100644
index 0000000..09a26ff
--- /dev/null
+++ b/src/libipc/platform/linux/a0/atomic.h
@@ -0,0 +1,36 @@
+#ifndef A0_SRC_ATOMIC_H
+#define A0_SRC_ATOMIC_H
+
+#include "a0/inline.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+A0_STATIC_INLINE
+void a0_barrier() {
+  // 'atomic_thread_fence' is not supported with ‘-fsanitize=thread’
+  __sync_synchronize();
+}
+
+#define a0_atomic_fetch_add(P, V) __atomic_fetch_add((P), (V), __ATOMIC_RELAXED)
+#define a0_atomic_add_fetch(P, V) __atomic_add_fetch((P), (V), __ATOMIC_RELAXED)
+
+#define a0_atomic_fetch_and(P, V) __atomic_fetch_and((P), (V), __ATOMIC_RELAXED)
+#define a0_atomic_and_fetch(P, V) __atomic_and_fetch((P), (V), __ATOMIC_RELAXED)
+
+#define a0_atomic_fetch_or(P, V) __atomic_fetch_or((P), (V), __ATOMIC_RELAXED)
+#define a0_atomic_or_fetch(P, V) __atomic_or_fetch((P), (V), __ATOMIC_RELAXED)
+
+#define a0_atomic_load(P) __atomic_load_n((P), __ATOMIC_RELAXED)
+#define a0_atomic_store(P, V) __atomic_store_n((P), (V), __ATOMIC_RELAXED)
+
+// TODO(lshamis): Switch from __sync to __atomic.
+#define a0_cas_val(P, OV, NV) __sync_val_compare_and_swap((P), (OV), (NV))
+#define a0_cas(P, OV, NV) __sync_bool_compare_and_swap((P), (OV), (NV))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // A0_SRC_ATOMIC_H
diff --git a/src/libipc/platform/linux/a0/clock.h b/src/libipc/platform/linux/a0/clock.h
new file mode 100644
index 0000000..7b2a88b
--- /dev/null
+++ b/src/libipc/platform/linux/a0/clock.h
@@ -0,0 +1,60 @@
+#ifndef A0_SRC_CLOCK_H
+#define A0_SRC_CLOCK_H
+
+#include "a0/err.h"
+#include "a0/inline.h"
+
+#include <stdint.h>
+#include <time.h>
+
+#include "err_macro.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static const int64_t NS_PER_SEC = 1e9;
+
+typedef struct timespec timespec_t;
+
+A0_STATIC_INLINE
+a0_err_t a0_clock_now(clockid_t clk, timespec_t* out) {
+  A0_RETURN_SYSERR_ON_MINUS_ONE(clock_gettime(clk, out));
+  return A0_OK;
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_clock_add(timespec_t ts, int64_t add_nsec, timespec_t* out) {
+  out->tv_sec = ts.tv_sec + add_nsec / NS_PER_SEC;
+  out->tv_nsec = ts.tv_nsec + add_nsec % NS_PER_SEC;
+  if (out->tv_nsec >= NS_PER_SEC) {
+    out->tv_sec++;
+    out->tv_nsec -= NS_PER_SEC;
+  } else if (out->tv_nsec < 0) {
+    out->tv_sec--;
+    out->tv_nsec += NS_PER_SEC;
+  }
+
+  return A0_OK;
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_clock_convert(
+    clockid_t orig_clk,
+    timespec_t orig_ts,
+    clockid_t target_clk,
+    timespec_t* target_ts) {
+  timespec_t orig_now;
+  A0_RETURN_ERR_ON_ERR(a0_clock_now(orig_clk, &orig_now));
+  timespec_t target_now;
+  A0_RETURN_ERR_ON_ERR(a0_clock_now(target_clk, &target_now));
+
+  int64_t add_nsec = (orig_ts.tv_sec - orig_now.tv_sec) * NS_PER_SEC + (orig_ts.tv_nsec - orig_now.tv_nsec);
+  return a0_clock_add(target_now, add_nsec, target_ts);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // A0_SRC_CLOCK_H
diff --git a/src/libipc/platform/linux/a0/empty.h b/src/libipc/platform/linux/a0/empty.h
new file mode 100644
index 0000000..69fef8a
--- /dev/null
+++ b/src/libipc/platform/linux/a0/empty.h
@@ -0,0 +1,13 @@
+#ifndef A0_EMPTY_H
+#define A0_EMPTY_H
+
+// Bah. Why is there no consistent way to zero initialize a struct?
+#ifdef __cplusplus
+#define A0_EMPTY \
+  {}
+#else
+#define A0_EMPTY \
+  { 0 }
+#endif
+
+#endif  // A0_EMPTY_H
diff --git a/src/libipc/platform/linux/a0/err.c b/src/libipc/platform/linux/a0/err.c
new file mode 100644
index 0000000..a48b858
--- /dev/null
+++ b/src/libipc/platform/linux/a0/err.c
@@ -0,0 +1,50 @@
+#include "a0/err.h"
+#include "a0/thread_local.h"
+
+#include <errno.h>
+#include <string.h>
+
+A0_THREAD_LOCAL int a0_err_syscode;
+A0_THREAD_LOCAL char a0_err_msg[1024];
+
+const char* a0_strerror(a0_err_t err) {
+  switch (err) {
+    case A0_OK: {
+      return strerror(0);
+    }
+    case A0_ERR_SYS: {
+      return strerror(a0_err_syscode);
+    }
+    case A0_ERR_CUSTOM_MSG: {
+      return a0_err_msg;
+    }
+    case A0_ERR_INVALID_ARG: {
+      return strerror(EINVAL);
+    }
+    case A0_ERR_RANGE: {
+      return "Index out of bounds";
+    }
+    case A0_ERR_AGAIN: {
+      return "Not available yet";
+    }
+    case A0_ERR_FRAME_LARGE: {
+      return "Frame size too large";
+    }
+    case A0_ERR_ITER_DONE: {
+      return "Done iterating";
+    }
+    case A0_ERR_NOT_FOUND: {
+      return "Not found";
+    }
+    case A0_ERR_BAD_PATH: {
+      return "Invalid path";
+    }
+    case A0_ERR_BAD_TOPIC: {
+      return "Invalid topic name";
+    }
+    default: {
+      break;
+    }
+  }
+  return "";
+}
diff --git a/src/libipc/platform/linux/a0/err.h b/src/libipc/platform/linux/a0/err.h
new file mode 100644
index 0000000..05b7007
--- /dev/null
+++ b/src/libipc/platform/linux/a0/err.h
@@ -0,0 +1,33 @@
+#ifndef A0_ERR_H
+#define A0_ERR_H
+
+#include "a0/thread_local.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef enum a0_err_e {
+  A0_OK = 0,
+  A0_ERR_SYS = 1,
+  A0_ERR_CUSTOM_MSG = 2,
+  A0_ERR_INVALID_ARG = 3,
+  A0_ERR_RANGE = 4,
+  A0_ERR_AGAIN = 5,
+  A0_ERR_ITER_DONE = 6,
+  A0_ERR_NOT_FOUND = 7,
+  A0_ERR_FRAME_LARGE = 8,
+  A0_ERR_BAD_PATH = 9,
+  A0_ERR_BAD_TOPIC = 10,
+} a0_err_t;
+
+extern A0_THREAD_LOCAL int a0_err_syscode;
+extern A0_THREAD_LOCAL char a0_err_msg[1024];
+
+const char* a0_strerror(a0_err_t);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // A0_ERR_H
diff --git a/src/libipc/platform/linux/a0/err_macro.h b/src/libipc/platform/linux/a0/err_macro.h
new file mode 100644
index 0000000..6683efc
--- /dev/null
+++ b/src/libipc/platform/linux/a0/err_macro.h
@@ -0,0 +1,52 @@
+#ifndef A0_SRC_ERR_MACRO_H
+#define A0_SRC_ERR_MACRO_H
+
+#include "a0/err.h"
+#include "a0/inline.h"
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+A0_STATIC_INLINE
+a0_err_t A0_MAKE_SYSERR(int syserr) {
+  a0_err_syscode = syserr;
+  return A0_ERR_SYS;
+}
+
+A0_STATIC_INLINE
+int A0_SYSERR(a0_err_t err) {
+  return err == A0_ERR_SYS ? a0_err_syscode : 0;
+}
+
+A0_STATIC_INLINE_RECURSIVE
+a0_err_t A0_MAKE_MSGERR(const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  if (fmt) {
+    vsnprintf(a0_err_msg, sizeof(a0_err_msg), fmt, args);  // NOLINT(clang-analyzer-valist.Uninitialized): https://bugs.llvm.org/show_bug.cgi?id=41311
+    va_end(args);
+    return A0_ERR_CUSTOM_MSG;
+  }
+  va_end(args);
+  return A0_OK;
+}
+
+#define A0_RETURN_SYSERR_ON_MINUS_ONE(X) \
+  do {                                   \
+    if ((X) == -1) {                     \
+      a0_err_syscode = errno;            \
+      return A0_ERR_SYS;                 \
+    }                                    \
+  } while (0)
+
+#define A0_RETURN_ERR_ON_ERR(X) \
+  do {                          \
+    a0_err_t _err = (X);        \
+    if (_err) {                 \
+      return _err;              \
+    }                           \
+  } while (0)
+
+#endif  // A0_SRC_ERR_MACRO_H
diff --git a/src/libipc/platform/linux/a0/ftx.h b/src/libipc/platform/linux/a0/ftx.h
new file mode 100644
index 0000000..d0d4c3d
--- /dev/null
+++ b/src/libipc/platform/linux/a0/ftx.h
@@ -0,0 +1,111 @@
+#ifndef A0_SRC_FTX_H
+#define A0_SRC_FTX_H
+
+#include "a0/err.h"
+#include "a0/inline.h"
+#include "a0/time.h"
+
+#include <limits.h>
+#include <linux/futex.h>
+#include <stdint.h>
+#include <syscall.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "clock.h"
+#include "err_macro.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// FUTEX_WAIT and FUTEX_WAIT_REQUEUE_PI default to CLOCK_MONOTONIC,
+// but FUTEX_LOCK_PI always uses CLOCK_REALTIME.
+//
+// Until someone tells me otherwise, I assume this is bad decision making
+// and I will instead standardize all things on CLOCK_BOOTTIME.
+
+// Futex.
+// Operations rely on the address.
+// It should not be copied or moved.
+typedef uint32_t a0_ftx_t;
+
+A0_STATIC_INLINE
+a0_err_t a0_futex(a0_ftx_t* uaddr,
+                  int futex_op,
+                  int val,
+                  uintptr_t timeout_or_val2,
+                  a0_ftx_t* uaddr2,
+                  int val3) {
+  A0_RETURN_SYSERR_ON_MINUS_ONE(syscall(SYS_futex, uaddr, futex_op, val, timeout_or_val2, uaddr2, val3));
+  return A0_OK;
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_ftx_wait(a0_ftx_t* ftx, int confirm_val, const a0_time_mono_t* time_mono) {
+  if (!time_mono) {
+    return a0_futex(ftx, FUTEX_WAIT, confirm_val, 0, NULL, 0);
+  }
+
+  timespec_t ts_mono;
+  A0_RETURN_ERR_ON_ERR(a0_clock_convert(CLOCK_BOOTTIME, time_mono->ts, CLOCK_MONOTONIC, &ts_mono));
+  return a0_futex(ftx, FUTEX_WAIT, confirm_val, (uintptr_t)&ts_mono, NULL, 0);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_ftx_wake(a0_ftx_t* ftx, int cnt) {
+  return a0_futex(ftx, FUTEX_WAKE, cnt, 0, NULL, 0);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_ftx_signal(a0_ftx_t* ftx) {
+  return a0_ftx_wake(ftx, 1);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_ftx_broadcast(a0_ftx_t* ftx) {
+  return a0_ftx_wake(ftx, INT_MAX);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_ftx_lock_pi(a0_ftx_t* ftx, const a0_time_mono_t* time_mono) {
+  if (!time_mono) {
+    return a0_futex(ftx, FUTEX_LOCK_PI, 0, 0, NULL, 0);
+  }
+
+  timespec_t ts_wall;
+  A0_RETURN_ERR_ON_ERR(a0_clock_convert(CLOCK_BOOTTIME, time_mono->ts, CLOCK_REALTIME, &ts_wall));
+  return a0_futex(ftx, FUTEX_LOCK_PI, 0, (uintptr_t)&ts_wall, NULL, 0);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_ftx_trylock_pi(a0_ftx_t* ftx) {
+  return a0_futex(ftx, FUTEX_TRYLOCK_PI, 0, 0, NULL, 0);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_ftx_unlock_pi(a0_ftx_t* ftx) {
+  return a0_futex(ftx, FUTEX_UNLOCK_PI, 0, 0, NULL, 0);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_ftx_cmp_requeue_pi(a0_ftx_t* ftx, int confirm_val, a0_ftx_t* requeue_ftx, int max_requeue) {
+  return a0_futex(ftx, FUTEX_CMP_REQUEUE_PI, 1, max_requeue, requeue_ftx, confirm_val);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_ftx_wait_requeue_pi(a0_ftx_t* ftx, int confirm_val, const a0_time_mono_t* time_mono, a0_ftx_t* requeue_ftx) {
+  if (!time_mono) {
+    return a0_futex(ftx, FUTEX_WAIT_REQUEUE_PI, confirm_val, 0, requeue_ftx, 0);
+  }
+
+  timespec_t ts_mono;
+  A0_RETURN_ERR_ON_ERR(a0_clock_convert(CLOCK_BOOTTIME, time_mono->ts, CLOCK_MONOTONIC, &ts_mono));
+  return a0_futex(ftx, FUTEX_WAIT_REQUEUE_PI, confirm_val, (uintptr_t)&ts_mono, requeue_ftx, 0);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // A0_SRC_FTX_H
diff --git a/src/libipc/platform/linux/a0/inline.h b/src/libipc/platform/linux/a0/inline.h
new file mode 100644
index 0000000..a605540
--- /dev/null
+++ b/src/libipc/platform/linux/a0/inline.h
@@ -0,0 +1,8 @@
+#ifndef A0_INLINE_H
+#define A0_INLINE_H
+
+#define A0_STATIC_INLINE static inline __attribute__((always_inline))
+
+#define A0_STATIC_INLINE_RECURSIVE static inline
+
+#endif  // A0_INLINE_H
diff --git a/src/libipc/platform/linux/a0/mtx.c b/src/libipc/platform/linux/a0/mtx.c
new file mode 100644
index 0000000..00022b6
--- /dev/null
+++ b/src/libipc/platform/linux/a0/mtx.c
@@ -0,0 +1,420 @@
+#include "a0/err.h"
+#include "a0/inline.h"
+#include "a0/mtx.h"
+#include "a0/thread_local.h"
+#include "a0/tid.h"
+#include "a0/time.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <linux/futex.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <syscall.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "atomic.h"
+#include "clock.h"
+#include "err_macro.h"
+#include "ftx.h"
+
+// TSAN is worth the pain of properly annotating our mutex.
+
+// clang-format off
+#if defined(__SANITIZE_THREAD__)
+  #define A0_TSAN_ENABLED
+#elif defined(__has_feature)
+  #if __has_feature(thread_sanitizer)
+    #define A0_TSAN_ENABLED
+  #endif
+#endif
+// clang-format on
+
+const unsigned __tsan_mutex_linker_init = 1 << 0;
+const unsigned __tsan_mutex_write_reentrant = 1 << 1;
+const unsigned __tsan_mutex_read_reentrant = 1 << 2;
+const unsigned __tsan_mutex_not_static = 1 << 8;
+const unsigned __tsan_mutex_read_lock = 1 << 3;
+const unsigned __tsan_mutex_try_lock = 1 << 4;
+const unsigned __tsan_mutex_try_lock_failed = 1 << 5;
+const unsigned __tsan_mutex_recursive_lock = 1 << 6;
+const unsigned __tsan_mutex_recursive_unlock = 1 << 7;
+
+#ifdef A0_TSAN_ENABLED
+
+void __tsan_mutex_create(void* addr, unsigned flags);
+void __tsan_mutex_destroy(void* addr, unsigned flags);
+void __tsan_mutex_pre_lock(void* addr, unsigned flags);
+void __tsan_mutex_post_lock(void* addr, unsigned flags, int recursion);
+int __tsan_mutex_pre_unlock(void* addr, unsigned flags);
+void __tsan_mutex_post_unlock(void* addr, unsigned flags);
+void __tsan_mutex_pre_signal(void* addr, unsigned flags);
+void __tsan_mutex_post_signal(void* addr, unsigned flags);
+void __tsan_mutex_pre_divert(void* addr, unsigned flags);
+void __tsan_mutex_post_divert(void* addr, unsigned flags);
+
+#else
+
+#define _u_ __attribute__((unused))
+
+A0_STATIC_INLINE void _u_ __tsan_mutex_create(_u_ void* addr, _u_ unsigned flags) {}
+A0_STATIC_INLINE void _u_ __tsan_mutex_destroy(_u_ void* addr, _u_ unsigned flags) {}
+A0_STATIC_INLINE void _u_ __tsan_mutex_pre_lock(_u_ void* addr, _u_ unsigned flags) {}
+A0_STATIC_INLINE void _u_ __tsan_mutex_post_lock(_u_ void* addr,
+                                                 _u_ unsigned flags,
+                                                 _u_ int recursion) {}
+A0_STATIC_INLINE int _u_ __tsan_mutex_pre_unlock(_u_ void* addr, _u_ unsigned flags) {
+  return 0;
+}
+A0_STATIC_INLINE void _u_ __tsan_mutex_post_unlock(_u_ void* addr, _u_ unsigned flags) {}
+A0_STATIC_INLINE void _u_ __tsan_mutex_pre_signal(_u_ void* addr, _u_ unsigned flags) {}
+A0_STATIC_INLINE void _u_ __tsan_mutex_post_signal(_u_ void* addr, _u_ unsigned flags) {}
+A0_STATIC_INLINE void _u_ __tsan_mutex_pre_divert(_u_ void* addr, _u_ unsigned flags) {}
+A0_STATIC_INLINE void _u_ __tsan_mutex_post_divert(_u_ void* addr, _u_ unsigned flags) {}
+
+#endif
+
+A0_THREAD_LOCAL bool a0_robust_init = false;
+
+A0_STATIC_INLINE
+void a0_robust_reset() {
+  a0_robust_init = 0;
+}
+
+A0_STATIC_INLINE
+void a0_robust_reset_atfork() {
+  pthread_atfork(NULL, NULL, &a0_robust_reset);
+}
+
+static pthread_once_t a0_robust_reset_atfork_once;
+
+typedef struct robust_list robust_list_t;
+typedef struct robust_list_head robust_list_head_t;
+
+A0_THREAD_LOCAL robust_list_head_t a0_robust_head;
+
+A0_STATIC_INLINE
+void robust_init() {
+  a0_robust_head.list.next = &a0_robust_head.list;
+  a0_robust_head.futex_offset = offsetof(a0_mtx_t, ftx);
+  a0_robust_head.list_op_pending = NULL;
+  syscall(SYS_set_robust_list, &a0_robust_head.list, sizeof(a0_robust_head));
+}
+
+A0_STATIC_INLINE
+void init_thread() {
+  if (a0_robust_init) {
+    return;
+  }
+
+  pthread_once(&a0_robust_reset_atfork_once, a0_robust_reset_atfork);
+  robust_init();
+  a0_robust_init = true;
+}
+
+A0_STATIC_INLINE
+void robust_op_start(a0_mtx_t* mtx) {
+  init_thread();
+  a0_robust_head.list_op_pending = (struct robust_list*)mtx;
+  a0_barrier();
+}
+
+A0_STATIC_INLINE
+void robust_op_end(a0_mtx_t* mtx) {
+  (void)mtx;
+  a0_barrier();
+  a0_robust_head.list_op_pending = NULL;
+}
+
+A0_STATIC_INLINE
+bool robust_is_head(a0_mtx_t* mtx) {
+  return mtx == (a0_mtx_t*)&a0_robust_head;
+}
+
+A0_STATIC_INLINE
+void robust_op_add(a0_mtx_t* mtx) {
+  a0_mtx_t* old_first = (a0_mtx_t*)a0_robust_head.list.next;
+
+  mtx->prev = (a0_mtx_t*)&a0_robust_head;
+  mtx->next = old_first;
+
+  a0_barrier();
+
+  a0_robust_head.list.next = (robust_list_t*)mtx;
+  if (!robust_is_head(old_first)) {
+    old_first->prev = mtx;
+  }
+}
+
+A0_STATIC_INLINE
+void robust_op_del(a0_mtx_t* mtx) {
+  a0_mtx_t* prev = mtx->prev;
+  a0_mtx_t* next = mtx->next;
+  prev->next = next;
+  if (!robust_is_head(next)) {
+    next->prev = prev;
+  }
+}
+
+A0_STATIC_INLINE
+uint32_t ftx_tid(a0_ftx_t ftx) {
+  return ftx & FUTEX_TID_MASK;
+}
+
+A0_STATIC_INLINE
+bool ftx_owner_died(a0_ftx_t ftx) {
+  return ftx & FUTEX_OWNER_DIED;
+}
+
+static const uint32_t FTX_NOTRECOVERABLE = FUTEX_TID_MASK | FUTEX_OWNER_DIED;
+
+A0_STATIC_INLINE
+bool ftx_notrecoverable(a0_ftx_t ftx) {
+  return (ftx & FTX_NOTRECOVERABLE) == FTX_NOTRECOVERABLE;
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_mtx_timedlock_robust(a0_mtx_t* mtx, const a0_time_mono_t* timeout) {
+  const uint32_t tid = a0_tid();
+
+  int syserr = EINTR;
+  while (syserr == EINTR) {
+    // Can't lock if borked.
+    if (ftx_notrecoverable(a0_atomic_load(&mtx->ftx))) {
+      return A0_MAKE_SYSERR(ENOTRECOVERABLE);
+    }
+
+    // Try to lock without kernel involvement.
+    if (a0_cas(&mtx->ftx, 0, tid)) {
+      return A0_OK;
+    }
+
+    // Ask the kernel to lock.
+    syserr = A0_SYSERR(a0_ftx_lock_pi(&mtx->ftx, timeout));
+  }
+
+  if (!syserr) {
+    if (ftx_owner_died(a0_atomic_load(&mtx->ftx))) {
+      return A0_MAKE_SYSERR(EOWNERDEAD);
+    }
+    return A0_OK;
+  }
+
+  return A0_MAKE_SYSERR(syserr);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_mtx_timedlock_impl(a0_mtx_t* mtx, const a0_time_mono_t* timeout) {
+  // Note: __tsan_mutex_pre_lock should come here, but tsan doesn't provide
+  //       a way to "fail" a lock. Only a trylock.
+  robust_op_start(mtx);
+  const a0_err_t err = a0_mtx_timedlock_robust(mtx, timeout);
+  if (!err || A0_SYSERR(err) == EOWNERDEAD) {
+    __tsan_mutex_pre_lock(mtx, 0);
+    robust_op_add(mtx);
+    __tsan_mutex_post_lock(mtx, 0, 0);
+  }
+  robust_op_end(mtx);
+  return err;
+}
+
+a0_err_t a0_mtx_timedlock(a0_mtx_t* mtx, a0_time_mono_t timeout) {
+  return a0_mtx_timedlock_impl(mtx, &timeout);
+}
+
+a0_err_t a0_mtx_lock(a0_mtx_t* mtx) {
+  return a0_mtx_timedlock_impl(mtx, NULL);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_mtx_trylock_impl(a0_mtx_t* mtx) {
+  const uint32_t tid = a0_tid();
+
+  // Try to lock without kernel involvement.
+  uint32_t old = a0_cas_val(&mtx->ftx, 0, tid);
+
+  // Did it work?
+  if (!old) {
+    robust_op_add(mtx);
+    return A0_OK;
+  }
+
+  // Is the lock still usable?
+  if (ftx_notrecoverable(old)) {
+    return A0_MAKE_SYSERR(ENOTRECOVERABLE);
+  }
+
+  // Is the owner still alive?
+  if (!ftx_owner_died(old)) {
+    return A0_MAKE_SYSERR(EBUSY);
+  }
+
+  // Oh, the owner died. Ask the kernel to fix the state.
+  a0_err_t err = a0_ftx_trylock_pi(&mtx->ftx);
+  if (!err) {
+    robust_op_add(mtx);
+    if (ftx_owner_died(a0_atomic_load(&mtx->ftx))) {
+      return A0_MAKE_SYSERR(EOWNERDEAD);
+    }
+    return A0_OK;
+  }
+
+  // EAGAIN means that somebody else beat us to it.
+  // Anything else means we're borked.
+  if (A0_SYSERR(err) == EAGAIN) {
+    return A0_MAKE_SYSERR(EBUSY);
+  }
+  return A0_MAKE_SYSERR(ENOTRECOVERABLE);
+}
+
+a0_err_t a0_mtx_trylock(a0_mtx_t* mtx) {
+  __tsan_mutex_pre_lock(mtx, __tsan_mutex_try_lock);
+  robust_op_start(mtx);
+  a0_err_t err = a0_mtx_trylock_impl(mtx);
+  robust_op_end(mtx);
+  if (!err || A0_SYSERR(err) == EOWNERDEAD) {
+    __tsan_mutex_post_lock(mtx, __tsan_mutex_try_lock, 0);
+  } else {
+    __tsan_mutex_post_lock(mtx, __tsan_mutex_try_lock | __tsan_mutex_try_lock_failed, 0);
+  }
+  return err;
+}
+
+a0_err_t a0_mtx_consistent(a0_mtx_t* mtx) {
+  const uint32_t val = a0_atomic_load(&mtx->ftx);
+
+  // Why fix what isn't broken?
+  if (!ftx_owner_died(val)) {
+    return A0_MAKE_SYSERR(EINVAL);
+  }
+
+  // Is it yours to fix?
+  if (ftx_tid(val) != a0_tid()) {
+    return A0_MAKE_SYSERR(EPERM);
+  }
+
+  // Fix it!
+  a0_atomic_and_fetch(&mtx->ftx, ~FUTEX_OWNER_DIED);
+
+  return A0_OK;
+}
+
+a0_err_t a0_mtx_unlock(a0_mtx_t* mtx) {
+  const uint32_t tid = a0_tid();
+
+  const uint32_t val = a0_atomic_load(&mtx->ftx);
+
+  // Only the owner can unlock.
+  if (ftx_tid(val) != tid) {
+    return A0_MAKE_SYSERR(EPERM);
+  }
+
+  __tsan_mutex_pre_unlock(mtx, 0);
+
+  // If the mutex was acquired with EOWNERDEAD, the caller is responsible
+  // for fixing the state and marking the mutex consistent. If they did
+  // not mark it consistent and are unlocking... then we are unrecoverably
+  // borked!
