ce stream positions:
      </p>
<pre class="programlisting"><span class="identifier">position_cache</span> <span class="identifier">positions</span><span class="special">{</span><span class="identifier">input</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">input</span><span class="special">.</span><span class="identifier">end</span><span class="special">()};</span>
<span class="keyword">auto</span> <span class="identifier">as