="special">,</span> <span class="identifier">phoenix</span><span class="special">::</span><span class="identifier">evaluator</span><span class="special">(</span><a href="http://www.boost.org/doc/libs/release/doc/html/boost/proto/_.html" target="_top"><code class="computeroutput"><span class="identifier">proto</span><span class="special">::</span><span class="identifier">_</span></code></a><span class="special">,</span> <span class="identifier">phoenix</span><span class="special">::</span><span class="identi