头里: /* Data structure definitions for div and ldiv runtimes. */#ifndef _DIV_T_DEFINEDtypedef struct _div_t { int quot; int rem; } div_t;typedef struct _ldiv_t { long quot; long rem; } ldiv_t;#define _DIV_T_DEFINED #endif只有 #ifndef _DIV_T_DEFINED 才定义, 所以: #undef _DIV_T_DEFINED #include <stdlib.h>
div_t, ldiv_t structures Store values returned by div and ldiv, respectively. STDLIB.H
long quot;
long rem;
} ldiv_t;
/* Data structure definitions for div and ldiv runtimes. */#ifndef _DIV_T_DEFINEDtypedef struct _div_t {
int quot;
int rem;
} div_t;typedef struct _ldiv_t {
long quot;
long rem;
} ldiv_t;#define _DIV_T_DEFINED
#endif只有 #ifndef _DIV_T_DEFINED 才定义,
所以:
#undef _DIV_T_DEFINED
#include <stdlib.h>
Store values returned by div and ldiv, respectively.
STDLIB.H