Tie::RefHash(3p) Perl Programmers Reference Guide Tie::RefHash(3p) #

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

NNAAMMEE #

 Tie::RefHash - Use references as hash keys

VVEERRSSIIOONN #

 version 1.40

SSYYNNOOPPSSIISS #

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

     untie HASHVARIABLE;

DDEESSCCRRIIPPTTIIOONN #

 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 ppeerrllffuunncc(1) and ppeerrllttiiee(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.

EEXXAAMMPPLLEE #

     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";
     }

TTHHRREEAADD SSUUPPPPOORRTT #

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

SSTTOORRAABBLLEE SSUUPPPPOORRTT #

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

SSEEEE AALLSSOO #

 ppeerrll(1), ppeerrllffuunncc(1), ppeerrllttiiee(1)

SSUUPPPPOORRTT #

 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>).

AAUUTTHHOORRSS #

 Gurusamy Sarathy <gsar@activestate.com>

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

CCOONNTTRRIIBBUUTTOORRSS #

 •   Yuval Kogman <nothingmuch@woobling.org>

 •   Karen Etheridge <ether@cpan.org>

 •   Florian Ragwitz <rafl@debian.org>

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

CCOOPPYYRRIIGGHHTT AANNDD LLIICCEENNCCEE #

 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.

perl v5.36.3 2023-02-15 Tie::RefHash(3p)