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/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include <type_traits>
#include "mongo/platform/compiler.h"
namespace mongo {
template <typename F>
class [[nodiscard]] ScopeGuard {
public:
explicit ScopeGuard(const F& f) : _func(f) {}
explicit ScopeGuard(F && f) : _func(std::move(f)) {}
// Can only be move-constructed, to support being returned from a function.
ScopeGuard(const ScopeGuard&) = delete;
ScopeGuard(ScopeGuard && o) : _func(std::move(o._func)), _dismissed(o._dismissed) {
o._dismissed = true;
}
ScopeGuard& operator=(const ScopeGuard&) = delete;
ScopeGuard& operator=(ScopeGuard&&) = delete;
~ScopeGuard() {
if (_dismissed)
return;
_func();
}
void dismiss() noexcept {
_dismissed = true;
}
private:
F _func;
bool _dismissed = false;
};
template <typename F>
auto makeGuard(F&& fun) {
return ScopeGuard<std::decay_t<F>>(std::forward<F>(fun));
}
} // namespace mongo
#define MONGO_SCOPEGUARD_CAT2(s1, s2) s1##s2
#define MONGO_SCOPEGUARD_CAT(s1, s2) MONGO_SCOPEGUARD_CAT2(s1, s2)
#define MONGO_SCOPEGUARD_ANON(str) MONGO_SCOPEGUARD_CAT(str, __LINE__)
#define ON_BLOCK_EXIT(...) auto MONGO_SCOPEGUARD_ANON(onBlockExit) = makeGuard(__VA_ARGS__)
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