towupper - transliterate lowercase wide-character code to uppercase
wint_t towupper(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 towupper() function has as a domain a type wint_t, the value of which the application shall ensure is a character representable as a wchar_t, and a wide-character code corresponding to a valid character in the current locale or the value of WEOF. If the argument has any other value, the behavior is undefined. If the argument of towupper() represents a lowercase wide-character code, and there exists a corresponding uppercase wide-character code (as defined by character type information in the program locale category LC_CTYPE ), the result shall be the corresponding uppercase wide-character code. All other arguments in the domain are returned unchanged.
Upon successful completion, towupper() shall return the uppercase letter corresponding to the argument passed. Otherwise, it shall return the argument unchanged.
No errors are defined.
setlocale(), the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale, <wctype.h>, <wchar.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.