protected static function extractVariable($str, &$var=null, &$regex=null) {
		list($p1, $p2) 	= explodeList(':', $str, 2);
		// Optionnal only if there is a default value
		if( $p2 ) {
			// {regex|type:variable}
			$var	= $p2;
			$regex	= $p1;
			if( ctype_alpha($regex) && isset(static::$typesRegex[$regex]) ) {
				$regex = static::$typesRegex[$regex];
			}
		} else {
			// {variable}, regex=[^\/]+
			$var	= $p1;
			$regex	= '[^\/]+';
		}
	}