title: Is it possible to "store" a template parameter pack without expanding it?
body: <p>I was experimenting with C++0x variadic templates when I stumbled upon this issue:</p>
  
  <pre><code>template &lt; typename ...Args &gt;
  struct identities
  {
      typedef Args type; //compile error: "parameter packs not expanded with '...'
  };
  
  //The following code just shows an example of potential use, but has no relation
  //with what I am actually trying to achieve.
  template &lt; typename T &gt;
  struct convert_in_tuple
  {
      typedef std::tuple&lt; typename T::type... &gt; type;
  };
  
  typedef convert_in_tuple&lt; identities&lt; int, float &gt; &gt;::type int_float_tuple;
  </code></pre>
  
  <p>GCC 4.5.0 gives me an error when I try to typedef the template parameters pack.</p>
  
  <p>Basically, I would like to "store" the parameters pack in a typedef, without unpacking it. Is it possible? If not, is there some reason why this is not allowed?</p>