+  uint32_t new_val = 0;
+  if (ftx_owner_died(val)) {
+    new_val = FTX_NOTRECOVERABLE;
+  }
+
+  robust_op_start(mtx);
+  robust_op_del(mtx);
+
+  // If the futex is exactly equal to tid, then there are no waiters and the
+  // kernel doesn't need to get involved.
+  if (!a0_cas(&mtx->ftx, tid, new_val)) {
+    // Ask the kernel to wake up a waiter.
+    a0_ftx_unlock_pi(&mtx->ftx);
+    if (new_val) {
+      a0_atomic_or_fetch(&mtx->ftx, new_val);
+    }
+  }
+
+  robust_op_end(mtx);
+  __tsan_mutex_post_unlock(mtx, 0);
+
+  return A0_OK;
+}
+
+// TODO(lshamis): Handle ENOTRECOVERABLE
+A0_STATIC_INLINE
+a0_err_t a0_cnd_timedwait_impl(a0_cnd_t* cnd, a0_mtx_t* mtx, const a0_time_mono_t* timeout) {
+  const uint32_t init_cnd = a0_atomic_load(cnd);
+
+  // Unblock other threads to do the things that will eventually signal this wait.
+  a0_err_t err = a0_mtx_unlock(mtx);
+  if (err) {
+    return err;
+  }
+
+  __tsan_mutex_pre_lock(mtx, 0);
+  robust_op_start(mtx);
+
+  do {
+    // Priority-inheritance-aware wait until awoken or timeout.
+    err = a0_ftx_wait_requeue_pi(cnd, init_cnd, timeout, &mtx->ftx);
+  } while (A0_SYSERR(err) == EINTR);
+
+  // We need to manually lock on timeout.
+  // Note: We keep the timeout error.
+  if (A0_SYSERR(err) == ETIMEDOUT) {
+    a0_mtx_timedlock_robust(mtx, NULL);
+  }
+  // Someone else grabbed and mutated the resource between the unlock and wait.
+  // No need to wait.
+  if (A0_SYSERR(err) == EAGAIN) {
+    err = a0_mtx_timedlock_robust(mtx, NULL);
+  }
+
+  robust_op_add(mtx);
+
+  // If no higher priority error, check the previous owner didn't die.
+  if (!err) {
+    err = ftx_owner_died(a0_atomic_load(&mtx->ftx)) ? EOWNERDEAD : A0_OK;
+  }
+
+  robust_op_end(mtx);
+  __tsan_mutex_post_lock(mtx, 0, 0);
+  return err;
+}
+
+a0_err_t a0_cnd_timedwait(a0_cnd_t* cnd, a0_mtx_t* mtx, a0_time_mono_t timeout) {
+  // Let's not unlock the mutex if we're going to get EINVAL due to a bad timeout.
+  if ((timeout.ts.tv_sec < 0 || timeout.ts.tv_nsec < 0 || (!timeout.ts.tv_sec && !timeout.ts.tv_nsec) || timeout.ts.tv_nsec >= NS_PER_SEC)) {
+    return A0_MAKE_SYSERR(EINVAL);
+  }
+  return a0_cnd_timedwait_impl(cnd, mtx, &timeout);
+}
+
+a0_err_t a0_cnd_wait(a0_cnd_t* cnd, a0_mtx_t* mtx) {
+  return a0_cnd_timedwait_impl(cnd, mtx, NULL);
+}
+
+A0_STATIC_INLINE
+a0_err_t a0_cnd_wake(a0_cnd_t* cnd, a0_mtx_t* mtx, uint32_t cnt) {
+  uint32_t val = a0_atomic_add_fetch(cnd, 1);
+
+  while (true) {
+    a0_err_t err = a0_ftx_cmp_requeue_pi(cnd, val, &mtx->ftx, cnt);
+    if (A0_SYSERR(err) != EAGAIN) {
+      return err;
+    }
+
+    // Another thread is also trying to wake this condition variable.
+    val = a0_atomic_load(cnd);
+  }
+}
+
+a0_err_t a0_cnd_signal(a0_cnd_t* cnd, a0_mtx_t* mtx) {
+  return a0_cnd_wake(cnd, mtx, 1);
+}
+
+a0_err_t a0_cnd_broadcast(a0_cnd_t* cnd, a0_mtx_t* mtx) {
+  return a0_cnd_wake(cnd, mtx, INT_MAX);
+}
diff --git a/src/libipc/platform/linux/a0/mtx.h b/src/libipc/platform/linux/a0/mtx.h
new file mode 100644
index 0000000..d27ce17
--- /dev/null
+++ b/src/libipc/platform/linux/a0/mtx.h
@@ -0,0 +1,57 @@
+#ifndef A0_MTX_H
+#define A0_MTX_H
+
+#include "a0/err.h"
+#include "a0/time.h"
+#include "a0/unused.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef uint32_t a0_ftx_t;
+
+// https://stackoverflow.com/questions/61645966/is-typedef-allowed-before-definition
+struct a0_mtx_s;
+
+typedef struct a0_mtx_s a0_mtx_t;
+
+// Mutex implementation designed for IPC.
+//
+// Similar to pthread_mutex_t with the following flags fixed:
+// * Process shared.
+// * Robust.
+// * Error checking.
+// * Priority inheriting.
+//
+// Unlike pthread_mutex_t, timespec are expected to use CLOCK_BOOTTIME.
+//
+// struct a0_mtx_s "Inherits" from robust_list, which requires:
+// * The first field MUST be a next pointer.
+// * There must be a futex, which makes the mutex immovable.
+//
+// Note: a mutex MUST be unlocked before being freed or unmapped.
+struct a0_mtx_s {
+  a0_mtx_t* next;
+  a0_mtx_t* prev;
+  a0_ftx_t ftx;
+};
+
+a0_err_t a0_mtx_lock(a0_mtx_t*) A0_WARN_UNUSED_RESULT;
+a0_err_t a0_mtx_timedlock(a0_mtx_t*, a0_time_mono_t) A0_WARN_UNUSED_RESULT;
+a0_err_t a0_mtx_trylock(a0_mtx_t*) A0_WARN_UNUSED_RESULT;
+a0_err_t a0_mtx_consistent(a0_mtx_t*);
+a0_err_t a0_mtx_unlock(a0_mtx_t*);
+
+typedef a0_ftx_t a0_cnd_t;
+
+a0_err_t a0_cnd_wait(a0_cnd_t*, a0_mtx_t*);
+a0_err_t a0_cnd_timedwait(a0_cnd_t*, a0_mtx_t*, a0_time_mono_t);
+a0_err_t a0_cnd_signal(a0_cnd_t*, a0_mtx_t*);
+a0_err_t a0_cnd_broadcast(a0_cnd_t*, a0_mtx_t*);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // A0_MTX_H
diff --git a/src/libipc/platform/linux/a0/strconv.c b/src/libipc/platform/linux/a0/strconv.c
new file mode 100644
index 0000000..70eedbf
--- /dev/null
+++ b/src/libipc/platform/linux/a0/strconv.c
@@ -0,0 +1,64 @@
+#include "strconv.h"
+
+#include "a0/err.h"
+
+#include <string.h>
+
+static const char DECIMAL_DIGITS[] =
+    "00010203040506070809"
+    "10111213141516171819"
+    "20212223242526272829"
+    "30313233343536373839"
+    "40414243444546474849"
+    "50515253545556575859"
+    "60616263646566676869"
+    "70717273747576777879"
+    "80818283848586878889"
+    "90919293949596979899";
+
+a0_err_t a0_u32_to_str(uint32_t val, char* buf_start, char* buf_end, char** start_ptr) {
+  return a0_u64_to_str(val, buf_start, buf_end, start_ptr);
+}
+
+a0_err_t a0_u64_to_str(uint64_t val, char* buf_start, char* buf_end, char** start_ptr) {
+  uint64_t orig_val = val;
+  char* ptr = buf_end;
+  while (val >= 10) {
+    ptr -= 2;
+    memcpy(ptr, &DECIMAL_DIGITS[2 * (val % 100)], sizeof(uint16_t));
+    val /= 100;
+  }
+  if (val) {
+    *--ptr = (char)('0' + val);
+  }
+  memset(buf_start, '0', ptr - buf_start);
+  ptr -= (!orig_val);
+  if (start_ptr) {
+    *start_ptr = ptr;
+  }
+  return A0_OK;
+}
+
+a0_err_t a0_str_to_u32(const char* start, const char* end, uint32_t* out) {
+  *out = 0;
+  for (const char* ptr = start; ptr < end; ptr++) {
+    if (*ptr < '0' || *ptr > '9') {
+      return A0_ERR_INVALID_ARG;
+    }
+    *out *= 10;
+    *out += *ptr - '0';
+  }
+  return A0_OK;
+}
+
+a0_err_t a0_str_to_u64(const char* start, const char* end, uint64_t* out) {
+  *out = 0;
+  for (const char* ptr = start; ptr < end; ptr++) {
+    if (*ptr < '0' || *ptr > '9') {
+      return A0_ERR_INVALID_ARG;
+    }
+    *out *= 10;
+    *out += *ptr - '0';
+  }
+  return A0_OK;
+}
diff --git a/src/libipc/platform/linux/a0/strconv.h b/src/libipc/platform/linux/a0/strconv.h
new file mode 100644
index 0000000..2f5b743
--- /dev/null
+++ b/src/libipc/platform/linux/a0/strconv.h
@@ -0,0 +1,31 @@
+#ifndef A0_SRC_STRCONV_H
+#define A0_SRC_STRCONV_H
+
+#include "a0/err.h"
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Converts a uint32 or uint64 to string.
+// The entire buffer will be populated, if not with given the value, then with '0'.
+// Populates the buffer from the back.
+// start_ptr, if not null, will be set to the point within the buffer where the number starts.
+// Does NOT check for overflow.
+a0_err_t a0_u32_to_str(uint32_t val, char* buf_start, char* buf_end, char** start_ptr);
+a0_err_t a0_u64_to_str(uint64_t val, char* buf_start, char* buf_end, char** start_ptr);
+
+// Converts a string to uint32 or uint64.
+// The string may have leading '0's.
+// Returns A0_ERR_INVALID_ARG if any character is not a digit.
+// Does NOT check for overflow.
+a0_err_t a0_str_to_u32(const char* start, const char* end, uint32_t* out);
+a0_err_t a0_str_to_u64(const char* start, const char* end, uint64_t* out);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // A0_SRC_STRCONV_H
diff --git a/src/libipc/platform/linux/a0/thread_local.h b/src/libipc/platform/linux/a0/thread_local.h
new file mode 100644
index 0000000..8e49813
--- /dev/null
+++ b/src/libipc/platform/linux/a0/thread_local.h
@@ -0,0 +1,10 @@
+#ifndef A0_THREAD_LOCAL_H
+#define A0_THREAD_LOCAL_H
+
+#ifdef __cplusplus
+#define A0_THREAD_LOCAL thread_local
+#else
+#define A0_THREAD_LOCAL _Thread_local
+#endif  // __cplusplus
+
+#endif  // A0_THREAD_LOCAL_H
diff --git a/src/libipc/platform/linux/a0/tid.c b/src/libipc/platform/linux/a0/tid.c
new file mode 100644
index 0000000..9ad016a
--- /dev/null
+++ b/src/libipc/platform/linux/a0/tid.c
@@ -0,0 +1,30 @@
+#include "a0/inline.h"
+#include "a0/thread_local.h"
+#include "a0/tid.h"
+
+#include <pthread.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <syscall.h>
+#include <unistd.h>
+
+A0_THREAD_LOCAL uint32_t a0_tid_cache = 0;
+static pthread_once_t a0_tid_reset_atfork_once;
+
+A0_STATIC_INLINE
+void a0_tid_reset() {
+  a0_tid_cache = 0;
+}
+
+A0_STATIC_INLINE
+void a0_tid_reset_atfork() {
+  pthread_atfork(NULL, NULL, &a0_tid_reset);
+}
+
+uint32_t a0_tid() {
+  if (!a0_tid_cache) {
+    a0_tid_cache = syscall(SYS_gettid);
+    pthread_once(&a0_tid_reset_atfork_once, a0_tid_reset_atfork);
+  }
+  return a0_tid_cache;
+}
diff --git a/src/libipc/platform/linux/a0/tid.h b/src/libipc/platform/linux/a0/tid.h
new file mode 100644
index 0000000..11cb71c
--- /dev/null
+++ b/src/libipc/platform/linux/a0/tid.h
@@ -0,0 +1,16 @@
+#ifndef A0_TID_H
+#define A0_TID_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+uint32_t a0_tid();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // A0_TID_H
diff --git a/src/libipc/platform/linux/a0/time.c b/src/libipc/platform/linux/a0/time.c
new file mode 100644
index 0000000..09a79b4
--- /dev/null
+++ b/src/libipc/platform/linux/a0/time.c
@@ -0,0 +1,124 @@
+#include "a0/empty.h"
+#include "a0/err.h"
+#include "a0/time.h"
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include "clock.h"
+#include "err_macro.h"
+#include "strconv.h"
+
+const char A0_TIME_MONO[] = "a0_time_mono";
+
+a0_err_t a0_time_mono_now(a0_time_mono_t* out) {
+  return a0_clock_now(CLOCK_BOOTTIME, &out->ts);
+}
+
+a0_err_t a0_time_mono_str(a0_time_mono_t time_mono, char mono_str[20]) {
+  // Mono time as unsigned integer with up to 20 chars: "18446744072709551615"
+  uint64_t ns = time_mono.ts.tv_sec * NS_PER_SEC + time_mono.ts.tv_nsec;
+  mono_str[19] = '\0';
+  return a0_u64_to_str(ns, mono_str, mono_str + 19, NULL);
+}
+
+a0_err_t a0_time_mono_parse(const char mono_str[20], a0_time_mono_t* out) {
+  uint64_t ns;
+  A0_RETURN_ERR_ON_ERR(a0_str_to_u64(mono_str, mono_str + 19, &ns));
+  out->ts.tv_sec = ns / NS_PER_SEC;
+  out->ts.tv_nsec = ns % NS_PER_SEC;
+  return A0_OK;
+}
+
+a0_err_t a0_time_mono_add(a0_time_mono_t time_mono, int64_t add_nsec, a0_time_mono_t* out) {
+  return a0_clock_add(time_mono.ts, add_nsec, &out->ts);
+}
+
+const char A0_TIME_WALL[] = "a0_time_wall";
+
+a0_err_t a0_time_wall_now(a0_time_wall_t* out) {
+  A0_RETURN_SYSERR_ON_MINUS_ONE(clock_gettime(CLOCK_REALTIME, &out->ts));
+  return A0_OK;
+}
+
+a0_err_t a0_time_wall_str(a0_time_wall_t wall_time, char wall_str[36]) {
+  // Wall time in RFC 3999 Nano: "2006-01-02T15:04:05.999999999-07:00"
+  struct tm wall_tm;
+  gmtime_r(&wall_time.ts.tv_sec, &wall_tm);
+
+  strftime(&wall_str[0], 20, "%Y-%m-%dT%H:%M:%S", &wall_tm);
+  snprintf(&wall_str[19], 17, ".%09ld-00:00", wall_time.ts.tv_nsec);
+  wall_str[35] = '\0';
+
+  return A0_OK;
+}
+
+a0_err_t a0_time_wall_parse(const char wall_str[36], a0_time_wall_t* out) {
+  // strptime requires _GNU_SOURCE, which we don't want, so we do it our selves.
+  // Hard code "%Y-%m-%dT%H:%M:%S" + ".%09ld-00:00" pattern.
+
+  struct tm wall_tm = A0_EMPTY;
+  // %Y
+  A0_RETURN_ERR_ON_ERR(a0_str_to_u32(wall_str + 0, wall_str + 4, (uint32_t*)&wall_tm.tm_year));
+  wall_tm.tm_year -= 1900;
+  // -
+  if (wall_str[4] != '-') {
+    return A0_ERR_INVALID_ARG;
+  }
+  // %m
+  A0_RETURN_ERR_ON_ERR(a0_str_to_u32(wall_str + 5, wall_str + 7, (uint32_t*)&wall_tm.tm_mon));
+  if (wall_tm.tm_mon < 1 || wall_tm.tm_mon > 12) {
+    return A0_ERR_INVALID_ARG;
+  }
+  wall_tm.tm_mon--;
+  // -
+  if (wall_str[7] != '-') {
+    return A0_ERR_INVALID_ARG;
+  }
+  // %d
+  A0_RETURN_ERR_ON_ERR(a0_str_to_u32(wall_str + 8, wall_str + 10, (uint32_t*)&wall_tm.tm_mday));
+  if (wall_tm.tm_mday < 1 || wall_tm.tm_mday > 31) {
+    return A0_ERR_INVALID_ARG;
+  }
+  // T
+  if (wall_str[10] != 'T') {
+    return A0_ERR_INVALID_ARG;
+  }
+  // %H
+  A0_RETURN_ERR_ON_ERR(a0_str_to_u32(wall_str + 11, wall_str + 13, (uint32_t*)&wall_tm.tm_hour));
+  if (wall_tm.tm_hour > 24) {
+    return A0_ERR_INVALID_ARG;
+  }
+  // :
+  if (wall_str[13] != ':') {
+    return A0_ERR_INVALID_ARG;
+  }
+  // %M
+  A0_RETURN_ERR_ON_ERR(a0_str_to_u32(wall_str + 14, wall_str + 16, (uint32_t*)&wall_tm.tm_min));
+  if (wall_tm.tm_min > 60) {
+    return A0_ERR_INVALID_ARG;
+  }
+  // :
+  if (wall_str[16] != ':') {
+    return A0_ERR_INVALID_ARG;
+  }
+  // %S
+  A0_RETURN_ERR_ON_ERR(a0_str_to_u32(wall_str + 17, wall_str + 19, (uint32_t*)&wall_tm.tm_sec));
+  if (wall_tm.tm_sec > 61) {
+    return A0_ERR_INVALID_ARG;
+  }
+  // .
+  if (wall_str[19] != '.') {
+    return A0_ERR_INVALID_ARG;
+  }
+
+  if (memcmp(wall_str + 29, "-00:00", 6) != 0) {
+    return A0_ERR_INVALID_ARG;
+  }
+
+  // Use timegm, cause it's a pain to compute months/years to seconds.
+  out->ts.tv_sec = timegm(&wall_tm);
+  return a0_str_to_u64(wall_str + 20, wall_str + 29, (uint64_t*)&out->ts.tv_nsec);
+}
diff --git a/src/libipc/platform/linux/a0/time.h b/src/libipc/platform/linux/a0/time.h
new file mode 100644
index 0000000..77e49c4
--- /dev/null
+++ b/src/libipc/platform/linux/a0/time.h
@@ -0,0 +1,97 @@
+/**
+ * \file time.h
+ * \rst
+ *
+ * Mono Time
+ * ---------
+ *
+ * | Mono time is a number of nanoseconds from machine boottime.
+ * | This time cannot decrease and duration between ticks is constant.
+ * | This time is not related to wall clock time.
+ * | This time is most suitable for measuring durations.
+ * |
+ * | As a string, it is represented as a 20 char number:
+ * | **18446744072709551615**
+ * |
+ * | Note that this uses CLOCK_BOOTTIME under the hood, not CLOCK_MONOTONIC.
+ *
+ * Wall Time
+ * ---------
+ *
+ * | Wall time is an time object representing human-readable wall clock time.
+ * | This time can decrease and duration between ticks is not constant.
+ * | This time is most related to wall clock time.
+ * | This time is not suitable for measuring durations.
+ * |
+ * | As a string, it is represented as a 36 char RFC 3999 Nano / ISO 8601:
+ * | **2006-01-02T15:04:05.999999999-07:00**
+ *
+ * \endrst
+ */
+
+#ifndef A0_TIME_H
+#define A0_TIME_H
+
+#include "a0/err.h"
+
+#include <stdint.h>
+#include <time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** \addtogroup TIME_MONO
+ *  @{
+ */
+
+/// Header key for mono timestamps.
+extern const char A0_TIME_MONO[];
+
+/// Monotonic timestamp. Despite the name, uses CLOCK_BOOTTIME.
+typedef struct a0_time_mono_s {
+  struct timespec ts;
+} a0_time_mono_t;
+
+/// Get the current mono timestamps.
+a0_err_t a0_time_mono_now(a0_time_mono_t*);
+
+/// Stringify a given mono timestamps.
+a0_err_t a0_time_mono_str(a0_time_mono_t, char mono_str[20]);
+
+/// Parse a stringified mono timestamps.
+a0_err_t a0_time_mono_parse(const char mono_str[20], a0_time_mono_t*);
+
+/// Add a duration in nanoseconds to a mono timestamp.
+a0_err_t a0_time_mono_add(a0_time_mono_t, int64_t add_nsec, a0_time_mono_t*);
+
+/** @}*/
+
+/** \addtogroup TIME_WALL
+ *  @{
+ */
+
+/// Header key for wall timestamps.
+extern const char A0_TIME_WALL[];
+
+/// Wall clock timestamp.
+typedef struct a0_time_wall_s {
+  struct timespec ts;
+} a0_time_wall_t;
+
+/// Get the current wall timestamps.
+a0_err_t a0_time_wall_now(a0_time_wall_t*);
+
+/// Stringify a given wall timestamps.
+a0_err_t a0_time_wall_str(a0_time_wall_t, char wall_str[36]);
+
+/// Parse a stringified wall timestamps.
+a0_err_t a0_time_wall_parse(const char wall_str[36], a0_time_wall_t*);
+
+/** @}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // A0_TRANSPORT_H
diff --git a/src/libipc/platform/linux/a0/unused.h b/src/libipc/platform/linux/a0/unused.h
new file mode 100644
index 0000000..8b1025a
--- /dev/null
+++ b/src/libipc/platform/linux/a0/unused.h
@@ -0,0 +1,7 @@
+#ifndef A0_UNUSED_H
+#define A0_UNUSED_H
+
+#define A0_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#define A0_MAYBE_UNUSED(X) ((void)(X))
+
+#endif  // A0_UNUSED_H
diff --git a/src/libipc/platform/linux/condition.h b/src/libipc/platform/linux/condition.h
new file mode 100644
index 0000000..c4f00ca
--- /dev/null
+++ b/src/libipc/platform/linux/condition.h
@@ -0,0 +1,66 @@
+#pragma once
+
+#include "libipc/utility/log.h"
+#include "libipc/mutex.h"
+
+#include "get_wait_time.h"
+#include "sync_obj_impl.h"
+
+#include "a0/err_macro.h"
+#include "a0/mtx.h"
+
+namespace ipc {
+namespace detail {
+namespace sync {
+
+class condition : public sync::obj_impl<a0_cnd_t> {
+public:
+    condition() = default;
+    ~condition() = default;
+
+    bool wait(ipc::sync::mutex &mtx, std::uint64_t tm) noexcept {
+        if (!valid()) return false;
+        if (tm == invalid_value) {
+            int eno = A0_SYSERR(a0_cnd_wait(native(), static_cast<a0_mtx_t *>(mtx.native())));
+            if (eno != 0) {
+                ipc::error("fail condition wait[%d]\n", eno);
+                return false;
+            }
+        } else {
+            auto ts = detail::make_timespec(tm);
+            int eno = A0_SYSERR(a0_cnd_timedwait(native(), static_cast<a0_mtx_t *>(mtx.native()), {ts}));
+            if (eno != 0) {
+                if (eno != ETIMEDOUT) {
+                    ipc::error("fail condition timedwait[%d]: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",
+                                eno, tm, ts.tv_sec, ts.tv_nsec);
+                }
+                return false;
+            }
+        }
+        return true;
+    }
+
+    bool notify(ipc::sync::mutex &mtx) noexcept {
+        if (!valid()) return false;
+        int eno = A0_SYSERR(a0_cnd_signal(native(), static_cast<a0_mtx_t *>(mtx.native())));
+        if (eno != 0) {
+            ipc::error("fail condition notify[%d]\n", eno);
+            return false;
+        }
+        return true;
+    }
+
+    bool broadcast(ipc::sync::mutex &mtx) noexcept {
+        if (!valid()) return false;
+        int eno = A0_SYSERR(a0_cnd_broadcast(native(), static_cast<a0_mtx_t *>(mtx.native())));
+        if (eno != 0) {
+            ipc::error("fail condition broadcast[%d]\n", eno);
+            return false;
+        }
+        return true;
+    }
+};
+
+} // namespace sync
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/linux/get_wait_time.h b/src/libipc/platform/linux/get_wait_time.h
new file mode 100644
index 0000000..ffaf2d2
--- /dev/null
+++ b/src/libipc/platform/linux/get_wait_time.h
@@ -0,0 +1,46 @@
+#pragma once
+
+#include <cstdint>
+#include <cinttypes>
+#include <system_error>
+
+#include "libipc/utility/log.h"
+
+#include "a0/time.h"
+#include "a0/err_macro.h"
+
+namespace ipc {
+namespace detail {
+
+inline bool calc_wait_time(timespec &ts, std::uint64_t tm /*ms*/) noexcept {
+    std::int64_t add_ns = static_cast<std::int64_t>(tm * 1000000ull);
+    if (add_ns < 0) {
+        ipc::error("invalid time = " PRIu64 "\n", tm);
+        return false;
+    }
+    a0_time_mono_t now;
+    int eno = A0_SYSERR(a0_time_mono_now(&now));
+    if (eno != 0) {
+        ipc::error("fail get time[%d]\n", eno);
+        return false;
+    }
+    a0_time_mono_t *target = reinterpret_cast<a0_time_mono_t *>(&ts);
+    if ((eno = A0_SYSERR(a0_time_mono_add(now, add_ns, target))) != 0) {
+        ipc::error("fail get time[%d]\n", eno);
+        return false;
+    }
+    return true;
+}
+
+inline timespec make_timespec(std::uint64_t tm /*ms*/) noexcept(false) {
+    timespec ts {};
+    if (!calc_wait_time(ts, tm)) {
+        ipc::error("fail calc_wait_time: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",
+                    tm, ts.tv_sec, ts.tv_nsec);
+        throw std::system_error{static_cast<int>(errno), std::system_category()};
+    }
+    return ts;
+}
+
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/linux/mutex.h b/src/libipc/platform/linux/mutex.h
new file mode 100644
index 0000000..52956e1
--- /dev/null
+++ b/src/libipc/platform/linux/mutex.h
@@ -0,0 +1,213 @@
+#pragma once
+
+#include <cstdint>
+#include <system_error>
+#include <mutex>
+#include <atomic>
+
+#include "libipc/platform/detail.h"
+#include "libipc/utility/log.h"
+#include "libipc/memory/resource.h"
+#include "libipc/shm.h"
+
+#include "get_wait_time.h"
+#include "sync_obj_impl.h"
+
+#include "a0/err_macro.h"
+#include "a0/mtx.h"
+
+namespace ipc {
+namespace detail {
+namespace sync {
+
+class robust_mutex : public sync::obj_impl<a0_mtx_t> {
+public:
+    bool lock(std::uint64_t tm) noexcept {
+        if (!valid()) return false;
+        for (;;) {
+            auto ts = detail::make_timespec(tm);
+            int eno = A0_SYSERR(
+                (tm == invalid_value) ? a0_mtx_lock(native()) 
+                                      : a0_mtx_timedlock(native(), {ts}));
+            switch (eno) {
+            case 0:
+                return true;
+            case ETIMEDOUT:
+                return false;
+            case EOWNERDEAD: {
+                    int eno2 = A0_SYSERR(a0_mtx_consistent(native()));
+                    if (eno2 != 0) {
+                        ipc::error("fail mutex lock[%d] -> consistent[%d]\n", eno, eno2);
+                        return false;
+                    }
+                    int eno3 = A0_SYSERR(a0_mtx_unlock(native()));
+                    if (eno3 != 0) {
+                        ipc::error("fail mutex lock[%d] -> unlock[%d]\n", eno, eno3);
+                        return false;
+                    }
+                }
+                break; // loop again
+            default:
+                ipc::error("fail mutex lock[%d]\n", eno);
+                return false;
+            }
+        }
+    }
+
+    bool try_lock() noexcept(false) {
+        if (!valid()) return false;
+        int eno = A0_SYSERR(a0_mtx_timedlock(native(), {detail::make_timespec(0)}));
+        switch (eno) {
+        case 0:
+            return true;
+        case ETIMEDOUT:
+            return false;
+        case EOWNERDEAD: {
+                int eno2 = A0_SYSERR(a0_mtx_consistent(native()));
+                if (eno2 != 0) {
+                    ipc::error("fail mutex try_lock[%d] -> consistent[%d]\n", eno, eno2);
+                    break;
+                }
+                int eno3 = A0_SYSERR(a0_mtx_unlock(native()));
+                if (eno3 != 0) {
+                    ipc::error("fail mutex try_lock[%d] -> unlock[%d]\n", eno, eno3);
+                    break;
+                }
+            }
+            break;
+        default:
+            ipc::error("fail mutex try_lock[%d]\n", eno);
+            break;
+        }
+        throw std::system_error{eno, std::system_category()};
+    }
+
+    bool unlock() noexcept {
+        if (!valid()) return false;
+        int eno = A0_SYSERR(a0_mtx_unlock(native()));
+        if (eno != 0) {
+            ipc::error("fail mutex unlock[%d]\n", eno);
+            return false;
+        }
+        return true;
+    }
+};
+
+class mutex {
+    robust_mutex *mutex_ = nullptr;
+    std::atomic<std::int32_t> *ref_ = nullptr;
+
+    struct curr_prog {
+        struct shm_data {
+            robust_mutex mtx;
+            std::atomic<std::int32_t> ref;
+
+            struct init {
+                char const *name;
+            };
+            shm_data(init arg)
+                : mtx{}, ref{0} { mtx.open(arg.name); }
+        };
+        ipc::map<ipc::string, shm_data> mutex_handles;
+        std::mutex lock;
+
+        static curr_prog &get() {
+            static curr_prog info;
+            return info;
+        }
+    };
+
+    void acquire_mutex(char const *name) {
+        if (name == nullptr) {
+            return;
+        }
+        auto &info = curr_prog::get();
+        IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
+        auto it = info.mutex_handles.find(name);
+        if (it == info.mutex_handles.end()) {
+            it = info.mutex_handles
+                   .emplace(std::piecewise_construct, 
+                            std::forward_as_tuple(name),
+                            std::forward_as_tuple(curr_prog::shm_data::init{name}))
+                   .first;
+        }
+        mutex_ = &it->second.mtx;
+        ref_   = &it->second.ref;
+    }
+
+    template <typename F>
+    void release_mutex(ipc::string const &name, F &&clear) {
+        if (name.empty()) return;
+        auto &info = curr_prog::get();
+        IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
+        auto it = info.mutex_handles.find(name);
+        if (it == info.mutex_handles.end()) {
+            return;
+        }
+        if (clear()) {
+            info.mutex_handles.erase(it);
+        }
+    }
+
+public:
+    mutex() = default;
+    ~mutex() = default;
+
+    static void init() {
+        // Avoid exception problems caused by static member initialization order.
