525     public static function mb_strpos($haystack, $needle, $offset = 0, $encoding = null)  argument
529             return strpos($haystack, $needle, $offset);
543         return iconv_strpos($haystack, $needle, $offset, $encoding);
546     public static function mb_strrpos($haystack, $needle, $offset = 0, $encoding = null)  argument
550             return strrpos($haystack, $needle, $offset);
558                     $haystack = self::mb_substr($haystack, 0, $offset, $encoding);
562                 $haystack = self::mb_substr($haystack, $offset, 2147483647, $encoding);
567             ? iconv_strrpos($haystack, $needle, $encoding)
568             : self::mb_strlen($haystack, $encoding);
670     public static function mb_stripos($haystack, $needle, $offset = 0, $encoding = null)  argument
672         [$haystack, $needle] = str_replace(self::SIMPLE_CASE_FOLD[0], self::SIMPLE_CASE_FOLD[1], [
673             self::mb_convert_case($haystack, \MB_CASE_LOWER, $encoding),
677         return self::mb_strpos($haystack, $needle, $offset, $encoding);
680     public static function mb_stristr($haystack, $needle, $part = false, $encoding = null)  argument
682         $pos = self::mb_stripos($haystack, $needle, 0, $encoding);
684         return self::getSubpart($pos, $part, $haystack, $encoding);
687     public static function mb_strrchr($haystack, $needle, $part = false, $encoding = null)  argument
691             $pos = strrpos($haystack, $needle);
694             $pos = iconv_strrpos($haystack, $needle, $encoding);
697         return self::getSubpart($pos, $part, $haystack, $encoding);
700     public static function mb_strrichr($haystack, $needle, $part = false, $encoding = null)  argument
703         $pos = self::mb_strripos($haystack, $needle, $encoding);
705         return self::getSubpart($pos, $part, $haystack, $encoding);
708     public static function mb_strripos($haystack, $needle, $offset = 0, $encoding = null)  argument
710         $haystack = self::mb_convert_case($haystack, \MB_CASE_LOWER, $encoding);
713         $haystack = str_replace(self::SIMPLE_CASE_FOLD[0], self::SIMPLE_CASE_FOLD[1], $haystack);
716         return self::mb_strrpos($haystack, $needle, $offset, $encoding);
719     public static function mb_strstr($haystack, $needle, $part = false, $encoding = null)  argument
721         $pos = strpos($haystack, $needle);
726             return substr($haystack, 0, $pos);
729         return substr($haystack, $pos);
784     public static function mb_substr_count($haystack, $needle, $encoding = null)  argument
786         return substr_count($haystack, $needle);
900     private static function getSubpart($pos, $part, $haystack, $encoding)  argument
906             return self::mb_substr($haystack, 0, $pos, $encoding);
909         return self::mb_substr($haystack, $pos, null, $encoding);