title: Chisel3: Vec indexWhere expected Bool, actual Any
body: <p>In Chisel, I have a Vec of Bools coming into a module. I would like to know the index of the first False which occurs.</p>
  <p>To obtain this, I tried to use the following:</p>
  <pre class="lang-scala prettyprint-override"><code>val faultIndex = Wire(UInt)
  
  faultIndex := comparison.indexWhere(x:Bool =&gt; x === false.B)
  </code></pre>
  <p>When I put this in, an error was highlighted:</p>
  <pre><code>Unspecified value parameters: from: Int
  Type mismatch, expected Bool =&gt; Bool, actual: Bool =&gt; Any
  Type mismatch, expected Bool =&gt; Boolean, actual: Bool =&gt; Any
  Cannot resolve symbol x
  Cannot resolve symbol x
  </code></pre>
  <p>What is the proper way to use this function?</p>