### <wctype.h>

The <wctype.h> include file declares functions used to classify wide characters:

iswalnum | iswctype | iswprint | iswxdigit
iswalpha | iswdigit | iswpunct | towlower
iswblank | iswgraph | iswspace | towupper
iswcntrl | islower | iswupper | wctype

<wctype.h> also defines the types wint_t and wctype_t, and the macro WEOF, which expands to a constant expression of type wint_t whose value does not correspond to any member of the extended character set and indicates EOF.