                   <span class="special">*</span> <span class="identifier">v</span><span class="special">;</span>

  <span class="keyword">return</span> <span class="identifier">sum</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>
            Calling the function like so:
          </p>
<pre class="programlisting"><span class="identifier">mp_type</span> <span class="identifier">pid4</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special"