title: Variable length template arguments list?
body: <p>I remember seing something like this being done:</p>
  
  <pre><code>template &lt;ListOfTypenames&gt;
  class X : public ListOfTypenames {};
  </code></pre>
  
  <p>that is, X inherits from a variable length list of typenames passed as the template arguments. This code is hypothetical, of course.</p>
  
  <p>I can't find any reference for this, though. Is it possible? Is it C++0x?</p>