title: Swift: binary operator '==' cannot be applied to operands of type "protocol"
body: <p>I have a protocol:</p>
  
  <pre><code>protocol ProfileManagerDelegete {
  func dataHaveUpdated(type: ReturnType)
  </code></pre>
  
  <p>}</p>
  
  <p>and create a protocol array, and add/remove listener:</p>
  
  <pre><code>var listeners: [ProfileManagerDelegete] = []
  
  func addListener(listener: ProfileManagerDelegete) {
      listeners.append(listener)
  }
  
  func removeLister(listener: ProfileManagerDelegete) {
      for lis in listeners {
          if lis == listener { // this line error
              //remove listener
          }
      }
  }
  </code></pre>
  
  <p>Anyone can help ?</p>