title: Does the Swift compiler optimize empty closures?
body: <p>I'm curious to know whether the Swift 1.2 compiler optimizes empty closures. Are the following two statements equivalent?</p>
  
  <p>1:</p>
  
  <pre><code>self.presentViewController(alertController, animated: true) {}
  </code></pre>
  
  <p>2:</p>
  
  <pre><code>self.presentViewController(alertController, animated: true, completion: nil)
  </code></pre>
  
  <p>Thanks!</p>