tdlight/tdutils/td/utils/ScopeGuard.h

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//
2021-01-01 13:57:46 +01:00
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2021
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#pragma once
#include "td/utils/common.h"
#include <cstdlib>
#include <memory>
#include <type_traits>
#include <utility>
namespace td {
class Guard {
public:
Guard() = default;
Guard(const Guard &other) = delete;
Guard &operator=(const Guard &other) = delete;
Guard(Guard &&other) = default;
Guard &operator=(Guard &&other) = default;
virtual ~Guard() = default;
virtual void dismiss() {
std::abort();
}
};
template <class FunctionT>
class LambdaGuard final : public Guard {
public:
explicit LambdaGuard(const FunctionT &func) : func_(func) {
}
explicit LambdaGuard(FunctionT &&func) : func_(std::move(func)) {
}
LambdaGuard(const LambdaGuard &other) = delete;
LambdaGuard &operator=(const LambdaGuard &other) = delete;
LambdaGuard(LambdaGuard &&other) : func_(std::move(other.func_)), dismissed_(other.dismissed_) {
other.dismissed_ = true;
}
LambdaGuard &operator=(LambdaGuard &&other) = delete;
void dismiss() {
dismissed_ = true;
}
~LambdaGuard() {
if (!dismissed_) {
func_();
}
}
private:
FunctionT func_;
bool dismissed_ = false;
};
template <class F>
unique_ptr<Guard> create_lambda_guard(F &&f) {
return make_unique<LambdaGuard<F>>(std::forward<F>(f));
}
template <class F>
std::shared_ptr<Guard> create_shared_lambda_guard(F &&f) {
return std::make_shared<LambdaGuard<F>>(std::forward<F>(f));
}
enum class ScopeExit {};
template <class FunctionT>
auto operator+(ScopeExit, FunctionT &&func) {
return LambdaGuard<std::decay_t<FunctionT>>(std::forward<FunctionT>(func));
}
} // namespace td
#define SCOPE_EXIT auto TD_CONCAT(SCOPE_EXIT_VAR_, __LINE__) = ::td::ScopeExit() + [&]