#!/usr/bin/env perl

use strict;
use warnings;
use Var::Pairs;

my %hash = (foo => 1, bar => 2);

for my $pair1 (pairs %hash) {
	for my $pair2 (pairs %hash) {
		printf "%s %s\n", $pair1, $pair2;
	}
}

__END__
bar => 2 bar => 2
bar => 2 foo => 1
foo => 1 bar => 2
foo => 1 foo => 1