#! perl -slw
use strict;
use Clone qw[clone];
use Data::Dumper;
use Storable qw[dclone freeze];
use Benchmark qw[cmpthese];

sub deepcopy{
        return $_[0] unless ref $_[0];
        return [ map{ deepcopy($_) } @{$_[0]} ] if ref $_[0] eq 'ARRAY';
        return { map{ deepcopy($_) } %{$_[0]} } if ref $_[0] eq 'HASH';
        return \do{ ${$_[0]} };
}

sub factorial { my ($f,$n) = (1,shift); $f *= $n-- while( $n ); $f; }

sub multicheck {
        my $check = factorial($#_);
        my ($i, @ok) = (0, (0) x @_);
        while (@_) {
                my $first = shift;
                for my $next (@_) {
                        $ok[$i] += ($first eq $next);
                }
                $i++;
        }
        my $count = do{ local $a; $a += $_ for @ok; $a; };
        return $count == $check;
}

my @rs = \do{1..5};
my @rrs1 = \(@rs);
my @rrs2 = \(@rs);
my %h1 = do{ my $key='A'; map{ $key++ => $_} 1..5; };
my %hash = ( rs=> \@rs, rrs1=> \@rrs1, rrs2=> \@rrs2, h1=>\%h1 );

$hash{self} = $hash{rs};

my $DeepCopy    = deepcopy( \%hash );
my $CloneCopy   = clone( \%hash );
my $StorableCopy= dclone( \%hash );
#print Dumper [\%hash, $CloneCopy, $StorableCopy, $DeepCopy];

=pod Comment (moan)

The following code should, according to my reading of the Data::Dumper pod, result in
$DDumperCopy becoming a ref to a copy of %hash,, but it doesn't? :(

my $DDumperCopy;
$Data::Dumper::Purity = 1;
$DDumperCopy = eval( Dumper(\%hash) ) and warn $@ if $@;
print Dumper $DDumperCopy;

=cut

cmpthese( -1, {
        DeepCopy        => '$DeepCopy = deepcopy( \%hash );',
        CloneCopy       => '$CloneCopy = clone( \$hash );',
        StorableCopy=> '$StorableCopy = dclone( \%hash );',
#       DDumperCopy     => '',
});

my $strDeepCopy         = freeze( $DeepCopy );
my $strCloneCopy        = freeze( $CloneCopy );
my $strStorableCopy     = freeze( $StorableCopy );

print "\nDifferences found!"
        unless multicheck( $strDeepCopy, $strCloneCopy, $strStorableCopy );

#print Dumper $DeepCopy, $CloneCopy, $StorableCopy
#       unless multicheck( $strDeepCopy, $strCloneCopy, $strStorableCopy );