Re: Is this correct C++?

From:
Greg Herlihy <greghe@mac.com>
Newsgroups:
comp.lang.c++.moderated
Date:
Sun, 25 Oct 2009 13:13:01 CST
Message-ID:
<b0e1ef19-8bfc-4c1d-aba0-0783823e865b@s6g2000vbp.googlegroups.com>
On Oct 16, 11:10 am, Daniel Kr?gler <daniel.krueg...@googlemail.com>
wrote:

On 16 Okt., 02:15, Gerasimos Karvounis <Gerasimos.Karvou...@gmx.de>
wrote:

But, if I change the declaration of B into:

class __declspec(dllexport) B {
        public:
                B(), // Notice the comma instead of a semicolon!
                B(int i);
        private:
                int mValue;
};

Then my compiler reports error C2487: member of dll interface class may
not be declared with dll interface

...

2. Is it a compiler bug?


It's hard to say, because __declspec is a non-standard
component. In which way it interferes with the declaration
sequence is out of the scope of the standard.


The "__declspec" identifier is not "non-standard" C++. To call
__declspec "non-standard" means that its presence in a program
violates - or at least - disregards the C++ Standard. The clear
implication is that a compiler that recognizes this "non-standard"
identifier - cannot be a "true" (or "valid" or "conforming") C++
compiler.

In reality, "__declspec" is an "implementation-defined" identifier,
and one that fully conforms to the C++ Standard: "Each name that
contains a double underscore (__) ... is reserved to the
implementation for any use."[?17.4.3.1.2].

Furthermore, there is no basis for concluding that __declspec somehow
"interferes" with the Standard C++ meaning of the declaration. And in
fact, it does not.

Greg

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