FIX: C1001 Error for typedef Within the Class Declaration

 Last reviewed: September 18, 1997
Article ID: Q122300
2.00 WINDOWS NT kbtool kbfixlist

The information in this article applies to:

  • The Microsoft C/C++ Compiler (CL.EXE), included with Microsoft Visual C++, 32-bit Edition, version 2.0

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
};

Additional reference words: 2.00 9.00 buglist2.00
KBCategory: kbtool kbfixlist kbbuglist
KBSubcategory: CPPIss
Keywords : CPPIss kbbuglist kbfixlist kbtool
Version : 2.00
Platform : NT WINDOWS
Solution Type : kbfix

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Last reviewed: September 18, 1997
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