n>
    <span class="k">template</span><span class="o">&lt;</span><span class="k">class</span> <span class="nc">T</span><span class="p">,</span> <span class="k">class</span> <span class="nc">U</span><span class="o">&gt;</span>
    <span class="n">T</span> <span class="k">operator</span><span class="p">()(</span><span class="n">T</span> <span class="n">x</span><span class="p">,</span> <span class="n">U</span> <span class="n">y</span><span class="p">)</span> <span class="k">const</span>
    <span class="p">{</