ppg清漆编号:关于 c++ 中的 long

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我想知道long在c++里指什么变量?范围多大?(比如int指整形)谢了!

long是修饰符,当它与int一起使用时,支持的数字范围:-2,147,483,648到2,147,483,647。占32位(4个字节)的内存空间。
当它与double一起使用时,占128位(16个字节)空间。

limit.h中定义了所有类型的范围
其中long int
#define LONG_MIN (-2147483647L - 1) /* minimum (signed) long value */
#define LONG_MAX 2147483647L /* maximum (signed) long value */

limit.h完整定义:
/***
*limits.h - implementation dependent values
*
* Copyright (c) 1985-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Contains defines for a number of implementation dependent values
* which are commonly used in C programs.
* [ANSI]
*
* [Public]
*
****/

#if _MSC_VER > 1000
#pragma once
#endif

#ifndef _INC_LIMITS
#define _INC_LIMITS

#if !defined(_WIN32) && !defined(_MAC)
#error ERROR: Only Mac or Win32 targets supported!
#endif

#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
#define CHAR_MIN 0
#define CHAR_MAX UCHAR_MAX
#endif /* _CHAR_UNSIGNED */

#define MB_LEN_MAX 2 /* 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 */

#if _INTEGRAL_MAX_BITS >= 8
#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 */
#endif

#if _INTEGRAL_MAX_BITS >= 16
#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 */
#endif

#if _INTEGRAL_MAX_BITS >= 32
#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 */
#endif

#if _INTEGRAL_MAX_BITS >= 64
/* 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
#endif

#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

#ifdef _POSIX_

#define _POSIX_ARG_MAX 4096
#define _POSIX_CHILD_MAX 6
#define _POSIX_LINK_MAX 8
#define _POSIX_MAX_CANON 255
#define _POSIX_MAX_INPUT 255
#define _POSIX_NAME_MAX 14
#define _POSIX_NGROUPS_MAX 0
#define _POSIX_OPEN_MAX 16
#define _POSIX_PATH_MAX 255
#define _POSIX_PIPE_BUF 512
#define _POSIX_SSIZE_MAX 32767
#define _POSIX_STREAM_MAX 8
#define _POSIX_TZNAME_MAX 3

#define ARG_MAX 14500 /* 16k heap, minus overhead */
#define LINK_MAX 1024
#define MAX_CANON _POSIX_MAX_CANON
#define MAX_INPUT _POSIX_MAX_INPUT
#define NAME_MAX 255
#define NGROUPS_MAX 16
#define OPEN_MAX 32
#define PATH_MAX 512
#define PIPE_BUF _POSIX_PIPE_BUF
#define SSIZE_MAX _POSIX_SSIZE_MAX
#define STREAM_MAX 20
#define TZNAME_MAX 10

#endif /* POSIX */

#endif /* _INC_LIMITS */