Q167966: FIX: C2248: Statics in Friends, No Access to Protected Members

Article: Q167966
Product(s): Microsoft C Compiler
Version(s): 5.0,6.0
Operating System(s): 
Keyword(s): kbcode kbtool kbVC500bug kbVC600bug kbNoUpdatekbbuglist
Last Modified: 10-FEB-2002

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The information in this article applies to:

- The C/C++ Compiler (CL.EXE), used with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, versions 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
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SYMPTOMS
========

When you create a static object created in a friend function, it is denied
access to protected members of a class and compiler error C2248 appears as
follows:

  'member' : cannot access protected member declared in class 'class'

RESOLUTION
==========

Create the static object using the new operator.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

This problem was corrected in Microsoft Visual C++ .NET.

MORE INFORMATION
================

The following sample demonstrates the problem and the workaround.

Sample Code
-----------

     #include <iostream>

     //#define WORKAROUND //Uncomment this line for workaround

     class A
     {
     protected:
     A() { std::cout << "A()" << std::endl ;}
     ~A() { std::cout << "~A()" << std::endl ;};

     friend A* GetA();
     };

     A* GetA()
     {
     #ifndef WORKAROUND

       static A a ;
       return &a ;

     #else

       static A *pA = new A;
       return pA;

     #endif
     }

     void main()
     {
      A *pA = GetA() ;
     }

Additional query words:

======================================================================
Keywords          : kbcode kbtool kbVC500bug kbVC600bug kbNoUpdate kbbuglist
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : :5.0,6.0
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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