C++ Reference: Standard C++ Library reference: C Library: cwctype

C++官网参考链接：https://cplusplus.com/reference/cwctype/

头文件
(wctype.h)
宽字符类型
这个头文件声明了一组函数，用于分类和转换单个宽字符。
有关如何使用"C"语言环境对标准ASCII字符集进行分类的更多信息，请参阅。

功能
字符分类函数
它们检查作为形参传递的字符是否属于某个类别：
iswalnum    Check if wide character is alphanumeric (function)
iswalpha    Check if wide character is alphabetic (function)
iswblank    Check if wide character is blank (function)
iswcntrl    Check if wide character is a control character (function)
iswdigit    Check if wide character is decimal digit (function)
iswgraph    Check if wide character has graphical representation (function)
iswlower    Check if wide character is lowercase letter (function)
iswprint    Check if wide character is printable (function)
iswpunct    Check if wide character is punctuation character (function)
iswspace    Check if wide character is a white-space (function)
iswupper    Check if wide character is uppercase letter (function)
iswxdigit    Check if wide character is hexadecimal digit (function) 

字符转换功能
两个在字母大小写之间转换的函数：
towlower    Convert uppercase wide character to lowercase (function)
towupper    Convert lowercase wide character to uppercase (function)

可扩展的分类/转换函数 
iswctype    Check if wide character has property (function)
towctrans    Convert using transformation (function)
wctrans    Return character transformation (function)
wctype    Return character property (function)

类型
wctrans_t    Wide character transformation (type)
wctype_t    Wide character type (type)
wint_t    Wide character integral type (type)

常量
WEOF    Wide End-of-File (constant)