title: Type casting in for-in loop
body: <p>I have this for-in loop:</p>
  
  <pre><code>for button in view.subviews {
  }
  </code></pre>
  
  <p>Now I want button to be cast into a custom class so I can use its properties.</p>
  
  <p>I tried this: <code>for button in view.subviews as AClass</code></p>
  
  <p>But it doesnt work and gives me an error:<code>'AClass' does not conform to protocol 'SequenceType'</code></p>
  
  <p>And I tried this: <code>for button:AClass in view.subviews</code></p>
  
  <p>But neither does that work.</p>