Re: [boost] [TypeIndex] Peer review period for library acceptance begins, ending Thurs 21st Nov

Subject: Re: [boost] [TypeIndex] Peer review period for library acceptance begins, ending Thurs 21st Nov
From: Antony Polukhin (antoshkka_at_[hidden])
Date: 2013-11-15 10:45:31

2013/11/15 Steven Watanabe <watanabesj_at_[hidden]>

> AMDG
>
> On 11/15/2013 05:50 AM, Antony Polukhin wrote:
> >
> > But this error appears only when we mutate data (
> > https://svn.boost.org/trac/boost/wiki/Guidelines/WarningsGuidelinessearch
> > for "strict-aliasing rules")
> >
>
> ...and can be arbitrarily broken by (unknown) future
> optimizations, with no recourse.  We wouldn't have
> all the problems with strict aliasing that we do today
> if programmers 10 years ago hadn't made exactly the
> same argument that you are, now.  (Sure, it's undefined
> behavior, but we know what the compiler actually does,
> so it's really okay...).

You're absolutely right. I've liked the idea of "make it in a way that user
won't notice a difference but typeid issues will be solved" so much, that
turned a blind eye to a hack with UB.

This will be fixed (possibly code from v1.0 will be taken, which had no
boost::type_info and contained type_index class that had a pointer to
std::type_info).

Do you have other ideas of what can be fixed/improved?

-- 
Best regards,
Antony Polukhin