FIX: C1001 Error for typedef Within the Class Declaration (122300)

The information in this article applies to:

Microsoft Visual C++, 32-bit Editions 2.0
Microsoft Visual C++, 32-bit Editions 6.0

This article was previously published under Q122300

SYMPTOMS

Compiling the code that uses a class declaration with a typedef of itself, as demonstrated by the sample code in the More Information section, produces this error:

fatal error C1001: INTERNAL COMPILER ERROR
(compiler file 'msc1.cpp', line 1056)
Please choose the Technical Support command on the Visual C++ Help menu, or open the Technical Support help file for more information

RESOLUTION

Use a forward declaration for the class, and place the typedef line before the class declaration:

   class A;
   typedef A B;

Alternatively, enclose the returned typedef name in parentheses to indicate that the constructor is used to return the value (see AltRetB in the sample code).

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 Microsoft Visual C++, 32-bit Edition, version 4.0.

MORE INFORMATION

Sample Code

/* Compile options needed: none
*/ 

class A
{
   typedef A B;

   B RetB() { return B(*this); }      // this causes the error

   B AltRetB() { return (B)(*this); } // this line is OK
};

Modification Type:	Major	Last Reviewed:	10/24/2003
Keywords:	kbbug kbCompiler kbCPPonly kbfix KB122300