Tie::RefHash(3p)

Tie::RefHash3p

Use references as hash keys

Usage

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

Version

version 1.41

Overview

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.

Examples

    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.

Support

Bugs may be submitted through the RT bug tracker <https://rt.cpan.org/Public/Dist/Display.html?Name=Tie-RefHash> (or [email protected] <mailto:[email protected]>).

Contributors

•

Yuval Kogman <[email protected]>

•

Karen Etheridge <[email protected]>

•

Florian Ragwitz <[email protected]>

•

Lukas Mai <[email protected]>

•

Jerry D. Hedden <[email protected]>

•

tusooa <[email protected]>

Releases

32 releases since OpenBSD 5.0; the text changed 20 times.

  1. 5.0–5.3
  2. 5.4–5.5
  3. 5.6
  4. 5.7
  5. 5.8–5.9
  6. 6.0
  7. 6.1
  8. 6.2
  9. 6.3–6.4
  10. 6.5
  11. 6.6
  12. 6.7
  13. 6.8
  14. 6.9–7.2
  15. 7.3
  16. 7.4
  17. 7.5
  18. 7.6
  19. 7.7–7.8
  20. 7.9
  21. 8.0

Authors

Gurusamy Sarathy <[email protected]>

Tie::RefHash::Nestable by Ed Avis <[email protected]>

From man 8.0-current-20261101 in OpenBSD 8.0-current (2026-11-01). Parsed by carta from the page's man source.