Singleton

Singleton.h

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

	public:
		cSingleton( void )
		{
			assert( !ms_Singleton );
			int offset = (int)(T*)1 - (int)(cSingleton <T>*)(T*)1;  //这里的offset主要处理多重继承，及虚继承的情况地址的偏移量
			ms_Singleton = (T*)((int)this + offset);
		}
		~cSingleton( 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* cSingleton<T>::ms_Singleton = 0x0;

//要实现单件功能的类必须继承这个类才行的
//class CTeminator : public cSingleton<CTeminator>