title: Presenting UIAlertController ActionSheet in popover on iPhone
body: <p>I'm creating and presenting an <code>ActionSheet</code> as follows:</p>
  
  <pre><code>let alertController = UIAlertController(title: nil, message: nil, preferredStyle: .ActionSheet)
  alertController.modalPresentationStyle = .Popover
  
  // Add some buttons
  
  alertController.popoverPresentationController?.delegate = self
  alertController.popoverPresentationController?.barButtonItem = someBarButton
  
  self.presentViewController(alertController, animated: true, completion: nil)
  </code></pre>
  
  <p>This works fine on the iPad, but <code>alertController.popoverPresentationController</code> is <code>nil</code> on the iPhone.</p>
  
  <p>I've successfully presented popovers on the iPhone using adaptive segue style <strong>Present As Popover</strong> in interface builder and implementing <code>adaptivePresentationStyleForPresentationController</code> delegate method to return the correct <code>UIModalPresentationStyle</code> but I'm stuck how to do it in code with <code>UIAlertController</code> as it has no <code>popoverPresentationController</code> on the iPhone</p>