st, bases&lt;&gt; &gt;::type base_list;

    typedef typename parameter::value_type&lt;
      args, tag::held_type, class_type&gt;::type held_type;

    typedef typename parameter::value_type&lt;
      args, tag::copyable, void&gt;::type copyable;
};

}}
</pre>
</div>
</div>
<div class="section" id="exercising-the-code-so-far">
<h3>2.4.2&nbsp;&nbsp;&nbsp;Exercising the Code So Far</h3>
<div class="compound">
<p class="compound-first">Revisiting our original examples,</p>
<pre class="compound-middle literal-