title: Is it possible to type hint more than one type?
body: <p>Can I allow two different types using type hinting?</p>
  
  <p>E.g. parameter <code>$requester</code> could be either of <code>User</code> or <code>File</code>:</p>
  
  <pre><code>function log (User|File $requester) {
  
  }
  </code></pre>