DOCUMENT:Q163995  30-JUL-2001  [visualc]
TITLE   :FIX: C2989 Declaring Template Class in a Namespace
PRODUCT :Microsoft C Compiler
PROD/VER:4.2
OPER/SYS:
KEYWORDS:kbCompiler kbCPPonly kbLangCPP kbVC kbVC500fix kbHWx86

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The information in this article applies to:

 - The C/C++ Compiler (CL.EXE), included with:
    - Microsoft Visual C++, 32-bit Enterprise Edition, version 4.2 
    - Microsoft Visual C++, 32-bit Professional Edition, version 4.2 
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SYMPTOMS
========

A template class is defined inside a namespace that has the same name as a
non-template class declared at global scope. When you compile this construct,
the following error message appears:

   

   error C2989: '<classname>' : template class has already been defined as
   a non-template class

RESOLUTION
==========

There are 3 ways to work around this problem.

1. Change the name of one of the classes involved. If this is possible, it may
   be the best solution because having two different classes with the same name
   could lead to confusion.

2. Move the definition of the non-template class so that it appears after the
   definition of the template class. See sample code below.

3. Move the definition of the non-template class into a namespace (other than
   the one the template class is defined in).

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug was corrected in Visual C++ version 5.0.

MORE INFORMATION
================

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

    /* Compile options needed: none
    */ 
    class test {}; // Move this line below namespace tester for resolution #2.
    namespace tester {
        template <class T> class test {};
    }

Additional query words: C2989 template namespace

======================================================================
Keywords          : kbCompiler kbCPPonly kbLangCPP kbVC kbVC500fix kbHWx86 
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : 4.2
Issue type        : kbbug
Solution Type     : kbfix

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