Swiftでラベルのタッチを検知する方法

Objective-Cの例をSwiftで書く時に、downcastの所でしばらく悩んだので。

class ViewController: UIViewController {

    let TAG_LABEL1 = 1

    var label1: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

        self.label1 = UILabel(frame: CGRectMake(0, 0, 100, 100))
        self.label1.text = "Foo"
        self.label1.layer.position = CGPoint(x: 100, y: 100)
        self.label1.userInteractionEnabled = true
        self.label1.tag = self.TAG_LABEL1
        self.view.addSubview(self.label1);

    }

    override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
        super.touchesEnded(touches, withEvent: event)

        for touch: AnyObject in touches {
            var t: UITouch = touch as UITouch
            if t.view.tag == self.label1.tag {
                NSLog("Label touched")
            }
        }
    }

}