entifier">string</span><span class="special">::</span><span class="identifier">const_iterator</span><span class="special">;</span>
<span class="keyword">using</span> <span class="identifier">position_cache</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">x3</span><span class="special">::</span><span class="identifier">position_cache</span><span class="special