title: Swift: How to use for-in loop with an optional?
body: <p>What's the proper way to use for-in loop with an optional?</p>
  
  <p>Right now I always perform an optional binding before looping it.  Are there other idioms?</p>
  
  <pre><code>let optionalInt:[Int]? = [1, 2, 3]
  
  if let optionalInt = optionalInt {
    for i in optionalInt {
      print(i)
    }
  }
  </code></pre>