 </li>
<li class="listitem">
            No stateful allocator support.
          </li>
<li class="listitem">
            There is no way to defer the commitment of the type for <code class="computeroutput"><span class="identifier">body_</span></code> to after the headers are read
            in.
          </li>
<li class="listitem">
            The message model includes a "source" and "destination."
            This is extraneous metadata associated with the connection which is not
            part of the