title: Does Scalatest provider a matcher for NaN?
body: <p>Does Scalatest provide a matcher for <code>NaN</code> and infinities?</p>
  
  <p>I would like to make these assertions a bit more descriptive if there's a way:</p>
  
  <pre class="lang-scala prettyprint-override"><code>Double.NaN.isNaN shouldBe true
  Double.NegativeInfinity.isInfinite shouldBe true
  </code></pre>