ion
              call operator of the given visitor on the content of the given
              <code class="computeroutput"><a class="link" href="variant.html" title="Class template variant">variant</a></code> operand.</li>
<li class="listitem">Overloads accepting two operands invoke the binary
              function call operator of the given visitor on the content of
              the given <code class="computeroutput"><a class="link" href="variant.html" title="Class template variant">variant</a></code>
 