use Tk;
use strict;
use warnings;
use Scalar::Util qw/weaken isweak/;
use Devel::Peek qw/Dump/;;
package Test;
sub DESTROY {
    print "destroying ",shift,"\n";
}

package Tk::MyWidget;
require Tk::Frame;
our @ISA = ('Tk::Frame');
Tk::Widget->Construct('MyWidget');
sub Populate{
    my ($self,$args) = @_;
    $self->SUPER::Populate($args);
    $self->ConfigSpecs(-attr => ['PASSIVE',undef,undef,undef]);
}

package main;
my $ref;
{
my $val = 0;
 $ref = \$val;
}
bless $ref ,'Test';

my $copy = $ref;
weaken $ref;
#Dump $ref;
my $mw = tkinit;
my $w = $mw->MyWidget(-attr => $ref,
                   )->pack;
$mw->update;

#Dump $ref;
print "undefining copy:\n";
undef $copy;
print "undefined copy\n";

print "configuring:\n";
$w->configure(-attr => 1);
$mw->update;
print "configured\n";

print "destroying w:\n";
$w->destroy;
$mw->update;
print "destroyed w:\n";