title: Concrete class type conforming to protocol in Swift
body: <p>I need to declare a variable with type <code>UIViewController</code> that conforms to a custom protocol I made. Normally, I would do this in ObjC:</p>
  
  <pre><code>UIViewController&lt;MyProtocol&gt; *thingie;
  </code></pre>
  
  <p>But, I have no idea how to accomplish that in swift.</p>
  
  <hr>
  
  <p>I'm just casting the object for now, till something useful shows up:</p>
  
  <pre><code>let conformingObject = viewController as MyProtocol
  </code></pre>