78 lines
1.9 KiB
C++
78 lines
1.9 KiB
C++
//
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// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2020
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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#pragma once
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#include "td/utils/common.h"
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#include <cstdlib>
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#include <memory>
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#include <type_traits>
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#include <utility>
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namespace td {
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class Guard {
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public:
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Guard() = default;
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Guard(const Guard &other) = delete;
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Guard &operator=(const Guard &other) = delete;
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Guard(Guard &&other) = default;
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Guard &operator=(Guard &&other) = default;
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virtual ~Guard() = default;
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virtual void dismiss() {
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std::abort();
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}
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};
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template <class FunctionT>
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class LambdaGuard : public Guard {
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public:
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explicit LambdaGuard(const FunctionT &func) : func_(func) {
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}
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explicit LambdaGuard(FunctionT &&func) : func_(std::move(func)) {
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}
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LambdaGuard(const LambdaGuard &other) = delete;
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LambdaGuard &operator=(const LambdaGuard &other) = delete;
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LambdaGuard(LambdaGuard &&other) : func_(std::move(other.func_)), dismissed_(other.dismissed_) {
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other.dismissed_ = true;
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}
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LambdaGuard &operator=(LambdaGuard &&other) = delete;
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void dismiss() {
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dismissed_ = true;
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}
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~LambdaGuard() {
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if (!dismissed_) {
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func_();
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}
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}
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private:
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FunctionT func_;
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bool dismissed_ = false;
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};
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template <class F>
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unique_ptr<Guard> create_lambda_guard(F &&f) {
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return make_unique<LambdaGuard<F>>(std::forward<F>(f));
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}
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template <class F>
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std::shared_ptr<Guard> create_shared_lambda_guard(F &&f) {
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return std::make_shared<LambdaGuard<F>>(std::forward<F>(f));
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}
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enum class ScopeExit {};
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template <class FunctionT>
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auto operator+(ScopeExit, FunctionT &&func) {
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return LambdaGuard<std::decay_t<FunctionT>>(std::forward<FunctionT>(func));
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}
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} // namespace td
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#define SCOPE_EXIT auto TD_CONCAT(SCOPE_EXIT_VAR_, __LINE__) = ::td::ScopeExit() + [&]
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