Call me crazy, but whenever I need a deep copy, I use freezethaw... just to be sure, 'cause data structures have a tendency to grow beyond their original intentions... 
#!/usr/bin/perl -w

use strict;
use Data::Dumper;
use FreezeThaw qw/ thaw freeze /;

my $ds = { -foo => [ -bar => [0, 1], 3 ],
           -ping => 1 };

$ds->{-zort} = \$ds;

my ($dsft) = thaw freeze $ds;

$dsft->{-ping} = 2;

print Dumper [$ds, $dsft];

[download]
See... $ds and $dsft are two different objects now! yay. And no matter how they change, the deep copy will work for ever and ever. 
[admin@ensim admin]$ perl ./test.pl
$VAR1 = [
          {
            '-zort' => \$VAR1->[0],
            '-ping' => 1,
            '-foo' => [
                        '-bar',
                        [
                          0,
                          1
                        ],
                        3
                      ]
          },
          {
            '-ping' => 2,
            '-zort' => \$VAR1->[1],
            '-foo' => [
                        '-bar',
                        [
                          '0',
                          '1'
                        ],
                        '3'
                      ]
          }
        ];
[admin@ensim admin]$

[download]

In reply to Re: (jeffa) 2Re: Trying to solve N-Queens by eduardo
in thread Trying to solve N-Queens by jeffa

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