VC++常用定义（如SAFE_DELETE等）

#ifndef SAFE_DELETE
#define SAFE_DELETE(p) { if(p){delete(p); (p)=NULL;} }

#endif

#ifndef SAFE_DELETE_ARRAY

#define SAFE_DELETE_ARRAY(p) { if(p){delete[] (p); (p)=NULL;} }

#endif

#ifndef SAFE_RELEASE

#define SAFE_RELEASE(p) { if(p){ (p)->Release(); (p)=NULL;} }

#endif