citra/src/common/scope_exit.h

// SPDX-FileCopyrightText: 2014 Citra Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#pragma once

#include <utility>
#include "common/common_funcs.h"

namespace detail {
template <typename Func>
struct ScopeExitHelper {
    explicit ScopeExitHelper(Func&& func_) : func(std::move(func_)) {}
    ~ScopeExitHelper() {
        if (active) {
            func();
        }
    }

    void Cancel() {
        active = false;
    }

    Func func;
    bool active{true};
};

template <typename Func>
ScopeExitHelper<Func> ScopeExit(Func&& func) {
    return ScopeExitHelper<Func>(std::forward<Func>(func));
}
} // namespace detail

/**
 * 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(body) auto CONCAT2(scope_exit_helper_, __LINE__) = detail::ScopeExit([&]() body)

/**
 * 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(body) detail::ScopeExit([&]() body)