#!/users/contrib/bin/perl

package Release;

use strict;
use warnings;

sub new {
  my $class = shift;
  my ($sub, @args) = @_;
  bless \sub {
    $sub->(@args);
  }, $class;
}

sub cancel {
  ${$_[0]} = sub {};
}

sub DESTROY {
  ${$_[0]}->();
}

package main;

use strict;
use warnings;

for (1..3) {
  my $foo = Release->new(sub {my ($num, $msg) = @_; print "Foo $msg\n"}, $_, "destroyed");
  print "$_\n";
  $foo->cancel if $_ == 2;
  print "Release foo\n";
}
print "Done\n";