Here's the deep copy sub that I use in some of my objects:

sub deep_copy
{
        my $self = shift;
        my $this = shift;
        unless (ref $this) {
                $this;
        } elsif (ref $this eq 'ARRAY') {
                [map $self->deep_copy($_), @$this];
        } elsif (ref $this eq 'HASH') {
                +{map{$_ => $self->deep_copy($this->{$_})} keys %$this
+};
        }
}
[download]

Here's the sub that calls it:

sub copy
{
        my $self = shift;
        return $self->deep_copy($self);
}
[download]

of course, this works because I assume my object will only either have hashrefs, arrayrefs or scalars.