1 /* Copyright (C) 2009 Wildfire Games. 2 * This file is part of 0 A.D. 3 * 4 * 0 A.D. is free software: you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation, either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * 0 A.D. is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with 0 A.D. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 /* 19 * template base class for Singletons 20 */ 21 22 /* 23 USAGE: class myClass : Singleton<myClass>{}; 24 25 Modified from http://gamedev.net/reference/articles/article1954.asp 26 */ 27 28 #ifndef INCLUDED_SINGLETON 29 #define INCLUDED_SINGLETON 30 31 #include "lib/debug.h" 32 33 template<typename T> 34 class Singleton 35 { 36 static T* ms_singleton; 37 38 public: Singleton()39 Singleton() 40 { 41 ENSURE( !ms_singleton ); 42 ms_singleton = static_cast<T*>(this); 43 } 44 ~Singleton()45 ~Singleton() 46 { 47 ENSURE( ms_singleton ); 48 ms_singleton = 0; 49 } 50 GetSingleton()51 static T& GetSingleton() 52 { 53 ENSURE( ms_singleton ); 54 return *ms_singleton; 55 } 56 GetSingletonPtr()57 static T* GetSingletonPtr() 58 { 59 ENSURE( ms_singleton ); 60 return ms_singleton; 61 } 62 IsInitialised()63 static bool IsInitialised() 64 { 65 return (ms_singleton != 0); 66 } 67 }; 68 69 template <typename T> 70 T* Singleton<T>::ms_singleton = 0; 71 72 #endif 73