+        curr_prog::get();
+    }
+
+    a0_mtx_t const *native() const noexcept {
+        return valid() ? mutex_->native() : nullptr;
+    }
+
+    a0_mtx_t *native() noexcept {
+        return valid() ? mutex_->native() : nullptr;
+    }
+
+    bool valid() const noexcept {
+        return (mutex_ != nullptr) && (ref_ != nullptr) && mutex_->valid();
+    }
+
+    bool open(char const *name) noexcept {
+        close();
+        acquire_mutex(name);
+        if (!valid()) {
+            return false;
+        }
+        ref_->fetch_add(1, std::memory_order_relaxed);
+        return true;
+    }
+
+    void close() noexcept {
+        if ((mutex_ != nullptr) && (ref_ != nullptr)) {
+            if (mutex_->name() != nullptr) {
+                release_mutex(mutex_->name(), [this] {
+                    return ref_->fetch_sub(1, std::memory_order_relaxed) <= 1;
+                });
+            } else mutex_->close();
+        }
+        mutex_ = nullptr;
+        ref_   = nullptr;
+    }
+
+    bool lock(std::uint64_t tm) noexcept {
+        if (!valid()) return false;
+        return mutex_->lock(tm);
+    }
+
+    bool try_lock() noexcept(false) {
+        if (!valid()) return false;
+        return mutex_->try_lock();
+    }
+
+    bool unlock() noexcept {
+        if (!valid()) return false;
+        return mutex_->unlock();
+    }
+};
+
+} // namespace sync
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/linux/sync_obj_impl.h b/src/libipc/platform/linux/sync_obj_impl.h
new file mode 100644
index 0000000..e28f95d
--- /dev/null
+++ b/src/libipc/platform/linux/sync_obj_impl.h
@@ -0,0 +1,69 @@
+#pragma once
+
+#include "libipc/utility/log.h"
+#include "libipc/shm.h"
+
+#include "a0/empty.h"
+
+namespace ipc {
+namespace detail {
+namespace sync {
+
+template <typename SyncT>
+class obj_impl {
+public:
+    using sync_t = SyncT;
+
+protected:
+    ipc::shm::handle shm_;
+    sync_t *h_ = nullptr;
+
+    sync_t *acquire_handle(char const *name) {
+        if (!shm_.acquire(name, sizeof(sync_t))) {
+            ipc::error("[acquire_handle] fail shm.acquire: %s\n", name);
+            return nullptr;
+        }
+        return static_cast<sync_t *>(shm_.get());
+    }
+
+public:
+    obj_impl() = default;
+    ~obj_impl() = default;
+
+    sync_t const *native() const noexcept {
+        return h_;
+    }
+
+    sync_t *native() noexcept {
+        return h_;
+    }
+
+    char const *name() const noexcept {
+        return shm_.name();
+    }
+
+    bool valid() const noexcept {
+        return h_ != nullptr;
+    }
+
+    bool open(char const *name) noexcept {
+        close();
+        if ((h_ = acquire_handle(name)) == nullptr) {
+            return false;
+        }
+        if (shm_.ref() > 1) {
+            return true;
+        }
+        *h_ = A0_EMPTY;
+        return true;
+    }
+
+    void close() noexcept {
+        shm_.release();
+        h_ = nullptr;
+    }
+};
+
+} // namespace sync
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/platform.c b/src/libipc/platform/platform.c
new file mode 100644
index 0000000..49cc977
--- /dev/null
+++ b/src/libipc/platform/platform.c
@@ -0,0 +1,13 @@
+
+#include "libipc/platform/detail.h"
+#if defined(IPC_OS_WINDOWS_)
+#elif defined(IPC_OS_LINUX_)
+#include "libipc/platform/linux/a0/err.c"
+#include "libipc/platform/linux/a0/mtx.c"
+#include "libipc/platform/linux/a0/strconv.c"
+#include "libipc/platform/linux/a0/tid.c"
+#include "libipc/platform/linux/a0/time.c"
+#elif defined(IPC_OS_QNX_)
+#else/*IPC_OS*/
+#   error "Unsupported platform."
+#endif
diff --git a/src/libipc/platform/platform.cpp b/src/libipc/platform/platform.cpp
new file mode 100644
index 0000000..b77cbc9
--- /dev/null
+++ b/src/libipc/platform/platform.cpp
@@ -0,0 +1,9 @@
+
+#include "libipc/platform/detail.h"
+#if defined(IPC_OS_WINDOWS_)
+#include "libipc/platform/win/shm_win.cpp"
+#elif defined(IPC_OS_LINUX_) || defined(IPC_OS_QNX_)
+#include "libipc/platform/posix/shm_posix.cpp"
+#else/*IPC_OS*/
+#   error "Unsupported platform."
+#endif
diff --git a/src/libipc/platform/posix/condition.h b/src/libipc/platform/posix/condition.h
new file mode 100644
index 0000000..d283d68
--- /dev/null
+++ b/src/libipc/platform/posix/condition.h
@@ -0,0 +1,141 @@
+#pragma once
+
+#include <cstdint>
+#include <cstring>
+
+#include <pthread.h>
+
+#include "libipc/utility/log.h"
+#include "libipc/utility/scope_guard.h"
+#include "libipc/mutex.h"
+#include "libipc/shm.h"
+
+#include "get_wait_time.h"
+
+namespace ipc {
+namespace detail {
+namespace sync {
+
+class condition {
+    ipc::shm::handle shm_;
+    pthread_cond_t *cond_ = nullptr;
+
+    pthread_cond_t *acquire_cond(char const *name) {
+        if (!shm_.acquire(name, sizeof(pthread_cond_t))) {
+            ipc::error("[acquire_cond] fail shm.acquire: %s\n", name);
+            return nullptr;
+        }
+        return static_cast<pthread_cond_t *>(shm_.get());
+    }
+
+public:
+    condition() = default;
+    ~condition() = default;
+
+    pthread_cond_t const *native() const noexcept {
+        return cond_;
+    }
+
+    pthread_cond_t *native() noexcept {
+        return cond_;
+    }
+
+    bool valid() const noexcept {
+        static const char tmp[sizeof(pthread_cond_t)] {};
+        return (cond_ != nullptr)
+            && (std::memcmp(tmp, cond_, sizeof(pthread_cond_t)) != 0);
+    }
+
+    bool open(char const *name) noexcept {
+        close();
+        if ((cond_ = acquire_cond(name)) == nullptr) {
+            return false;
+        }
+        if (shm_.ref() > 1) {
+            return valid();
+        }
+        ::pthread_cond_destroy(cond_);
+        auto finally = ipc::guard([this] { close(); }); // close when failed
+        // init condition
+        int eno;
+        pthread_condattr_t cond_attr;
+        if ((eno = ::pthread_condattr_init(&cond_attr)) != 0) {
+            ipc::error("fail pthread_condattr_init[%d]\n", eno);
+            return false;
+        }
+        IPC_UNUSED_ auto guard_cond_attr = guard([&cond_attr] { ::pthread_condattr_destroy(&cond_attr); });
+        if ((eno = ::pthread_condattr_setpshared(&cond_attr, PTHREAD_PROCESS_SHARED)) != 0) {
+            ipc::error("fail pthread_condattr_setpshared[%d]\n", eno);
+            return false;
+        }
+        *cond_ = PTHREAD_COND_INITIALIZER;
+        if ((eno = ::pthread_cond_init(cond_, &cond_attr)) != 0) {
+            ipc::error("fail pthread_cond_init[%d]\n", eno);
+            return false;
+        }
+        finally.dismiss();
+        return valid();
+    }
+
+    void close() noexcept {
+        if ((shm_.ref() <= 1) && cond_ != nullptr) {
+            int eno;
+            if ((eno = ::pthread_cond_destroy(cond_)) != 0) {
+                ipc::error("fail pthread_cond_destroy[%d]\n", eno);
+            }
+        }
+        shm_.release();
+        cond_ = nullptr;
+    }
+
+    bool wait(ipc::sync::mutex &mtx, std::uint64_t tm) noexcept {
+        if (!valid()) return false;
+        switch (tm) {
+        case invalid_value: {
+                int eno;
+                if ((eno = ::pthread_cond_wait(cond_, static_cast<pthread_mutex_t *>(mtx.native()))) != 0) {
+                    ipc::error("fail pthread_cond_wait[%d]\n", eno);
+                    return false;
+                }
+            }
+            break;
+        default: {
+                auto ts = detail::make_timespec(tm);
+                int eno;
+                if ((eno = ::pthread_cond_timedwait(cond_, static_cast<pthread_mutex_t *>(mtx.native()), &ts)) != 0) {
+                    if (eno != ETIMEDOUT) {
+                        ipc::error("fail pthread_cond_timedwait[%d]: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",
+                                   eno, tm, ts.tv_sec, ts.tv_nsec);
+                    }
+                    return false;
+                }
+            }
+            break;
+        }
+        return true;
+    }
+
+    bool notify(ipc::sync::mutex &) noexcept {
+        if (!valid()) return false;
+        int eno;
+        if ((eno = ::pthread_cond_signal(cond_)) != 0) {
+            ipc::error("fail pthread_cond_signal[%d]\n", eno);
+            return false;
+        }
+        return true;
+    }
+
+    bool broadcast(ipc::sync::mutex &) noexcept {
+        if (!valid()) return false;
+        int eno;
+        if ((eno = ::pthread_cond_broadcast(cond_)) != 0) {
+            ipc::error("fail pthread_cond_broadcast[%d]\n", eno);
+            return false;
+        }
+        return true;
+    }
+};
+
+} // namespace sync
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/posix/get_wait_time.h b/src/libipc/platform/posix/get_wait_time.h
new file mode 100644
index 0000000..785cd75
--- /dev/null
+++ b/src/libipc/platform/posix/get_wait_time.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <cstdint>
+#include <system_error>
+
+#include <sys/time.h>
+#include <time.h>
+#include <errno.h>
+
+#include "libipc/utility/log.h"
+
+namespace ipc {
+namespace detail {
+
+inline bool calc_wait_time(timespec &ts, std::uint64_t tm /*ms*/) noexcept {
+    timeval now;
+    int eno = ::gettimeofday(&now, NULL);
+    if (eno != 0) {
+        ipc::error("fail gettimeofday [%d]\n", eno);
+        return false;
+    }
+    ts.tv_nsec = (now.tv_usec + (tm % 1000) * 1000) * 1000;
+    ts.tv_sec  =  now.tv_sec  + (tm / 1000) + (ts.tv_nsec / 1000000000l);
+    ts.tv_nsec %= 1000000000l;
+    return true;
+}
+
+inline timespec make_timespec(std::uint64_t tm /*ms*/) noexcept(false) {
+    timespec ts {};
+    if (!calc_wait_time(ts, tm)) {
+        ipc::error("fail calc_wait_time: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",
+                    tm, ts.tv_sec, ts.tv_nsec);
+        throw std::system_error{static_cast<int>(errno), std::system_category()};
+    }
+    return ts;
+}
+
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/posix/mutex.h b/src/libipc/platform/posix/mutex.h
new file mode 100644
index 0000000..9025b17
--- /dev/null
+++ b/src/libipc/platform/posix/mutex.h
@@ -0,0 +1,252 @@
+#pragma once
+
+#include <cstring>
+#include <cassert>
+#include <cstdint>
+#include <system_error>
+#include <mutex>
+#include <atomic>
+
+#include <pthread.h>
+
+#include "libipc/platform/detail.h"
+#include "libipc/utility/log.h"
+#include "libipc/utility/scope_guard.h"
+#include "libipc/memory/resource.h"
+#include "libipc/shm.h"
+
+#include "get_wait_time.h"
+
+namespace ipc {
+namespace detail {
+namespace sync {
+
+class mutex {
+    ipc::shm::handle *shm_ = nullptr;
+    std::atomic<std::int32_t> *ref_ = nullptr;
+    pthread_mutex_t *mutex_ = nullptr;
+
+    struct curr_prog {
+        struct shm_data {
+            ipc::shm::handle shm;
+            std::atomic<std::int32_t> ref;
+
+            struct init {
+                char const *name;
+                std::size_t size;
+            };
+            shm_data(init arg)
+                : shm{arg.name, arg.size}, ref{0} {}
+        };
+        ipc::map<ipc::string, shm_data> mutex_handles;
+        std::mutex lock;
+
+        static curr_prog &get() {
+            static curr_prog info;
+            return info;
+        }
+    };
+
+    pthread_mutex_t *acquire_mutex(char const *name) {
+        if (name == nullptr) {
+            return nullptr;
+        }
+        auto &info = curr_prog::get();
+        IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
+        auto it = info.mutex_handles.find(name);
+        if (it == info.mutex_handles.end()) {
+          it = info.mutex_handles
+                   .emplace(std::piecewise_construct,
+                            std::forward_as_tuple(name),
+                            std::forward_as_tuple(curr_prog::shm_data::init{
+                                name, sizeof(pthread_mutex_t)}))
+                   .first;
+        }
+        shm_ = &it->second.shm;
+        ref_ = &it->second.ref;
+        if (shm_ == nullptr) {
+            return nullptr;
+        }
+        return static_cast<pthread_mutex_t *>(shm_->get());
+    }
+
+    template <typename F>
+    void release_mutex(ipc::string const &name, F &&clear) {
+        if (name.empty()) return;
+        auto &info = curr_prog::get();
+        IPC_UNUSED_ std::lock_guard<std::mutex> guard {info.lock};
+        auto it = info.mutex_handles.find(name);
+        if (it == info.mutex_handles.end()) {
+            return;
+        }
+        if (clear()) {
+            info.mutex_handles.erase(it);
+        }
+    }
+
+    static pthread_mutex_t const &zero_mem() {
+        static const pthread_mutex_t tmp{};
+        return tmp;
+    }
+
+public:
+    mutex() = default;
+    ~mutex() = default;
+
+    static void init() {
+        // Avoid exception problems caused by static member initialization order.
+        zero_mem();
+        curr_prog::get();
+    }
+
+    pthread_mutex_t const *native() const noexcept {
+        return mutex_;
+    }
+
+    pthread_mutex_t *native() noexcept {
+        return mutex_;
+    }
+
+    bool valid() const noexcept {
+        return (shm_ != nullptr) && (ref_ != nullptr) && (mutex_ != nullptr)
+            && (std::memcmp(&zero_mem(), mutex_, sizeof(pthread_mutex_t)) != 0);
+    }
+
+    bool open(char const *name) noexcept {
+        close();
+        if ((mutex_ = acquire_mutex(name)) == nullptr) {
+            return false;
+        }
+        auto self_ref = ref_->fetch_add(1, std::memory_order_relaxed);
+        if (shm_->ref() > 1 || self_ref > 0) {
+            return valid();
+        }
+        ::pthread_mutex_destroy(mutex_);
+        auto finally = ipc::guard([this] { close(); }); // close when failed
+        // init mutex
+        int eno;
+        pthread_mutexattr_t mutex_attr;
+        if ((eno = ::pthread_mutexattr_init(&mutex_attr)) != 0) {
+            ipc::error("fail pthread_mutexattr_init[%d]\n", eno);
+            return false;
+        }
+        IPC_UNUSED_ auto guard_mutex_attr = guard([&mutex_attr] { ::pthread_mutexattr_destroy(&mutex_attr); });
+        if ((eno = ::pthread_mutexattr_setpshared(&mutex_attr, PTHREAD_PROCESS_SHARED)) != 0) {
+            ipc::error("fail pthread_mutexattr_setpshared[%d]\n", eno);
+            return false;
+        }
+        if ((eno = ::pthread_mutexattr_setrobust(&mutex_attr, PTHREAD_MUTEX_ROBUST)) != 0) {
+            ipc::error("fail pthread_mutexattr_setrobust[%d]\n", eno);
+            return false;
+        }
+        *mutex_ = PTHREAD_MUTEX_INITIALIZER;
+        if ((eno = ::pthread_mutex_init(mutex_, &mutex_attr)) != 0) {
+            ipc::error("fail pthread_mutex_init[%d]\n", eno);
+            return false;
+        }
+        finally.dismiss();
+        return valid();
+    }
+
+    void close() noexcept {
+        if ((ref_ != nullptr) && (shm_ != nullptr) && (mutex_ != nullptr)) {
+            if (shm_->name() != nullptr) {
+                release_mutex(shm_->name(), [this] {
+                    auto self_ref = ref_->fetch_sub(1, std::memory_order_relaxed);
+                    if ((shm_->ref() <= 1) && (self_ref <= 1)) {
+                        int eno;
+                        if ((eno = ::pthread_mutex_destroy(mutex_)) != 0) {
+                            ipc::error("fail pthread_mutex_destroy[%d]\n", eno);
+                        }
+                        return true;
+                    }
+                    return false;
+                });
+            } else shm_->release();
+        }
+        shm_   = nullptr;
+        ref_   = nullptr;
+        mutex_ = nullptr;
+    }
+
+    bool lock(std::uint64_t tm) noexcept {
+        if (!valid()) return false;
+        for (;;) {
+            auto ts = detail::make_timespec(tm);
+            int eno = (tm == invalid_value) 
+                ? ::pthread_mutex_lock(mutex_) 
+                : ::pthread_mutex_timedlock(mutex_, &ts);
+            switch (eno) {
+            case 0:
+                return true;
+            case ETIMEDOUT:
+                return false;
+            case EOWNERDEAD: {
+                    if (shm_->ref() > 1) {
+                        shm_->sub_ref();
+                    }
+                    int eno2 = ::pthread_mutex_consistent(mutex_);
+                    if (eno2 != 0) {
+                        ipc::error("fail pthread_mutex_lock[%d], pthread_mutex_consistent[%d]\n", eno, eno2);
+                        return false;
+                    }
+                    int eno3 = ::pthread_mutex_unlock(mutex_);
+                    if (eno3 != 0) {
+                        ipc::error("fail pthread_mutex_lock[%d], pthread_mutex_unlock[%d]\n", eno, eno3);
+                        return false;
+                    }
+                }
+                break; // loop again
+            default:
+                ipc::error("fail pthread_mutex_lock[%d]\n", eno);
+                return false;
+            }
+        }
+    }
+
+    bool try_lock() noexcept(false) {
+        if (!valid()) return false;
+        auto ts = detail::make_timespec(0);
+        int eno = ::pthread_mutex_timedlock(mutex_, &ts);
+        switch (eno) {
+        case 0:
+            return true;
+        case ETIMEDOUT:
+            return false;
+        case EOWNERDEAD: {
+                if (shm_->ref() > 1) {
+                    shm_->sub_ref();
+                }
+                int eno2 = ::pthread_mutex_consistent(mutex_);
+                if (eno2 != 0) {
+                    ipc::error("fail pthread_mutex_timedlock[%d], pthread_mutex_consistent[%d]\n", eno, eno2);
+                    break;
+                }
+                int eno3 = ::pthread_mutex_unlock(mutex_);
+                if (eno3 != 0) {
+                    ipc::error("fail pthread_mutex_timedlock[%d], pthread_mutex_unlock[%d]\n", eno, eno3);
+                    break;
+                }
+            }
+            break;
+        default:
+            ipc::error("fail pthread_mutex_timedlock[%d]\n", eno);
+            break;
+        }
+        throw std::system_error{eno, std::system_category()};
+    }
+
+    bool unlock() noexcept {
+        if (!valid()) return false;
+        int eno;
+        if ((eno = ::pthread_mutex_unlock(mutex_)) != 0) {
+            ipc::error("fail pthread_mutex_unlock[%d]\n", eno);
+            return false;
+        }
+        return true;
+    }
+};
+
+} // namespace sync
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/posix/semaphore_impl.h b/src/libipc/platform/posix/semaphore_impl.h
new file mode 100644
index 0000000..d48bcd4
--- /dev/null
+++ b/src/libipc/platform/posix/semaphore_impl.h
@@ -0,0 +1,99 @@
+#pragma once
+
+#include <cstdint>
+
+#include <fcntl.h>      /* For O_* constants */
+#include <sys/stat.h>   /* For mode constants */
+#include <semaphore.h>
+#include <errno.h>
+
+#include "libipc/utility/log.h"
+#include "libipc/shm.h"
+
+#include "get_wait_time.h"
+
+namespace ipc {
+namespace detail {
+namespace sync {
+
+class semaphore {
+    ipc::shm::handle shm_;
+    sem_t *h_ = SEM_FAILED;
+
+public:
+    semaphore() = default;
+    ~semaphore() noexcept = default;
+
+    sem_t *native() const noexcept {
+        return h_;
+    }
+
+    bool valid() const noexcept {
+        return h_ != SEM_FAILED;
+    }
+
+    bool open(char const *name, std::uint32_t count) noexcept {
+        close();
+        if (!shm_.acquire(name, 1)) {
+            ipc::error("[open_semaphore] fail shm.acquire: %s\n", name);
+            return false;
+        }
+        h_ = ::sem_open(name, O_CREAT, 0666, static_cast<unsigned>(count));
+        if (h_ == SEM_FAILED) {
+            ipc::error("fail sem_open[%d]: %s\n", errno, name);
+            return false;
+        }
+        return true;
+    }
+
+    void close() noexcept {
+        if (!valid()) return;
+        if (::sem_close(h_) != 0) {
+            ipc::error("fail sem_close[%d]: %s\n", errno);
+        }
+        h_ = SEM_FAILED;
+        if (shm_.name() != nullptr) {
+            std::string name = shm_.name();
+            if (shm_.release() <= 1) {
+                if (::sem_unlink(name.c_str()) != 0) {
+                    ipc::error("fail sem_unlink[%d]: %s, name: %s\n", errno, name.c_str());
+                }
+            }
+        }
+    }
+
+    bool wait(std::uint64_t tm) noexcept {
+        if (!valid()) return false;
+        if (tm == invalid_value) {
+            if (::sem_wait(h_) != 0) {
+                ipc::error("fail sem_wait[%d]: %s\n", errno);
+                return false;
+            }
+        } else {
+            auto ts = detail::make_timespec(tm);
+            if (::sem_timedwait(h_, &ts) != 0) {
+                if (errno != ETIMEDOUT) {
+                    ipc::error("fail sem_timedwait[%d]: tm = %zd, tv_sec = %ld, tv_nsec = %ld\n",
+                                errno, tm, ts.tv_sec, ts.tv_nsec);
+                }
+                return false;
+            }
+        }
+        return true;
+    }
+
+    bool post(std::uint32_t count) noexcept {
+        if (!valid()) return false;
+        for (std::uint32_t i = 0; i < count; ++i) {
+            if (::sem_post(h_) != 0) {
+                ipc::error("fail sem_post[%d]: %s\n", errno);
+                return false;
+            }
+        }
+        return true;
+    }
+};
+
+} // namespace sync
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/posix/shm_posix.cpp b/src/libipc/platform/posix/shm_posix.cpp
new file mode 100644
index 0000000..e29bd6f
--- /dev/null
+++ b/src/libipc/platform/posix/shm_posix.cpp
@@ -0,0 +1,200 @@
+
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <atomic>
+#include <string>
+#include <utility>
+#include <cstring>
+
+#include "libipc/shm.h"
+#include "libipc/def.h"
+#include "libipc/pool_alloc.h"
+
+#include "libipc/utility/log.h"
+#include "libipc/memory/resource.h"
+
+namespace {
+
+struct info_t {
+    std::atomic<std::int32_t> acc_;
+};
+
+struct id_info_t {
+    int         fd_   = -1;
+    void*       mem_  = nullptr;
+    std::size_t size_ = 0;
+    ipc::string name_;
+};
+
+constexpr std::size_t calc_size(std::size_t size) {
+    return ((((size - 1) / alignof(info_t)) + 1) * alignof(info_t)) + sizeof(info_t);
+}
+
+inline auto& acc_of(void* mem, std::size_t size) {
+    return reinterpret_cast<info_t*>(static_cast<ipc::byte_t*>(mem) + size - sizeof(info_t))->acc_;
+}
+
+} // internal-linkage
+
+namespace ipc {
+namespace shm {
+
+id_t acquire(char const * name, std::size_t size, unsigned mode) {
+    if (!is_valid_string(name)) {
+        ipc::error("fail acquire: name is empty\n");
+        return nullptr;
+    }
+    // For portable use, a shared memory object should be identified by name of the form /somename.
