iswupper - test for an upper-case letter wide-character code
int iswupper(wint_t wc);
The iswupper() function tests whether wc is a wide-character code representing a character of class upper in the program's current locale, see the Locale specification.
In all cases wc is a wint_t, the value of which must be a wide-character code corresponding to a valid character in the current locale or must equal the value of the macro WEOF. If the argument has any other value, the behaviour is undefined.
The iswupper() function returns non-zero if wc is an upper-case letter wide-character code; otherwise it returns 0.
No errors are defined.
To ensure applications portability, especially across natural languages, only this function and those listed in the SEE ALSO section should be used for classification of wide-character codes.
iswalnum(), iswalpha(), iswcntrl(), iswdigit(), iswgraph(), iswlower(), iswprint(), iswpunct(), iswspace(), iswxdigit(), setlocale(), <wctype.h>, <wchar.h>, the Locale specification.