Re: [boost] Re: Variant implementation change (was re: unions) final summary

From: Douglas Gregor (gregod_at_[hidden])
Date: 2003-10-09 15:01:36

On Thursday 09 October 2003 03:16 pm, E. Gladyshev wrote:
> --- Brock Peabody <brock.peabody_at_[hidden]> wrote:
> > (3) Bitwise copying of non POD types, no matter how you call it, is
> > undefined.  This is _fact_.
>
> The "reusing storage" concept in the standard is undefined too then.
> The whole variant idea is undefined then.
> Look at it this way, you are not copying a non POD type
> all you do is copying the content of a storage that you program
> allocated. It is not even funny anymore that you keep going back
> to this "undefined copying" stuff.

If you have not done so, please read:
  http://aspn.activestate.com/ASPN/Mail/Message/boost/1311813

This is the basis by which we have concluded that solutions requiring copying 
the individual bits lead to undefined behavior. If you believe that you have 
a solution, please present it and describe why it does not lead to undefined 
behavior, referencing the clauses David Abrahams has cited in the above 
message.

Please do note that you are refuting something that is considered to have 
already been proven in prior discussions, which have been cited. In this 
circumstance, the burden of proof falls on you.

        Doug