+    // see: https://man7.org/linux/man-pages/man3/shm_open.3.html
+    ipc::string op_name = ipc::string{"/"} + name;
+    // Open the object for read-write access.
+    int flag = O_RDWR;
+    switch (mode) {
+    case open:
+        size = 0;
+        break;
+    // The check for the existence of the object, 
+    // and its creation if it does not exist, are performed atomically.
+    case create:
+        flag |= O_CREAT | O_EXCL;
+        break;
+    // Create the shared memory object if it does not exist.
+    default:
+        flag |= O_CREAT;
+        break;
+    }
+    int fd = ::shm_open(op_name.c_str(), flag, S_IRUSR | S_IWUSR |
+                                               S_IRGRP | S_IWGRP |
+                                               S_IROTH | S_IWOTH);
+    if (fd == -1) {
+        ipc::error("fail shm_open[%d]: %s\n", errno, op_name.c_str());
+        return nullptr;
+    }
+    auto ii = mem::alloc<id_info_t>();
+    ii->fd_   = fd;
+    ii->size_ = size;
+    ii->name_ = std::move(op_name);
+    return ii;
+}
+
+std::int32_t get_ref(id_t id) {
+    if (id == nullptr) {
+        return 0;
+    }
+    auto ii = static_cast<id_info_t*>(id);
+    if (ii->mem_ == nullptr || ii->size_ == 0) {
+        return 0;
+    }
+    return acc_of(ii->mem_, ii->size_).load(std::memory_order_acquire);
+}
+
+void sub_ref(id_t id) {
+    if (id == nullptr) {
+        ipc::error("fail sub_ref: invalid id (null)\n");
+        return;
+    }
+    auto ii = static_cast<id_info_t*>(id);
+    if (ii->mem_ == nullptr || ii->size_ == 0) {
+        ipc::error("fail sub_ref: invalid id (mem = %p, size = %zd)\n", ii->mem_, ii->size_);
+        return;
+    }
+    acc_of(ii->mem_, ii->size_).fetch_sub(1, std::memory_order_acq_rel);
+}
+
+void * get_mem(id_t id, std::size_t * size) {
+    if (id == nullptr) {
+        ipc::error("fail get_mem: invalid id (null)\n");
+        return nullptr;
+    }
+    auto ii = static_cast<id_info_t*>(id);
+    if (ii->mem_ != nullptr) {
+        if (size != nullptr) *size = ii->size_;
+        return ii->mem_;
+    }
+    int fd = ii->fd_;
+    if (fd == -1) {
+        ipc::error("fail get_mem: invalid id (fd = -1)\n");
+        return nullptr;
+    }
+    if (ii->size_ == 0) {
+        struct stat st;
+        if (::fstat(fd, &st) != 0) {
+            ipc::error("fail fstat[%d]: %s, size = %zd\n", errno, ii->name_.c_str(), ii->size_);
+            return nullptr;
+        }
+        ii->size_ = static_cast<std::size_t>(st.st_size);
+        if ((ii->size_ <= sizeof(info_t)) || (ii->size_ % sizeof(info_t))) {
+            ipc::error("fail get_mem: %s, invalid size = %zd\n", ii->name_.c_str(), ii->size_);
+            return nullptr;
+        }
+    }
+    else {
+        ii->size_ = calc_size(ii->size_);
+        if (::ftruncate(fd, static_cast<off_t>(ii->size_)) != 0) {
+            ipc::error("fail ftruncate[%d]: %s, size = %zd\n", errno, ii->name_.c_str(), ii->size_);
+            return nullptr;
+        }
+    }
+    void* mem = ::mmap(nullptr, ii->size_, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (mem == MAP_FAILED) {
+        ipc::error("fail mmap[%d]: %s, size = %zd\n", errno, ii->name_.c_str(), ii->size_);
+        return nullptr;
+    }
+    ::close(fd);
+    ii->fd_  = -1;
+    ii->mem_ = mem;
+    if (size != nullptr) *size = ii->size_;
+    acc_of(mem, ii->size_).fetch_add(1, std::memory_order_release);
+    return mem;
+}
+
+std::int32_t release(id_t id) {
+    if (id == nullptr) {
+        ipc::error("fail release: invalid id (null)\n");
+        return -1;
+    }
+    std::int32_t ret = -1;
+    auto ii = static_cast<id_info_t*>(id);
+    if (ii->mem_ == nullptr || ii->size_ == 0) {
+        ipc::error("fail release: invalid id (mem = %p, size = %zd), name = %s\n", 
+                    ii->mem_, ii->size_, ii->name_.c_str());
+    }
+    else if ((ret = acc_of(ii->mem_, ii->size_).fetch_sub(1, std::memory_order_acq_rel)) <= 1) {
+        ::munmap(ii->mem_, ii->size_);
+        if (!ii->name_.empty()) {
+            ::shm_unlink(ii->name_.c_str());
+        }
+    }
+    else ::munmap(ii->mem_, ii->size_);
+    mem::free(ii);
+    return ret;
+}
+
+void remove(id_t id) {
+    if (id == nullptr) {
+        ipc::error("fail remove: invalid id (null)\n");
+        return;
+    }
+    auto ii = static_cast<id_info_t*>(id);
+    auto name = std::move(ii->name_);
+    release(id);
+    if (!name.empty()) {
+        ::shm_unlink(name.c_str());
+    }
+}
+
+void remove(char const * name) {
+    if (!is_valid_string(name)) {
+        ipc::error("fail remove: name is empty\n");
+        return;
+    }
+    ::shm_unlink(name);
+}
+
+} // namespace shm
+} // namespace ipc
diff --git a/src/libipc/platform/win/condition.h b/src/libipc/platform/win/condition.h
new file mode 100644
index 0000000..538aa08
--- /dev/null
+++ b/src/libipc/platform/win/condition.h
@@ -0,0 +1,119 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <mutex>
+
+#include <Windows.h>
+
+#include "libipc/utility/log.h"
+#include "libipc/utility/scope_guard.h"
+#include "libipc/platform/detail.h"
+#include "libipc/mutex.h"
+#include "libipc/semaphore.h"
+#include "libipc/shm.h"
+
+namespace ipc {
+namespace detail {
+namespace sync {
+
+class condition {
+    ipc::sync::semaphore sem_;
+    ipc::sync::mutex lock_;
+    ipc::shm::handle shm_;
+
+    std::int32_t &counter() {
+        return *static_cast<std::int32_t *>(shm_.get());
+    }
+
+public:
+    condition() = default;
+    ~condition() noexcept = default;
+
+    auto native() noexcept {
+        return sem_.native();
+    }
+
+    auto native() const noexcept {
+        return sem_.native();
+    }
+
+    bool valid() const noexcept {
+        return sem_.valid() && lock_.valid() && shm_.valid();
+    }
+
+    bool open(char const *name) noexcept {
+        close();
+        if (!sem_.open((std::string{name} + "_COND_SEM_").c_str())) {
+            return false;
+        }
+        auto finally_sem = ipc::guard([this] { sem_.close(); }); // close when failed
+        if (!lock_.open((std::string{name} + "_COND_LOCK_").c_str())) {
+            return false;
+        }
+        auto finally_lock = ipc::guard([this] { lock_.close(); }); // close when failed
+        if (!shm_.acquire((std::string{name} + "_COND_SHM_").c_str(), sizeof(std::int32_t))) {
+            return false;
+        }
+        finally_lock.dismiss();
+        finally_sem.dismiss();
+        return valid();
+    }
+
+    void close() noexcept {
+        if (!valid()) return;
+        sem_.close();
+        lock_.close();
+        shm_.release();
+    }
+
+    bool wait(ipc::sync::mutex &mtx, std::uint64_t tm) noexcept {
+        if (!valid()) return false;
+        auto &cnt = counter();
+        {
+            IPC_UNUSED_ std::lock_guard<ipc::sync::mutex> guard {lock_};
+            cnt = (cnt < 0) ? 1 : cnt + 1;
+        }
+        DWORD ms = (tm == invalid_value) ? INFINITE : static_cast<DWORD>(tm);
+        /**
+         * \see
+         *  - https://www.microsoft.com/en-us/research/wp-content/uploads/2004/12/ImplementingCVs.pdf
+         *  - https://docs.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-signalobjectandwait
+        */
+        bool rs = ::SignalObjectAndWait(mtx.native(), sem_.native(), ms, FALSE) == WAIT_OBJECT_0;
+        bool rl = mtx.lock(); // INFINITE
+        if (!rs) {
+            IPC_UNUSED_ std::lock_guard<ipc::sync::mutex> guard {lock_};
+            cnt -= 1;
+        }
+        return rs && rl;
+    }
+
+    bool notify(ipc::sync::mutex &) noexcept {
+        if (!valid()) return false;
+        auto &cnt = counter();
+        if (!lock_.lock()) return false;
+        bool ret = false;
+        if (cnt > 0) {
+            ret = sem_.post(1);
+            cnt -= 1;
+        }
+        return lock_.unlock() && ret;
+    }
+
+    bool broadcast(ipc::sync::mutex &) noexcept {
+        if (!valid()) return false;
+        auto &cnt = counter();
+        if (!lock_.lock()) return false;
+        bool ret = false;
+        if (cnt > 0) {
+            ret = sem_.post(cnt);
+            cnt = 0;
+        }
+        return lock_.unlock() && ret;
+    }
+};
+
+} // namespace sync
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/win/get_sa.h b/src/libipc/platform/win/get_sa.h
new file mode 100644
index 0000000..74b68d4
--- /dev/null
+++ b/src/libipc/platform/win/get_sa.h
@@ -0,0 +1,35 @@
+#pragma once
+
+#include <securitybaseapi.h>
+
+namespace ipc {
+namespace detail {
+
+inline LPSECURITY_ATTRIBUTES get_sa() {
+    static struct initiator {
+
+        SECURITY_DESCRIPTOR sd_;
+        SECURITY_ATTRIBUTES sa_;
+
+        bool succ_ = false;
+
+        initiator() {
+            if (!::InitializeSecurityDescriptor(&sd_, SECURITY_DESCRIPTOR_REVISION)) {
+                ipc::error("fail InitializeSecurityDescriptor[%d]\n", static_cast<int>(::GetLastError()));
+                return;
+            }
+            if (!::SetSecurityDescriptorDacl(&sd_, TRUE, NULL, FALSE)) {
+                ipc::error("fail SetSecurityDescriptorDacl[%d]\n", static_cast<int>(::GetLastError()));
+                return;
+            }
+            sa_.nLength = sizeof(SECURITY_ATTRIBUTES);
+            sa_.bInheritHandle = FALSE;
+            sa_.lpSecurityDescriptor = &sd_;
+            succ_ = true;
+        }
+    } handle;
+    return handle.succ_ ? &handle.sa_ : nullptr;
+}
+
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/win/mutex.h b/src/libipc/platform/win/mutex.h
new file mode 100644
index 0000000..c0cb543
--- /dev/null
+++ b/src/libipc/platform/win/mutex.h
@@ -0,0 +1,98 @@
+#pragma once
+
+#include <cstdint>
+#include <system_error>
+
+#include <Windows.h>
+
+#include "libipc/utility/log.h"
+
+#include "to_tchar.h"
+#include "get_sa.h"
+
+namespace ipc {
+namespace detail {
+namespace sync {
+
+class mutex {
+    HANDLE h_ = NULL;
+
+public:
+    mutex() noexcept = default;
+    ~mutex() noexcept = default;
+
+    static void init() {}
+
+    HANDLE native() const noexcept {
+        return h_;
+    }
+
+    bool valid() const noexcept {
+        return h_ != NULL;
+    }
+
+    bool open(char const *name) noexcept {
+        close();
+        h_ = ::CreateMutex(detail::get_sa(), FALSE, detail::to_tchar(name).c_str());
+        if (h_ == NULL) {
+            ipc::error("fail CreateMutex[%lu]: %s\n", ::GetLastError(), name);
+            return false;
+        }
+        return true;
+    }
+
+    void close() noexcept {
+        if (!valid()) return;
+        ::CloseHandle(h_);
+        h_ = NULL;
+    }
+
+    bool lock(std::uint64_t tm) noexcept {
+        DWORD ret, ms = (tm == invalid_value) ? INFINITE : static_cast<DWORD>(tm);
+        for(;;) {
+            switch ((ret = ::WaitForSingleObject(h_, ms))) {
+            case WAIT_OBJECT_0:
+                return true;
+            case WAIT_TIMEOUT:
+                return false;
+            case WAIT_ABANDONED:
+                ipc::log("fail WaitForSingleObject[%lu]: WAIT_ABANDONED, try again.\n", ::GetLastError());
+                if (!unlock()) {
+                    return false;
+                }
+                break; // loop again
+            default:
+                ipc::error("fail WaitForSingleObject[%lu]: 0x%08X\n", ::GetLastError(), ret);
+                return false;
+            }
+        }
+    }
+
+    bool try_lock() noexcept(false) {
+        DWORD ret = ::WaitForSingleObject(h_, 0);
+        switch (ret) {
+        case WAIT_OBJECT_0:
+            return true;
+        case WAIT_TIMEOUT:
+            return false;
+        case WAIT_ABANDONED:
+            unlock();
+            IPC_FALLTHROUGH_;
+        default:
+            ipc::error("fail WaitForSingleObject[%lu]: 0x%08X\n", ::GetLastError(), ret);
+            throw std::system_error{static_cast<int>(ret), std::system_category()};
+        }
+    }
+
+    bool unlock() noexcept {
+        if (!::ReleaseMutex(h_)) {
+            ipc::error("fail ReleaseMutex[%lu]\n", ::GetLastError());
+            return false;
+        }
+        return true;
+    }
+};
+
+} // namespace sync
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/win/semaphore.h b/src/libipc/platform/win/semaphore.h
new file mode 100644
index 0000000..5c44846
--- /dev/null
+++ b/src/libipc/platform/win/semaphore.h
@@ -0,0 +1,74 @@
+#pragma once
+
+#include <cstdint>
+
+#include <Windows.h>
+
+#include "libipc/utility/log.h"
+
+#include "to_tchar.h"
+#include "get_sa.h"
+
+namespace ipc {
+namespace detail {
+namespace sync {
+
+class semaphore {
+    HANDLE h_ = NULL;
+
+public:
+    semaphore() noexcept = default;
+    ~semaphore() noexcept = default;
+
+    HANDLE native() const noexcept {
+        return h_;
+    }
+
+    bool valid() const noexcept {
+        return h_ != NULL;
+    }
+
+    bool open(char const *name, std::uint32_t count) noexcept {
+        close();
+        h_ = ::CreateSemaphore(detail::get_sa(), 
+                               static_cast<LONG>(count), LONG_MAX, 
+                               detail::to_tchar(name).c_str());
+        if (h_ == NULL) {
+            ipc::error("fail CreateSemaphore[%lu]: %s\n", ::GetLastError(), name);
+            return false;
+        }
+        return true;
+    }
+
+    void close() noexcept {
+        if (!valid()) return;
+        ::CloseHandle(h_);
+        h_ = NULL;
+    }
+
+    bool wait(std::uint64_t tm) noexcept {
+        DWORD ret, ms = (tm == invalid_value) ? INFINITE : static_cast<DWORD>(tm);
+        switch ((ret = ::WaitForSingleObject(h_, ms))) {
+        case WAIT_OBJECT_0:
+            return true;
+        case WAIT_TIMEOUT:
+            return false;
+        case WAIT_ABANDONED:
+        default:
+            ipc::error("fail WaitForSingleObject[%lu]: 0x%08X\n", ::GetLastError(), ret);
+            return false;
+        }
+    }
+
+    bool post(std::uint32_t count) noexcept {
+        if (!::ReleaseSemaphore(h_, static_cast<LONG>(count), NULL)) {
+            ipc::error("fail ReleaseSemaphore[%lu]\n", ::GetLastError());
+            return false;
+        }
+        return true;
+    }
+};
+
+} // namespace sync
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/platform/win/shm_win.cpp b/src/libipc/platform/win/shm_win.cpp
new file mode 100644
index 0000000..06efccf
--- /dev/null
+++ b/src/libipc/platform/win/shm_win.cpp
@@ -0,0 +1,140 @@
+
+#include <Windows.h>
+
+#include <string>
+#include <utility>
+
+#include "libipc/shm.h"
+#include "libipc/def.h"
+#include "libipc/pool_alloc.h"
+
+#include "libipc/utility/log.h"
+#include "libipc/memory/resource.h"
+
+#include "to_tchar.h"
+#include "get_sa.h"
+
+namespace {
+
+struct id_info_t {
+    HANDLE      h_    = NULL;
+    void*       mem_  = nullptr;
+    std::size_t size_ = 0;
+};
+
+} // internal-linkage
+
+namespace ipc {
+namespace shm {
+
+id_t acquire(char const * name, std::size_t size, unsigned mode) {
+    if (!is_valid_string(name)) {
+        ipc::error("fail acquire: name is empty\n");
+        return nullptr;
+    }
+    HANDLE h;
+    auto fmt_name = ipc::detail::to_tchar(name);
+    // Opens a named file mapping object.
+    if (mode == open) {
+        h = ::OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, fmt_name.c_str());
+        if (h == NULL) {
+          ipc::error("fail OpenFileMapping[%d]: %s\n", static_cast<int>(::GetLastError()), name);
+          return nullptr;
+        }
+    }
+    // Creates or opens a named file mapping object for a specified file.
+    else {
+        h = ::CreateFileMapping(INVALID_HANDLE_VALUE, detail::get_sa(), PAGE_READWRITE | SEC_COMMIT,
+                                0, static_cast<DWORD>(size), fmt_name.c_str());
+        DWORD err = ::GetLastError();
+        // If the object exists before the function call, the function returns a handle to the existing object 
+        // (with its current size, not the specified size), and GetLastError returns ERROR_ALREADY_EXISTS.
+        if ((mode == create) && (err == ERROR_ALREADY_EXISTS)) {
+            if (h != NULL) ::CloseHandle(h);
+            h = NULL;
+        }
+        if (h == NULL) {
+          ipc::error("fail CreateFileMapping[%d]: %s\n", static_cast<int>(err), name);
+          return nullptr;
+        }
+    }
+    auto ii = mem::alloc<id_info_t>();
+    ii->h_    = h;
+    ii->size_ = size;
+    return ii;
+}
+
+std::int32_t get_ref(id_t) {
+    return 0;
+}
+
+void sub_ref(id_t) {
+    // Do Nothing.
+}
+
+void * get_mem(id_t id, std::size_t * size) {
+    if (id == nullptr) {
+        ipc::error("fail get_mem: invalid id (null)\n");
+        return nullptr;
+    }
+    auto ii = static_cast<id_info_t*>(id);
+    if (ii->mem_ != nullptr) {
+        if (size != nullptr) *size = ii->size_;
+        return ii->mem_;
+    }
+    if (ii->h_ == NULL) {
+        ipc::error("fail to_mem: invalid id (h = null)\n");
+        return nullptr;
+    }
+    LPVOID mem = ::MapViewOfFile(ii->h_, FILE_MAP_ALL_ACCESS, 0, 0, 0);
+    if (mem == NULL) {
+        ipc::error("fail MapViewOfFile[%d]\n", static_cast<int>(::GetLastError()));
+        return nullptr;
+    }
+    MEMORY_BASIC_INFORMATION mem_info;
+    if (::VirtualQuery(mem, &mem_info, sizeof(mem_info)) == 0) {
+        ipc::error("fail VirtualQuery[%d]\n", static_cast<int>(::GetLastError()));
+        return nullptr;
+    }
+    ii->mem_  = mem;
+    ii->size_ = static_cast<std::size_t>(mem_info.RegionSize);
+    if (size != nullptr) *size = ii->size_;
+    return static_cast<void *>(mem);
+}
+
+std::int32_t release(id_t id) {
+    if (id == nullptr) {
+        ipc::error("fail release: invalid id (null)\n");
+        return -1;
+    }
+    auto ii = static_cast<id_info_t*>(id);
+    if (ii->mem_ == nullptr || ii->size_ == 0) {
+        ipc::error("fail release: invalid id (mem = %p, size = %zd)\n", ii->mem_, ii->size_);
+    }
+    else ::UnmapViewOfFile(static_cast<LPCVOID>(ii->mem_));
+    if (ii->h_ == NULL) {
+        ipc::error("fail release: invalid id (h = null)\n");
+    }
+    else ::CloseHandle(ii->h_);
+    mem::free(ii);
+    return 0;
+}
+
+void remove(id_t id) {
+    if (id == nullptr) {
+        ipc::error("fail release: invalid id (null)\n");
+        return;
+    }
+    release(id);
+}
+
+void remove(char const * name) {
+    if (!is_valid_string(name)) {
+        ipc::error("fail remove: name is empty\n");
+        return;
+    }
+    // Do Nothing.
+}
+
+} // namespace shm
+} // namespace ipc
diff --git a/src/libipc/platform/win/to_tchar.h b/src/libipc/platform/win/to_tchar.h
new file mode 100644
index 0000000..7f78043
--- /dev/null
+++ b/src/libipc/platform/win/to_tchar.h
@@ -0,0 +1,74 @@
+#pragma once
+
+#include <Windows.h>
+
+#include <type_traits>
+#include <string>
+#include <locale>
+#include <codecvt>
+#include <cstring>
+#include <stdexcept>
+#include <cstddef>
+
+#include "libipc/utility/concept.h"
+#include "libipc/memory/resource.h"
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+namespace detail {
+
+struct has_value_type_ {
+    template <typename T> static std::true_type  check(typename T::value_type *);
+    template <typename T> static std::false_type check(...);
+};
+
+template <typename T, typename U, typename = decltype(has_value_type_::check<U>(nullptr))>
+struct is_same_char : std::is_same<T, U> {};
+
+template <typename T, typename U>
+struct is_same_char<T, U, std::true_type> : std::is_same<T, typename U::value_type> {};
+
+template <typename T, typename S, typename R = S>
+using IsSameChar = ipc::require<is_same_char<T, S>::value, R>;
+
+////////////////////////////////////////////////////////////////
+/// to_tchar implementation
+////////////////////////////////////////////////////////////////
+
+template <typename T = TCHAR>
+constexpr auto to_tchar(ipc::string &&str) -> IsSameChar<T, ipc::string, ipc::string &&> {
+    return std::move(str); // noconv
+}
+
+/**
+ * \remarks codecvt_utf8_utf16/std::wstring_convert is deprecated
+ * \see https://codingtidbit.com/2020/02/09/c17-codecvt_utf8-is-deprecated/
+ *      https://stackoverflow.com/questions/42946335/deprecated-header-codecvt-replacement
+ *      https://en.cppreference.com/w/cpp/locale/codecvt/in
+ *      https://docs.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-multibytetowidechar
+*/
+template <typename T = TCHAR>
+auto to_tchar(ipc::string &&external) -> IsSameChar<T, ipc::wstring> {
+    if (external.empty()) {
+        return {}; // noconv
+    }
+    /**
+     * CP_ACP       : The system default Windows ANSI code page.
+     * CP_MACCP     : The current system Macintosh code page.
+     * CP_OEMCP     : The current system OEM code page.
+     * CP_SYMBOL    : Symbol code page (42).
+     * CP_THREAD_ACP: The Windows ANSI code page for the current thread.
+     * CP_UTF7      : UTF-7. Use this value only when forced by a 7-bit transport mechanism. Use of UTF-8 is preferred.
+     * CP_UTF8      : UTF-8.
