package Boolean;

my $true  = bless(\(my $data = -1));  # Like BASIC
my $false = bless(\(my $data =  0));

use overload
   '!'    => sub { ${$_[0]} ? $false : $true },
   'bool' => sub { ${$_[0]} };

sub boolean($) { $_[0] ? $true : $false }
sub true()     { $true }
sub false()    { $false }

1;