Re: [boost] [unordered] [MultiIndex] iterator_to

Subject: Re: [boost] [unordered] [MultiIndex] iterator_to
From: Daniel James (daniel_james_at_[hidden])
Date: 2008-11-18 13:49:06

Sorry about the slow reply.

2008/11/10 David Abrahams <dave_at_[hidden]>:
>
> If I could prevail upon Daniel James to add iterator_to to
> Boost.Unordered so it will be there in the future, I'd gladly backport
> that change into my version

I'm not sure if it's that simple. The nodes aren't PODs so I don't
think 'offsetof' can't be used to get their address (or can it? I've
never used it). MultiIndex copes by using aligned_storage and manually
constructing the value in place, so that it can get the containing
structures address. Which is a possibiliy for the unordered
containers, and could help implement emplace for compilers without
variadic templates (or for allocators without a variadic construct
method) so it might be a good idea anyway. So I'll look into doing
that.

Daniel