title: How to capture inner matched value in indexWhere vector expression?
body: <p>Using a Vector[Vector[Int]] reference v, and the expression to find a given number num:</p>
  
  <pre><code>val posX = v.indexWhere(_.indexOf(num) &gt; -1)
  </code></pre>
  
  <p>Is there any way to capture the value of _.indexOf(num) to use after the expression (i.e. the posY value)? The following signals an error 'Illegal start of simple expression':</p>
  
  <pre><code>val posX = v.indexWhere((val posY = _.indexOf(num)) &gt; -1)
  </code></pre>