C++ Reference: Standard C++ Library reference: C Library: climits

C++官方参考链接：https://cplusplus.com/reference/climits/ 

头文件 
<climits> (limits.h)
整型的大小
此头文件为所使用的特定系统和编译器实现定义了具有基本整数类型限制的常量。
基本浮点类型的限制定义在<cfloat>（float.h）中。
宽度特定的整型和其他类型定义类型的限制定义在<cstdint>（stdint.h）中。

宏常量

name	expresses	possible value*
CHAR_BIT	Number of bits in a char object (byte)	8 or greater*
SCHAR_MIN	Minimum value for an object of type signed char	-127 (-2^7+1) or less*
SCHAR_MAX	Maximum value for an object of type signed char	127 (2^7-1) or greater*
UCHAR_MAX	Maximum value for an object of type unsigned char	255 (2^8-1) or greater*
CHAR_MIN	Minimum value for an object of type char	either SCHAR_MIN or 0
CHAR_MAX	Maximum value for an object of type char	either SCHAR_MAX or UCHAR_MAX
MB_LEN_MAX	Maximum number of bytes in a multibyte character, for any locale	1 or greater*
SHRT_MIN	Minimum value for an object of type short int	-32767 (-2^15+1) or less*
SHRT_MAX	Maximum value for an object of type short int	32767 (2^15-1) or greater*
USHRT_MAX	Maximum value for an object of type unsigned short int	65535 (2^16-1) or greater*
INT_MIN	Minimum value for an object of type int	-32767 (-2^15+1) or less*
INT_MAX	Maximum value for an object of type int	32767 (2^15-1) or greater*
UINT_MAX	Maximum value for an object of type unsigned int	65535 (2^16-1) or greater*
LONG_MIN	Minimum value for an object of type long int	-2147483647 (-2^31+1) or less*
LONG_MAX	Maximum value for an object of type long int	2147483647 (2^31-1) or greater*
ULONG_MAX	Maximum value for an object of type unsigned long int	4294967295 (2^32-1) or greater*
LLONG_MIN	Minimum value for an object of type long long int	-9223372036854775807 (-2^63+1) or less*
LLONG_MAX	Maximum value for an object of type long long int	9223372036854775807 (2^63-1) or greater*
ULLONG_MAX	Maximum value for an object of type unsigned long long int	18446744073709551615 (2^64-1) or greater*

*实际值取决于特定的系统和库实现，但应反映这些类型在目标平台的限制。 

兼容性
LLONG_MIN、LLONG_MAX和ULLONG_MAX是为符合1999年或以后的C标准（只包括2011年以后的C++标准：C++11）的库定义的。