FIX: Compiler May Generate Invalid Errors for Local Classes

WINDOWS   | WINDOWS NT

The information in this article applies to:

• The Microsoft C/C++ Compiler (CL.EXE), included with:

      - Microsoft Visual C++ for Windows, versions 1.0 and 1.5
      - Microsoft Visual C++, 32-bit Edition, versions 1.0 and 2.0
  

SYMPTOMS

The compiler may incorrectly generate the following error messages when compiling code that declares a local class that derives virtually from another class:

    C2517: 'identifier' : right of '::' is undefined
    C2270: 'identifier' : modifiers not allowed on nonmember functions
    C2561: 'identifier' : function must return a value

   C2653: 'identifier' : is not a class name
   C2561: 'identifier' : function must return a value

RESOLUTION

To avoid the error messages, either do not derive the local class virtually or do not declare both the parent and the derived class as local classes.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This problem was fixed in Microsoft Visual C++, 32-bit Edition, version 4.0.

MORE INFORMATION

Sample Code

/* Compile options needed: none
*/

   void main()
   {
       class B { public: int bi; };             // Class local to main
       class D : virtual public B { int di; };      // Class derived from
                                                // Local class B
       D d;
   }