Tie::RefHash(3pm)                               Perl Programmers Reference Guide                               Tie::RefHash(3pm)



NAME
       Tie::RefHash - use references as hash keys

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.

RELIC SUPPORT
       This version of Tie::RefHash seems to no longer work with 5.004. This has not been throughly investigated. Patches
       welcome ;-)

MAINTAINER
       Yuval Kogman <nothingmuchATwoobling.org>

AUTHOR
       Gurusamy Sarathy        gsarATactivestate.com

       'Nestable' by Ed Avis   edATmembled.com

SEE ALSO
       perl(1), perlfunc(1), perltie(1)



perl v5.12.4                                               2011-06-07                                          Tie::RefHash(3pm)