title: In Swift, how do I explicitly specify a return value for map with anonymous closure arguments?
body: <p>Say I call <code>map</code> like this, using the anonymous closure argument <code>$0</code>:</p>
  
  <pre class="lang-swift prettyprint-override"><code>array.map {
    return $0.description
  }
  </code></pre>
  
  <p>How would I explicitly define that map returns a <code>string</code>? This doesn’t work:</p>
  
  <pre class="lang-swift prettyprint-override"><code>array.map { -&gt; String
    return $0.description
  }
  </code></pre>
  
  <blockquote>
    <p>Contextual type for closure argument list expects 1 argument, which cannot be implicitly ignored</p>
  </blockquote>
  
  <p>Does that mean if I want to specify a return value I have to name my arguments?</p>
  
  <p>[EDIT: I know I do not need an explicit return type here; still would like how to specify one]</p>