/* * Copyright (c) 2022 Huawei Device Co., Ltd. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef SCOPE_GUARD_H #define SCOPE_GUARD_H namespace Updater { /* * The RAII feature is used to implement scope exit protection so that resources * can be released and the closure action can be performed in a unified manner when * the scope exits. */ namespace Detail { template class ScopeGuard { public: ScopeGuard(ExitAction &&action) : action_(action), enable_(true) {} ~ScopeGuard() { if (enable_) { action_(); } } void Disable() { enable_ = false; } private: ExitAction action_; bool enable_; }; struct ScopeExitGuardHelper {}; template static inline ScopeGuard operator + (ScopeExitGuardHelper, ExitAction &&action) { return ScopeGuard(std::forward(action)); } } #define ON_SCOPE_EXIT(id) auto onScopeExitGuard##id = Detail::ScopeExitGuardHelper {} + [ & ] #define CANCEL_SCOPE_EXIT_GUARD(id) onScopeExitGuard##id.Disable() } #endif