PRB: Debugger Can't Evaluate Cast of Enum to (long*)

• The Visual Workbench Integrated Debugger, included with: - Microsoft Visual C++, 32-bit Edition, version 2.0, 2.1, 4.0, 5.0 on

       the following platforms:
       - x86
       - MIPS (not available for version 5.0)
  

  - Microsoft Visual C++ version 2.0 Cross-Development Edition

       for Macintosh
  

SYMPTOMS

The Visual Workbench Debugger expression evaluator cannot evaluate the cast of an enumerator to a pointer to a long in C++ code. If you attempt to enter an expression of this type in the debugger's watch window, an error occurs. For example, if you try to watch the enumerator 'a' as shown in the sample code below, the debugger gives this error:

   (long*)a = CXX0019: Error: bad type cast

RESOLUTION

If the enumerator is assigned to a pointer to a long at compile time, the debugger can watch the pointer (see the Sample Code section below).

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The following sample code demonstrates the problem. Entering (long*)a in the Watch window causes error CXX0019.

Sample Code

   /* Compile options needed: /Zi /Od test.cpp
   */

   enum {a=1, b=2, c=3};

   void main()
   {
      long *ptr;
      ptr = (long*)a;  // Cast works correctly in code.
   }

Keywords          : WBDebug
Version           : 2.0 2.1 4.0 5.0
Platform          : MACINTOSH NT WINDOWS
Issue type        : kbprb