Re: [boost] More shared_ptr_from_this ruminations

From: Thomas Witt (witt_at_[hidden])
Date: 2002-09-21 10:26:50

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On Saturday 21 September 2002 16:52, David Abrahams wrote:
> I just remembered why it seemed so strange to implicitly limit the source
> pointer to 'this': I once needed the facility, but wouldn't have used it
> that way. The use case is simple. I was building a hierarchical GUI
> framework where parents owned their children (with shared pointers), and
> each child had raw parent back-pointers. It would've been nice to be able
> to return a shared_ptr to the parent in the external interface. Of course,
> we didn't have weak_ptr when I was doing that - I suppose weak_ptr would
> have been a superior interface.

I was dealing with a similar scheme recently. I discovered what I think is 
another big advantage of weak_ptr<T>, T the backpointer does not have to be 
an complete type when generating shared_ptr<T>. Unfortunately you cannot 
initialize waek_ptr<T> back pointers during T construction. So choose your 
poison.

- --Thomas

- -- 
Dipl.-Ing. Thomas Witt
Institut fuer Verkehrswesen, Eisenbahnbau und -betrieb, Universitaet Hannover
voice: [phone] - 4273, fax: [phone]
http://www.ive.uni-hannover.de
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