dentifier">base_from_member</span><span class="special">();</span>

    <span class="keyword">template</span><span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">T1</span> <span class="special">&gt;</span>
    <span class="keyword">explicit</span>  <span class="identifier">base_from_member</span><span class="special">(</span> <span class="identifier">T1</span> <span class="identifier">x1</span> <span class="special">);</span>

    <span class="keyword">template</s