I want to do the same with ruby but it is impossible. only false and nil can be considered "false" values. it is hard coded in the source of the ruby.

bool.pl

package BooleanClass;
use Moose;
has 'bool_value' => ( 
  is => 'ro', 
	isa => 'Bool'
);

use overload 
	'bool' => \&_to_bool;

sub _to_bool { 
	shift->bool_value; 
};

package main;
use Test::More tests => 2;

subtest "true values" => sub {
	plan tests => 2;	
	my $true  = BooleanClass->new( bool_value => 1 );

	ok($true,                "should be true");
	is($true->bool_value, 1, "should return 1");
};
 
subtest "false values" => sub {
	plan tests => 2;
	my $false = BooleanClass->new( bool_value => 0 );	

	ok(!$false,               "should be false");	
	is($false->bool_value, 0, "should return 0");
};

__END__

1..2
    1..2
    ok 1 - should be true
    ok 2 - should return 1
ok 1 - true values
    1..2
    ok 1 - should be false
    ok 2 - should return 0
ok 2 - false values

bool.py

class BooleanClass:
	def __init__(self, value):
		self.value = value
		
	def __nonzero__(self):
		return self.value
		
t = BooleanClass(True)
f = BooleanClass(False)

assert t, "should be true"
assert not f, "should be false"