Name

wcscspn function — Counts initial characters that do not match a span set

Synopsis

size_t wcscspn(const wchar_t* str, const wchar_t* spanset)

The wcscspn function returns the number of wide characters at the start of str that are not in the wide string spanset. Thus, the c in its name means complement, that is, wcscspn counts characters that are in the complement of the span set.