#ifndef __STDDEF_H#define __STDDEF_H #ifndef NULL#ifdef __cplusplus#define NULL 0#else#define NULL ((void*)0)#endif#endif#define offsetof(ty,mem) ((size_t) &(((ty *)0)->mem)) typedef long ptrdiff_t;#ifndef _SIZE_T#define _SIZE_Ttypedef unsigned long size_t;#endif#ifndef _WCHAR_T#define _WCHAR_Ttypedef unsigned short wchar_t;#endif #endif /* __STDDEF_H */