for my $pair (
    sub {
        my @pairs;
        while (my ($k,$v) = each %h) { push @pairs, [$k,$v] }
        @pairs
    }->()
) {
    my ($k,$v) = @$pair;
    ...
}

##</code><code>##

while (my ($k,$v) = each %h) {
    ...
}

##</code><code>##

for my $k (keys %h) {
    my $v = $h{$k};
    ...
}