title: "Ambiguous type name 'index' in Array'" Swift
body: <p><img src="https://i.stack.imgur.com/1gh34.png" alt="enter image description here"></p>
  
  <p>This is my code: </p>
  
  <pre><code>func didMarkAsFavoriteContact(_ contact: Contact) {
      var outerIndex: Array.Index? = nil
  }
  </code></pre>