   Some using declarations:
          </p>
<p>
</p>
<pre class="programlisting"><span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">karma</span><span class="special">::</span><span class="identifier">symbols</span><span class="special">;</span>
</pre>
<p>
          </p>
<p>
            Basic usage of <code class="computeroutput"><span class="identifier">symbol</spa