wcsrtombs
size_t wcsrtombs(char * __restrict, const wchar_t ** __restrict, size_t,
ps = &locale->wcsrtombs;
__mbstate_t wcsrtombs;
nbytes = wcsrtombs(NULL, (const wchar_t **)&p, 0, &mbs);
if ((nbytes = wcsrtombs(convbuf, (const wchar_t **)&p,
nbytes = wcsrtombs(NULL, (const wchar_t **)&p, 0, &mbs);
if ((nbytes = wcsrtombs(convbuf, (const wchar_t **)&p,