perldoc > Tie::RefHash

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🏷️ NAME

Tie::RefHash - Use references as hash keys

🚀 Quick Reference

Use Case	Command	Description
🔑 Use references as hash keys	tie %hash, 'Tie::RefHash';	Allows any reference (array, hash, scalar, etc.) as a hash key.
🔗 Nested hashes with references	tie %hash, 'Tie::RefHash::Nestable';	Enables references as keys in nested hashes-of-hashes.
🔓 Untie a tied hash	untie %hash;	Detach the tie and recover original hash.
🧵 Threading support	CLONE method	Built-in support for cloning tied hash across threads.
💾 Storable serialization	Storable hooks	Semantically correct serialization of tied refhashes.

📦 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 AT rt.org <mailto:bug-Tie-RefHash AT rt.org>).

👤 AUTHORS

• Gurusamy Sarathy <gsar AT activestate.com>
• Tie::RefHash::Nestable by Ed Avis <ed AT membled.com>

🤝 CONTRIBUTORS

• Yuval Kogman <nothingmuch AT woobling.org>
• Karen Etheridge <ether AT cpan.org>
• Florian Ragwitz <rafl AT debian.org>
• Jerry D. Hedden <jdhedden AT cpan.org>

©️ COPYRIGHT AND LICENCE

This software is copyright (c) 2006 by יובל קוג'מן (Yuval Kogman) <nothingmuch AT 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.

🏷️ NAME 🚀 Quick Reference 📦 VERSION 📝 SYNOPSIS 📖 DESCRIPTION 🧪 EXAMPLE 🧵 THREAD SUPPORT 💾 STORABLE SUPPORT 🔗 SEE ALSO 🆘 SUPPORT 👤 AUTHORS 🤝 CONTRIBUTORS ©️ COPYRIGHT AND LICENCE