require 5.004;
    use Tie::RefHash;
    tie HASHVARIABLE, 'Tie::RefHash', LIST;
untie HASHVARIABLE;
It is implemented using the standard perl 
TIEHASH interface. Please see the tie entry in perlfunc(1) and perltie(1) for more
information.
    use Tie::RefHash;
    tie %h, 'Tie::RefHash';
    $a = [];
    $b = {};
    $c = \*main;
    $d = \"gunk";
    $e = sub { 'foo' };
    %h = ($a => 1, $b => 2, $c => 3, $d => 4, $e => 5);
    $a->[0] = 'foo';
    $b->{foo} = 'bar';
    for (keys %h) {
       print ref($_), "\n";
    }
perl(1), perlfunc(1), perltie(1)