518     public static function mb_strpos($haystack, $needle, $offset = 0, $encoding = null)  argument
522             return strpos($haystack, $needle, $offset);
536         return iconv_strpos($haystack, $needle, $offset, $encoding);
539     public static function mb_strrpos($haystack, $needle, $offset = 0, $encoding = null)  argument
543             return strrpos($haystack, $needle, $offset);
551                     $haystack = self::mb_substr($haystack, 0, $offset, $encoding);
555                 $haystack = self::mb_substr($haystack, $offset, 2147483647, $encoding);
560             ? iconv_strrpos($haystack, $needle, $encoding)
561             : self::mb_strlen($haystack, $encoding);
663     public static function mb_stripos($haystack, $needle, $offset = 0, $encoding = null)  argument
665         [$haystack, $needle] = str_replace(self::SIMPLE_CASE_FOLD[0], self::SIMPLE_CASE_FOLD[1], [
666             self::mb_convert_case($haystack, \MB_CASE_LOWER, $encoding),
670         return self::mb_strpos($haystack, $needle, $offset, $encoding);
673     public static function mb_stristr($haystack, $needle, $part = false, $encoding = null)  argument
675         $pos = self::mb_stripos($haystack, $needle, 0, $encoding);
677         return self::getSubpart($pos, $part, $haystack, $encoding);
680     public static function mb_strrchr($haystack, $needle, $part = false, $encoding = null)  argument
684             $pos = strrpos($haystack, $needle);
687             $pos = iconv_strrpos($haystack, $needle, $encoding);
690         return self::getSubpart($pos, $part, $haystack, $encoding);
693     public static function mb_strrichr($haystack, $needle, $part = false, $encoding = null)  argument
696         $pos = self::mb_strripos($haystack, $needle, $encoding);
698         return self::getSubpart($pos, $part, $haystack, $encoding);
701     public static function mb_strripos($haystack, $needle, $offset = 0, $encoding = null)  argument
703         $haystack = self::mb_convert_case($haystack, \MB_CASE_LOWER, $encoding);
706         $haystack = str_replace(self::SIMPLE_CASE_FOLD[0], self::SIMPLE_CASE_FOLD[1], $haystack);
709         return self::mb_strrpos($haystack, $needle, $offset, $encoding);
712     public static function mb_strstr($haystack, $needle, $part = false, $encoding = null)  argument
714         $pos = strpos($haystack, $needle);
719             return substr($haystack, 0, $pos);
722         return substr($haystack, $pos);
777     public static function mb_substr_count($haystack, $needle, $encoding = null)  argument
779         return substr_count($haystack, $needle);
874     private static function getSubpart($pos, $part, $haystack, $encoding)  argument
880             return self::mb_substr($haystack, 0, $pos, $encoding);
883         return self::mb_substr($haystack, $pos, null, $encoding);