html" title="http::message::payload_size"><code class="computeroutput"><span class="identifier">message</span><span class="special">::</span><span class="identifier">payload_size</span></code></a> will return
                  <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span></code>.
                </p>
                <p>
                  * A call to <a class="link" href="../ref/boost__beast__http__message/prepare_payload