title: How to do an availability check on class variables
body: <p>My current project supports iOS 7+ and in one of my view controllers I'm trying to use both UIAlertView and UIAlertController.</p>
  
  <p>I have the #available conditional working in my methods, but I'm not sure how to wrap the vars.</p>
  
  <p>When I have:</p>
  
  <pre><code>var alertController: UIAlertController!
  var alertView: UIAlertView!
  </code></pre>
  
  <p>I get an error message telling me UIAlertController is only available in iOS 8+ and the option to 'Fix It' by "Adding @available to enclosing class". However I think this marks the entire class, and that's not what I want.</p>