7.25.1 Introduction
The header <wctype.h> declares three data types, one macro, and many functions.[1]
The types declared are
wint_t
described in 7.24.1;
wctrans_t
which is a scalar type that can hold values which represent locale-specific character mappings; and
wctype_t
which is a scalar type that can hold values which represent locale-specific character classifications.
The macro defined is WEOF (described in 7.24.1).
The functions declared are grouped as follows:
Functions that provide wide character classification;
Extensible functions that provide wide character classification;
Functions that provide wide character case mapping;
Extensible functions that provide wide character mapping.
For all functions described in this subclause that accept an argument of type wint_t, the value shall be representable as a wchar_t or shall equal the value of the macro WEOF. If this argument has any other value, the behavior is undefined.
The behavior of these functions is affected by the LC_CTYPE category of the current locale.
Footnotes