protected static function convertUnicodeCharacters($str, $inCharacterClass, $dotAll)
	{
		// Replace \x{....} with \u.... -- Note that only BMP characters are supported
		$str = preg_replace('((?<!\\\\)(?:\\\\\\\\)*\\K\\\\x\\{([0-9a-f]{4})\\})i', '\\u$1', $str);

		// Unfold Unicode properties such as \pL
		$str = self::unfoldUnicodeProperties($str, $inCharacterClass, $dotAll);

		return $str;
	}