mbsrtowcs
size_t mbsrtowcs(wchar_t * __restrict, const char ** __restrict, size_t,
PROTO_NORMAL(mbsrtowcs);
return (mbsrtowcs(pwcs, &sp, n, &mbs));
DEF_STRONG(mbsrtowcs);
nwc = mbsrtowcs(s, (const char **)&mbp, n, &mbs);