525     public static function mb_strpos($haystack, $needle, $offset = 0, $encoding = null)  argument
529             return strpos($haystack, $needle, $offset);
532         $needle = (string) $needle;
533         if ('' === $needle) {
543         return iconv_strpos($haystack, $needle, $offset, $encoding);
546     public static function mb_strrpos($haystack, $needle, $offset = 0, $encoding = null)  argument
550             return strrpos($haystack, $needle, $offset);
557                 if (0 > $offset += self::mb_strlen($needle)) {
566         $pos = '' !== $needle || 80000 > \PHP_VERSION_ID
567             ? iconv_strrpos($haystack, $needle, $encoding)
670     public static function mb_stripos($haystack, $needle, $offset = 0, $encoding = null)  argument
672         [$haystack, $needle] = str_replace(self::SIMPLE_CASE_FOLD[0], self::SIMPLE_CASE_FOLD[1], [
674             self::mb_convert_case($needle, \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, $encoding);
687     public static function mb_strrchr($haystack, $needle, $part = false, $encoding = null)  argument
691             $pos = strrpos($haystack, $needle);
693             $needle = self::mb_substr($needle, 0, 1, $encoding);
694             $pos = iconv_strrpos($haystack, $needle, $encoding);
700     public static function mb_strrichr($haystack, $needle, $part = false, $encoding = null)  argument
702         $needle = self::mb_substr($needle, 0, 1, $encoding);
703         $pos = self::mb_strripos($haystack, $needle, $encoding);
708     public static function mb_strripos($haystack, $needle, $offset = 0, $encoding = null)  argument
711         $needle = self::mb_convert_case($needle, \MB_CASE_LOWER, $encoding);
714         $needle = str_replace(self::SIMPLE_CASE_FOLD[0], self::SIMPLE_CASE_FOLD[1], $needle);
716         return self::mb_strrpos($haystack, $needle, $offset, $encoding);
719     public static function mb_strstr($haystack, $needle, $part = false, $encoding = null)  argument
721         $pos = strpos($haystack, $needle);
784     public static function mb_substr_count($haystack, $needle, $encoding = null)  argument
786         return substr_count($haystack, $needle);