amp;</span> <span class="identifier">arc</span><span class="special">,</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">radius</span><span class="special">)</span> <span class="special">:</span> <span class="identifier">m_arc</span><span class="special">(</span><span class="identifier">arc</span><span class="special">),</span> <span class="identifier">m_radius</span><span class="special">(</span><span class="identifier">ra