pan class="keyword">return</span> <span class="identifier">result_type</span><span class="special">();</span>
    <span class="special">}</span>
<span class="special">};</span>
</pre>
<p>
        </p>
<p>
          This one above is our main generator. It's a simple function object with
          2 (unused) arguments. These arguments are
        </p>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
              The actual terminal value obtained by proto. In this case, eithe