


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


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.




perl v5.10.1                2009-10-12                          1





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


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 ;-)

MAINTAINER
       Yuval Kogman <nothingmuch@woobling.org>

AUTHOR
       Gurusamy Sarathy        gsar@activestate.com

       'Nestable' by Ed Avis   ed@membled.com

SEE ALSO
       perl(1), perlfunc(1), perltie(1)






































perl v5.10.1                2009-10-12                          2


