一个通用的单体模板

#include <cassert.h>

template<typename T> class Singleton
{
 static T* ms_Singleton;

public:

 Singleton( void )
 {
 assert( !ms_Singleton);
 int offset = (int)(T*)1 - (int)(Singleton<T>*)(T*)1;
 ms_Singleton = (T*)((int)this + offset);
 }
 ~Singleton(void)
 { assert(ms_Singleton); ms_Singleton = 0;}
 static T& GetSingleton(void)
 { assert(ms_Singleton); return (*ms_Singleton); }
 static T* GetSingletonPtr(void)
 { return ms_Singleton; }
};

template<typename T> T* Singleton<T>::ms_Singleton = 0;

class TextureMgr : public Singleton<TextureMgr>
{
 public:
 Texture* GetTexture(const char* name);
}