Symfony\Component\Routing\Loader\FileLoader::isAbsolutePath PHP Method

    static protected function isAbsolutePath($file)
    {
        if ($file[0] == '/' || $file[0] == '\\' 
            || (strlen($file) > 3 && ctype_alpha($file[0]) 
                && $file[1] == ':' 
                && ($file[2] == '\\' || $file[2] == '/')
            )
        ) {
            return true;
        }

        return false;
    }