in reply to Deallocating HASH pointer

You only need to worry about memory if you have a circular reference (say a "parent" link). 
$tree = undef;

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might be better. You'll get a warning later if you try to use it.

See WeakRef and Data::Structure::Util's has_circular_ref

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Re: Re: Deallocating HASH pointer
by ysth (Canon) on May 11, 2004 at 09:31 UTC
    You'll get a warning later if you try to use it.
    Not necessarily: 
    #line 1
use strict;
use warnings;
our $tree;

$tree = {};
$$tree{autov} = "ivify";
warn %$tree;
# vs.
$tree = undef;
$$tree{autov} = "ivify";
warn %$tree;

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Re: Re: Deallocating HASH pointer
by Steve_p (Priest) on May 11, 2004 at 11:17 UTC
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Re: Re: Deallocating HASH pointer
by eXile (Priest) on May 11, 2004 at 15:15 UTC
    you might even want to do: 
    undef $tree

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    this will remove the complete $tree variable from your scope, not just 'undef' it.
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