Re: Is it just me or just Microsoft?

From:

"Alf P. Steinbach" <alfps@start.no>

Newsgroups:

comp.lang.c,comp.lang.c++

Date:

Sun, 15 Jul 2007 04:22:25 +0200

Message-ID:

<139j176opc4jm56@corp.supernews.com>

* Ark Khasin:

Due to a peculiar need (code instrumentation) I came across unexpected
behavior of Visual Studio 6.0 and 2005 (doing the same thing):

#include <stdio.h>
#define CAT1(a,b) a ## b
#define CAT(a,b) CAT1(a,b)
#define MYNUM(n) CAT(n,__LINE__)
const int x = MYNUM(35); //OK
int z=MYNUM(78); //OK
int main(int argc)
{
    static int y=MYNUM(21); //error!
    //6.0: error C2064: term doesn't evaluate to a function
    //2005 adds: taking 26451848 arguments.

    printf("%d %d\n", x, y );
    return 0;
}

Doesn't matter if I compile as C or as C++ (if I am not mistaken, the
preprocessor is the same).
No problem with another compiler (IAR for ARM)...
[Microsoft claims strict standard compliance in the C++ department]

Any suggestions?

Visual C++ __LINE__ is broken in many versions of that compiler, when
you compile with support for "Edit and Continue" (option /ZI), and that
may be what you're up against. As an alternative you can use
non-standard __COUNTER__. And the only thing that makes that compiler
specific information slightly on-topic here is that it's an issue with
Marginean's original scope guard (which is of general interest to the
C++ community), which needs to be modified for use with Visual C++.

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