          <span class="keyword">typename</span> SFn&gt;      <span class="comment">// A policy object that can compute the distance between two iterators of type Iterator</span>
<a name="l00052"></a>00052                              <span class="comment">// and can advance an iterator of type Iterator a given number of Iterator's units  </span>
<a name="l00053"></a><a class="code" href="g_i_l_0036.html">00053</a> <span class="keyword">class </span><a class="code" href="g_i_l_0036.html" title="An adaptor ov