494     public static function mb_strpos($haystack, $needle, $offset = 0, $encoding = null)  argument
498             return strpos($haystack, $needle, $offset);
512         return \iconv_strpos($haystack, $needle, $offset, $encoding);
515     public static function mb_strrpos($haystack, $needle, $offset = 0, $encoding = null)  argument
519             return strrpos($haystack, $needle, $offset);
522         if ($offset != (int) $offset) {
523             $offset = 0;
524         } elseif ($offset = (int) $offset) {
525             if ($offset < 0) {
526                 if (0 > $offset += self::mb_strlen($needle)) {
527                     $haystack = self::mb_substr($haystack, 0, $offset, $encoding);
529                 $offset = 0;
531                 $haystack = self::mb_substr($haystack, $offset, 2147483647, $encoding);
539         return false !== $pos ? $offset + $pos : false;
638     public static function mb_stripos($haystack, $needle, $offset = 0, $encoding = null)  argument
643         return self::mb_strpos($haystack, $needle, $offset, $encoding);
674     public static function mb_strripos($haystack, $needle, $offset = 0, $encoding = null)  argument
679         return self::mb_strrpos($haystack, $needle, $offset, $encoding);