Nil.pm

package Object::Nil;
use strict;
use warnings;
use overload
    '0+' => sub { 0 },
    '""' => sub { '' },
    'eq' => sub { ref $_[1] && $_[1]->isa(__PACKAGE__) },
    '==' => sub { ref $_[1] && $_[1]->isa(__PACKAGE__) },
    'ne' => sub { not $_[0] eq $_[1] },
    '!=' => sub { not $_[0] == $_[1] },
    fallback => 1;

our $Instance;

sub new {
    $Instance = bless { }, shift unless defined $Instance;
    $Instance;
}

1;

__END__

=head1 NAME

Object::Nil - The nil object

=head1 SYNOPSIS

  use Object::Nil;
  my $nil = Object::Nil->new;
  "$nil";     # => ''
  $nil eq ''; # => undef

=head1 DESCRIPTION

This module provides the nil object which evaluats to an empty string
in string context and 0 in numeric context, but returns false when
compared with them.

=head1 COPYRIGHT

Unpokopo

=cut