Re: [boost] [cpo-proposal] presentation of the idea

Subject: Re: [boost] [cpo-proposal] presentation of the idea
From: Larry Evans (cppljevans_at_[hidden])
Date: 2013-08-27 08:09:08

On 08/27/13 06:44, Thorsten Ottosen wrote:
> On 23-08-2013 17:08, Larry Evans wrote:
> 
>> AFAICT, this shows the offset_ptr would solve the problem of moving
>> the storage in case the storage needs to be resized.
>>
>> Am I missing something?
> 
> I can't tell. Some interprocess experts might want to way in here?
> 
> Anyway, I can live with a container that has unstable
> pointers/references after push_back. std::vector<T> is like that,
> so what's exactly the difference here?
> 
The offset_ptr<polymorophic_object> solves the unstable
pointer problem caused by moving the storage buffer.
That's one problem 1st mentioned by Rob Stewart here:

http://article.gmane.org/gmane.comp.lib.boost.devel/243582

and then again by Ben Pope here:

http://article.gmane.org/gmane.comp.lib.boost.devel/243633

The code I last posted shows the offset_ptr still points to
the *this even after the move, although the raw pointer
points to the old location.  Also, no virtual methods are
needed to preserve this stable pointer feature.  Using
just offset_ptr seems to do the job.

-regards,
Larry