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

     1  #include <wchar.h>
     2  
     3  size_t wcsspn(const wchar_t *s, const wchar_t *c)
     4  {
     5  	const wchar_t *a;
     6  	for (a=s; *s && wcschr(c, *s); s++);
     7  	return s-a;
     8  }