title: getting the index of partial tuple in a list
body: <p>I want to find the index of an item in a list </p>
  
  <pre><code>scala&gt; type BarType = (String,Int)
  defined type alias BarType
  
  scala&gt; val bar:BarType =  ("A",2)
  bar: BarType = (A,2)
  
  scala&gt; val bars = List(bar)
  bars: List[BarType] = List((A,2))
  </code></pre>
  
  <p>I want to find the element that contains "A" regardless to the second item in the tuple something like </p>
  
  <pre><code>bars.indexOf(("A",_))
  </code></pre>
  
  <p>but this fails </p>
  
  <pre><code>&lt;console&gt;:11: error: missing parameter type for expanded function ((x$1) =&gt; scala.Tuple2("A", x$1))
                bars.indexOf(("A",_))
  </code></pre>
  
  <p>is there a straightforward way to do it ?</p>