Re: [boost] Status of Hash Collections?

From: Daniel James (daniel_james_at_[hidden])
Date: 2006-11-01 05:54:40

On 01/11/06, John Maddock <john_at_[hidden]> wrote:
> I don't know about address, but you are allowed to assume that all
> allocators compare equal.  Does that help?

I've been trying to fully support allocators in order to support
allocators such as the one from Ion's shared memory library. I realise
that most implementations don't do this so it's probably not vital.
And it's still an open issue how swap should be implemented:

http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#431

Allocator::address is actually the more important issue, as I use it
to destruct nodes. If it can throw I really should change the
implementation so that it doesn't. While I'd prefer not to, it's not
too bad. I'll have to remove an optimisation for iteration. Also, I'm
constructing the value in nodes separately from the pointers, in order
to avoid an extra temporary, but I won't be able to destruct them
separately. It feels wrong to destruct them in a different manner to
their construction, but I don't think it'll cause any problems in
practise.

Daniel