use 5.6.0;
use strict;

package MyConstants;

use Exporter;
our @ISA = qw(Exporter};

our @EXPORT_OK = qw(Foo Bar);

my $foo = 5;
sub Foo { $_[0] ? $foo = $_[0] : $foo }

my $bar = 3;
sub Bar { $_[0] ? $bar = $_[0] : $bar }

1;

__END__