span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">info</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">what</span><span class="special">)</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">basic_info_walker</span><span cla