[boost] Re: [noncopyable.hpp] small fix for Borland

From: David B. Held (dheld_at_[hidden])
Date: 2004-01-07 06:16:08

"Lars Gullik Bjønnes" <larsbj_at_[hidden]> wrote in message
news:m3vfno2hy2.fsf_at_tyfon.gullik.net...
> "David B. Held" <dheld_at_[hidden]> writes:
>
> >> Probably can't get any better on BCB.
> >
> | Actually, you probably can't get much better on any compiler, for
> | reasons listed in one of the threads on SmartPtr, and mentioned
> | in Andrei's & my Oct '03 CUJ article.
>
> Gcc says size is 4, or are you talking of something differnt?

GCC *might* be wrong to say that. ;)  I believe there's currently a
DR on the subject, but I might mistaken.  To sum up, there is a way
to read the standard that requires each base class to have a
unique address, which would require them to have non-zero size.
EBO works because the base class can share an address with
the derived class.  But two non-virtual base classes might not
be allowed to share an address.  That said, I'm very happy that
gcc gives sizeof(4) anyway, and I found that of the compilers I had
to test, it was always the most aggressive in making things small.

Dave

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