github.com/afumu/libc@v0.0.6/musl/src/string/wcscspn.c (about)

     1  #include <wchar.h>
     2  
     3  size_t wcscspn(const wchar_t *s, const wchar_t *c)
     4  {
     5  	const wchar_t *a;
     6  	if (!c[0]) return wcslen(s);
     7  	if (!c[1]) return (s=wcschr(a=s, *c)) ? s-a : wcslen(a);
     8  	for (a=s; *s && !wcschr(c, *s); s++);
     9  	return s-a;
    10  }