具体内容可查看stdint.h文件

/* exact-width signed integer types */

typedef   signed          char int8_t;

typedef   signed short     int int16_t;

typedef   signed           int int32_t;

typedef   signed       __INT64 int64_t;

/* exact-width unsigned integer types */

typedef unsigned          char uint8_t;

typedef unsigned short     int uint16_t;

typedef unsigned           int uint32_t;

typedef unsigned       __INT64 uint64_t;

/* 7.18.1.2 */

/* smallest type of at least n bits */

/* minimum-width signed integer types */

typedef   signed          char int_least8_t;

typedef   signed short     int int_least16_t;

typedef   signed           int int_least32_t;

typedef   signed       __INT64 int_least64_t;

/* minimum-width unsigned integer types */

typedef unsigned          char uint_least8_t;

typedef unsigned short     int uint_least16_t;

typedef unsigned           int uint_least32_t;

typedef unsigned       __INT64 uint_least64_t;

/* 7.18.1.3 */

/* fastest minimum-width signed integer types */

typedef   signed           int int_fast8_t;

typedef   signed           int int_fast16_t;

typedef   signed           int int_fast32_t;

typedef   signed       __INT64 int_fast64_t;

/* fastest minimum-width unsigned integer types */

typedef unsigned           int uint_fast8_t;

typedef unsigned           int uint_fast16_t;

typedef unsigned           int uint_fast32_t;

typedef unsigned       __INT64 uint_fast64_t;

/* 7.18.1.4 integer types capable of holding object pointers */

#if __sizeof_ptr == 8

typedef   signed       __INT64 intptr_t;

typedef unsigned       __INT64 uintptr_t;

#else

typedef   signed           int intptr_t;

typedef unsigned           int uintptr_t;

#endif

/* 7.18.1.5 greatest-width integer types */

typedef   signed     __LONGLONG intmax_t;

typedef unsigned     __LONGLONG uintmax_t;