ABM2/Engine/singleton.h

   1 #ifndef SINGLETON_H_INCLUDED\r
   2 #define SINGLETON_H_INCLUDED\r
   3 \r
   4 template<typename T>\r
   5 class Singleton\r
   6 {\r
   7         static T* ms_singleton;\r
   8         public:\r
   9                 Singleton()\r
  10                 {\r
  11                         assert(!ms_singleton);\r
  12                         //use a cunning trick to get the singleton pointing to the start of the whole, rather than\r
  13                         //the start of the Singleton part of the object\r
  14                         int offset = (int)(T*)1 - (int)(Singleton <T>*)(T*)1;\r
  15                         ms_singleton = (T*)((int)this + offset);\r
  16                 }\r
  17                 ~Singleton()\r
  18                 {\r
  19                         assert(ms_singleton);\r
  20                         ms_singleton=0;\r
  21                 }\r
  22                 static inline T& GetSingleton()\r
  23                 {\r
  24                         assert(ms_singleton);\r
  25                         return *ms_singleton;\r
  26                 }\r
  27                 static inline T* GetSingletonPtr()\r
  28                 {\r
  29                         assert(ms_singleton);\r
  30                         return ms_singleton;\r
  31                 }\r
  32 };\r
  33 \r
  34 template <typename T> T* Singleton <T>::ms_singleton = 0;\r
  35 \r
  36 #endif\r