1 /* 2 * Copyright 2014 Google Inc. All rights reserved. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef FRUIT_CLASS_CONSTRUCTION_TRACKER_H 18 #define FRUIT_CLASS_CONSTRUCTION_TRACKER_H 19 20 #include <cstddef> 21 22 /** 23 * This class is useful to keep track of how many instances of a given type are created during the entire program 24 * execution. 25 * 26 * Example use: 27 * class Foo : public ConstructionTracker<Foo> { 28 * ... 29 * }; 30 * 31 * int main() { 32 * ... 33 * assert(Foo::num_objects_constructed == 3); 34 * } 35 */ 36 template <typename T> 37 struct ConstructionTracker { 38 static std::size_t num_objects_constructed; 39 40 ConstructionTracker() { 41 ++num_objects_constructed; 42 } 43 }; 44 45 template <typename T> 46 std::size_t ConstructionTracker<T>::num_objects_constructed = 0; 47 48 #endif // FRUIT_CLASS_CONSTRUCTION_TRACKER_H 49
