span class="identifier">unused_type</span></code>)
              </p></dd>
</dl>
</div>
<p>
          The <span class="emphasis"><em>what</em></span> function should be obvious. It provides some
          information about <span class="quote">&#8220;<span class="quote">what</span>&#8221;</span> the parser is. It is used as a debugging
          aid, for example.
        </p>
<div class="variablelist">
<p class="title"><b>P::template attribute&lt;context&gt;::type</b></p>
<dl>
<dt><span class="term"><code cl