Tie::RefHash - use references as hash keys
require 5.004; use Tie::RefHash; tie HASHVARIABLE, 'Tie::RefHash', LIST; tie HASHVARIABLE, 'Tie::RefHash::Nestable', LIST; untie HASHVARIABLE;
Perl Programmers Reference Guide Tie::RefHash(3) 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 ;-) LICENSE This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself MAINTAINER Yuval Kogman <nothingmuch@woobling.org> AUTHOR Gurusamy Sarathy gsar@activestate.com 'Nestable' by Ed Avis ed@membled.com ATTRIBUTES See attributes(7) for descriptions of the following attributes: +---------------+-----------------------+ |ATTRIBUTE TYPE | ATTRIBUTE VALUE | +---------------+-----------------------+ |Availability | runtime/perl-532 | +---------------+-----------------------+ |Stability | Pass-through volatile | +---------------+-----------------------+ SEE ALSO perl(1), perlfunc(1), perltie(1) NOTES Source code for open source software components in Oracle Solaris can be found at https://www.oracle.com/downloads/opensource/solaris-source- code-downloads.html. This software was built from source available at https://github.com/oracle/solaris-userland. The original community source was downloaded from http://www.cpan.org/src/5.0/perl-5.32.0.tar.gz. Further information about this software can be found on the open source community website at https://www.perl.org/. perl v5.32.0 2020-06-14 Tie::RefHash(3)