title: Most efficient way to cast List<SubClass> to List<BaseClass>
body: <p>I have a <code>List&lt;SubClass&gt;</code> that I want to treat as a <code>List&lt;BaseClass&gt;</code>.  It seems like it shouldn't be a problem since casting a <code>SubClass</code> to a <code>BaseClass</code> is a snap, but my compiler complains that the cast is impossible.</p>
  
  <p>So, what's the best way to get a reference to the same objects as a <code>List&lt;BaseClass&gt;</code>?</p>
  
  <p>Right now I'm just making a new list and copying the old list:</p>
  
  <pre><code>List&lt;BaseClass&gt; convertedList = new ArrayList&lt;BaseClass&gt;(listOfSubClass)
  </code></pre>
  
  <p>But as I understand it that has to create an entirely new list.  I'd like a reference to the original list, if possible!</p>