concept">ArgumentPack</span></a>:
a bundle of references to the actual arguments, tagged with their
keywords.  The values of the actual arguments are extracted from
the <span class="concept">ArgumentPack</span> by <em>indexing</em> it with keyword objects:</p>
<pre class="literal-block">
BOOST_PARAMETER_NAME(name)
BOOST_PARAMETER_NAME(index)

struct myclass_impl
{
    template &lt;class ArgumentPack&gt;
    myclass_impl(ArgumentPack const&amp; args)
    {
        std::cout &lt;&lt; &quot;name = &quot; &lt;&