__offsetof
#define __offsetof(type, field) ((size_t)(&((type *)0)->field))
#define __offsetof(type, field) __builtin_offsetof(type, field)
#define __offsetof(type, field) __builtin_offsetof(type, field)
#define __offsetof(type, field) ((size_t)(&((type *)0)->field))
#define __offsetof(type, field) \