103 lines
2.3 KiB
C++
103 lines
2.3 KiB
C++
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/*
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The Capo Library
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Code covered by the MIT License
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Author: mutouyun (http://orzz.org)
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*/
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#pragma once
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#include "capo/noncopyable.hpp"
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#include "capo/unused.hpp"
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#include "capo/make.hpp"
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#include <utility> // std::forward, std::move
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#include <algorithm> // std::swap
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#include <functional> // std::function
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namespace capo {
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////////////////////////////////////////////////////////////////
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/// Execute guard function when the enclosing scope exits
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////////////////////////////////////////////////////////////////
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template <typename F = std::function<void()>>
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class scope_guard : capo::noncopyable
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{
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F destructor_;
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mutable bool dismiss_;
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public:
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template <typename F_>
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scope_guard(F_&& destructor)
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: destructor_(std::forward<F_>(destructor))
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, dismiss_(false)
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{}
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scope_guard(scope_guard&& rhs)
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: destructor_(std::move(rhs.destructor_))
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, dismiss_(true) // dismiss rhs
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{
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std::swap(dismiss_, rhs.dismiss_);
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}
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~scope_guard(void)
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{
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try { do_exit(); }
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/*
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In the realm of exceptions, it is fundamental that you can do nothing
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if your "undo/recover" action fails.
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*/
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catch(...) { /* Do nothing */ }
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}
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void dismiss(void) const noexcept
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{
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dismiss_ = true;
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}
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void do_exit(void)
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{
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if (!dismiss_)
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{
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dismiss_ = true;
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destructor_();
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}
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}
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void swap(scope_guard& rhs)
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{
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std::swap(destructor_, rhs.destructor_);
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std::swap(dismiss_, rhs.dismiss_);
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}
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};
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namespace detail_scope_guard {
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struct helper
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{
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template <typename F>
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auto operator=(F&& destructor) -> decltype(capo::make<scope_guard>(std::forward<F>(destructor)))
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{
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return capo::make<scope_guard>(std::forward<F>(destructor));
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}
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};
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} // namespace detail_scope_guard
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#define CAPO_SCOPE_GUARD_V_(L) CAPO_UNUSED_ scope_guard_##L##__
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#define CAPO_SCOPE_GUARD_L_(L) auto CAPO_SCOPE_GUARD_V_(L) = capo::detail_scope_guard::helper{}
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/*
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Do things like this:
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-->
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CAPO_SCOPE_GUARD_ = [ptr]
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{
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if (ptr) free(ptr);
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};
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*/
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#define CAPO_SCOPE_GUARD_ CAPO_SCOPE_GUARD_L_(__LINE__)
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////////////////////////////////////////////////////////////////
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} // namespace capo
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