------- Comment #179 from schaub-johannes at web dot de 2010-06-20 00:01
-------
(In reply to comment #158)
> Subject: Re: [4.0/4.1/4.2/4.3 Regression] placement new does not change the
> dynamic type as it should
>
> "rguenther at suse dot de" <gcc-bugzi...@gcc.gnu.org> writes:
>
> [...]
>
> | > Now, if I understand your argument below correctly, you are saying
> | > that even if we fixed the union rules for C++, we may still be facing
> | > the same problem because assignment to POD objects does not just mean
> | > that the object was there before, but that we are actually starting a
> | > new one. Do I understand your argument correctly?
> |
> | Yes.
>
> Then, I'm not sure I agree with that. I'll raise it as part of the
> union problem.
>
I'm sorry for commenting this late, but were there any outcomes of the
discussion about changing the dynamic type by assignments for non-PODs (maybe
on the reflector)? The way I see it, and how Richard may see it, is by 3.8/1
which says
The lifetime of an object of type T begins when
- storage with the proper alignment and size for type T is obtained
The lifetime of an object of type T ends when
- the storage which the object occupies is reused or released.
This isn't specific to unions, but it never seems to define what constitutes a
"reuse", but Richard seems to interpret this to include assignments and so do
I, and i've always used this interpretation to explain the mechanism by which
unions change their active member.
--
schaub-johannes at web dot de changed:
What |Removed |Added
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CC| |schaub-johannes at web dot
| |de
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29286
