[PATCH] Fix C++ strict-aliasing issues with memcpy folding

[Paolo Carlini]

Hi,
>> About this, just wanted to point out that in Pittsburgh this paper will
>> be discussed again
>>
>>  http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2981.pdf
>>
>> whereas in Santa Cruz concerns have been raised exactly about those
>> placement new of subobjects vs aliasing. In my opinion the proposed
>> solution to the long standing issue with std::pair is otherwise very
>> nice and I would really encourage you to check it vs aliasing...
>>     
> I missed the Santa Cruz meeting.  What was the concerns about aliasing?
>   
I don't remember the details, but essentially Doug was afraid that the
scheme you can still see at the beginning of the Proposed Wording
(remnant of the previous version) could not be completely safe wrt
aliasing: nobody in the room could really confirm or deny that and the
discussion stalled. Lately, I think I read on the reflector that Pablo
has hopes it is safe, actually. Some input would be definitely welcome,
I think.

Paolo.