-label m-flat m-primary">constexpr</span>
            </dt>
            <dd>indicating if the given closure wrapper is a default wrapper (i.e., empty)</dd>
          </dl>
        </section>
        <section id="typeless-methods">
          <h2><a href="#typeless-methods">Constructors, destructors, conversion operators</a></h2>
          <dl class="m-doc">
            <dt id="ad0037e70726a054527a923821ec2d95a">
              <span class="m-doc-wrap-bumper"><a href="#ad0037e70726a054527a923821ec2d95a" class=