DOCUMENT:Q122300  24-JUN-2002  [visualc]
TITLE   :FIX: C1001 Error for typedef Within the Class Declaration
PRODUCT :Microsoft C Compiler
PROD/VER::2.0,6.0
OPER/SYS:
KEYWORDS:kbCompiler kbCPPonly kbVCkbbuglist kbfixlist

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

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

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 query words: 2.00 9.00 buglist2.00

======================================================================
Keywords          : kbCompiler kbCPPonly kbVC kbbuglist kbfixlist
Technology        : kbVCsearch kbAudDeveloper kbVC600 kbVC200 kbVC32bitSearch
Version           : :2.0,6.0
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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