+    */
+    int size_needed = ::MultiByteToWideChar(CP_UTF8, 0, &external[0], (int)external.size(), NULL, 0);
+    if (size_needed <= 0) {
+        return {};
+    }
+    ipc::wstring internal(size_needed, L'\0');
+    ::MultiByteToWideChar(CP_UTF8, 0, &external[0], (int)external.size(), &internal[0], size_needed);
+    return internal;
+}
+
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/policy.h b/src/libipc/policy.h
new file mode 100644
index 0000000..f88ab5d
--- /dev/null
+++ b/src/libipc/policy.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <type_traits>
+
+#include "libipc/def.h"
+#include "libipc/prod_cons.h"
+
+#include "libipc/circ/elem_array.h"
+
+namespace ipc {
+namespace policy {
+
+template <template <typename, std::size_t...> class Elems, typename Flag>
+struct choose;
+
+template <typename Flag>
+struct choose<circ::elem_array, Flag> {
+    using flag_t = Flag;
+
+    template <std::size_t DataSize, std::size_t AlignSize>
+    using elems_t = circ::elem_array<ipc::prod_cons_impl<flag_t>, DataSize, AlignSize>;
+};
+
+} // namespace policy
+} // namespace ipc
diff --git a/src/libipc/pool_alloc.cpp b/src/libipc/pool_alloc.cpp
new file mode 100644
index 0000000..c945759
--- /dev/null
+++ b/src/libipc/pool_alloc.cpp
@@ -0,0 +1,17 @@
+#include "libipc/pool_alloc.h"
+
+#include "libipc/memory/resource.h"
+
+namespace ipc {
+namespace mem {
+
+void* pool_alloc::alloc(std::size_t size) {
+    return async_pool_alloc::alloc(size);
+}
+
+void pool_alloc::free(void* p, std::size_t size) {
+    async_pool_alloc::free(p, size);
+}
+
+} // namespace mem
+} // namespace ipc
diff --git a/src/libipc/prod_cons.h b/src/libipc/prod_cons.h
new file mode 100644
index 0000000..c9004bb
--- /dev/null
+++ b/src/libipc/prod_cons.h
@@ -0,0 +1,433 @@
+#pragma once
+
+#include <atomic>
+#include <utility>
+#include <cstring>
+#include <type_traits>
+#include <cstdint>
+
+#include "libipc/def.h"
+
+#include "libipc/platform/detail.h"
+#include "libipc/circ/elem_def.h"
+#include "libipc/utility/log.h"
+#include "libipc/utility/utility.h"
+
+namespace ipc {
+
+////////////////////////////////////////////////////////////////
+/// producer-consumer implementation
+////////////////////////////////////////////////////////////////
+
+template <typename Flag>
+struct prod_cons_impl;
+
+template <>
+struct prod_cons_impl<wr<relat::single, relat::single, trans::unicast>> {
+
+    template <std::size_t DataSize, std::size_t AlignSize>
+    struct elem_t {
+        std::aligned_storage_t<DataSize, AlignSize> data_ {};
+    };
+
+    alignas(cache_line_size) std::atomic<circ::u2_t> rd_; // read index
+    alignas(cache_line_size) std::atomic<circ::u2_t> wt_; // write index
+
+    constexpr circ::u2_t cursor() const noexcept {
+        return 0;
+    }
+
+    template <typename W, typename F, typename E>
+    bool push(W* /*wrapper*/, F&& f, E* elems) {
+        auto cur_wt = circ::index_of(wt_.load(std::memory_order_relaxed));
+        if (cur_wt == circ::index_of(rd_.load(std::memory_order_acquire) - 1)) {
+            return false; // full
+        }
+        std::forward<F>(f)(&(elems[cur_wt].data_));
+        wt_.fetch_add(1, std::memory_order_release);
+        return true;
+    }
+
+    /**
+     * In single-single-unicast, 'force_push' means 'no reader' or 'the only one reader is dead'.
+     * So we could just disconnect all connections of receiver, and return false.
+    */
+    template <typename W, typename F, typename E>
+    bool force_push(W* wrapper, F&&, E*) {
+        wrapper->elems()->disconnect_receiver(~static_cast<circ::cc_t>(0u));
+        return false;
+    }
+
+    template <typename W, typename F, typename R, typename E>
+    bool pop(W* /*wrapper*/, circ::u2_t& /*cur*/, F&& f, R&& out, E* elems) {
+        auto cur_rd = circ::index_of(rd_.load(std::memory_order_relaxed));
+        if (cur_rd == circ::index_of(wt_.load(std::memory_order_acquire))) {
+            return false; // empty
+        }
+        std::forward<F>(f)(&(elems[cur_rd].data_));
+        std::forward<R>(out)(true);
+        rd_.fetch_add(1, std::memory_order_release);
+        return true;
+    }
+};
+
+template <>
+struct prod_cons_impl<wr<relat::single, relat::multi , trans::unicast>>
+     : prod_cons_impl<wr<relat::single, relat::single, trans::unicast>> {
+
+    template <typename W, typename F, typename E>
+    bool force_push(W* wrapper, F&&, E*) {
+        wrapper->elems()->disconnect_receiver(1);
+        return false;
+    }
+
+    template <typename W, typename F, typename R, 
+              template <std::size_t, std::size_t> class E, std::size_t DS, std::size_t AS>
+    bool pop(W* /*wrapper*/, circ::u2_t& /*cur*/, F&& f, R&& out, E<DS, AS>* elems) {
+        byte_t buff[DS];
+        for (unsigned k = 0;;) {
+            auto cur_rd = rd_.load(std::memory_order_relaxed);
+            if (circ::index_of(cur_rd) ==
+                circ::index_of(wt_.load(std::memory_order_acquire))) {
+                return false; // empty
+            }
+            std::memcpy(buff, &(elems[circ::index_of(cur_rd)].data_), sizeof(buff));
+            if (rd_.compare_exchange_weak(cur_rd, cur_rd + 1, std::memory_order_release)) {
+                std::forward<F>(f)(buff);
+                std::forward<R>(out)(true);
+                return true;
+            }
+            ipc::yield(k);
+        }
+    }
+};
+
+template <>
+struct prod_cons_impl<wr<relat::multi , relat::multi, trans::unicast>>
+     : prod_cons_impl<wr<relat::single, relat::multi, trans::unicast>> {
+
+    using flag_t = std::uint64_t;
+
+    template <std::size_t DataSize, std::size_t AlignSize>
+    struct elem_t {
+        std::aligned_storage_t<DataSize, AlignSize> data_ {};
+        std::atomic<flag_t> f_ct_ { 0 }; // commit flag
+    };
+
+    alignas(cache_line_size) std::atomic<circ::u2_t> ct_; // commit index
+
+    template <typename W, typename F, typename E>
+    bool push(W* /*wrapper*/, F&& f, E* elems) {
+        circ::u2_t cur_ct, nxt_ct;
+        for (unsigned k = 0;;) {
+            cur_ct = ct_.load(std::memory_order_relaxed);
+            if (circ::index_of(nxt_ct = cur_ct + 1) ==
+                circ::index_of(rd_.load(std::memory_order_acquire))) {
+                return false; // full
+            }
+            if (ct_.compare_exchange_weak(cur_ct, nxt_ct, std::memory_order_acq_rel)) {
+                break;
+            }
+            ipc::yield(k);
+        }
+        auto* el = elems + circ::index_of(cur_ct);
+        std::forward<F>(f)(&(el->data_));
+        // set flag & try update wt
+        el->f_ct_.store(~static_cast<flag_t>(cur_ct), std::memory_order_release);
+        while (1) {
+            auto cac_ct = el->f_ct_.load(std::memory_order_acquire);
+            if (cur_ct != wt_.load(std::memory_order_relaxed)) {
+                return true;
+            }
+            if ((~cac_ct) != cur_ct) {
+                return true;
+            }
+            if (!el->f_ct_.compare_exchange_strong(cac_ct, 0, std::memory_order_relaxed)) {
+                return true;
+            }
+            wt_.store(nxt_ct, std::memory_order_release);
+            cur_ct = nxt_ct;
+            nxt_ct = cur_ct + 1;
+            el = elems + circ::index_of(cur_ct);
+        }
+        return true;
+    }
+
+    template <typename W, typename F, typename E>
+    bool force_push(W* wrapper, F&&, E*) {
+        wrapper->elems()->disconnect_receiver(1);
+        return false;
+    }
+
+    template <typename W, typename F, typename R, 
+              template <std::size_t, std::size_t> class E, std::size_t DS, std::size_t AS>
+    bool pop(W* /*wrapper*/, circ::u2_t& /*cur*/, F&& f, R&& out, E<DS, AS>* elems) {
+        byte_t buff[DS];
+        for (unsigned k = 0;;) {
+            auto cur_rd = rd_.load(std::memory_order_relaxed);
+            auto cur_wt = wt_.load(std::memory_order_acquire);
+            auto id_rd  = circ::index_of(cur_rd);
+            auto id_wt  = circ::index_of(cur_wt);
+            if (id_rd == id_wt) {
+                auto* el = elems + id_wt;
+                auto cac_ct = el->f_ct_.load(std::memory_order_acquire);
+                if ((~cac_ct) != cur_wt) {
+                    return false; // empty
+                }
+                if (el->f_ct_.compare_exchange_weak(cac_ct, 0, std::memory_order_relaxed)) {
+                    wt_.store(cur_wt + 1, std::memory_order_release);
+                }
+                k = 0;
+            }
+            else {
+                std::memcpy(buff, &(elems[circ::index_of(cur_rd)].data_), sizeof(buff));
+                if (rd_.compare_exchange_weak(cur_rd, cur_rd + 1, std::memory_order_release)) {
+                    std::forward<F>(f)(buff);
+                    std::forward<R>(out)(true);
+                    return true;
+                }
+                ipc::yield(k);
+            }
+        }
+    }
+};
+
+template <>
+struct prod_cons_impl<wr<relat::single, relat::multi, trans::broadcast>> {
+
+    using rc_t = std::uint64_t;
+
+    enum : rc_t {
+        ep_mask = 0x00000000ffffffffull,
+        ep_incr = 0x0000000100000000ull
+    };
+
+    template <std::size_t DataSize, std::size_t AlignSize>
+    struct elem_t {
+        std::aligned_storage_t<DataSize, AlignSize> data_ {};
+        std::atomic<rc_t> rc_ { 0 }; // read-counter
+    };
+
+    alignas(cache_line_size) std::atomic<circ::u2_t> wt_;   // write index
+    alignas(cache_line_size) rc_t epoch_ { 0 };             // only one writer
+
+    circ::u2_t cursor() const noexcept {
+        return wt_.load(std::memory_order_acquire);
+    }
+
+    template <typename W, typename F, typename E>
+    bool push(W* wrapper, F&& f, E* elems) {
+        E* el;
+        for (unsigned k = 0;;) {
+            circ::cc_t cc = wrapper->elems()->connections(std::memory_order_relaxed);
+            if (cc == 0) return false; // no reader
+            el = elems + circ::index_of(wt_.load(std::memory_order_relaxed));
+            // check all consumers have finished reading this element
+            auto cur_rc = el->rc_.load(std::memory_order_acquire);
+            circ::cc_t rem_cc = cur_rc & ep_mask;
+            if ((cc & rem_cc) && ((cur_rc & ~ep_mask) == epoch_)) {
+                return false; // has not finished yet
+            }
+            // consider rem_cc to be 0 here
+            if (el->rc_.compare_exchange_weak(
+                        cur_rc, epoch_ | static_cast<rc_t>(cc), std::memory_order_release)) {
+                break;
+            }
+            ipc::yield(k);
+        }
+        std::forward<F>(f)(&(el->data_));
+        wt_.fetch_add(1, std::memory_order_release);
+        return true;
+    }
+
+    template <typename W, typename F, typename E>
+    bool force_push(W* wrapper, F&& f, E* elems) {
+        E* el;
+        epoch_ += ep_incr;
+        for (unsigned k = 0;;) {
+            circ::cc_t cc = wrapper->elems()->connections(std::memory_order_relaxed);
+            if (cc == 0) return false; // no reader
+            el = elems + circ::index_of(wt_.load(std::memory_order_relaxed));
+            // check all consumers have finished reading this element
+            auto cur_rc = el->rc_.load(std::memory_order_acquire);
+            circ::cc_t rem_cc = cur_rc & ep_mask;
+            if (cc & rem_cc) {
+                ipc::log("force_push: k = %u, cc = %u, rem_cc = %u\n", k, cc, rem_cc);
+                cc = wrapper->elems()->disconnect_receiver(rem_cc); // disconnect all invalid readers
+                if (cc == 0) return false; // no reader
+            }
+            // just compare & exchange
+            if (el->rc_.compare_exchange_weak(
+                        cur_rc, epoch_ | static_cast<rc_t>(cc), std::memory_order_release)) {
+                break;
+            }
+            ipc::yield(k);
+        }
+        std::forward<F>(f)(&(el->data_));
+        wt_.fetch_add(1, std::memory_order_release);
+        return true;
+    }
+
+    template <typename W, typename F, typename R, typename E>
+    bool pop(W* wrapper, circ::u2_t& cur, F&& f, R&& out, E* elems) {
+        if (cur == cursor()) return false; // acquire
+        auto* el = elems + circ::index_of(cur++);
+        std::forward<F>(f)(&(el->data_));
+        for (unsigned k = 0;;) {
+            auto cur_rc = el->rc_.load(std::memory_order_acquire);
+            if ((cur_rc & ep_mask) == 0) {
+                std::forward<R>(out)(true);
+                return true;
+            }
+            auto nxt_rc = cur_rc & ~static_cast<rc_t>(wrapper->connected_id());
+            if (el->rc_.compare_exchange_weak(cur_rc, nxt_rc, std::memory_order_release)) {
+                std::forward<R>(out)((nxt_rc & ep_mask) == 0);
+                return true;
+            }
+            ipc::yield(k);
+        }
+    }
+};
+
+template <>
+struct prod_cons_impl<wr<relat::multi, relat::multi, trans::broadcast>> {
+
+    using rc_t   = std::uint64_t;
+    using flag_t = std::uint64_t;
+
+    enum : rc_t {
+        rc_mask = 0x00000000ffffffffull,
+        ep_mask = 0x00ffffffffffffffull,
+        ep_incr = 0x0100000000000000ull,
+        ic_mask = 0xff000000ffffffffull,
+        ic_incr = 0x0000000100000000ull
+    };
+
+    template <std::size_t DataSize, std::size_t AlignSize>
+    struct elem_t {
+        std::aligned_storage_t<DataSize, AlignSize> data_ {};
+        std::atomic<rc_t  > rc_   { 0 }; // read-counter
+        std::atomic<flag_t> f_ct_ { 0 }; // commit flag
+    };
+
+    alignas(cache_line_size) std::atomic<circ::u2_t> ct_;   // commit index
+    alignas(cache_line_size) std::atomic<rc_t> epoch_ { 0 };
+
+    circ::u2_t cursor() const noexcept {
+        return ct_.load(std::memory_order_acquire);
+    }
+
+    constexpr static rc_t inc_rc(rc_t rc) noexcept {
+        return (rc & ic_mask) | ((rc + ic_incr) & ~ic_mask);
+    }
+
+    constexpr static rc_t inc_mask(rc_t rc) noexcept {
+        return inc_rc(rc) & ~rc_mask;
+    }
+
+    template <typename W, typename F, typename E>
+    bool push(W* wrapper, F&& f, E* elems) {
+        E* el;
+        circ::u2_t cur_ct;
+        rc_t epoch = epoch_.load(std::memory_order_acquire);
+        for (unsigned k = 0;;) {
+            circ::cc_t cc = wrapper->elems()->connections(std::memory_order_relaxed);
+            if (cc == 0) return false; // no reader
+            el = elems + circ::index_of(cur_ct = ct_.load(std::memory_order_relaxed));
+            // check all consumers have finished reading this element
+            auto cur_rc = el->rc_.load(std::memory_order_relaxed);
+            circ::cc_t rem_cc = cur_rc & rc_mask;
+            if ((cc & rem_cc) && ((cur_rc & ~ep_mask) == epoch)) {
+                return false; // has not finished yet
+            }
+            else if (!rem_cc) {
+                auto cur_fl = el->f_ct_.load(std::memory_order_acquire);
+                if ((cur_fl != cur_ct) && cur_fl) {
+                    return false; // full
+                }
+            }
+            // consider rem_cc to be 0 here
+            if (el->rc_.compare_exchange_weak(
+                        cur_rc, inc_mask(epoch | (cur_rc & ep_mask)) | static_cast<rc_t>(cc), std::memory_order_relaxed) &&
+                epoch_.compare_exchange_weak(epoch, epoch, std::memory_order_acq_rel)) {
+                break;
+            }
+            ipc::yield(k);
+        }
+        // only one thread/process would touch here at one time
+        ct_.store(cur_ct + 1, std::memory_order_release);
+        std::forward<F>(f)(&(el->data_));
+        // set flag & try update wt
+        el->f_ct_.store(~static_cast<flag_t>(cur_ct), std::memory_order_release);
+        return true;
+    }
+
+    template <typename W, typename F, typename E>
+    bool force_push(W* wrapper, F&& f, E* elems) {
+        E* el;
+        circ::u2_t cur_ct;
+        rc_t epoch = epoch_.fetch_add(ep_incr, std::memory_order_release) + ep_incr;
+        for (unsigned k = 0;;) {
+            circ::cc_t cc = wrapper->elems()->connections(std::memory_order_relaxed);
+            if (cc == 0) return false; // no reader
+            el = elems + circ::index_of(cur_ct = ct_.load(std::memory_order_relaxed));
+            // check all consumers have finished reading this element
+            auto cur_rc = el->rc_.load(std::memory_order_acquire);
+            circ::cc_t rem_cc = cur_rc & rc_mask;
+            if (cc & rem_cc) {
+                ipc::log("force_push: k = %u, cc = %u, rem_cc = %u\n", k, cc, rem_cc);
+                cc = wrapper->elems()->disconnect_receiver(rem_cc); // disconnect all invalid readers
+                if (cc == 0) return false; // no reader
+            }
+            // just compare & exchange
+            if (el->rc_.compare_exchange_weak(
+                        cur_rc, inc_mask(epoch | (cur_rc & ep_mask)) | static_cast<rc_t>(cc), std::memory_order_relaxed)) {
+                if (epoch == epoch_.load(std::memory_order_acquire)) {
+                    break;
+                }
+                else if (push(wrapper, std::forward<F>(f), elems)) {
+                    return true;
+                }
+                epoch = epoch_.fetch_add(ep_incr, std::memory_order_release) + ep_incr;
+            }
+            ipc::yield(k);
+        }
+        // only one thread/process would touch here at one time
+        ct_.store(cur_ct + 1, std::memory_order_release);
+        std::forward<F>(f)(&(el->data_));
+        // set flag & try update wt
+        el->f_ct_.store(~static_cast<flag_t>(cur_ct), std::memory_order_release);
+        return true;
+    }
+
+    template <typename W, typename F, typename R, typename E, std::size_t N>
+    bool pop(W* wrapper, circ::u2_t& cur, F&& f, R&& out, E(& elems)[N]) {
+        auto* el = elems + circ::index_of(cur);
+        auto cur_fl = el->f_ct_.load(std::memory_order_acquire);
+        if (cur_fl != ~static_cast<flag_t>(cur)) {
+            return false; // empty
+        }
+        ++cur;
+        std::forward<F>(f)(&(el->data_));
+        for (unsigned k = 0;;) {
+            auto cur_rc = el->rc_.load(std::memory_order_acquire);
+            if ((cur_rc & rc_mask) == 0) {
+                std::forward<R>(out)(true);
+                el->f_ct_.store(cur + N - 1, std::memory_order_release);
+                return true;
+            }
+            auto nxt_rc = inc_rc(cur_rc) & ~static_cast<rc_t>(wrapper->connected_id());
+            bool last_one = false;
+            if ((last_one = (nxt_rc & rc_mask) == 0)) {
+                el->f_ct_.store(cur + N - 1, std::memory_order_release);
+            }
+            if (el->rc_.compare_exchange_weak(cur_rc, nxt_rc, std::memory_order_release)) {
+                std::forward<R>(out)(last_one);
+                return true;
+            }
+            ipc::yield(k);
+        }
+    }
+};
+
+} // namespace ipc
diff --git a/src/libipc/queue.h b/src/libipc/queue.h
new file mode 100644
index 0000000..e2335ab
--- /dev/null
+++ b/src/libipc/queue.h
@@ -0,0 +1,223 @@
+#pragma once
+
+#include <type_traits>
+#include <new>
+#include <utility>  // [[since C++14]]: std::exchange
+#include <algorithm>
+#include <atomic>
+#include <tuple>
+#include <thread>
+#include <chrono>
+#include <string>
+#include <cassert>  // assert
+
+#include "libipc/def.h"
+#include "libipc/shm.h"
+#include "libipc/rw_lock.h"
+
+#include "libipc/utility/log.h"
+#include "libipc/platform/detail.h"
+#include "libipc/circ/elem_def.h"
+#include "libipc/memory/resource.h"
+
+namespace ipc {
+namespace detail {
+
+class queue_conn {
+protected:
+    circ::cc_t connected_ = 0;
+    shm::handle elems_h_;
+
+    template <typename Elems>
+    Elems* open(char const * name) {
+        if (!is_valid_string(name)) {
+            ipc::error("fail open waiter: name is empty!\n");
+            return nullptr;
+        }
+        if (!elems_h_.acquire(name, sizeof(Elems))) {
+            return nullptr;
+        }
+        auto elems = static_cast<Elems*>(elems_h_.get());
+        if (elems == nullptr) {
+            ipc::error("fail acquire elems: %s\n", name);
+            return nullptr;
+        }
+        elems->init();
+        return elems;
+    }
+
+    void close() {
+        elems_h_.release();
+    }
+
+public:
+    queue_conn() = default;
+    queue_conn(const queue_conn&) = delete;
+    queue_conn& operator=(const queue_conn&) = delete;
+
+    bool connected() const noexcept {
+        return connected_ != 0;
+    }
+
+    circ::cc_t connected_id() const noexcept {
+        return connected_;
+    }
+
+    template <typename Elems>
+    auto connect(Elems* elems) noexcept
+                         /*needs 'optional' here*/
+     -> std::tuple<bool, bool, decltype(std::declval<Elems>().cursor())> {
+        if (elems == nullptr) return {};
+        // if it's already connected, just return
+        if (connected()) return {connected(), false, 0};
+        connected_ = elems->connect_receiver();
+        return {connected(), true, elems->cursor()};
+    }
+
+    template <typename Elems>
+    bool disconnect(Elems* elems) noexcept {
+        if (elems == nullptr) return false;
+        // if it's already disconnected, just return false
+        if (!connected()) return false;
+        elems->disconnect_receiver(std::exchange(connected_, 0));
+        return true;
+    }
+};
+
+template <typename Elems>
+class queue_base : public queue_conn {
+    using base_t = queue_conn;
+
+public:
+    using elems_t  = Elems;
+    using policy_t = typename elems_t::policy_t;
+
+protected:
+    elems_t * elems_ = nullptr;
+    decltype(std::declval<elems_t>().cursor()) cursor_ = 0;
+    bool sender_flag_ = false;
+
+public:
+    using base_t::base_t;
+
+    queue_base() = default;
+
+    explicit queue_base(char const * name)
+        : queue_base{} {
+        elems_ = queue_conn::template open<elems_t>(name);
+    }
+
+    explicit queue_base(elems_t * elems) noexcept
+        : queue_base{} {
+        assert(elems != nullptr);
+        elems_ = elems;
+    }
+
+    /* not virtual */ ~queue_base() {
+        base_t::close();
+    }
+
+    bool open(char const * name) noexcept {
+        base_t::close();
+        elems_ = queue_conn::template open<elems_t>(name);
+        return elems_ != nullptr;
+    }
+
+    elems_t       * elems()       noexcept { return elems_; }
+    elems_t const * elems() const noexcept { return elems_; }
+
+    bool ready_sending() noexcept {
+        if (elems_ == nullptr) return false;
+        return sender_flag_ || (sender_flag_ = elems_->connect_sender());
+    }
+
+    void shut_sending() noexcept {
+        if (elems_ == nullptr) return;
+        if (!sender_flag_) return;
+        elems_->disconnect_sender();
+    }
+
+    bool connect() noexcept {
+        auto tp = base_t::connect(elems_);
+        if (std::get<0>(tp) && std::get<1>(tp)) {
+            cursor_ = std::get<2>(tp);
+            return true;
+        }
+        return std::get<0>(tp);
+    }
+
+    bool disconnect() noexcept {
+        return base_t::disconnect(elems_);
+    }
+
+    std::size_t conn_count() const noexcept {
+        return (elems_ == nullptr) ? static_cast<std::size_t>(invalid_value) : elems_->conn_count();
+    }
+
+    bool valid() const noexcept {
+        return elems_ != nullptr;
+    }
+
+    bool empty() const noexcept {
+        return !valid() || (cursor_ == elems_->cursor());
+    }
+
+    template <typename T, typename F, typename... P>
+    bool push(F&& prep, P&&... params) {
+        if (elems_ == nullptr) return false;
+        return elems_->push(this, [&](void* p) {
+            if (prep(p)) ::new (p) T(std::forward<P>(params)...);
+        });
+    }
+
+    template <typename T, typename F, typename... P>
+    bool force_push(F&& prep, P&&... params) {
+        if (elems_ == nullptr) return false;
+        return elems_->force_push(this, [&](void* p) {
+            if (prep(p)) ::new (p) T(std::forward<P>(params)...);
+        });
+    }
+
+    template <typename T, typename F>
+    bool pop(T& item, F&& out) {
+        if (elems_ == nullptr) {
+            return false;
+        }
+        return elems_->pop(this, &(this->cursor_), [&item](void* p) {
+            ::new (&item) T(std::move(*static_cast<T*>(p)));
+        }, std::forward<F>(out));
+    }
+};
+
+} // namespace detail
+
+template <typename T, typename Policy>
+class queue final : public detail::queue_base<typename Policy::template elems_t<sizeof(T), alignof(T)>> {
+    using base_t = detail::queue_base<typename Policy::template elems_t<sizeof(T), alignof(T)>>;
+
+public:
+    using value_t = T;
+
+    using base_t::base_t;
+
+    template <typename... P>
+    bool push(P&&... params) {
+        return base_t::template push<T>(std::forward<P>(params)...);
+    }
+
+    template <typename... P>
+    bool force_push(P&&... params) {
+        return base_t::template force_push<T>(std::forward<P>(params)...);
+    }
+
+    bool pop(T& item) {
+        return base_t::pop(item, [](bool) {});
+    }
+
+    template <typename F>
+    bool pop(T& item, F&& out) {
+        return base_t::pop(item, std::forward<F>(out));
+    }
+};
+
+} // namespace ipc
diff --git a/src/libipc/shm.cpp b/src/libipc/shm.cpp
new file mode 100644
index 0000000..28885b6
--- /dev/null
+++ b/src/libipc/shm.cpp
@@ -0,0 +1,113 @@
+
+#include <string>
+#include <utility>
+
+#include "libipc/shm.h"
+
+#include "libipc/utility/pimpl.h"
+#include "libipc/utility/log.h"
+#include "libipc/memory/resource.h"
+
+namespace ipc {
+namespace shm {
+
+class handle::handle_ : public pimpl<handle_> {
+public:
+    shm::id_t id_ = nullptr;
+    void*     m_  = nullptr;
+
+    ipc::string n_;
+    std::size_t s_ = 0;
+};
+
+handle::handle()
+    : p_(p_->make()) {
+}
+
+handle::handle(char const * name, std::size_t size, unsigned mode)
+    : handle() {
+    acquire(name, size, mode);
+}
+
+handle::handle(handle&& rhs)
+    : handle() {
+    swap(rhs);
+}
+
+handle::~handle() {
+    release();
+    p_->clear();
+}
+
+void handle::swap(handle& rhs) {
+    std::swap(p_, rhs.p_);
+}
+
+handle& handle::operator=(handle rhs) {
+    swap(rhs);
+    return *this;
+}
+
+bool handle::valid() const noexcept {
+    return impl(p_)->m_ != nullptr;
+}
+
+std::size_t handle::size() const noexcept {
+    return impl(p_)->s_;
+}
+
+char const * handle::name() const noexcept {
+    return impl(p_)->n_.c_str();
+}
+
+std::int32_t handle::ref() const noexcept {
+    return shm::get_ref(impl(p_)->id_);
+}
+
+void handle::sub_ref() noexcept {
+    shm::sub_ref(impl(p_)->id_);
+}
+
+bool handle::acquire(char const * name, std::size_t size, unsigned mode) {
+    if (!is_valid_string(name)) {
+        ipc::error("fail acquire: name is empty\n");
+        return false;
+    }
+    if (size == 0) {
+        ipc::error("fail acquire: size is 0\n");
+        return false;
+    }
+    release();
+    impl(p_)->n_  = name;
+    impl(p_)->id_ = shm::acquire(name, size, mode);
+    impl(p_)->m_  = shm::get_mem(impl(p_)->id_, &(impl(p_)->s_));
+    return valid();
+}
+
+std::int32_t handle::release() {
+    if (impl(p_)->id_ == nullptr) return -1;
+    return shm::release(detach());
+}
+
+void* handle::get() const {
+    return impl(p_)->m_;
+}
+
+void handle::attach(id_t id) {
+    if (id == nullptr) return;
+    release();
+    impl(p_)->id_ = id;
+    impl(p_)->m_  = shm::get_mem(impl(p_)->id_, &(impl(p_)->s_));
+}
+
+id_t handle::detach() {
+    auto old = impl(p_)->id_;
+    impl(p_)->id_ = nullptr;
+    impl(p_)->m_  = nullptr;
+    impl(p_)->s_  = 0;
+    impl(p_)->n_.clear();
+    return old;
+}
+
+} // namespace shm
+} // namespace ipc
diff --git a/src/libipc/sync/condition.cpp b/src/libipc/sync/condition.cpp
new file mode 100644
index 0000000..36896a7
--- /dev/null
+++ b/src/libipc/sync/condition.cpp
@@ -0,0 +1,77 @@
+
+#include "libipc/condition.h"
+
+#include "libipc/utility/pimpl.h"
+#include "libipc/utility/log.h"
+#include "libipc/memory/resource.h"
+#include "libipc/platform/detail.h"
+#if defined(IPC_OS_WINDOWS_)
+#include "libipc/platform/win/condition.h"
+#elif defined(IPC_OS_LINUX_)
+#include "libipc/platform/linux/condition.h"
+#elif defined(IPC_OS_QNX_)
+#include "libipc/platform/posix/condition.h"
+#else/*IPC_OS*/
+#   error "Unsupported platform."
