'advancedBy' is unavailable in Xcode 8
<p>Currently, I've been using XCode 8 and on the line</p>

<pre><code>let range = key.startIndex...key.startIndex.advancedBy(0)
</code></pre>

<p>I get the error:</p>

<blockquote>
  <p>error: 'advancedBy' is unavailable: To advance an index by n steps call 'index(_:offsetBy:)' on the CharacterView instance that produced the index.</p>
</blockquote>

<p>How can I fix this?</p>

<p>A screenshot of the error is below:</p>

<p><a href="https://i.stack.imgur.com/FQvd5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FQvd5.png" alt="advancedBy is unavailable"></a></p>