wcwidth - number of column positions of a wide-character code
The wcwidth() function shall determine the number of column positions required for the wide character wc. The application shall ensure that the value of wc is a character representable as a wchar_t, and is a wide-character code corresponding to a valid character in the current locale.
The wcwidth() function shall either return 0 (if wc is a null wide-character code), or return the number of column positions to be occupied by the wide-character code wc, or return -1 (if wc does not correspond to a printable wide-character code).
No errors are defined.
This function was removed from the final ISO/IEC 9899:1990/Amendment 1:1995 (E), and the return value for a non-printable wide character is not specified.
wcswidth() , the Base Definitions volume of IEEE Std 1003.1-2001, <wchar.h>
First released as a World-wide Portability Interface in Issue 4. Derived from the MSE working draft.
The Open Group Corrigendum U021/12 is applied. This function is marked as an extension.
The DESCRIPTION is updated to avoid use of the term "must" for application requirements.