computeroutput"><span class="identifier">http_request</span></code>)
        and one for responses (<code class="computeroutput"><span class="identifier">http_response</span></code>).
        Each interface maintains a private shared pointer to an implementation class.
        Public member function calls are routed to the internal implementation. This
        is the first implementation class, which forms the base class for both the
        request and response implementations:
      </p>
<pre class="progr