lass="identifier">size_t</span> <span class="identifier">bytes_transferred</span>
<span class="special">);</span>
</pre>
<p>
                A return value of 0 indicates that the write operation is complete.
                A non-zero return value indicates the maximum number of bytes to
                be written on the next call to the stream's async_write_some function.
              </p>
</dd>
<dt><span class="term">handler</span></dt>
<dd>
<p>
                The handler to be called when the write op