p14_t">C++14 compatible generic function object</a></code>
              that accepts either one, two or arbitrary count of arguments and invoke
              <code class="computeroutput"><a class="link" href="apply_visitor.html" title="Function apply_visitor">apply_visitor</a></code> using
              these arguments and <code class="computeroutput">visitor</code>, thus behaving as
              specified above. (This behavior is particularly useful, for
              example, when one needs to operate o