limits.h头文件的作用

limits.h专门用于检测整型数据数据类型的表达值范围。

附源码:

/***
*limits.h - implementation dependent values
*
*       Copyright (c) Microsoft Corporation.  All rights reserved.
*
*Purpose:
*       Contains defines for a number of implementation dependent values
*       which are commonly used in C programs.
*       [ANSI]
*
*       [Public]
*
****/

#pragma once

#include 

#ifndef _INC_LIMITS
#define _INC_LIMITS

#define CHAR_BIT      8         /* number of bits in a char */
#define SCHAR_MIN   (-128)      /* minimum signed char value */
#define SCHAR_MAX     127       /* maximum signed char value */
#define UCHAR_MAX     0xff      /* maximum unsigned char value */

#ifndef _CHAR_UNSIGNED
#define CHAR_MIN    SCHAR_MIN   /* mimimum char value */
#define CHAR_MAX    SCHAR_MAX   /* maximum char value */
#else  /* _CHAR_UNSIGNED */
#define CHAR_MIN      0
#define CHAR_MAX    UCHAR_MAX
#endif  /* _CHAR_UNSIGNED */

#define MB_LEN_MAX    5             /* max. # bytes in multibyte char */
#define SHRT_MIN    (-32768)        /* minimum (signed) short value */
#define SHRT_MAX      32767         /* maximum (signed) short value */
#define USHRT_MAX     0xffff        /* maximum unsigned short value */
#define INT_MIN     (-2147483647 - 1) /* minimum (signed) int value */
#define INT_MAX       2147483647    /* maximum (signed) int value */
#define UINT_MAX      0xffffffff    /* maximum unsigned int value */
#define LONG_MIN    (-2147483647L - 1) /* minimum (signed) long value */
#define LONG_MAX      2147483647L   /* maximum (signed) long value */
#define ULONG_MAX     0xffffffffUL  /* maximum unsigned long value */
#define LLONG_MAX     9223372036854775807i64       /* maximum signed long long int value */
#define LLONG_MIN   (-9223372036854775807i64 - 1)  /* minimum signed long long int value */
#define ULLONG_MAX    0xffffffffffffffffui64       /* maximum unsigned long long int value */

#define _I8_MIN     (-127i8 - 1)    /* minimum signed 8 bit value */
#define _I8_MAX       127i8         /* maximum signed 8 bit value */
#define _UI8_MAX      0xffui8       /* maximum unsigned 8 bit value */

#define _I16_MIN    (-32767i16 - 1) /* minimum signed 16 bit value */
#define _I16_MAX      32767i16      /* maximum signed 16 bit value */
#define _UI16_MAX     0xffffui16    /* maximum unsigned 16 bit value */

#define _I32_MIN    (-2147483647i32 - 1) /* minimum signed 32 bit value */
#define _I32_MAX      2147483647i32 /* maximum signed 32 bit value */
#define _UI32_MAX     0xffffffffui32 /* maximum unsigned 32 bit value */

/* minimum signed 64 bit value */
#define _I64_MIN    (-9223372036854775807i64 - 1)
/* maximum signed 64 bit value */
#define _I64_MAX      9223372036854775807i64
/* maximum unsigned 64 bit value */
#define _UI64_MAX     0xffffffffffffffffui64

#if _INTEGRAL_MAX_BITS >= 128
/* minimum signed 128 bit value */
#define _I128_MIN   (-170141183460469231731687303715884105727i128 - 1)
/* maximum signed 128 bit value */
#define _I128_MAX     170141183460469231731687303715884105727i128
/* maximum unsigned 128 bit value */
#define _UI128_MAX    0xffffffffffffffffffffffffffffffffui128
#endif  /* _INTEGRAL_MAX_BITS >= 128 */

#ifndef SIZE_MAX
#ifdef _WIN64
#define SIZE_MAX _UI64_MAX
#else  /* _WIN64 */
#define SIZE_MAX UINT_MAX
#endif  /* _WIN64 */
#endif  /* SIZE_MAX */

#if __STDC_WANT_SECURE_LIB__
#ifndef RSIZE_MAX
#define RSIZE_MAX    (SIZE_MAX >> 1)
#endif  /* RSIZE_MAX */
#endif  /* __STDC_WANT_SECURE_LIB__ */


#endif  /* _INC_LIMITS */