AsOptional.swift

@IBAction func touched(sender: AnyObject) {
  if let button = sender as? Button {
    button.setTitle("Touched", forState: .Normal)
  }
}

@IBAction func touched(sender: AnyObject) {
  if sender is UISegmentedControl {
    let segmentedControl = sender as UISegmentedControl
    let selectedIndex = segmentedControl.selectedSegmentIndex
  }
}