BUG: C2061, C2062, C2226, C2039 Occur When Using enum types

• Microsoft C/C++ Compiler (CL.EXE), included with:
  • Microsoft C/C++ for MS-DOS, version 7.0
  • Microsoft Visual C++ for Windows, versions 1.0, 1.5
  • Microsoft Visual C++ 32-bit Edition, versions 1.0, 2.0, 4.0, 4.1, 4.2, 5.0

SYMPTOMS

The compilers listed above may misinterpret a combination of an enumerated type, a default parameter, and a constructor or function notation cast as a syntax error and may incorrectly generate one of the following:

error C2226: syntax error : unexpected type '<type>'

error C2062: syntax error : unexpected type '<type>'

error C2039: '<class>' : is not a member of '<class2>'

error C2061: syntax error : identifier 'identifier'

CAUSE

The C++ compiler incorrectly parses declarations in which an enumerated type is used as a parameter to either a constructor or a function notation cast in a default parameter list. If there are other syntax errors in the declaration line in question, then it is possible that an erroneous error other than the ones listed might occur. The sample code shown below gives examples of how to generate these errors.

This problem occurs only if an explicit construction [for example, A(A::FALSE)] or function notation cast [that is, int(FALSE)] is called with an enumerated type as an argument. If the compiler is allowed to do an implicit conversion, the error will not occur:

   void Func(int i = FALSE) { printf("%d\n",i); };
   B(A a = A::FALSE); 

RESOLUTION

In most cases (such as the examples below), the construction or function notation cast is not explicitly needed, in which case it can be removed. If this is not the case, the type cast (as opposed to function notation cast) syntax for the function should be used instead. For example, the above functions would be modified to:

   void Func(int i = (int) FALSE) { printf("%d\n",i); };
   B(A a = (A) A::FALSE); 

STATUS

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

Sample Code

TEST1.CPP

   /* The following code generates error C2061 or error C2226: */ 
   /* Compiler options needed: none */ 

   enum tagBool {FALSE,TRUE};

   class A
   {
   public:

     A(tagBool tc);

   };

   void Func(A a = A(FALSE)); 

TEST2.CPP

   /* The following code generates error C2061 or error C2062. */ 
   /* Compiler options needed: none */ 

   enum tagBool {FALSE,TRUE};

   void Func(int i = int(FALSE)) { printf("%d\n",i); }; 

TEST3.CPP

   /* The following code generates the C2039 error. */ 
   /* Using Visual C++ 4.0 and later, the following code compiles */ 
   /* correctly. Compiler options needed: none */ 

   class A
   {
   public:

     enum tagBool {FALSE,TRUE};
     A(tagBool tc);

   };

   class B
   {
   public:

     B(A a = A(A::FALSE));

   }; 

Additional query words: 8.00 8.00c 9.00

Keywords : kbVC100bug kbVC150bug kbVC400bug kbVC410bug kbVC420bug kbVC500bug kbVC600bug
Version :
Platform : MS-DOS NT WINDOWS
Issue type : kbbug