lass="special">::</span><span class="identifier">parser</span><span class="special">::</span><span class="identifier">position_cache_tag</span><span class="special">;</span>

<span class="keyword">auto</span> <span class="keyword">const</span> <span class="identifier">parser</span> <span class="special">=</span>
    <span class="comment">// we pass our position_cache to the parser so we can access</span>
    <span class="comment">// it later in our on_sucess handlers</span>
    <span class="identifier">with