Re: [boost] Re: Re: Re: Re: TR2 and C++0x heads up

From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-04-26 10:37:14

Gennadiy Rozental wrote:
>> By PBSP, do you mean policy-based smart pointers in general, or a
>> Loki-derived smart pointer in particular?
>
> You may  say in general or Loki-derived - depend on point of view. I
> have many objections to Loki solution (and some of it's derivatives).
> But what I have in mind is similar. Do you have any other alternative
> model?

If you ask me for my personal opinion: I have little use for the Conversion 
and the Checking policies. However I do need an easier way of specifying a 
deleter (ala Howard's unique_ptr) and a ConstPropagation policy (with the 
default being No for shallow copy and Yes for deep copy).

In addition, I'm not happy with the integration of shared/weak/intrusive_ptr 
in the current model. To be really flexible, a policy-based incarnation of a 
reference counted pointer needs to leave its aspects configurable, covering 
the whole spectrum from a simple counted_ptr to full-featured shared_ptr 
(with or without weak_ptr support in both cases) and possibly covering the 
unsafe/basic/strong thread safety axis as well. This might imply a policy 
controlling whether conversions from smart_ptr<T> to smart_ptr<U> are 
allowed (because disallowing these allows alternative implementations or 
omitting one pointer from the control block.)

My needs may not be typical, of course.