title: What happens while wrapping and unwrapping an optional in Swift?
body: <p>When a <code>var</code> is marked as an optional Swift wraps it and when actual value is needed unwrapping is performed.</p>
  
  <pre><code>var anOptional : String? = "wrapping"
  print("\(anOptional!)  unwrapping")
  </code></pre>
  
  <p>What actually  happens during wrapping and unwrapping of an optional?</p>