Q150885: FIX: C2321 Expanding Template with a Pointer to a Nested Class

Article: Q150885
Product(s): Microsoft C Compiler
Version(s): winnt:4.0,4.1,4.2,5.0
Operating System(s): 
Keyword(s): kbnokeyword kbVC400bug kbVC410bug kbVC420bug kbVC500bug kbVC600fix
Last Modified: 30-JUL-2001

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The information in this article applies to:

- The C/C++ Compiler (CL.EXE), used with:
   - Microsoft Visual C++, 32-bit Editions, versions 4.0, 4.1 
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 4.2 
   - Microsoft Visual C++, 32-bit Professional Edition, version 4.2 
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
   - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 
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SYMPTOMS
========

At the point where a class template is expanded using the new operator to a
nested class, the compiler reports the following errors:

  [FileName](10) : error C2321: syntax error : unexpected 'A::B'

  [FileName](27) : fatal error C1004: unexpected end of file found

STATUS
======

This bug was corrected in Microsoft Visual C++, version 6.0.

RESOLUTION
==========

There are two possible workarounds to this problem. Each is stated in terms of
the sample code below:

- Remove t(new T()) from the initializer list and add t = new T(); to the body
  of the constructor. This workaround assumes class T is not a reference or a
  constant pointer.

- Change the definitions of class A and class B so that B is no longer nested
  in the definition of A.

Sample Code
-----------

  /* Compile options needed: None */ 
  template <class T> class C
  {
  public:
     C();
  private:
     T *t;
  };

  template <class T> C<T>::C() : t(new T())  // error
  {
  }

  lass A
  {
  public:

     class B
     {
     };

  };

  main()
  {

     C<A::B> c;
     return 0;

  }

Additional query words:

======================================================================
Keywords          : kbnokeyword kbVC400bug kbVC410bug kbVC420bug kbVC500bug kbVC600fix 
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : winnt:4.0,4.1,4.2,5.0
Issue type        : kbbug
Solution Type     : kbfix

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