+#endif
+
+namespace ipc {
+namespace sync {
+
+class condition::condition_ : public ipc::pimpl<condition_> {
+public:
+    ipc::detail::sync::condition cond_;
+};
+
+condition::condition()
+    : p_(p_->make()) {
+}
+
+condition::condition(char const * name)
+    : condition() {
+    open(name);
+}
+
+condition::~condition() {
+    close();
+    p_->clear();
+}
+
+void const *condition::native() const noexcept {
+    return impl(p_)->cond_.native();
+}
+
+void *condition::native() noexcept {
+    return impl(p_)->cond_.native();
+}
+
+bool condition::valid() const noexcept {
+    return impl(p_)->cond_.valid();
+}
+
+bool condition::open(char const *name) noexcept {
+    if (!is_valid_string(name)) {
+        ipc::error("fail condition open: name is empty\n");
+        return false;
+    }
+    return impl(p_)->cond_.open(name);
+}
+
+void condition::close() noexcept {
+    impl(p_)->cond_.close();
+}
+
+bool condition::wait(ipc::sync::mutex &mtx, std::uint64_t tm) noexcept {
+    return impl(p_)->cond_.wait(mtx, tm);
+}
+
+bool condition::notify(ipc::sync::mutex &mtx) noexcept {
+    return impl(p_)->cond_.notify(mtx);
+}
+
+bool condition::broadcast(ipc::sync::mutex &mtx) noexcept {
+    return impl(p_)->cond_.broadcast(mtx);
+}
+
+} // namespace sync
+} // namespace ipc
diff --git a/src/libipc/sync/mutex.cpp b/src/libipc/sync/mutex.cpp
new file mode 100644
index 0000000..91bd0bb
--- /dev/null
+++ b/src/libipc/sync/mutex.cpp
@@ -0,0 +1,77 @@
+
+#include "libipc/mutex.h"
+
+#include "libipc/utility/pimpl.h"
+#include "libipc/utility/log.h"
+#include "libipc/memory/resource.h"
+#include "libipc/platform/detail.h"
+#if defined(IPC_OS_WINDOWS_)
+#include "libipc/platform/win/mutex.h"
+#elif defined(IPC_OS_LINUX_)
+#include "libipc/platform/linux/mutex.h"
+#elif defined(IPC_OS_QNX_)
+#include "libipc/platform/posix/mutex.h"
+#else/*IPC_OS*/
+#   error "Unsupported platform."
+#endif
+
+namespace ipc {
+namespace sync {
+
+class mutex::mutex_ : public ipc::pimpl<mutex_> {
+public:
+    ipc::detail::sync::mutex lock_;
+};
+
+mutex::mutex()
+    : p_(p_->make()) {
+}
+
+mutex::mutex(char const * name)
+    : mutex() {
+    open(name);
+}
+
+mutex::~mutex() {
+    close();
+    p_->clear();
+}
+
+void const *mutex::native() const noexcept {
+    return impl(p_)->lock_.native();
+}
+
+void *mutex::native() noexcept {
+    return impl(p_)->lock_.native();
+}
+
+bool mutex::valid() const noexcept {
+    return impl(p_)->lock_.valid();
+}
+
+bool mutex::open(char const *name) noexcept {
+    if (!is_valid_string(name)) {
+        ipc::error("fail mutex open: name is empty\n");
+        return false;
+    }
+    return impl(p_)->lock_.open(name);
+}
+
+void mutex::close() noexcept {
+    impl(p_)->lock_.close();
+}
+
+bool mutex::lock(std::uint64_t tm) noexcept {
+    return impl(p_)->lock_.lock(tm);
+}
+
+bool mutex::try_lock() noexcept(false) {
+    return impl(p_)->lock_.try_lock();
+}
+
+bool mutex::unlock() noexcept {
+    return impl(p_)->lock_.unlock();
+}
+
+} // namespace sync
+} // namespace ipc
diff --git a/src/libipc/sync/semaphore.cpp b/src/libipc/sync/semaphore.cpp
new file mode 100644
index 0000000..e58e8ec
--- /dev/null
+++ b/src/libipc/sync/semaphore.cpp
@@ -0,0 +1,71 @@
+
+#include "libipc/semaphore.h"
+
+#include "libipc/utility/pimpl.h"
+#include "libipc/utility/log.h"
+#include "libipc/memory/resource.h"
+#include "libipc/platform/detail.h"
+#if defined(IPC_OS_WINDOWS_)
+#include "libipc/platform/win/semaphore.h"
+#elif defined(IPC_OS_LINUX_) || defined(IPC_OS_QNX_)
+#include "libipc/platform/posix/semaphore_impl.h"
+#else/*IPC_OS*/
+#   error "Unsupported platform."
+#endif
+
+namespace ipc {
+namespace sync {
+
+class semaphore::semaphore_ : public ipc::pimpl<semaphore_> {
+public:
+    ipc::detail::sync::semaphore sem_;
+};
+
+semaphore::semaphore()
+    : p_(p_->make()) {
+}
+
+semaphore::semaphore(char const * name, std::uint32_t count)
+    : semaphore() {
+    open(name, count);
+}
+
+semaphore::~semaphore() {
+    close();
+    p_->clear();
+}
+
+void const *semaphore::native() const noexcept {
+    return impl(p_)->sem_.native();
+}
+
+void *semaphore::native() noexcept {
+    return impl(p_)->sem_.native();
+}
+
+bool semaphore::valid() const noexcept {
+    return impl(p_)->sem_.valid();
+}
+
+bool semaphore::open(char const *name, std::uint32_t count) noexcept {
+    if (!is_valid_string(name)) {
+        ipc::error("fail semaphore open: name is empty\n");
+        return false;
+    }
+    return impl(p_)->sem_.open(name, count);
+}
+
+void semaphore::close() noexcept {
+    impl(p_)->sem_.close();
+}
+
+bool semaphore::wait(std::uint64_t tm) noexcept {
+    return impl(p_)->sem_.wait(tm);
+}
+
+bool semaphore::post(std::uint32_t count) noexcept {
+    return impl(p_)->sem_.post(count);
+}
+
+} // namespace sync
+} // namespace ipc
diff --git a/src/libipc/sync/waiter.cpp b/src/libipc/sync/waiter.cpp
new file mode 100644
index 0000000..3a04abf
--- /dev/null
+++ b/src/libipc/sync/waiter.cpp
@@ -0,0 +1,22 @@
+#include "libipc/waiter.h"
+
+#include "libipc/platform/detail.h"
+#if defined(IPC_OS_WINDOWS_)
+#include "libipc/platform/win/mutex.h"
+#elif defined(IPC_OS_LINUX_)
+#include "libipc/platform/linux/mutex.h"
+#elif defined(IPC_OS_QNX_)
+#include "libipc/platform/posix/mutex.h"
+#else/*IPC_OS*/
+#   error "Unsupported platform."
+#endif
+
+namespace ipc {
+namespace detail {
+
+void waiter::init() {
+    ipc::detail::sync::mutex::init();
+}
+
+} // namespace detail
+} // namespace ipc
diff --git a/src/libipc/utility/concept.h b/src/libipc/utility/concept.h
new file mode 100644
index 0000000..7e2b583
--- /dev/null
+++ b/src/libipc/utility/concept.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <type_traits>  // std::enable_if
+
+namespace ipc {
+
+// concept helpers
+
+template <bool Cond, typename R = void>
+using require = typename std::enable_if<Cond, R>::type;
+
+#ifdef IPC_CONCEPT_
+#   error "IPC_CONCEPT_ has been defined."
+#endif
+
+#define IPC_CONCEPT_(NAME, WHAT)                                       \
+template <typename T>                                                  \
+class NAME {                                                           \
+private:                                                               \
+    template <typename Type>                                           \
+    static std::true_type check(decltype(std::declval<Type>().WHAT)*); \
+    template <typename Type>                                           \
+    static std::false_type check(...);                                 \
+public:                                                                \
+    using type = decltype(check<T>(nullptr));                          \
+    constexpr static auto value = type::value;                         \
+}
+
+} // namespace ipc
diff --git a/src/libipc/utility/id_pool.h b/src/libipc/utility/id_pool.h
new file mode 100644
index 0000000..24d32e4
--- /dev/null
+++ b/src/libipc/utility/id_pool.h
@@ -0,0 +1,103 @@
+#pragma once
+
+#include <type_traits>  // std::aligned_storage_t
+#include <cstring>      // std::memcmp
+#include <cstdint>
+
+#include "libipc/def.h"
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+
+using storage_id_t = std::int32_t;
+
+template <std::size_t DataSize, std::size_t AlignSize>
+struct id_type;
+
+template <std::size_t AlignSize>
+struct id_type<0, AlignSize> {
+    uint_t<8> id_;
+
+    id_type& operator=(storage_id_t val) {
+        id_ = static_cast<uint_t<8>>(val);
+        return (*this);
+    }
+
+    operator uint_t<8>() const {
+        return id_;
+    }
+};
+
+template <std::size_t DataSize, std::size_t AlignSize>
+struct id_type : id_type<0, AlignSize> {
+    std::aligned_storage_t<DataSize, AlignSize> data_;
+};
+
+template <std::size_t DataSize  = 0,
+          std::size_t AlignSize = (ipc::detail::min)(DataSize, alignof(std::max_align_t))>
+class id_pool {
+
+    static constexpr std::size_t limited_max_count() {
+        return ipc::detail::min<std::size_t>(large_msg_cache, (std::numeric_limits<uint_t<8>>::max)());
+    }
+
+public:
+    enum : std::size_t {
+        /* eliminate error: taking address of temporary */
+        max_count = limited_max_count()
+    };
+
+private:
+    id_type<DataSize, AlignSize> next_[max_count];
+    uint_t<8> cursor_ = 0;
+    bool prepared_ = false;
+
+public:
+    void prepare() {
+        if (!prepared_ && this->invalid()) this->init();
+        prepared_ = true;
+    }
+
+    void init() {
+        for (storage_id_t i = 0; i < max_count;) {
+            i = next_[i] = (i + 1);
+        }
+    }
+
+    bool invalid() const {
+        static id_pool inv;
+        return std::memcmp(this, &inv, sizeof(id_pool)) == 0;
+    }
+
+    bool empty() const {
+        return cursor_ == max_count;
+    }
+
+    storage_id_t acquire() {
+        if (empty()) return -1;
+        storage_id_t id = cursor_;
+        cursor_ = next_[id]; // point to next
+        return id;
+    }
+
+    bool release(storage_id_t id) {
+        if (id < 0) return false;
+        next_[id] = cursor_;
+        cursor_ = static_cast<uint_t<8>>(id); // put it back
+        return true;
+    }
+
+    void       * at(storage_id_t id)       { return &(next_[id].data_); }
+    void const * at(storage_id_t id) const { return &(next_[id].data_); }
+};
+
+template <typename T>
+class obj_pool : public id_pool<sizeof(T), alignof(T)> {
+    using base_t = id_pool<sizeof(T), alignof(T)>;
+
+public:
+    T       * at(storage_id_t id)       { return reinterpret_cast<T       *>(base_t::at(id)); }
+    T const * at(storage_id_t id) const { return reinterpret_cast<T const *>(base_t::at(id)); }
+};
+
+} // namespace ipc
diff --git a/src/libipc/utility/log.h b/src/libipc/utility/log.h
new file mode 100644
index 0000000..d06da12
--- /dev/null
+++ b/src/libipc/utility/log.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <cstdio>
+#include <utility>
+
+namespace ipc {
+namespace detail {
+
+template <typename O>
+void print(O out, char const * str) {
+    std::fprintf(out, "%s", str);
+}
+
+template <typename O, typename P1, typename... P>
+void print(O out, char const * fmt, P1&& p1, P&&... params) {
+    std::fprintf(out, fmt, std::forward<P1>(p1), std::forward<P>(params)...);
+}
+
+} // namespace detail
+
+inline void log(char const * fmt) {
+    ipc::detail::print(stdout, fmt);
+}
+
+template <typename P1, typename... P>
+void log(char const * fmt, P1&& p1, P&&... params) {
+    ipc::detail::print(stdout, fmt, std::forward<P1>(p1), std::forward<P>(params)...);
+}
+
+inline void error(char const * str) {
+    ipc::detail::print(stderr, str);
+}
+
+template <typename P1, typename... P>
+void error(char const * fmt, P1&& p1, P&&... params) {
+    ipc::detail::print(stderr, fmt, std::forward<P1>(p1), std::forward<P>(params)...);
+}
+
+} // namespace ipc
diff --git a/src/libipc/utility/pimpl.h b/src/libipc/utility/pimpl.h
new file mode 100644
index 0000000..8d4711d
--- /dev/null
+++ b/src/libipc/utility/pimpl.h
@@ -0,0 +1,64 @@
+#pragma once
+
+#include <new>
+#include <utility>
+
+#include "libipc/platform/detail.h"
+#include "libipc/utility/concept.h"
+#include "libipc/pool_alloc.h"
+
+namespace ipc {
+
+// pimpl small object optimization helpers
+
+template <typename T, typename R = T*>
+using IsImplComfortable = ipc::require<(sizeof(T) <= sizeof(T*)), R>;
+
+template <typename T, typename R = T*>
+using IsImplUncomfortable = ipc::require<(sizeof(T) > sizeof(T*)), R>;
+
+template <typename T, typename... P>
+IPC_CONSTEXPR_ auto make_impl(P&&... params) -> IsImplComfortable<T> {
+    T* buf {};
+    ::new (&buf) T { std::forward<P>(params)... };
+    return buf;
+}
+
+template <typename T>
+IPC_CONSTEXPR_ auto impl(T* const (& p)) -> IsImplComfortable<T> {
+    return reinterpret_cast<T*>(&const_cast<char &>(reinterpret_cast<char const &>(p)));
+}
+
+template <typename T>
+IPC_CONSTEXPR_ auto clear_impl(T* p) -> IsImplComfortable<T, void> {
+    if (p != nullptr) impl(p)->~T();
+}
+
+template <typename T, typename... P>
+IPC_CONSTEXPR_ auto make_impl(P&&... params) -> IsImplUncomfortable<T> {
+    return mem::alloc<T>(std::forward<P>(params)...);
+}
+
+template <typename T>
+IPC_CONSTEXPR_ auto clear_impl(T* p) -> IsImplUncomfortable<T, void> {
+    mem::free(p);
+}
+
+template <typename T>
+IPC_CONSTEXPR_ auto impl(T* const (& p)) -> IsImplUncomfortable<T> {
+    return p;
+}
+
+template <typename T>
+struct pimpl {
+    template <typename... P>
+    IPC_CONSTEXPR_ static T* make(P&&... params) {
+        return make_impl<T>(std::forward<P>(params)...);
+    }
+
+    IPC_CONSTEXPR_ void clear() {
+        clear_impl(static_cast<T*>(const_cast<pimpl*>(this)));
+    }
+};
+
+} // namespace ipc
diff --git a/src/libipc/utility/scope_guard.h b/src/libipc/utility/scope_guard.h
new file mode 100644
index 0000000..9f42149
--- /dev/null
+++ b/src/libipc/utility/scope_guard.h
@@ -0,0 +1,64 @@
+#pragma once
+
+#include <utility>      // std::forward, std::move
+#include <algorithm>    // std::swap
+#include <type_traits>  // std::decay
+
+namespace ipc {
+
+////////////////////////////////////////////////////////////////
+/// Execute guard function when the enclosing scope exits
+////////////////////////////////////////////////////////////////
+
+template <typename F>
+class scope_guard {
+    F destructor_;
+    mutable bool dismiss_;
+
+public:
+    template <typename D>
+    scope_guard(D && destructor)
+        : destructor_(std::forward<D>(destructor))
+        , dismiss_(false) {
+    }
+
+    scope_guard(scope_guard&& rhs)
+        : destructor_(std::move(rhs.destructor_))
+        , dismiss_(true) /* dismiss rhs */ {
+        std::swap(dismiss_, rhs.dismiss_);
+    }
+
+    ~scope_guard() {
+        try { do_exit(); }
+        /**
+         * In the realm of exceptions, it is fundamental that you can do nothing
+         * if your "undo/recover" action fails.
+        */
+        catch (...) { /* Do nothing */ }
+    }
+
+    void swap(scope_guard & rhs) {
+        std::swap(destructor_, rhs.destructor_);
+        std::swap(dismiss_   , rhs.dismiss_);
+    }
+
+    void dismiss() const noexcept {
+        dismiss_ = true;
+    }
+
+    void do_exit() {
+        if (!dismiss_) {
+            dismiss_ = true;
+            destructor_();
+        }
+    }
+};
+
+template <typename D>
+constexpr auto guard(D && destructor) noexcept {
+    return scope_guard<std::decay_t<D>> {
+        std::forward<D>(destructor)
+    };
+}
+
+} // namespace ipc
\ No newline at end of file
diff --git a/src/libipc/utility/utility.h b/src/libipc/utility/utility.h
new file mode 100644
index 0000000..4b3a859
--- /dev/null
+++ b/src/libipc/utility/utility.h
@@ -0,0 +1,64 @@
+#pragma once
+
+#include <utility>      // std::forward, std::integer_sequence
+#include <cstddef>      // std::size_t
+#include <new>          // std::hardware_destructive_interference_size
+#include <type_traits>  // std::is_trivially_copyable
+
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+
+template <typename F, typename D>
+constexpr decltype(auto) static_switch(std::size_t /*i*/, std::index_sequence<>, F&& /*f*/, D&& def) {
+    return std::forward<D>(def)();
+}
+
+template <typename F, typename D, std::size_t N, std::size_t...I>
+constexpr decltype(auto) static_switch(std::size_t i, std::index_sequence<N, I...>, F&& f, D&& def) {
+    return (i == N) ? std::forward<F>(f)(std::integral_constant<std::size_t, N>{}) :
+                      static_switch(i, std::index_sequence<I...>{}, std::forward<F>(f), std::forward<D>(def));
+}
+
+template <std::size_t N, typename F, typename D>
+constexpr decltype(auto) static_switch(std::size_t i, F&& f, D&& def) {
+    return static_switch(i, std::make_index_sequence<N>{}, std::forward<F>(f), std::forward<D>(def));
+}
+
+template <typename F, std::size_t...I>
+IPC_CONSTEXPR_ void static_for(std::index_sequence<I...>, F&& f) {
+    IPC_UNUSED_ auto expand = { (std::forward<F>(f)(std::integral_constant<std::size_t, I>{}), 0)... };
+}
+
+template <std::size_t N, typename F>
+IPC_CONSTEXPR_ void static_for(F&& f) {
+    static_for(std::make_index_sequence<N>{}, std::forward<F>(f));
+}
+
+// Minimum offset between two objects to avoid false sharing.
