fusl/src/multibyte/mbsinit.c

/*
 * This code was written by Rich Felker in 2010; no copyright is claimed.
 * This code is in the public domain. Attribution is appreciated but
 * unnecessary.
 */

#include <wchar.h>

int mbsinit(const mbstate_t* st) {
  return !st || !*(unsigned*)st;
}