lass="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">d2</span><span class="special">::</span><span class="identifier">point_xy</span><span class="special">&lt;</span><span class="identifier">ttmath</span><span class="special">::</span><span class="identifier">Big</span><span class="special">&lt;</span><span class="number">1</span><span class="special">,</span><span class="nu