+enum {
+// #if __cplusplus >= 201703L
+//     cache_line_size = std::hardware_destructive_interference_size
+// #else /*__cplusplus < 201703L*/
+    cache_line_size = 64
+// #endif/*__cplusplus < 201703L*/
+};
+
+template <typename T, typename U>
+auto horrible_cast(U rhs) noexcept
+    -> typename std::enable_if<std::is_trivially_copyable<T>::value
+                            && std::is_trivially_copyable<U>::value, T>::type {
+    union {
+        T t;
+        U u;
+    } r = {};
+    r.u = rhs;
+    return r.t;
+}
+
+IPC_CONSTEXPR_ std::size_t make_align(std::size_t align, std::size_t size) {
+    // align must be 2^n
+    return (size + align - 1) & ~(align - 1);
+}
+
+} // namespace ipc
diff --git a/src/libipc/waiter.h b/src/libipc/waiter.h
new file mode 100644
index 0000000..628ce5e
--- /dev/null
+++ b/src/libipc/waiter.h
@@ -0,0 +1,87 @@
+#pragma once
+
+#include <utility>
+#include <string>
+#include <mutex>
+#include <atomic>
+
+#include "libipc/def.h"
+#include "libipc/mutex.h"
+#include "libipc/condition.h"
+#include "libipc/platform/detail.h"
+
+namespace ipc {
+namespace detail {
+
+class waiter {
+    ipc::sync::condition cond_;
+    ipc::sync::mutex     lock_;
+    std::atomic<bool>    quit_ {false};
+
+public:
+    static void init();
+
+    waiter() = default;
+    waiter(char const *name) {
+        open(name);
+    }
+
+    ~waiter() {
+        close();
+    }
+
+    bool valid() const noexcept {
+        return cond_.valid() && lock_.valid();
+    }
+
+    bool open(char const *name) noexcept {
+        quit_.store(false, std::memory_order_relaxed);
+        if (!cond_.open((std::string{name} + "_WAITER_COND_").c_str())) {
+            return false;
+        }
+        if (!lock_.open((std::string{name} + "_WAITER_LOCK_").c_str())) {
+            cond_.close();
+            return false;
+        }
+        return valid();
+    }
+
+    void close() noexcept {
+        cond_.close();
+        lock_.close();
+    }
+
+    template <typename F>
+    bool wait_if(F &&pred, std::uint64_t tm = ipc::invalid_value) noexcept {
+        IPC_UNUSED_ std::lock_guard<ipc::sync::mutex> guard {lock_};
+        while ([this, &pred] {
+                    return !quit_.load(std::memory_order_relaxed)
+                        && std::forward<F>(pred)();
+                }()) {
+            if (!cond_.wait(lock_, tm)) return false;
+        }
+        return true;
+    }
+
+    bool notify() noexcept {
+        {
+            IPC_UNUSED_ std::lock_guard<ipc::sync::mutex> barrier{lock_}; // barrier
+        }
+        return cond_.notify(lock_);
+    }
+
+    bool broadcast() noexcept {
+        {
+            IPC_UNUSED_ std::lock_guard<ipc::sync::mutex> barrier{lock_}; // barrier
+        }
+        return cond_.broadcast(lock_);
+    }
+
+    bool quit_waiting() {
+        quit_.store(true, std::memory_order_release);
+        return broadcast();
+    }
+};
+
+} // namespace detail
+} // namespace ipc
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
new file mode 100644
index 0000000..9398aa3
--- /dev/null
+++ b/test/CMakeLists.txt
@@ -0,0 +1,28 @@
+project(test-ipc)
+
+if(NOT MSVC)
+  add_compile_options(
+    -Wno-attributes 
+    -Wno-missing-field-initializers 
+    -Wno-unused-variable 
+    -Wno-unused-function)
+endif()
+
+include_directories(
+    ${LIBIPC_PROJECT_DIR}/include 
+    ${LIBIPC_PROJECT_DIR}/src
+    ${LIBIPC_PROJECT_DIR}/test
+    ${LIBIPC_PROJECT_DIR}/3rdparty
+    ${LIBIPC_PROJECT_DIR}/3rdparty/gtest/include)
+
+file(GLOB SRC_FILES
+    ${LIBIPC_PROJECT_DIR}/test/*.cpp
+    # ${LIBIPC_PROJECT_DIR}/test/profiler/*.cpp
+    )
+file(GLOB HEAD_FILES ${LIBIPC_PROJECT_DIR}/test/*.h)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES} ${HEAD_FILES})
+
+link_directories(${LIBIPC_PROJECT_DIR}/3rdparty/gperftools)
+target_link_libraries(${PROJECT_NAME} gtest gtest_main ipc)
+#target_link_libraries(${PROJECT_NAME} tcmalloc_minimal)
diff --git a/test/test.h b/test/test.h
new file mode 100644
index 0000000..6bfb3ed
--- /dev/null
+++ b/test/test.h
@@ -0,0 +1,86 @@
+#pragma once
+
+#include <iostream>
+#include <atomic>
+#include <thread>
+#include <string>
+#include <memory>
+#include <mutex>
+#include <utility>
+
+#include "gtest/gtest.h"
+
+#include "capo/stopwatch.hpp"
+
+#include "thread_pool.h"
+
+namespace ipc_ut {
+
+template <typename Dur>
+struct unit;
+
+template <> struct unit<std::chrono::nanoseconds> {
+    constexpr static char const * str() noexcept {
+        return "ns";
+    }
+};
+
+template <> struct unit<std::chrono::microseconds> {
+    constexpr static char const * str() noexcept {
+        return "us";
+    }
+};
+
+template <> struct unit<std::chrono::milliseconds> {
+    constexpr static char const * str() noexcept {
+        return "ms";
+    }
+};
+
+template <> struct unit<std::chrono::seconds> {
+    constexpr static char const * str() noexcept {
+        return "sec";
+    }
+};
+
+struct test_stopwatch {
+    capo::stopwatch<> sw_;
+    std::atomic_flag started_ = ATOMIC_FLAG_INIT;
+
+    void start() {
+        if (!started_.test_and_set()) {
+            sw_.start();
+        }
+    }
+
+    template <typename ToDur = std::chrono::nanoseconds>
+    void print_elapsed(int N, int Loops, char const * message = "") {
+        auto ts = sw_.elapsed<ToDur>();
+        std::cout << "[" << N << ", \t" << Loops << "] " << message << "\t"
+                  << (double(ts) / double(Loops)) << " " << unit<ToDur>::str() << std::endl;
+    }
+
+    template <int Factor, typename ToDur = std::chrono::nanoseconds>
+    void print_elapsed(int N, int M, int Loops, char const * message = "") {
+        auto ts = sw_.elapsed<ToDur>();
+        std::cout << "[" << N << "-" << M << ", \t" << Loops << "] " << message << "\t"
+                  << (double(ts) / double(Factor ? (Loops * Factor) : (Loops * N))) << " " << unit<ToDur>::str() << std::endl;
+    }
+
+    template <typename ToDur = std::chrono::nanoseconds>
+    void print_elapsed(int N, int M, int Loops, char const * message = "") {
+        print_elapsed<0, ToDur>(N, M, Loops, message);
+    }
+};
+
+inline static thread_pool & sender() {
+    static thread_pool pool;
+    return pool;
+}
+
+inline static thread_pool & reader() {
+    static thread_pool pool;
+    return pool;
+}
+
+} // namespace ipc_ut
\ No newline at end of file
diff --git a/test/test_ipc.cpp b/test/test_ipc.cpp
new file mode 100644
index 0000000..79b29a6
--- /dev/null
+++ b/test/test_ipc.cpp
@@ -0,0 +1,189 @@
+
+#include <vector>
+#include <iostream>
+#include <mutex>
+#include <atomic>
+#include <cstring>
+
+#include "libipc/ipc.h"
+#include "libipc/buffer.h"
+#include "libipc/memory/resource.h"
+
+#include "test.h"
+#include "thread_pool.h"
+
+#include "capo/random.hpp"
+
+using namespace ipc;
+
+namespace {
+
+constexpr int LoopCount   = 10000;
+constexpr int MultiMax    = 8;
+constexpr int TestBuffMax = 65536;
+
+struct msg_head {
+    int id_;
+};
+
+class rand_buf : public buffer {
+public:
+    rand_buf() {
+        int size = capo::random<>{(int)sizeof(msg_head), TestBuffMax}();
+        *this = buffer(new char[size], size, [](void * p, std::size_t) {
+            delete [] static_cast<char *>(p);
+        });
+    }
+
+    rand_buf(msg_head const &msg) {
+        *this = buffer(new msg_head{msg}, sizeof(msg), [](void * p, std::size_t) {
+            delete static_cast<msg_head *>(p);
+        });
+    }
+
+    rand_buf(rand_buf &&) = default;
+    rand_buf(rand_buf const & rhs) {
+        if (rhs.empty()) return;
+        void * mem = new char[rhs.size()];
+        std::memcpy(mem, rhs.data(), rhs.size());
+        *this = buffer(mem, rhs.size(), [](void * p, std::size_t) {
+            delete [] static_cast<char *>(p);
+        });
+    }
+
+    rand_buf(buffer && rhs)
+        : buffer(std::move(rhs)) {
+    }
+
+    void set_id(int k) noexcept {
+        get<msg_head *>()->id_ = k;
+    }
+
+    int get_id() const noexcept {
+        return get<msg_head *>()->id_;
+    }
+
+    using buffer::operator=;
+};
+
+template <relat Rp, relat Rc, trans Ts>
+void test_basic(char const * name) {
+    using que_t = chan<Rp, Rc, Ts>;
+    rand_buf test1, test2;
+
+    que_t que1 { name };
+    EXPECT_FALSE(que1.send(test1));
+    EXPECT_FALSE(que1.try_send(test2));
+
+    que_t que2 { que1.name(), ipc::receiver };
+    ASSERT_TRUE(que1.send(test1));
+    ASSERT_TRUE(que1.try_send(test2));
+
+    EXPECT_EQ(que2.recv(), test1);
+    EXPECT_EQ(que2.recv(), test2);
+}
+
+class data_set {
+    std::vector<rand_buf> datas_;
+
+public:
+    data_set() {
+        datas_.resize(LoopCount);
+        for (int i = 0; i < LoopCount; ++i) {
+            datas_[i].set_id(i);
+        }
+    }
+
+    std::vector<rand_buf> const &get() const noexcept {
+        return datas_;
+    }
+} const data_set__;
+
+template <relat Rp, relat Rc, trans Ts, typename Que = chan<Rp, Rc, Ts>>
+void test_sr(char const * name, int s_cnt, int r_cnt) {
+    ipc_ut::sender().start(static_cast<std::size_t>(s_cnt));
+    ipc_ut::reader().start(static_cast<std::size_t>(r_cnt));
+
+    std::atomic_thread_fence(std::memory_order_seq_cst);
+    ipc_ut::test_stopwatch sw;
+
+    for (int k = 0; k < s_cnt; ++k) {
+        ipc_ut::sender() << [name, &sw, r_cnt, k] {
+            Que que { name, ipc::sender };
+            ASSERT_TRUE(que.wait_for_recv(r_cnt));
+            sw.start();
+            for (int i = 0; i < (int)data_set__.get().size(); ++i) {
+                ASSERT_TRUE(que.send(data_set__.get()[i]));
+            }
+        };
+    }
+
+    for (int k = 0; k < r_cnt; ++k) {
+        ipc_ut::reader() << [name] {
+            Que que { name, ipc::receiver };
+            for (;;) {
+                rand_buf got { que.recv() };
+                ASSERT_FALSE(got.empty());
+                int i = got.get_id();
+                if (i == -1) {
+                    return;
+                }
+                ASSERT_TRUE((i >= 0) && (i < (int)data_set__.get().size()));
+                auto const &data_set = data_set__.get()[i];
+                if (data_set != got) {
+                    printf("data_set__.get()[%d] != got, size = %zd/%zd\n", 
+                            i, data_set.size(), got.size());
+                    ASSERT_TRUE(false);
+                }
+            }
+        };
+    }
+
+    ipc_ut::sender().wait_for_done();
+    Que que { name };
+    ASSERT_TRUE(que.wait_for_recv(r_cnt));
+    for (int k = 0; k < r_cnt; ++k) {
+        que.send(rand_buf{msg_head{-1}});
+    }
+    ipc_ut::reader().wait_for_done();
+    sw.print_elapsed<std::chrono::microseconds>(s_cnt, r_cnt, (int)data_set__.get().size(), name);
+}
+
+} // internal-linkage
+
+TEST(IPC, basic_ssu) {
+    test_basic<relat::single, relat::single, trans::unicast  >("ssu");
+}
+
+TEST(IPC, basic_smb) {
+    test_basic<relat::single, relat::multi , trans::broadcast>("smb");
+}
+
+TEST(IPC, basic_mmb) {
+    test_basic<relat::multi , relat::multi , trans::broadcast>("mmb");
+}
+
+TEST(IPC, 1v1) {
+    test_sr<relat::single, relat::single, trans::unicast  >("ssu", 1, 1);
+    //test_sr<relat::single, relat::multi , trans::unicast  >("smu", 1, 1);
+    //test_sr<relat::multi , relat::multi , trans::unicast  >("mmu", 1, 1);
+    test_sr<relat::single, relat::multi , trans::broadcast>("smb", 1, 1);
+    test_sr<relat::multi , relat::multi , trans::broadcast>("mmb", 1, 1);
+}
+
+TEST(IPC, 1vN) {
+    //test_sr<relat::single, relat::multi , trans::unicast  >("smu", 1, MultiMax);
+    //test_sr<relat::multi , relat::multi , trans::unicast  >("mmu", 1, MultiMax);
+    test_sr<relat::single, relat::multi , trans::broadcast>("smb", 1, MultiMax);
+    test_sr<relat::multi , relat::multi , trans::broadcast>("mmb", 1, MultiMax);
+}
+
+TEST(IPC, Nv1) {
+    //test_sr<relat::multi , relat::multi , trans::unicast  >("mmu", MultiMax, 1);
+    test_sr<relat::multi , relat::multi , trans::broadcast>("mmb", MultiMax, 1);
+}
+
+TEST(IPC, NvN) {
+    //test_sr<relat::multi , relat::multi , trans::unicast  >("mmu", MultiMax, MultiMax);
+    test_sr<relat::multi , relat::multi , trans::broadcast>("mmb", MultiMax, MultiMax);
+}
diff --git a/test/test_mem.cpp b/test/test_mem.cpp
new file mode 100644
index 0000000..e5da19e
--- /dev/null
+++ b/test/test_mem.cpp
@@ -0,0 +1,218 @@
+#include <vector>
+#include <array>
+#include <thread>
+#include <atomic>
+#include <cstddef>
+
+#include "capo/random.hpp"
+
+#include "libipc/memory/resource.h"
+#include "libipc/pool_alloc.h"
+
+// #include "gperftools/tcmalloc.h"
+
+#include "test.h"
+#include "thread_pool.h"
+
+namespace {
+
+constexpr int DataMin   = 4;
+constexpr int DataMax   = 256;
+constexpr int LoopCount = 8388608;
+constexpr int ThreadMax = 8;
+
+// constexpr int DataMin   = 256;
+// constexpr int DataMax   = 512;
+// constexpr int LoopCount = 2097152;
+
+std::vector<std::size_t> sizes__;
+std::vector<void*> ptr_cache__[ThreadMax];
+
+template <typename M>
+struct alloc_ix_t {
+    static std::vector<int> ix_;
+    static bool inited_;
+
+    alloc_ix_t() {
+        if (inited_) return;
+        inited_ = true;
+        M::init();
+    }
+
+    template <int ThreadsN>
+    static int index(std::size_t /*pid*/, std::size_t /*k*/, std::size_t n) {
+        return ix_[n];
+    }
+};
+
+template <typename M>
+std::vector<int> alloc_ix_t<M>::ix_(LoopCount);
+template <typename M>
+bool alloc_ix_t<M>::inited_ = false;
+
+struct alloc_FIFO : alloc_ix_t<alloc_FIFO> {
+    static void init() {
+        for (int i = 0; i < LoopCount; ++i) {
+            ix_[static_cast<std::size_t>(i)] = i;
+        }
+    }
+};
+
+struct alloc_LIFO : alloc_ix_t<alloc_LIFO> {
+    static void init() {
+        for (int i = 0; i < LoopCount; ++i) {
+            ix_[static_cast<std::size_t>(i)] = i;
+        }
+    }
+
+    template <int ThreadsN>
+    static int index(std::size_t pid, std::size_t k, std::size_t n) {
+        constexpr static int CacheSize = LoopCount / ThreadsN;
+        if (k) {
+            return ix_[(CacheSize * (2 * pid + 1)) - 1 - n];
+        }
+        else return ix_[n];
+    }
+};
+
+struct alloc_Random : alloc_ix_t<alloc_Random> {
+    static void init() {
+        capo::random<> rdm_index(0, LoopCount - 1);
+        for (int i = 0; i < LoopCount; ++i) {
+            ix_[static_cast<std::size_t>(i)] = rdm_index();
+        }
+    }
+};
+
+struct Init {
+    Init() {
+        capo::random<> rdm{ DataMin, DataMax };
+        for (int i = 0; i < LoopCount; ++i) {
+            sizes__.emplace_back(static_cast<std::size_t>(rdm()));
+        }
+        for (auto& vec : ptr_cache__) {
+            vec.resize(LoopCount, nullptr);
+        }
+    }
+} init__;
+
+template <typename AllocT, int ThreadsN>
+void benchmark_alloc(char const * message) {
+    std::string msg = std::to_string(ThreadsN) + "\t" + message;
+
+    constexpr static int CacheSize = LoopCount / ThreadsN;
+    ipc_ut::sender().start(static_cast<std::size_t>(ThreadsN));
+    ipc_ut::test_stopwatch sw;
+
+    for (int pid = 0; pid < ThreadsN; ++pid) {
+        ipc_ut::sender() << [&, pid] {
+            sw.start();
+            for (int n = (CacheSize * pid); n < (CacheSize * (pid + 1)); ++n) {
+                std::size_t s = sizes__[n];
+                AllocT::free(AllocT::alloc(s), s);
+            }
+        };
+    }
+
+    ipc_ut::sender().wait_for_done();
+    sw.print_elapsed<1>(DataMin, DataMax, LoopCount, msg.c_str());
+}
+
+template <typename AllocT, typename ModeT, int ThreadsN>
+void benchmark_alloc(char const * message) {
+    std::string msg = std::to_string(ThreadsN) + "\t" + message;
+
+    constexpr static int CacheSize = LoopCount / ThreadsN;
+    ModeT mode;
+    ipc_ut::sender().start(static_cast<std::size_t>(ThreadsN));
+    ipc_ut::test_stopwatch sw;
+
+    for (int pid = 0; pid < ThreadsN; ++pid) {
+        ipc_ut::sender() << [&, pid] {
+            auto& vec = ptr_cache__[pid];
+            sw.start();
+            for (std::size_t k = 0; k < 2; ++k)
+            for (int n = (CacheSize * pid); n < (CacheSize * (pid + 1)); ++n) {
+                int    m = mode.template index<ThreadsN>(pid, k, n);
+                void*& p = vec[static_cast<std::size_t>(m)];
+                std::size_t s  = sizes__[static_cast<std::size_t>(m)];
+                if (p == nullptr) {
+                    p = AllocT::alloc(s);
+                }
+                else {
+                    AllocT::free(p, s);
+                    p = nullptr;
+                }
+            }
+        };
+    }
+
+    ipc_ut::sender().wait_for_done();
+    sw.print_elapsed<1>(DataMin, DataMax, LoopCount, msg.c_str());
+}
+
+template <typename AllocT, typename ModeT, int ThreadsN>
+struct test_performance {
+    static void start(char const * message) {
+        test_performance<AllocT, ModeT, ThreadsN / 2>::start(message);
+        benchmark_alloc<AllocT, ModeT, ThreadsN>(message);
+    }
+};
+
+template <typename AllocT, typename ModeT>
+struct test_performance<AllocT, ModeT, 1> {
+    static void start(char const * message) {
+        benchmark_alloc<AllocT, ModeT, 1>(message);
+    }
+};
+
+template <typename AllocT, int ThreadsN>
+struct test_performance<AllocT, void, ThreadsN> {
+    static void start(char const * message) {
+        test_performance<AllocT, void, ThreadsN / 2>::start(message);
+        benchmark_alloc<AllocT, ThreadsN>(message);
+    }
+};
+
+template <typename AllocT>
+struct test_performance<AllocT, void, 1> {
+    static void start(char const * message) {
+        benchmark_alloc<AllocT, 1>(message);
+    }
+};
+
+// class tc_alloc {
+// public:
+//    static void clear() {}
+
+//    static void* alloc(std::size_t size) {
+//        return size ? tc_malloc(size) : nullptr;
+//    }
+
+//    static void free(void* p, std::size_t size) {
+//        tc_free_sized(p, size);
+//    }
+// };
+/*
+TEST(Memory, static_alloc) {
+    test_performance<ipc::mem::static_alloc, void        , ThreadMax>::start("alloc-free");
+    test_performance<ipc::mem::static_alloc, alloc_FIFO  , ThreadMax>::start("alloc-FIFO");
+    test_performance<ipc::mem::static_alloc, alloc_LIFO  , ThreadMax>::start("alloc-LIFO");
+    test_performance<ipc::mem::static_alloc, alloc_Random, ThreadMax>::start("alloc-Rand");
+}
+
+TEST(Memory, pool_alloc) {
+    test_performance<ipc::mem::async_pool_alloc, void        , ThreadMax>::start("alloc-free");
+    test_performance<ipc::mem::async_pool_alloc, alloc_FIFO  , ThreadMax>::start("alloc-FIFO");
+    test_performance<ipc::mem::async_pool_alloc, alloc_LIFO  , ThreadMax>::start("alloc-LIFO");
+    test_performance<ipc::mem::async_pool_alloc, alloc_Random, ThreadMax>::start("alloc-Rand");
+}
+*/
+// TEST(Memory, tc_alloc) {
+//     test_performance<tc_alloc, void       , ThreadMax>::start();
+//     test_performance<tc_alloc, alloc_FIFO  , ThreadMax>::start();
+//     test_performance<tc_alloc, alloc_LIFO  , ThreadMax>::start();
+//     test_performance<tc_alloc, alloc_Random, ThreadMax>::start();
+// }
+
+} // internal-linkage
diff --git a/test/test_platform.cpp b/test/test_platform.cpp
new file mode 100644
index 0000000..65fa513
--- /dev/null
+++ b/test/test_platform.cpp
@@ -0,0 +1,31 @@
+#if defined(WIN64) || defined(_WIN64) || defined(__WIN64__) || \
+    defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || \
+    defined(WINCE) || defined(_WIN32_WCE)
+
+#include <locale>
+#include <iostream>
+//#include <fstream>
+
+#include "test.h"
+
+#include "libipc/platform/win/to_tchar.h"
+
+TEST(Platform, to_tchar) {
+    char const *utf8 = "hello world, "
+                       "\xe4\xbd\xa0\xe5\xa5\xbd\xef\xbc"
+                       "\x8c\xe3\x81\x93\xe3\x82\x93\xe3"
+                       "\x81\xab\xe3\x81\xa1\xe3\x81\xaf";
+    wchar_t const *utf16 = L"hello world, \u4f60\u597d\uff0c\u3053\u3093\u306b\u3061\u306f";
+    {
+        ipc::string str = ipc::detail::to_tchar<char>(utf8);
+        EXPECT_STREQ(str.c_str(), utf8);
+    }
+    {
+        ipc::wstring wtr = ipc::detail::to_tchar<wchar_t>(utf8);
+        EXPECT_STREQ(wtr.c_str(), utf16);
+        //std::ofstream out("out.txt", std::ios::binary|std::ios::out);
+        //out.write((char const *)wtr.c_str(), wtr.size() * sizeof(wchar_t));
+    }
+}
+
+#endif/*WIN*/
\ No newline at end of file
diff --git a/test/test_queue.cpp b/test/test_queue.cpp
new file mode 100644
index 0000000..ab58943
--- /dev/null
+++ b/test/test_queue.cpp
@@ -0,0 +1,304 @@
+#include <iostream>
+#include <string>
+#include <type_traits>
+#include <memory>
+#include <new>
+#include <vector>
+#include <unordered_map>
+#include <climits>  // CHAR_BIT
+
+#include "libipc/prod_cons.h"
+#include "libipc/policy.h"
+#include "libipc/circ/elem_array.h"
+#include "libipc/queue.h"
+
+#include "test.h"
+
+namespace {
+
+struct msg_t {
+    int pid_;
+    int dat_;
+
+    msg_t() = default;
+    msg_t(int p, int d) : pid_(p), dat_(d) {}
+};
+
+template <ipc::relat Rp, ipc::relat Rc, ipc::trans Ts>
+using queue_t = ipc::queue<msg_t, ipc::policy::choose<ipc::circ::elem_array, ipc::wr<Rp, Rc, Ts>>>;
+
+template <ipc::relat Rp, ipc::relat Rc, ipc::trans Ts>
+struct elems_t : public queue_t<Rp, Rc, Ts>::elems_t {};
+
+bool operator==(msg_t const & m1, msg_t const & m2) noexcept {
+    return (m1.pid_ == m2.pid_) && (m1.dat_ == m2.dat_);
+}
+
+bool operator!=(msg_t const & m1, msg_t const & m2) noexcept {
+    return !(m1 == m2);
+}
+
+constexpr int LoopCount = 1000000;
+constexpr int PushRetry = 1000000;
+constexpr int ThreadMax = 8;
+
+template <typename Que>
+void push(Que & que, int p, int d) {
+    for (int n = 0; !que.push([](void*) { return true; }, p, d); ++n) {
+        ASSERT_NE(n, PushRetry);
+        std::this_thread::yield();
+    }
+}
+
+template <typename Que>
+msg_t pop(Que & que) {
+    msg_t msg;
+    while (!que.pop(msg)) {
+        std::this_thread::yield();
+    }
+    return msg;
+}
+
+template <ipc::trans Ts>
+struct quitter;
+
+template <>
+struct quitter<ipc::trans::unicast> {
+    template <typename Que>
+    static void emit(Que && que, int r_cnt) {
+        for (int k = 0; k < r_cnt; ++k) {
+            push(que, -1, -1);
+        }
+    }
+};
+
+template <>
+struct quitter<ipc::trans::broadcast> {
+    template <typename Que>
+    static void emit(Que && que, int /*r_cnt*/) {
+        push(que, -1, -1);
+    }
+};
+
+template <ipc::relat Rp, ipc::relat Rc, ipc::trans Ts>
+void test_sr(elems_t<Rp, Rc, Ts> && elems, int s_cnt, int r_cnt, char const * message) {
+    ipc_ut::sender().start(static_cast<std::size_t>(s_cnt));
+    ipc_ut::reader().start(static_cast<std::size_t>(r_cnt));
+    ipc_ut::test_stopwatch sw;
+
+    for (int k = 0; k < s_cnt; ++k) {
+        ipc_ut::sender() << [&elems, &sw, r_cnt, k] {
+            queue_t<Rp, Rc, Ts> que { &elems };
+            while (que.conn_count() != static_cast<std::size_t>(r_cnt)) {
+                std::this_thread::yield();
+            }
+            sw.start();
+            for (int i = 0; i < LoopCount; ++i) {
+                push(que, k, i);
+            }
+        };
+    }
+    for (int k = 0; k < r_cnt; ++k) {
+        ipc_ut::reader() << [&elems, k] {
+            queue_t<Rp, Rc, Ts> que { &elems };
+            ASSERT_TRUE(que.connect());
+            while (pop(que).pid_ >= 0) ;
+            ASSERT_TRUE(que.disconnect());
+        };
+    }
+
+    ipc_ut::sender().wait_for_done();
+    quitter<Ts>::emit(queue_t<Rp, Rc, Ts> { &elems }, r_cnt);
+    ipc_ut::reader().wait_for_done();
+    sw.print_elapsed(s_cnt, r_cnt, LoopCount, message);
+}
+
+} // internal-linkage
+
+TEST(Queue, check_size) {
+    using el_t = elems_t<ipc::relat::single, ipc::relat::multi, ipc::trans::broadcast>;
+
+    std::cout << "cq_t::head_size  = " << el_t::head_size << std::endl;
+    std::cout << "cq_t::data_size  = " << el_t::data_size << std::endl;
+    std::cout << "cq_t::elem_size  = " << el_t::elem_size << std::endl;
+    std::cout << "cq_t::block_size = " << el_t::block_size << std::endl;
+
+    EXPECT_EQ(static_cast<std::size_t>(el_t::data_size), sizeof(msg_t));
+
+    std::cout << "sizeof(elems_t<s, m, b>) = " << sizeof(el_t) << std::endl;
+}
+
+TEST(Queue, el_connection) {
+    {
+        elems_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> el;
+        EXPECT_TRUE(el.connect_sender());
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_FALSE(el.connect_sender());
+        }
+        el.disconnect_sender();
+        EXPECT_TRUE(el.connect_sender());
+    }
+    {
+        elems_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::unicast> el;
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_TRUE(el.connect_sender());
+        }
+    }
+    {
+        elems_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> el;
+        auto cc = el.connect_receiver();
+        EXPECT_NE(cc, 0);
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_EQ(el.connect_receiver(), 0);
+        }
+        EXPECT_EQ(el.disconnect_receiver(cc), 0);
+        EXPECT_EQ(el.connect_receiver(), cc);
+    }
+    {
+        elems_t<ipc::relat::single, ipc::relat::multi, ipc::trans::broadcast> el;
+        for (std::size_t i = 0; i < (sizeof(ipc::circ::cc_t) * CHAR_BIT); ++i) {
