title: Get Index of a Set<String> in Swift
body: <pre><code>let setOfStrings: Set&lt;String&gt; = ["ONE", "TWO", "THREE"];
  </code></pre>
  
  <p>It doesn't behave like and array, so <code>setOfStrings[0]</code> does not work.</p>
  
  <p>Any ideas?</p>