mblen
if ((clen = mblen(tmp2 + i, len - i)) < 0 ||
int mblen(const char *, size_t);
locale->mblen = initial;
rval = XLOCALE_CTYPE(locale)->__mbrtowc(NULL, s, n, &locale->mblen);
__mbstate_t mblen;
if ((w = mblen(s, (char*)e - s)) > 1)