GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages
Tie::RefHash(3) User Contributed Perl Documentation Tie::RefHash(3)

Tie::RefHash - Use references as hash keys

version 1.40

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

    untie HASHVARIABLE;

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.

    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";
    }

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

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

perl(1), perlfunc(1), perltie(1)

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>).

Gurusamy Sarathy <gsar@activestate.com>

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

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

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.

2020-10-10 perl v5.32.1

Search for    or go to Top of page |  Section 3 |  Main Index

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with ManDoc.