r">ReadHandler</span><span class="special">,</span>
    <span class="keyword">void</span><span class="special">(</span><span class="identifier">error_code</span><span class="special">)&gt;</span> <span class="identifier">completion</span><span class="special">{</span><span class="identifier">handler</span><span class="special">};</span>
<span class="identifier">read_op</span><span class="special">&lt;</span>
    <span class="identifier">DynamicBuffer</span><span class="special">,</span> <span class="keyword