iswupper - test for an uppercase letter wide-character code
int iswupper(wint_t wc);
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of IEEE Std 1003.1-2001 defers to the ISO C standard.
The iswupper() function shall test whether wc is a wide-character code representing a character of class upper in the program's current locale; see the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale.
The wc argument is a wint_t, the value of which the application shall ensure is a wide-character code corresponding to a valid character in the current locale, or equal to the value of the macro WEOF. If the argument has any other value, the behavior is undefined.
The iswupper() function shall return non-zero if wc is an uppercase letter wide-character code; otherwise, it shall return 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(), iswctype(), iswdigit(), iswgraph(), iswlower(), iswprint(), iswpunct(), iswspace(), iswxdigit(), setlocale(), the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale, <wchar.h>, <wctype.h>
First released in Issue 4.
The following change has been made in this issue for alignment with ISO/IEC 9899:1990/Amendment 1:1995 (E):
The DESCRIPTION is updated to avoid use of the term "must" for application requirements.