1Tie::RefHash(3)       User Contributed Perl Documentation      Tie::RefHash(3)
2
3
4

NAME

6       Tie::RefHash - Use references as hash keys
7

VERSION

9       version 1.40
10

SYNOPSIS

12           require 5.004;
13           use Tie::RefHash;
14           tie HASHVARIABLE, 'Tie::RefHash', LIST;
15           tie HASHVARIABLE, 'Tie::RefHash::Nestable', LIST;
16
17           untie HASHVARIABLE;
18

DESCRIPTION

20       This module provides the ability to use references as hash keys if you
21       first "tie" the hash variable to this module.  Normally, only the keys
22       of the tied hash itself are preserved as references; to use references
23       as keys in hashes-of-hashes, use Tie::RefHash::Nestable, included as
24       part of Tie::RefHash.
25
26       It is implemented using the standard perl TIEHASH interface.  Please
27       see the "tie" entry in perlfunc(1) and perltie(1) for more information.
28
29       The Nestable version works by looking for hash references being stored
30       and converting them to tied hashes so that they too can have references
31       as keys.  This will happen without warning whenever you store a
32       reference to one of your own hashes in the tied hash.
33

EXAMPLE

35           use Tie::RefHash;
36           tie %h, 'Tie::RefHash';
37           $a = [];
38           $b = {};
39           $c = \*main;
40           $d = \"gunk";
41           $e = sub { 'foo' };
42           %h = ($a => 1, $b => 2, $c => 3, $d => 4, $e => 5);
43           $a->[0] = 'foo';
44           $b->{foo} = 'bar';
45           for (keys %h) {
46              print ref($_), "\n";
47           }
48
49           tie %h, 'Tie::RefHash::Nestable';
50           $h{$a}->{$b} = 1;
51           for (keys %h, keys %{$h{$a}}) {
52              print ref($_), "\n";
53           }
54

THREAD SUPPORT

56       Tie::RefHash fully supports threading using the "CLONE" method.
57

STORABLE SUPPORT

59       Storable hooks are provided for semantically correct serialization and
60       cloning of tied refhashes.
61

SEE ALSO

63       perl(1), perlfunc(1), perltie(1)
64

SUPPORT

66       Bugs may be submitted through the RT bug tracker
67       <https://rt.cpan.org/Public/Dist/Display.html?Name=Tie-RefHash> (or
68       bug-Tie-RefHash@rt.cpan.org <mailto:bug-Tie-RefHash@rt.cpan.org>).
69

AUTHORS

71       Gurusamy Sarathy <gsar@activestate.com>
72
73       Tie::RefHash::Nestable by Ed Avis <ed@membled.com>
74

CONTRIBUTORS

76       •   Yuval Kogman <nothingmuch@woobling.org>
77
78       •   Karen Etheridge <ether@cpan.org>
79
80       •   Florian Ragwitz <rafl@debian.org>
81
82       •   Jerry D. Hedden <jdhedden@cpan.org>
83

85       This software is copyright (c) 2006 by יובל קוג'מן (Yuval Kogman)
86       <nothingmuch@woobling.org>.
87
88       This is free software; you can redistribute it and/or modify it under
89       the same terms as the Perl 5 programming language system itself.
90
91
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93perl v5.38.0                      2023-07-21                   Tie::RefHash(3)
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