function mb_substr($s, $start, $length = 2147483647, $enc = INF) { return s\Mbstring::mb_substr($s, $start, $length, $enc); }
function iconv_substr($s, $start, $length = 2147483647, $enc = INF) { INF === $enc && ($enc = s\Iconv::$internal_encoding); return s\Mbstring::mb_substr($s, $start, $length, $enc); }