pan>
        <span class="keyword">auto</span> <span class="keyword">const</span> <span class="identifier">bytes_used</span> <span class="special">=</span> <span class="identifier">p</span><span class="special">.</span><span class="identifier">put</span><span class="special">(</span><span class="identifier">buffer</span><span class="special">.</span><span class="identifier">data</span><span class="special">(),</span> <span class="identifier">ec</span><span class="special">);</span>

        <span class="com