Knowledge Base

BUG: Redefinition of Enum Data Type Does Not Cause an Error

Article ID: 128600

Article Last Modified on 7/5/2005

Microsoft Visual C++ 2.0 Professional Edition
Microsoft Visual C++ 2.1
Microsoft Visual C++ 4.0 Standard Edition
Microsoft Visual C++ 4.1 Subscription
Microsoft Visual C++ 4.2 Enterprise Edition
Microsoft Visual C++ 4.2 Professional Edition
Microsoft Visual C++ 5.0 Enterprise Edition
Microsoft Visual C++ 5.0 Professional Edition
Microsoft Visual C++ 6.0 Enterprise Edition
Microsoft Visual C++ 6.0 Professional Edition
Microsoft Visual C++ 6.0 Standard Edition

This article was previously published under Q128600

SYMPTOMS

When an enumerated type is declared in class scope, if it is declared again at global scope, the compiler will not generate an error. However, once redefined, the result of using those enumerated types is unpredictable.

RESOLUTION

An enumerated type should be defined only once within any scope.

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

Sample Code to Demonstrate Problem

/* Compiler options needed: /c
*/ 

class Test
{
  public:
    enum status {a = 2, b};
};

enum Test::status {a = 4, b, c};     // Should be an error

REFERENCES

"The Annotated C++ Reference Manual" by Ellis and Stroustrup (Jan 1994), section 7.2

Additional query words: kbVC400bug 9.00 9.10 10.10 10.20

Keywords: kbbug kbcpponly kbcompiler KB128600