/span><span class="special">::</span><span class="identifier">begin</span><span class="special">(</span> <span class="identifier">x_</span> <span class="special">);</span>
        <span class="keyword">typename</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_iterator</span><span class="special">&lt;</span> <span class="identifier">Deriv</span> <span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">dxdt</span>