title: Cannot Convert Derived Class to Base Class
body: <p>I am working on a transportation problem and cannot leap this hurdle. I am unable to convert the derived class <strong>StopsVisited</strong> to its base class <strong>Stops</strong>. The base class Stops is a collection of Stop. The derived class StopsVisited is a collection of StopVisited.</p>
  
  <p>The element StopVisited derives from Stop (definitions not shown).  </p>
  
  <p>I have a non-generics workaround where I simplly derive StopsVisited from Stops, but the generics afford me more felixibility.  I've tried to reduce it to its simplest form.  </p>
  
  <p>Base  </p>
  
  <pre><code>public abstract class Stops&lt;T&gt; where T : Stop 
  {
  
  }
  </code></pre>
  
  <p>Derived  </p>
  
  <pre><code>public class StopsVisited : Stops&lt;StopVisited&gt;
  {
  
  }
  </code></pre>
  
  <p>The problem:  </p>
  
  <pre><code>Stops&lt;Stop&gt; stops = new StopsVisited();
  </code></pre>
  
  <p>Gives me a </p>
  
  <blockquote>
    <p>Error 1 Cannot implicitly convert type 'StopsHeirarchy.StopsVisited' to 'StopsHeirarchy.Stops'   </p>
  </blockquote>
  
  <p>Any help is appreciated.</p>