+            ASSERT_NE(el.connect_receiver(), 0);
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_EQ(el.connect_receiver(), 0);
+        }
+    }
+}
+
+TEST(Queue, connection) {
+    {
+        elems_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> el;
+        queue_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> que{&el};
+        // sending
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_TRUE(que.ready_sending());
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            queue_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> que{&el};
+            ASSERT_FALSE(que.ready_sending());
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            que.shut_sending();
+        }
+        {
+            queue_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> que{&el};
+            EXPECT_TRUE(que.ready_sending());
+        }
+        // receiving
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_TRUE(que.connect());
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            queue_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> que{&el};
+            ASSERT_FALSE(que.connect());
+        }
+        EXPECT_TRUE(que.disconnect());
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_FALSE(que.disconnect());
+        }
+        {
+            queue_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> que{&el};
+            EXPECT_TRUE(que.connect());
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            queue_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast> que{&el};
+            ASSERT_FALSE(que.connect());
+        }
+    }
+    {
+        elems_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> el;
+        queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
+        // sending
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_TRUE(que.ready_sending());
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
+            ASSERT_TRUE(que.ready_sending());
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            que.shut_sending();
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
+            ASSERT_TRUE(que.ready_sending());
+        }
+        // receiving
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_TRUE(que.connect());
+        }
+        for (std::size_t i = 1; i < (sizeof(ipc::circ::cc_t) * CHAR_BIT); ++i) {
+            queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
+            ASSERT_TRUE(que.connect());
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
+            ASSERT_FALSE(que.connect());
+        }
+        ASSERT_TRUE(que.disconnect());
+        for (std::size_t i = 0; i < 10000; ++i) {
+            ASSERT_FALSE(que.disconnect());
+        }
+        {
+            queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
+            ASSERT_TRUE(que.connect());
+        }
+        for (std::size_t i = 0; i < 10000; ++i) {
+            queue_t<ipc::relat::multi, ipc::relat::multi, ipc::trans::broadcast> que{&el};
+            ASSERT_FALSE(que.connect());
+        }
+    }
+}
+
+TEST(Queue, prod_cons_1v1_unicast) {
+    test_sr(elems_t<ipc::relat::single, ipc::relat::single, ipc::trans::unicast>{}, 1, 1, "ssu");
+    test_sr(elems_t<ipc::relat::single, ipc::relat::multi , ipc::trans::unicast>{}, 1, 1, "smu");
+    test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::unicast>{}, 1, 1, "mmu");
+}
+
+TEST(Queue, prod_cons_1v1_broadcast) {
+    test_sr(elems_t<ipc::relat::single, ipc::relat::multi , ipc::trans::broadcast>{}, 1, 1, "smb");
+    test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::broadcast>{}, 1, 1, "mmb");
+}
+
+TEST(Queue, prod_cons_1vN_unicast) {
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::single, ipc::relat::multi , ipc::trans::unicast>{}, 1, i, "smu");
+    }
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::unicast>{}, 1, i, "mmu");
+    }
+}
+
+TEST(Queue, prod_cons_1vN_broadcast) {
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::single, ipc::relat::multi , ipc::trans::broadcast>{}, 1, i, "smb");
+    }
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::broadcast>{}, 1, i, "mmb");
+    }
+}
+
+TEST(Queue, prod_cons_NvN_unicast) {
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::unicast>{}, 1, i, "mmu");
+    }
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::unicast>{}, i, 1, "mmu");
+    }
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::unicast>{}, i, i, "mmu");
+    }
+}
+
+TEST(Queue, prod_cons_NvN_broadcast) {
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::broadcast>{}, 1, i, "mmb");
+    }
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::broadcast>{}, i, 1, "mmb");
+    }
+    for (int i = 1; i <= ThreadMax; ++i) {
+        test_sr(elems_t<ipc::relat::multi , ipc::relat::multi , ipc::trans::broadcast>{}, i, i, "mmb");
+    }
+}
diff --git a/test/test_shm.cpp b/test/test_shm.cpp
new file mode 100644
index 0000000..ed1f69c
--- /dev/null
+++ b/test/test_shm.cpp
@@ -0,0 +1,102 @@
+#include <cstring>
+#include <cstdint>
+#include <thread>
+
+#include "libipc/shm.h"
+#include "test.h"
+
+using namespace ipc::shm;
+
+namespace {
+
+TEST(SHM, acquire) {
+    handle shm_hd;
+    EXPECT_FALSE(shm_hd.valid());
+
+    EXPECT_TRUE(shm_hd.acquire("my-test-1", 1024));
+    EXPECT_TRUE(shm_hd.valid());
+    EXPECT_STREQ(shm_hd.name(), "my-test-1");
+
+    EXPECT_TRUE(shm_hd.acquire("my-test-2", 2048));
+    EXPECT_TRUE(shm_hd.valid());
+    EXPECT_STREQ(shm_hd.name(), "my-test-2");
+
+    EXPECT_TRUE(shm_hd.acquire("my-test-3", 4096));
+    EXPECT_TRUE(shm_hd.valid());
+    EXPECT_STREQ(shm_hd.name(), "my-test-3");
+}
+
+TEST(SHM, release) {
+    handle shm_hd;
+    EXPECT_FALSE(shm_hd.valid());
+    shm_hd.release();
+    EXPECT_FALSE(shm_hd.valid());
+    EXPECT_TRUE(shm_hd.acquire("release-test-1", 512));
+    EXPECT_TRUE(shm_hd.valid());
+    shm_hd.release();
+    EXPECT_FALSE(shm_hd.valid());
+}
+
+TEST(SHM, get) {
+    handle shm_hd;
+    EXPECT_TRUE(shm_hd.get() == nullptr);
+    EXPECT_TRUE(shm_hd.acquire("get-test", 2048));
+
+    auto mem = shm_hd.get();
+    EXPECT_TRUE(mem != nullptr);
+    EXPECT_TRUE(mem == shm_hd.get());
+
+    std::uint8_t buf[1024] = {};
+    EXPECT_TRUE(memcmp(mem, buf, sizeof(buf)) == 0);
+
+    handle shm_other(shm_hd.name(), shm_hd.size());
+    EXPECT_TRUE(shm_other.get() != shm_hd.get());
+}
+
+TEST(SHM, hello) {
+    handle shm_hd;
+    EXPECT_TRUE(shm_hd.acquire("hello-test", 128));
+    auto mem = shm_hd.get();
+    EXPECT_TRUE(mem != nullptr);
+
+    constexpr char hello[] = "hello!";
+    std::memcpy(mem, hello, sizeof(hello));
+    EXPECT_STREQ((char const *)shm_hd.get(), hello);
+
+    shm_hd.release();
+    EXPECT_TRUE(shm_hd.get() == nullptr);
+    EXPECT_TRUE(shm_hd.acquire("hello-test", 1024));
+
+    mem = shm_hd.get();
+    EXPECT_TRUE(mem != nullptr);
+    std::uint8_t buf[1024] = {};
+    EXPECT_TRUE(memcmp(mem, buf, sizeof(buf)) == 0);
+
+    std::memcpy(mem, hello, sizeof(hello));
+    EXPECT_STREQ((char const *)shm_hd.get(), hello);
+}
+
+TEST(SHM, mt) {
+    handle shm_hd;
+    EXPECT_TRUE(shm_hd.acquire("mt-test", 256));
+    constexpr char hello[] = "hello!";
+    std::memcpy(shm_hd.get(), hello, sizeof(hello));
+
+    std::thread {
+        [&shm_hd] {
+            handle shm_mt(shm_hd.name(), shm_hd.size());
+            shm_hd.release();
+            constexpr char hello[] = "hello!";
+            EXPECT_STREQ((char const *)shm_mt.get(), hello);
+        }
+    }.join();
+
+    EXPECT_TRUE(shm_hd.get() == nullptr);
+    EXPECT_FALSE(shm_hd.valid());
+
+    EXPECT_TRUE(shm_hd.acquire("mt-test", 1024));
+    std::uint8_t buf[1024] = {};
+    EXPECT_TRUE(memcmp(shm_hd.get(), buf, sizeof(buf)) == 0);
+}
+
+} // internal-linkage
diff --git a/test/test_sync.cpp b/test/test_sync.cpp
new file mode 100644
index 0000000..e905df9
--- /dev/null
+++ b/test/test_sync.cpp
@@ -0,0 +1,208 @@
+
+#include <thread>
+#include <iostream>
+#include <mutex>
+#include <chrono>
+#include <deque>
+#include <array>
+#include <cstdio>
+
+#include "test.h"
+
+#include "libipc/platform/detail.h"
+#if defined(IPC_OS_LINUX_)
+#include <pthread.h>
+#include <time.h>
+
+TEST(PThread, Robust) {
+    pthread_mutexattr_t ma;
+    pthread_mutexattr_init(&ma);
+    pthread_mutexattr_setpshared(&ma, PTHREAD_PROCESS_SHARED);
+    pthread_mutexattr_setrobust(&ma, PTHREAD_MUTEX_ROBUST);
+    pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+    pthread_mutex_init(&mutex, &ma);
+
+    std::thread{[&mutex] {
+        pthread_mutex_lock(&mutex);
+        // pthread_mutex_unlock(&mutex);
+    }}.join();
+
+    struct timespec tout;
+    clock_gettime(CLOCK_REALTIME, &tout);
+    int r = pthread_mutex_timedlock(&mutex, &tout);
+    EXPECT_EQ(r, EOWNERDEAD);
+
+    pthread_mutex_consistent(&mutex);
+    pthread_mutex_unlock(&mutex);
+    pthread_mutex_destroy(&mutex);
+}
+#elif defined(IPC_OS_WINDOWS_)
+#include <Windows.h>
+#include <tchar.h>
+
+TEST(PThread, Robust) {
+    HANDLE lock = CreateMutex(NULL, FALSE, _T("test-robust"));
+    std::thread{[] {
+        HANDLE lock = CreateMutex(NULL, FALSE, _T("test-robust"));
+        WaitForSingleObject(lock, 0);
+    }}.join();
+
+    DWORD r = WaitForSingleObject(lock, 0);
+    EXPECT_EQ(r, WAIT_ABANDONED);
+
+    CloseHandle(lock);
+}
+#endif // OS
+
+#include "libipc/mutex.h"
+
+TEST(Sync, Mutex) {
+    ipc::sync::mutex lock;
+    EXPECT_TRUE(lock.open("test-mutex-robust"));
+    std::thread{[] {
+        ipc::sync::mutex lock {"test-mutex-robust"};
+        EXPECT_TRUE(lock.valid());
+        EXPECT_TRUE(lock.lock());
+    }}.join();
+
+    EXPECT_THROW(lock.try_lock(), std::system_error);
+
+    // int i = 0;
+    // EXPECT_TRUE(lock.lock());
+    // i = 100;
+    // auto t2 = std::thread{[&i] {
+    //     ipc::sync::mutex lock {"test-mutex-robust"};
+    //     EXPECT_TRUE(lock.valid());
+    //     EXPECT_FALSE(lock.try_lock());
+    //     EXPECT_TRUE(lock.lock());
+    //     i += i;
+    //     EXPECT_TRUE(lock.unlock());
+    // }};
+    // std::this_thread::sleep_for(std::chrono::seconds(1));
+    // EXPECT_EQ(i, 100);
+    // EXPECT_TRUE(lock.unlock());
+    // t2.join();
+    // EXPECT_EQ(i, 200);
+}
+
+#include "libipc/semaphore.h"
+
+TEST(Sync, Semaphore) {
+    ipc::sync::semaphore sem;
+    EXPECT_TRUE(sem.open("test-sem"));
+    std::thread{[] {
+        ipc::sync::semaphore sem {"test-sem"};
+        EXPECT_TRUE(sem.post(1000));
+    }}.join();
+
+    for (int i = 0; i < 1000; ++i) {
+        EXPECT_TRUE(sem.wait(0));
+    }
+    EXPECT_FALSE(sem.wait(0));
+}
+
+#include "libipc/condition.h"
+
+TEST(Sync, Condition) {
+    ipc::sync::condition cond;
+    EXPECT_TRUE(cond.open("test-cond"));
+    ipc::sync::mutex lock;
+    EXPECT_TRUE(lock.open("test-mutex"));
+    std::deque<int> que;
+
+    auto job = [&que](int num) {
+        ipc::sync::condition cond {"test-cond"};
+        ipc::sync::mutex lock {"test-mutex"};
+        for (int i = 0; i < 10; ++i) {
+            int val = 0;
+            {
+                std::lock_guard<ipc::sync::mutex> guard {lock};
+                while (que.empty()) {
+                    ASSERT_TRUE(cond.wait(lock));
+                }
+                val = que.front();
+                que.pop_front();
+            }
+            EXPECT_NE(val, 0);
+            std::printf("test-cond-%d: %d\n", num, val);
+        }
+        for (;;) {
+            int val = 0;
+            {
+                std::lock_guard<ipc::sync::mutex> guard {lock};
+                while (que.empty()) {
+                    ASSERT_TRUE(cond.wait(lock, 1000));
+                }
+                val = que.front();
+                que.pop_front();
+            }
+            if (val == 0) {
+                std::printf("test-cond-%d: exit.\n", num);
+                return;
+            }
+            std::printf("test-cond-%d: %d\n", num, val);
+        }
+    };
+    std::array<std::thread, 10> test_conds;
+    for (int i = 0; i < (int)test_conds.size(); ++i) {
+        test_conds[i] = std::thread{job, i};
+    }
+
+    for (int i = 1; i < 100; ++i) {
+        {
+            std::lock_guard<ipc::sync::mutex> guard {lock};
+            que.push_back(i);
+            ASSERT_TRUE(cond.notify(lock));
+        }
+        std::this_thread::sleep_for(std::chrono::milliseconds(20));
+    }
+    for (int i = 1; i < 100; ++i) {
+        {
+            std::lock_guard<ipc::sync::mutex> guard {lock};
+            que.push_back(i);
+            ASSERT_TRUE(cond.broadcast(lock));
+        }
+        std::this_thread::sleep_for(std::chrono::milliseconds(20));
+    }
+    {
+        std::lock_guard<ipc::sync::mutex> guard {lock};
+        for (int i = 0; i < (int)test_conds.size(); ++i) {
+            que.push_back(0);
+        }
+        ASSERT_TRUE(cond.broadcast(lock));
+    }
+
+    for (auto &t : test_conds) t.join();
+}
+
+/**
+ * https://stackoverflow.com/questions/51730660/is-this-a-bug-in-glibc-pthread
+*/
+TEST(Sync, ConditionRobust) {
+    printf("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 1\n");
+    ipc::sync::condition cond {"test-cond"};
+    printf("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 2\n");
+    ipc::sync::mutex lock {"test-mutex"};
+    printf("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 3\n");
+    ASSERT_TRUE(lock.lock());
+    std::thread unlock {[] {
+        printf("WWWWWWWWWWWWWWWWWWWWWWWWWWWWWW 1\n");
+        ipc::sync::condition cond {"test-cond"};
+        printf("WWWWWWWWWWWWWWWWWWWWWWWWWWWWWW 2\n");
+        ipc::sync::mutex lock {"test-mutex"};
+        printf("WWWWWWWWWWWWWWWWWWWWWWWWWWWWWW 3\n");
+        {
+            std::lock_guard<ipc::sync::mutex> guard {lock};
+        }
+        std::this_thread::sleep_for(std::chrono::seconds(1));
+        printf("WWWWWWWWWWWWWWWWWWWWWWWWWWWWWW 4\n");
+        ASSERT_TRUE(cond.broadcast(lock));
+        printf("WWWWWWWWWWWWWWWWWWWWWWWWWWWWWW 5\n");
+    }};
+    printf("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 4\n");
+    ASSERT_TRUE(cond.wait(lock));
+    printf("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 5\n");
+    ASSERT_TRUE(lock.unlock());
+    printf("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 6\n");
+    unlock.join();
+}
\ No newline at end of file
diff --git a/test/test_thread_utility.cpp b/test/test_thread_utility.cpp
new file mode 100644
index 0000000..e052b09
--- /dev/null
+++ b/test/test_thread_utility.cpp
@@ -0,0 +1,203 @@
+#include <type_traits>
+#include <iostream>
+#include <shared_mutex> // std::shared_lock
+#include <utility>
+#include <thread>
+#include <future>       // std::async
+#include <atomic>
+#include <string>       // std::string
+
+#include "capo/spin_lock.hpp"
+#include "capo/type_name.hpp"
+
+#include "libipc/rw_lock.h"
+
+#include "test.h"
+#include "thread_pool.h"
+
+namespace {
+
+constexpr int LoopCount = 100000;
+constexpr int ThreadMax = 8;
+
+template <typename T>
+constexpr T acc(T b, T e) noexcept {
+    return (e + b) * (e - b + 1) / 2;
+}
+
+template <typename Mutex>
+struct lc_wrapper : Mutex {
+    void lock_shared  () { Mutex::lock  (); }
+    void unlock_shared() { Mutex::unlock(); }
+};
+
+template <typename Lc, int Loops = LoopCount>
+void benchmark_lc(int w, int r, char const * message) {
+    ipc_ut::sender().start(static_cast<std::size_t>(w));
+    ipc_ut::reader().start(static_cast<std::size_t>(r));
+    ipc_ut::test_stopwatch sw;
+
+    std::uint64_t data = 0;
+    std::uint64_t sum  = acc<std::uint64_t>(1, Loops) * w;
+    Lc lc;
+
+    for (int k = 0; k < r; ++k) {
+        ipc_ut::reader() << [sum, &lc, &data] {
+            while (1) {
+                {
+                    std::shared_lock<Lc> guard { lc };
+                    if (data == sum) break;
+                }
+                std::this_thread::yield();
+            }
+        };
+    }
+
+    for (int k = 0; k < w; ++k) {
+        ipc_ut::sender() << [&sw, &lc, &data] {
+            sw.start();
+            for (int i = 1; i <= Loops; ++i) {
+                {
+                    std::lock_guard<Lc> guard { lc };
+                    data += i;
+                }
+                std::this_thread::yield();
+            }
+        };
+    }
+
+    ipc_ut::sender().wait_for_done();
+    sw.print_elapsed(w, r, Loops, message);
+    ipc_ut::reader().wait_for_done();
+}
+
+void test_lock_performance(int w, int r) {
+    std::cout << "test_lock_performance: [" << w << "-" << r << "]" << std::endl;
+    benchmark_lc<ipc::rw_lock               >(w, r, "ipc::rw_lock");
+    benchmark_lc<lc_wrapper< ipc::spin_lock>>(w, r, "ipc::spin_lock");
+    benchmark_lc<lc_wrapper<capo::spin_lock>>(w, r, "capo::spin_lock");
+    benchmark_lc<lc_wrapper<std::mutex>     >(w, r, "std::mutex");
+    // benchmark_lc<std::shared_mutex          >(w, r, "std::shared_mutex");
+}
+
+} // internal-linkage
+
+//TEST(Thread, rw_lock) {
+//    for (int i = 1; i <= ThreadMax; ++i) test_lock_performance(i, 0);
+//    for (int i = 1; i <= ThreadMax; ++i) test_lock_performance(1, i);
+//    for (int i = 2; i <= ThreadMax; ++i) test_lock_performance(i, i);
+//}
+
+#if 0 // disable ipc::tls
+TEST(Thread, tls_main_thread) {
+    ipc::tls::pointer<int> p;
+    EXPECT_FALSE(p);
+    EXPECT_NE(p.create(123), nullptr);
+    EXPECT_EQ(*p, 123);
+}
+
+namespace {
+
+struct Foo {
+    std::atomic<int> * px_;
+    Foo(std::atomic<int> * px) : px_(px) {}
+    ~Foo() {
+        px_->fetch_add(1, std::memory_order_relaxed);
+    }
+};
+
+} // namespace
+
+TEST(Thread, tls_create_once) {
+    std::atomic<int> x { 0 };
+    Foo { &x };
+    EXPECT_EQ(x, 1);
+    {
+        ipc::tls::pointer<Foo> foo;
+        EXPECT_NE(foo.create(&x), nullptr);
+        EXPECT_EQ(x, 1);
+
+        std::thread {[&foo, &x] {
+            auto foo1 = foo.create_once(&x);
+            auto foo2 = foo.create_once(&x);
+            EXPECT_EQ(foo1, foo2);
+        }}.join();
+        EXPECT_EQ(x, 2);
+    }
+    EXPECT_EQ(x, 3);
+}
+
+TEST(Thread, tls_multi_thread) {
+    std::atomic<int> x { 0 };
+    {
+        ipc::tls::pointer<Foo> foo; // no create
+        EXPECT_EQ(x, 0);
+
+        ipc_ut::thread_pool pool { 10 };
+        for (int i = 0; i < 1000; ++i) {
+          pool << [&foo, &x] {
+            // foo.create_once(&x);
+            std::this_thread::sleep_for(std::chrono::milliseconds(1));
+          };
+        }
+        pool.wait_for_done();
+        EXPECT_EQ(x, 0); // thread_pool hasn't destructed.
+    }
+    // EXPECT_EQ(x, 10);
+}
+
+namespace {
+
+template <typename Tls, typename T>
+void benchmark_tls(char const * message) {
+    ipc_ut::thread_pool pool { static_cast<std::size_t>(ThreadMax) };
+    ipc_ut::test_stopwatch sw;
+    pool.wait_for_started();
+
+    for (int k = 0; k < ThreadMax; ++k) {
+        pool << [&sw] {
+            sw.start();
+            for (int i = 0; i < LoopCount * 10; ++i) {
+                *Tls::template get<T>() = i;
+            }
+        };
+    }
+
+    pool.wait_for_done();
+    sw.print_elapsed(ThreadMax, LoopCount * 10, message);
+}
+
+struct ipc_tls {
+    template <typename T>
+    static T * get() {
+        static ipc::tls::pointer<T> p;
+        return p.create_once();
+    }
+};
+
+struct std_tls {
+    template <typename T>
+    static T * get() {
+        thread_local T p;
+        return &p;
+    }
+};
+
+struct Str {
+    std::string str_;
+
+    Str & operator=(int i) {
+        str_ = std::to_string(i);
+        return *this;
+    }
+};
+
+} // internal-linkage
+
+TEST(Thread, tls_benchmark) {
+    benchmark_tls<std_tls, int>("std_tls: int");
+    benchmark_tls<ipc_tls, int>("ipc_tls: int");
+    benchmark_tls<std_tls, Str>("std_tls: Str");
+    benchmark_tls<ipc_tls, Str>("ipc_tls: Str");
+}
+#endif
\ No newline at end of file
diff --git a/test/test_waiter.cpp b/test/test_waiter.cpp
new file mode 100644
index 0000000..1996442
--- /dev/null
+++ b/test/test_waiter.cpp
@@ -0,0 +1,68 @@
+#include <thread>
+#include <iostream>
+
+#include "libipc/waiter.h"
+#include "test.h"
+
+namespace {
+
+TEST(Waiter, broadcast) {
+    for (int i = 0; i < 10; ++i) {
+        ipc::detail::waiter waiter;
+        std::thread ts[10];
+
+        int k = 0;
+        for (auto& t : ts) {
+            t = std::thread([&k] {
+                ipc::detail::waiter waiter {"test-ipc-waiter"};
+                EXPECT_TRUE(waiter.valid());
+                for (int i = 0; i < 9; ++i) {
+                    while (!waiter.wait_if([&k, &i] { return k == i; })) ;
+                }
+            });
+        }
+
+        EXPECT_TRUE(waiter.open("test-ipc-waiter"));
+        std::cout << "waiting for broadcast...\n";
+        for (k = 1; k < 10; ++k) {
+            std::cout << "broadcast: " << k << "\n";
+            ASSERT_TRUE(waiter.broadcast());
+            std::this_thread::sleep_for(std::chrono::milliseconds(100));
+        }
+        for (auto& t : ts) t.join();
+        std::cout << "quit... " << i << "\n";
+    }
+}
+
+TEST(Waiter, quit_waiting) {
+    ipc::detail::waiter waiter;
+    EXPECT_TRUE(waiter.open("test-ipc-waiter"));
+
+    std::thread t1 {
+        [&waiter] {
+            EXPECT_TRUE(waiter.wait_if([] { return true; }));
+        }
+    };
+
+    bool quit = false;
+    std::thread t2 {
+        [&quit] {
+            ipc::detail::waiter waiter {"test-ipc-waiter"};
+            EXPECT_TRUE(waiter.wait_if([&quit] { return !quit; }));
+        }
+    };
+
+    std::this_thread::sleep_for(std::chrono::milliseconds(100));
+    EXPECT_TRUE(waiter.quit_waiting());
+    t1.join();
+    ASSERT_TRUE(t2.joinable());
+
+    EXPECT_TRUE(waiter.open("test-ipc-waiter"));
+    std::cout << "nofify quit...\n";
+    quit = true;
+    EXPECT_TRUE(waiter.notify());
+    t2.join();
+    std::cout << "quit... \n";
+}
+
+} // internal-linkage
diff --git a/test/thread_pool.h b/test/thread_pool.h
new file mode 100644
index 0000000..99b5db1
--- /dev/null
+++ b/test/thread_pool.h
@@ -0,0 +1,123 @@
+#pragma once
+
+#include <thread>             // std::thread
+#include <mutex>              // std::mutex
+#include <condition_variable> // std::condition_variable
+#include <deque>              // std::deque
+#include <functional>         // std::function
+#include <utility>            // std::forward, std::move
+#include <cstddef>            // std::size_t
+#include <cassert>            // assert
+
+#include "capo/scope_guard.hpp"
+
+namespace ipc_ut {
+
+class thread_pool final {
+
+  std::deque<std::thread> workers_;
+  std::deque<std::function<void()>> jobs_;
+
+  std::mutex lock_;
+  std::condition_variable cv_jobs_;
+  std::condition_variable cv_empty_;
+
+  std::size_t waiting_cnt_ = 0;
+  bool quit_ = false;
+
+  static void proc(thread_pool * pool) {
+    assert(pool != nullptr);
+    std::function<void()> job;
+    for (;;) {
+      {
+        std::unique_lock<std::mutex> guard { pool->lock_ };
+        if (pool->quit_) return;
+        if (pool->jobs_.empty()) {
+          pool->waiting_cnt_ += 1;
+          CAPO_SCOPE_GUARD_ = [pool] {
+              pool->waiting_cnt_ -= 1;
+          };
+
+          if (pool->waiting_cnt_ == pool->workers_.size()) {
+            pool->cv_empty_.notify_all();
+          }
+          assert(pool->waiting_cnt_ <= pool->workers_.size());
+          do {
+            pool->cv_jobs_.wait(guard);
+            if (pool->quit_) return;
+          } while (pool->jobs_.empty());
+        }
+        assert(!pool->jobs_.empty());
+        job = std::move(pool->jobs_.front());
+        pool->jobs_.pop_front();
+      }
+      if (job) job();
+    }
+  }
+
+public:
+  thread_pool() = default;
+
+  ~thread_pool() {
+    {
+      std::lock_guard<std::mutex> guard { lock_ };
+      static_cast<void>(guard);
+      quit_ = true;
+    }
+    cv_jobs_.notify_all();
+    cv_empty_.notify_all();
+    for (auto & trd : workers_) trd.join();
+  }
+
+  explicit thread_pool(std::size_t n) : thread_pool() {
+    start(n);
+  }
+
+  void start(std::size_t n) {
+    std::unique_lock<std::mutex> guard { lock_ };
+    if (n <= workers_.size()) return;
+    for (std::size_t i = workers_.size(); i < n; ++i) {
+      workers_.push_back(std::thread { &thread_pool::proc, this });
+    }
+  }
+
+  std::size_t size() const noexcept {
+    return workers_.size();
+  }
+
+  std::size_t jobs_size() const noexcept {
+    return jobs_.size();
+  }
+
+  void wait_for_started() {
+    std::unique_lock<std::mutex> guard { lock_ };
+    if (quit_) return;
+    while (!workers_.empty() && (waiting_cnt_ != workers_.size())) {
+      cv_empty_.wait(guard);
+      if (quit_) return;
+    }
+  }
+
+  void wait_for_done() {
+    std::unique_lock<std::mutex> guard { lock_ };
+    if (quit_) return;
+    while (!jobs_.empty() || (waiting_cnt_ != workers_.size())) {
+      assert(waiting_cnt_ <= workers_.size());
+      cv_empty_.wait(guard);
+      if (quit_) return;
+    }
+  }
+
+  template <typename F>
+  thread_pool & operator<<(F && job) {
+    {
+      std::lock_guard<std::mutex> guard { lock_ };
+      static_cast<void>(guard);
+      jobs_.emplace_back(std::forward<F>(job));
+    }
+    cv_jobs_.notify_one();
+    return *this;
+  }
+};
+
+} // namespace ipc_ut
\ No newline at end of file