1 // Copyright 2021 The PDFium Authors 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CORE_FXCRT_SCOPED_SET_INSERTION_H_ 6 #define CORE_FXCRT_SCOPED_SET_INSERTION_H_ 7 8 #include <set> 9 #include <utility> 10 11 #include "core/fxcrt/fx_memory.h" 12 #include "third_party/base/check.h" 13 14 namespace fxcrt { 15 16 // Track the addition of an object to a set, removing it automatically when 17 // the ScopedSetInsertion goes out of scope. 18 template <typename T> 19 class ScopedSetInsertion { 20 public: 21 FX_STACK_ALLOCATED(); 22 ScopedSetInsertion(std::set<T> * org_set,const T & elem)23 ScopedSetInsertion(std::set<T>* org_set, const T& elem) 24 : set_(org_set), insert_results_(set_->insert(elem)) { 25 CHECK(insert_results_.second); 26 } 27 ScopedSetInsertion(const ScopedSetInsertion&) = delete; 28 ScopedSetInsertion& operator=(const ScopedSetInsertion&) = delete; ~ScopedSetInsertion()29 ~ScopedSetInsertion() { set_->erase(insert_results_.first); } 30 31 private: 32 std::set<T>* const set_; 33 const std::pair<typename std::set<T>::iterator, bool> insert_results_; 34 }; 35 36 } // namespace fxcrt 37 38 using fxcrt::ScopedSetInsertion; 39 40 #endif // CORE_FXCRT_SCOPED_SET_INSERTION_H_ 41