[boost] Re: versioned_ptr<T>: wish/announcement

From: Greg Colvin (gcolvin_at_[hidden])
Date: 1999-09-17 15:20:30

> Greg Colvin's weak_ptr<T> implementation uses a level
> of indirection. This has several weaknesses:
>     a) some of us *think* that we cannot afford that extra level of
> indirection. (I say "think" because I have been forced to swallow
> my words in similar circumstances. It's just that, as a hardware guy,
> I know that extra levels of pointers are the worst possible thing.)
>     b) it can only be used with dynamically allocated storage.
> You can't have such pointers to such pointees if the pointee is stack
> allocated.

Actually, the indirection didn't work, because you can't safely go from
Derived* to void* to Base*,  so my current implementation does without
it.  The cost is that weak_ptr is slower.