shadPS4/src/common/scope_exit.h

80 lines
1.8 KiB
C++

// SPDX-FileCopyrightText: 2014 Citra Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <utility>
namespace detail {
template <class F>
class ScopeGuard {
private:
F f;
bool active;
public:
constexpr ScopeGuard(F f_) : f(std::move(f_)), active(true) {}
constexpr ~ScopeGuard() {
if (active) {
f();
}
}
constexpr void Cancel() {
active = false;
}
constexpr ScopeGuard(ScopeGuard&& rhs) : f(std::move(rhs.f)), active(rhs.active) {
rhs.Cancel();
}
ScopeGuard& operator=(ScopeGuard&& rhs) = delete;
};
template <class F>
constexpr ScopeGuard<F> MakeScopeGuard(F f) {
return ScopeGuard<F>(std::move(f));
}
enum class ScopeGuardOnExit {};
template <typename F>
constexpr ScopeGuard<F> operator+(ScopeGuardOnExit, F&& f) {
return ScopeGuard<F>(std::forward<F>(f));
}
} // namespace detail
#define CONCATENATE_IMPL(s1, s2) s1##s2
#define CONCATENATE(s1, s2) CONCATENATE_IMPL(s1, s2)
#ifdef __COUNTER__
#define ANONYMOUS_VARIABLE(pref) CONCATENATE(pref, __COUNTER__)
#else
#define ANONYMOUS_VARIABLE(pref) CONCATENATE(pref, __LINE__)
#endif
/**
* This macro is similar to SCOPE_EXIT, except the object is caller managed. This is intended to be
* used when the caller might want to cancel the ScopeExit.
*/
#define SCOPE_GUARD detail::ScopeGuardOnExit() + [&]()
/**
* This macro allows you to conveniently specify a block of code that will run on scope exit. Handy
* for doing ad-hoc clean-up tasks in a function with multiple returns.
*
* Example usage:
* \code
* const int saved_val = g_foo;
* g_foo = 55;
* SCOPE_EXIT{ g_foo = saved_val; };
*
* if (Bar()) {
* return 0;
* } else {
* return 20;
* }
* \endcode
*/
#define SCOPE_EXIT auto ANONYMOUS_VARIABLE(SCOPE_EXIT_STATE_) = SCOPE_GUARD