Re: Erroneous for-loop variable used with /Zc:forScope

From:
"Victor Bazarov" <v.Abazarov@comAcast.net>
Newsgroups:
microsoft.public.vc.language
Date:
Mon, 20 Aug 2007 08:08:31 -0400
Message-ID:
<fac07u$skh$1@news.datemas.de>
Felipe wrote:

Even with /Zc:forScope used, Compiling this code with Visual C++
Express 2005 tells me he is using the i from the most nested for-loop,
which is wrong! And gives an error for not having a assignment
operator. Proving is trying to use the i from the nested for-loop.
This compiles fine on Visual C++ 7.1 (2003) Professional and Visual C+
+ Express 9.0 Beta 2.

int main()
{
 struct A {
   A& operator++();
   bool operator!=(int) const;
   //A& operator=(int);
 };
 for(int i = 0; i < 10; i++)
 {
   for(A i; i != 20; ++i)
   {

   }

   i = 5;
 }
}

The error message:
[..]
subprojects\misvc\src\tnef_conversion.cpp(333) : warning C4288:
nonstandard extension used : 'i' : loop control variable declared in
the for-loop is used outside the for-loop scope; it conflicts with the
declaration in the outer scope
       subprojects\misvc\src\tnef_conversion.cpp(328) : definition of
'i' used
       subprojects\misvc\src\tnef_conversion.cpp(326) : definition of
'i' ignored
subprojects\misvc\src\tnef_conversion.cpp(333) : error C2679: binary
'=' : no operator found which takes a right-hand operand of type
'int' (or there is no acceptable conversion)


It's an apparent bug in the compiler, which is fixed in the next version
(as you yourself determined). They must have broken it somewhere after
2003 and fixed it again in the upcoming 2008 (9.0 as you call it).

I can confirm that your code gives the same error with VC++ 2005 SP1.
IOW it's not fixed in their service pack.

V
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