[boost] Re: Fw: Why scoped_ptr dost provide custom deallocation?

From: Alisdair Meredith (alisdair.meredith_at_[hidden])
Date: 2003-02-14 06:36:14

Peter Dimov wrote:

> > And what if you use the deallocator as a template parameter?

> > Anyway: Do you know any smart-pointer class, which supports custom
> > deallocator and can transfer ownership? (auto_ptr does not support
> > custom deallocator and either smart_ptr or shared_ptr does not support
> > release() method).

> Both good questions. Do we have an answer?

These both sound like questions to be solved by the policy-pointer David
Held is formalising as we speak [based strongly on Andrei Alexandrescu's
smart_pointer class in the Loki library/Modern C++ Design book]

I would be worried to see extra template parameters appearing in
shared_pointer, as the big advantage it overs over the full-blown policy
implemetation is its simplicity to the user.

If that simplicity is no longer enough, then maybe you do need the full
policy implementation.  I too worry a little about increasing the size
of my pointers with an unused deallocator, but nothing in my profiling
has suggested this is a real problem in practice, simply an
implementation detail I am concerned about because I know it is there. 
This is one of the trade-offs of trying to use a general-purpose
library.

Well, that's my take on it anyway <g>

-- 
AlisdairM