ss="table-programlisting"> <span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span>
    <span class="identifier">error_code</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">error</span><span class="special">,</span>      <span class="comment">// result of operation</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">bytes_