ntifier">lvalue</span><span class="special">&lt;</span> <span class="identifier">Arg</span> <span class="special">&gt;</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">&gt;</span>
<span class="special">{</span>

  <span class="comment">// <a class="link" href="complement_base.html#id-1_3_2_6_4_2_1_1_6_40_3-bb">public member functions</a></span>
  <span class="identifier">result_type</span> <a class="link" href="complement_base.html#id-1_3_