64 lines
1.5 KiB
C
64 lines
1.5 KiB
C
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#pragma once
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#include <utility> // std::forward, std::move
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#include <algorithm> // std::swap
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#include <type_traits> // std::decay
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namespace ipc {
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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>
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class scope_guard {
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F destructor_;
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mutable bool dismiss_;
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public:
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template <typename D>
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scope_guard(D && destructor)
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: destructor_(std::forward<D>(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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std::swap(dismiss_, rhs.dismiss_);
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}
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~scope_guard() {
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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 swap(scope_guard & rhs) {
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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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void dismiss() const noexcept {
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dismiss_ = true;
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}
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void do_exit() {
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if (!dismiss_) {
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dismiss_ = true;
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destructor_();
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}
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}
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};
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template <typename D>
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constexpr auto guard(D && destructor) noexcept {
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return scope_guard<std::decay_t<D>> {
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std::forward<D>(destructor)
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};
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}
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} // namespace ipc
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