Query: tie::refhash
OS: osx
Section: 3pm
Format: Original Unix Latex Style Formatted with HTML and a Horizontal Scroll Bar
Tie::RefHash(3pm) Perl Programmers Reference Guide Tie::RefHash(3pm)NAMETie::RefHash - use references as hash keysSYNOPSISrequire 5.004; use Tie::RefHash; tie HASHVARIABLE, 'Tie::RefHash', LIST; tie HASHVARIABLE, 'Tie::RefHash::Nestable', LIST; untie HASHVARIABLE;DESCRIPTIONThis 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.EXAMPLEuse 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'; $b->{foo} = 'bar'; for (keys %h) { print ref($_), " "; } tie %h, 'Tie::RefHash::Nestable'; $h{$a}->{$b} = 1; for (keys %h, keys %{$h{$a}}) { print ref($_), " "; }THREAD SUPPORTTie::RefHash fully supports threading using the "CLONE" method.STORABLE SUPPORTStorable hooks are provided for semantically correct serialization and cloning of tied refhashes.RELIC SUPPORTThis version of Tie::RefHash seems to no longer work with 5.004. This has not been throughly investigated. Patches welcome ;-)LICENSEThis program is free software; you can redistribute it and/or modify it under the same terms as Perl itselfMAINTAINERYuval Kogman <nothingmuch@woobling.org>AUTHORGurusamy Sarathy gsar@activestate.com 'Nestable' by Ed Avis ed@membled.comSEE ALSOperl(1), perlfunc(1), perltie(1) perl v5.16.2 2012-10-11 Tie::RefHash(3pm)