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                         // This used to say "int" instead of long, but that breaks\r
  15                         // on 64 bit linux at least\r
  16                         long offset = (long)(T*)1 - (long)(Singleton <T>*)(T*)1;\r
  17                         ms_singleton = (T*)((long)this + offset);\r
  18                 }\r
  19                 ~Singleton()\r
  20                 {\r
  21                         assert(ms_singleton);\r
  22                         ms_singleton=0;\r
  23                 }\r
  24                 static inline T& GetSingleton()\r
  25                 {\r
  26                         assert(ms_singleton);\r
  27                         return *ms_singleton;\r
  28                 }\r
  29                 static inline T* GetSingletonPtr()\r
  30                 {\r
  31                         assert(ms_singleton);\r
  32                         return ms_singleton;\r
  33                 }\r
  34 };\r
  35 \r
  36 template <typename T> T* Singleton <T>::ms_singleton = 0;\r
  37 \r
  38 #endif\r