NAME

       Tie::RefHash - Use references as hash keys

VERSION

       version 1.40

SYNOPSIS

           require 5.004;
           use Tie::RefHash;
           tie HASHVARIABLE, 'Tie::RefHash', LIST;
           tie HASHVARIABLE, 'Tie::RefHash::Nestable', LIST;

           untie HASHVARIABLE;

DESCRIPTION

       This module provides the ability to use references as hash keys if you first "tie" the
       hash variable to this module.  Normally, only the keys of the tied hash itself are
       preserved as references; to use references as keys in hashes-of-hashes, use
       Tie::RefHash::Nestable, included as part of Tie::RefHash.

       It is implemented using the standard perl TIEHASH interface.  Please see the "tie" entry
       in perlfunc(1) and perltie(1) for more information.

       The Nestable version works by looking for hash references being stored and converting them
       to tied hashes so that they too can have references as keys.  This will happen without
       warning whenever you store a reference to one of your own hashes in the tied hash.

EXAMPLE

           use Tie::RefHash;
           tie %h, 'Tie::RefHash';
           $a = [];
           $b = {};
           $c = \*main;
           $d = \"gunk";
           $e = sub { 'foo' };
           %h = ($a => 1, $b => 2, $c => 3, $d => 4, $e => 5);
           $a->[0] = 'foo';
           $b->{foo} = 'bar';
           for (keys %h) {
              print ref($_), "\n";
           }

           tie %h, 'Tie::RefHash::Nestable';
           $h{$a}->{$b} = 1;
           for (keys %h, keys %{$h{$a}}) {
              print ref($_), "\n";
           }

THREAD SUPPORT

       Tie::RefHash fully supports threading using the "CLONE" method.

STORABLE SUPPORT

       Storable hooks are provided for semantically correct serialization and cloning of tied
       refhashes.

SEE ALSO

       perl(1), perlfunc(1), perltie(1)

SUPPORT

       Bugs may be submitted through the RT bug tracker
       <https://rt.cpan.org/Public/Dist/Display.html?Name=Tie-RefHash> (or
       bug-Tie-RefHash@rt.cpan.org <mailto:bug-Tie-RefHash@rt.cpan.org>).

AUTHORS

       Gurusamy Sarathy <gsar@activestate.com>

       Tie::RefHash::Nestable by Ed Avis <ed@membled.com>

CONTRIBUTORS

       •   Yuval Kogman <nothingmuch@woobling.org>

       •   Karen Etheridge <ether@cpan.org>

       •   Florian Ragwitz <rafl@debian.org>

       •   Jerry D. Hedden <jdhedden@cpan.org>

COPYRIGHT AND LICENCE

       This software is copyright (c) 2006 by יובל קוג'מן (Yuval Kogman)
       <nothingmuch@woobling.org>.

       This is free software; you can redistribute it and/or modify it under the same terms as
       the Perl 5 programming language system itself.