sub ret_iter4 {
    my @ranges = @_;
    my $last=1;
    $last *= @$_ for @ranges;
    my $iteration=0;
    return sub {
        return if $iteration >= $last;
        my $i = $iteration++;
        my $possibilities = $last;
        map {
            $possibilities /= @$_;
            my $this_iter_i = $i / $possibilities;
            $i %= $possibilities;
            $_->[$this_iter_i];
        } @ranges;
    }
}