pan class="keyword">const</span> <span class="identifier">tuple</span><span class="special">&lt;</span><span class="identifier">T1</span><span class="special">,</span> <span class="identifier">T2</span><span class="special">,</span> <span class="special">...,</span> <span class="identifier">TN</span><span class="special">&gt;&amp;</span> <span class="identifier">lhs</span><span class="special">,</span>
    <span class="keyword">const</span> <span class="identifier">tuple</span><span class="special">&lt;</sp