ord">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="special">...</span><span class="identifier">T</span> <span class="special">&gt;</span>
    <span class="keyword">explicit</span> <span class="keyword">constexpr</span>   <span class="identifier">base_from_member</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&amp;&amp;</span> <span class="special">...</span><span class="identifier">x</span> <span class="specia