title: Mono and Linq Aggregate method. Error trying to add items to a new list
body: <p>Why this code doesn't work?</p>
  
  <pre><code>public static IList&lt;float&gt; CreateModifiedList(IList&lt;float&gt; list)
  {
      IList&lt;float&gt; modifiedList= list.Aggregate(new List&lt;float&gt; (), (l, item) =&gt;l.Add(++item));
  
      return modifiedList;
  }
  </code></pre>
  
  <p>When I try to compile it using Mono I get the following error:</p>
  
  <blockquote>
    <p>error CS0029: Cannot implicitly convert type <code>void' to
    </code>System.Collections.Generic.List'</p>
  </blockquote>