title: Is there a benefit in assigning the last enum value in a list as -1?
body: <p>I've seen it in coding conventions at previous/current job(s), but I can't seem to find a reason online for why this would be the preferred way of writing an enum:</p>
  <pre><code>enum class Mode
  {
      Mode1,
      Mode2,
      Mode3,
      Mode4,
      Nil = -1
  };
  </code></pre>
  <p>What (if any) is the benefit of adding the <code>Nil = -1</code> line?</p>