title: How to use dequeueReusableCellWithIdentifier in Swift?
body: <p>If I uncomment</p>
  
  <pre><code>tableView(tableView: UITableView?, cellForRowAtIndexPath indexPath: NSIndexPath?)
  </code></pre>
  
  <p>I get an error on the line</p>
  
  <pre><code>let cell = tableView.dequeueReusableCellWithIdentifier("reuseIdentifier", forIndexPath: indexPath)
  </code></pre>
  
  <p>that says <code>UITableView? does not have a member named 'dequeueReusableCellWithIdentifier'</code></p>
  
  <p>If I unwrap the tableview then the error goes away, but in Objective-C we would normally check whether or not the cell exists, and if it does not we create a new one.  In Swift, since the boilerplate provided uses the <code>let</code> keyword and unwraps an optional, we can't reassign it if it's nil.</p>
  
  <p>What's the proper way to use dequeueReusableCellWithIdentifier in Swift?</p>