title: Unable to use for comprehension to map over List within Future
body: <p>I have this issue that I have to work around every time. I can't map over something that is contained within a Future using a for comprehension.</p>
  
  <p>Example:</p>
  
  <pre><code>import scala.concurrent.ExecutionContext.Implicits.global
  import scala.concurrent.Future
  
  val f = Future( List("A", "B", "C") )
  for {
    list &lt;- f
    e &lt;- list
  } yield (e -&gt; 1)
  </code></pre>
  
  <p>This gives me the error:</p>
  
  <pre><code> error: type mismatch;
   found   : List[(String, Int)]
   required: scala.concurrent.Future[?]
                e &lt;- list
                  ^
  </code></pre>
  
  <p>But if I do this it works fine: </p>
  
  <pre><code>f.map( _.map( (_ -&gt; 1) ) )
  </code></pre>
  
  <p>Should i not be able to do this by using a for comprehension, is the reason it works in my other example that I do not flatmap? I'm using Scala 2.10.0.</p>