[boost] Re: [boost] Re: [boost] Curaçao: reaction to smart pointer proposal

From: Peter Dimov (pdimov_at_[hidden])
Date: 2002-05-01 05:06:17

From: "Beman Dawes" <bdawes_at_[hidden]>
> At 02:53 PM 4/30/2002, Greg Colvin wrote:
>
>  >At 12:41 PM 04/28/2002, Beman wrote:
>  >
>  >>* LWG members are very concerned that "you don't have to pay for what
> you
>  >don't use." This is particularly true of memory; increased memory use
due
>  >to multiple inheritance or to accommodate weak_ptr, for example, is
> viewed
>  >as a serious problem.
>  >
>  >I don't really think that is such a big issue, unless shared objects
>  >are hardly shared at all, and maybe not even then.
>  >
>  >The overhead for the weak pointer need be only one word per object, not
>  >per pointer, and the smart pointer itself need be only one or two words.
>
> Well, the issue could be put to rest by providing sizeof() information for
> a number of compilers.  Test code should probably report sizeof()
> routinely, since it is something that people do care about.
>
> It isn't so much a concern for single smart pointers, but when you have a
> vector of smart pointers, sizeof() each smart pointer gets important.

An important point to keep in mind is that the memory footprint of a pointer
is not equal to its size.

Another important point is that in memory critical situations (actual, not
imaginary) I'd use a custom intrusive pointer anyway. ;-)