_citrus_utf8_ctype_mbrtowc
size_t _citrus_utf8_ctype_mbrtowc(wchar_t * __restrict,
r = _citrus_utf8_ctype_mbrtowc(NULL, *src + i,
r = _citrus_utf8_ctype_mbrtowc(dst + o, *src + i,
return _citrus_utf8_ctype_mbrtowc(pwc, s, n, ps);