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 "core/fxcrt/unowned_ptr.h" 13 #include "third_party/base/check.h" 14 15 namespace fxcrt { 16 17 // Track the addition of an object to a set, removing it automatically when 18 // the ScopedSetInsertion goes out of scope. 19 template <typename T> 20 class ScopedSetInsertion { 21 public: 22 FX_STACK_ALLOCATED(); 23 ScopedSetInsertion(std::set<T> * org_set,const T & elem)24 ScopedSetInsertion(std::set<T>* org_set, const T& elem) 25 : set_(org_set), insert_results_(set_->insert(elem)) { 26 CHECK(insert_results_.second); 27 } 28 ScopedSetInsertion(const ScopedSetInsertion&) = delete; 29 ScopedSetInsertion& operator=(const ScopedSetInsertion&) = delete; ~ScopedSetInsertion()30 ~ScopedSetInsertion() { set_->erase(insert_results_.first); } 31 32 private: 33 UnownedPtr<std::set<T>> const set_; 34 const std::pair<typename std::set<T>::iterator, bool> insert_results_; 35 }; 36 37 } // namespace fxcrt 38 39 using fxcrt::ScopedSetInsertion; 40 41 #endif // CORE_FXCRT_SCOPED_SET_INSERTION_H_ 42