includes all the relevant files from the boost/spirit/actor
        directory.
      </p>
<p>
        To distinguish between Spirit versions, you can inspect the version file:
      </p>
<pre class="programlisting"><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">version</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt