pan><span class="identifier">shared_ptr</span><span class="special">&lt;</span><span class="identifier">http</span><span class="special">::</span><span class="identifier">details</span><span class="special">::</span><span class="identifier">_http_request</span><span class="special">&gt;</span> <span class="identifier">_m_impl</span><span class="special">;</span>
<span class="special">};</span>
</pre>
<p>
        It is clear from this declaration that the goal of the message model in this
        library is 