title: Animate MapKit annotation coordinate change in Swift?
body: <p>When using MapKit in iOS 8 in Swift, how do I make it possible to animate a change in the map position of a custom annotation? I am saying this:</p>
  
  <pre><code>UIView.animateWithDuration(0.25) {
      var loc = ann.coordinate
      loc.latitude = loc.latitude + 0.0005
      loc.longitude = loc.longitude + 0.001
      ann.coordinate = loc
  }
  </code></pre>
  
  <p>...where <code>ann</code> is a custom annotation, MyAnnotation. The annotation is jumping, not animating, to the new coordinate position.</p>
  
  <p><strong>The annoying thing is that the animation works perfectly <em>if I write MyAnnotation in Objective-C</em>. But if I write it in Swift, I don't get the animation any more!</strong></p>
  
  <p>Just FYI, here is my Swift code for MyAnnotation:</p>
  
  <pre><code>class MyAnnotation : NSObject, MKAnnotation {
      var coordinate : CLLocationCoordinate2D
      var title: String!
      var subtitle: String!
  
      init(location coord:CLLocationCoordinate2D) {
          self.coordinate = coord
          super.init()
      }
  }
  </code></pre>