[boost] Re: Why a reference-linked shared_ptr?

From: Joe Gottman (jgottman_at_[hidden])
Date: 2003-12-31 19:47:37

"Rogier van Dalen" <R.C.van.Dalen_at_[hidden]> wrote in message
news:3FF2DE42.20600_at_umail.leidenuniv.nl...
> Hi all,
>
> First of all, I'm not sure this is the correct place to discuss this.
> Please point me to a better place if it's not.
>
> "A proposal to add general purpose smart pointers to the library"
> http://std.dkuug.dk/jtc1/sc22/wg21/docs/papers/2003/n1450.html
> is based mostly on the boost shared_ptr. It explicitly allows a
> reference-linked implementation though (III.A.4). Why? According to
> Andrei Alexandrescu (Modern C++ Design 7.5) the only advantage of that
> is that no extra object (reference counter) has to be allocated. I have
> not been able to think of or find any other advantage.
> But what to do with the deleter then, whose type is not in the
> shared_ptr template parameter list? There must be something I'm missing,
> or otherwise a linked list  implementation of shared_ptr is forced to
> allocate at least some free store for the deleter (or a vtable) -- 
> rendering the advantage void.
>
> Regards,
> Rogier

   Try posting this to the comp.std.c++ newsgroup.

Joe Gottman