pan class="identifier">karma</span><span class="special">::</span><span class="identifier">omit</span><span class="special">;</span>
    <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">generate</span><span class="special">;</span>

    <span class="keyword">return</span> <span class="identifier