put">apply_visitor</code> is dependent on
        the number of arguments on which it operates (i.e., other than the
        visitor). If your compiler does not support the rvalue references or reference qualifiers then all the 
        forwarding references from above degrade to non const lvalue reference. The function behaves as follows:

          <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">Overloads accepting one operand invoke the unary funct