title: Swift 2.0 Type of expression is ambiguous without more context `.FlexibleHeight`
body: <p>Using XCode 7.1, OS X 10.10.5</p>
  
  <p>I'm implementing ENSideMenu library, and am running into this error with two methods in the library: </p>
  
  <pre><code>    if (NSClassFromString("UIVisualEffectView") != nil) {
          // Add blur view
          var visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .Light)) as UIVisualEffectView
          visualEffectView.frame = sideMenuContainerView.bounds
          visualEffectView.autoresizingMask = .FlexibleHeight | .FlexibleWidth // error points to .FlexibleHeight
          sideMenuContainerView.addSubview(visualEffectView)
      }
      else {
          // TODO: add blur for ios 7
      }
  }
  
  public convenience init(sourceView: UIView, menuViewController: UIViewController, menuPosition: ENSideMenuPosition) {
      self.init(sourceView: sourceView, menuPosition: menuPosition)
      self.menuViewController = menuViewController
      self.menuViewController.view.frame = sideMenuContainerView.bounds
      self.menuViewController.view.autoresizingMask = .FlexibleHeight | .FlexibleWidth // error points to .FlexibleHeight
      sideMenuContainerView.addSubview(self.menuViewController.view)
  }
  </code></pre>
  
  <p>Both point to <code>.FlexibleHeight</code>.. What is the problem here? Thanks</p>