src/Debug/Utf8.php
public static function hasSpecial($str)
    {
        foreach (self::$special as $special) {
            if (\strpos($special, 'regex:') === 0) {
                if (\preg_match(\substr($special, 6), $str) > 0) {
                    return true;
                }
            } elseif (\strpos($str, $special) !== false) {
                return true;
            }
        }
    }
public static function hasSpecial($str)
    {
        foreach (self::$special as $special) {
            if (\strpos($special, 'regex:') === 0) {
                if (\preg_match(\substr($special, 6), $str) > 0) {
                    return true;
                }
            } elseif (\strpos($str, $special) !== false) {
                return true;
            }
        }
    }
Check UTF-8 string (or single-character) against list of special characters or regular-expressions

@param string $str String to check

@return boolean