scope_guard.h (1231B)
1 // Copyright (c) the JPEG XL Project Authors. All rights reserved. 2 // 3 // Use of this source code is governed by a BSD-style 4 // license that can be found in the LICENSE file. 5 6 #ifndef LIB_JXL_BASE_SCOPE_GUARD_H_ 7 #define LIB_JXL_BASE_SCOPE_GUARD_H_ 8 9 #include <utility> 10 11 namespace jxl { 12 13 template <typename Callback> 14 class ScopeGuard { 15 public: 16 // Discourage unnecessary moves / copies. 17 ScopeGuard(const ScopeGuard &) = delete; 18 ScopeGuard &operator=(const ScopeGuard &) = delete; 19 ScopeGuard &operator=(ScopeGuard &&) = delete; 20 21 // Pre-C++17 does not guarantee RVO -> require move constructor. 22 ScopeGuard(ScopeGuard &&other) : callback_(std::move(other.callback_)) { 23 other.armed_ = false; 24 } 25 26 template <typename CallbackParam> 27 ScopeGuard(CallbackParam &&callback, bool armed) 28 : callback_(std::forward<CallbackParam>(callback)), armed_(armed) {} 29 30 ~ScopeGuard() { 31 if (armed_) callback_(); 32 } 33 34 void Disarm() { armed_ = false; } 35 36 private: 37 Callback callback_; 38 bool armed_; 39 }; 40 41 template <typename Callback> 42 ScopeGuard<Callback> MakeScopeGuard(Callback &&callback) { 43 return ScopeGuard<Callback>{std::forward<Callback>(callback), true}; 44 } 45 46 } // namespace jxl 47 48 #endif // LIB_JXL_BASE_SCOPE_GUARD_H_