Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!dali.cs.montana.edu!caen!spool.mu.edu!uunet!godzilla!kohlrabi!robert
From: robert@kohlrabi.tcs.com (Robert Blumen)
Newsgroups: comp.lang.c++
Subject: Re: Object pointers, and destructors
Message-ID: <2289@godzilla.tcs.com>
Date: 31 May 91 22:59:58 GMT
References: <19944@sdcc6.ucsd.edu>
Sender: root@tcs.com
Reply-To: robert@kohlrabi.tcs.com (Robert Blumen)
Distribution: comp
Organization: Teknekron Communications Systems
Lines: 30


In article <19944@sdcc6.ucsd.edu>, cs162sbj@uape_5.ucsd.edu (....What
Is?....) writes:
|> [1]
|>	  I want to be
|> 	able to control pointer assignments the way I can control object
|> 	assignments, but I haven't been able to overload operators using
|> 	pointers to objects, just objects.  How is what I want to do
|> 	accomplished cleanly?

Perhaps you can do what you want by overload the per-class operator new,
operator delete, and operator &.  You can also define pointer objects that
have the desired semantics (most generically done using templates) and
use the pointer objects rather than regular pointers for the classes that
need ref counts.

|> [2] Why doesn't delete() automatically set the original pointer to
|> 	NULL?  I can't do it from within my destructor, and I can find no
|> 	reason to leave it pointing to freed memory.
|> 
You could do this yourself by writing your own ::operator delete and linking 
it into your code.  I can't say just why it doesn't do this, since not
doing so means that the post-delete pointer value is certainly invalid.  It
is consistent with the C++ philosophy "it doesn't work this way by default
but you can do it yourself"

-----------------------------------------------------------------------------
Robert Blumen                          | rblumen@tcs.com
Senior Software Engineer               | 2121 Allston Way, Berkeley, CA 94704
Teknekron Communications Systems, Inc. | (415) 649-3759