Q109678: FIX: CodeView/Visual Workbench Can’t Watch static const Member

Article: Q109678
Product(s): Microsoft Programming Utilities
Version(s): 1.0,1.5,2.0,4.0,4.01,4.1
Operating System(s): 
Keyword(s): kbDebug kbidekbbuglist kbfixlist
Last Modified: 26-JUN-2001

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The information in this article applies to:

- Microsoft CodeView for MS-DOS, versions 4.0, 4.01, 4.1 
- Microsoft CodeView for Windows, versions 4.0, 4.01, 4.1 
- The Visual Workbench Integrated Debugger, used with:
   - *EDITOR Please do not choose this product*Microsoft Visual C++ for Windows* use 1699, versions 1.0, 1.5 
   - *EDITOR Please do not choose this product*Microsoft Visual C++ 32-bit Edition* use 241, 265, 225, versions 1.0, 2.0 
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SYMPTOMS
========

If you try to watch a static const member of a class in CodeView or the Visual
Workbench debugger by placing a watch on classname::member, the debugger will
display the error

  CXX0030 expression not evaluatable

  -or-

  CXX0017 expression cannot be evaluated

or it will show invalid information. Also, if you try to watch the class that
contains the static const member and expand the class to look at the members,
the debugger will not display the correct information for the static const
member.

RESOLUTION
==========

You can work around this by making the member variable static and not const, or
by setting a watch on an instance of the class. For example, set the watch on
scmemGlobal.scInt in the sample code below.

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 Visual C++ version
2.1.

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

  /* Compile options needed: /Zi /Od
  */ 

  #include <stdio.h>

  class CSCMember
  {
  public:
      static const int scInt;
      static int sInt;
      const int cInt;
  public:
      CSCMember () : cInt(4) {};
  };

  const int CSCMember::scInt= 2;
  int CSCMember::sInt= 3;

  CSCMember scmemGlobal;

  void main ()
  {
      /*
      The first line prints the correct value, but you cannot
      watch the variable in the debugger by placing a watch on
      CSCMember::scInt or by watching the members of scmemGlobal.
      */ 
      printf ("static const member= %d\n", scmemGlobal.scInt);
      printf ("static member= %d\n", scmemGlobal.sInt);
      printf ("const member= %d\n", scmemGlobal.cInt);
  }

Additional query words: 4.00 4.10 1.00 1.10 1.50 2.00

======================================================================
Keywords          : kbDebug kbide kbbuglist kbfixlist
Technology        : kbVCsearch kbAudDeveloper kbCodeView kbZNotKeyword3
Version           : :1.0,1.5,2.0,4.0,4.01,4.1
Solution Type     : kbfix

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

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