"special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">qi</span></code>. These placeholders are specifically
            tailored for Spirit.
          </p></td></tr>
</table></div>
<p>
          The <code class="computeroutput"><span class="identifier">double_</span></code> parser attaches
          this action:
        </p>
<pre class="programlisting"><span class="identifier">ref</span><span class="special">(</span><span class="identifier">n</span>