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RE: C++ static integer class constants...
- From: "John Ratliff" <webmaster at technoplaza dot net>
- To: <gcc-help at gcc dot gnu dot org>
- Date: Sun, 16 Oct 2005 14:53:05 -0500
- Subject: RE: C++ static integer class constants...
> On Sun, Oct 16, 2005 at 02:02:09PM -0500, John Ratliff wrote:
> > This seems like a definite bug. The fact that it works in 3.4.2 and not
> in
> > 3.3.3 seems like a probable bug to me, but I will ask this question in a
> > standard C++ newsgroup so that someone intimately familiar with the
> standard
> > can give me a definitive answer, but I still think g++ 3.3 is wrong and
> g++
> > 3.4 is right.
> >
> > If I were taking the address of the constant, sure, it would have to
> have
> > storage space and I wouldn't expect it any other way.
> >
>
> I agree in that this is a weird behaviour, but I don't think it's
> exactly a bug, unless it is mandatory for a compiler to try
> everything possible before taking the address of a constant. Maybe
> GCC 3.3 simply couldn't find a way to use the constants directly.
On comp.lang.c++, Victor Bazarov says my example program is well-formed
standard C++ according to the ISO C++ standard.
"Since their address is never taken, the 'foo::A' and 'foo::B' are, in
fact, compile-time constant expressions that do not require storage.
The objects, therefore, don't need to be defined outside of the class
definition. g++ 3.3.3 is probably too old. It's even too old and non-
compliant in this particular case even with 1998 version of the C++
Standard. The standard was amended to allow const statics to be only
defined in the class definition if their address is not taken _even_
if they are "used" outside the class. [I am too lazy, though, to look
it up in the Standard...]" -- Victor Bazarov (comp.lang.c++)
I am going to upgrade to g++ 3.4, but I think it is a g++ 3.3.3 and 3.3.5
bug. I should go see if 3.3.6 fixed this.
Thanks,
--John Ratliff