/a>00070     <span class="keywordtype">void</span> increment() { _step_fn.advance(this-&gt;base_reference(),1); }
<a name="l00071"></a>00071     <span class="keywordtype">void</span> decrement() { _step_fn.advance(this-&gt;base_reference(),-1); }
<a name="l00072"></a>00072     <span class="keywordtype">void</span> advance(base_difference_type d) { _step_fn.advance(this-&gt;base_reference(),d); }
<a name="l00073"></a>00073     difference_type distance_to(<span class="keyword">const</span> <a class="code" hre