title: Value of type 'CustomTableCell' has no member delegate
body: <p>I have a subclass of UITableViewCell called CustomTableCell which is declared in a swift 4.1. file.</p>
  
  <p>In my view controller with the UITableView I have in cellForRowAt:</p>
  
  <pre><code>let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier") as! CustomTableCell
  cell.delegate = self
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>Value of type 'CustomTableCell' has no member delegate.
  </code></pre>
  
  <p>I declared the UITableViewDelegate at the top.</p>