DOCUMENT:Q241940  03-MAY-2001  [visualc]
TITLE   :BUG: C2954 Error When Using Class Template as Template-Parameter
PRODUCT :Microsoft C Compiler
PROD/VER:winnt:5.0,6.0
OPER/SYS:
KEYWORDS:kbCompiler kbCPPonly kbLangCPP kbVC kbVC500 kbVC500bug kbVC600 kbVC600bug

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

 - The C/C++ Compiler (CL.EXE), included with:
    - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
    - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 
    - Microsoft Visual C++, 32-bit Enterprise Edition, version 6.0 
    - Microsoft Visual C++, 32-bit Professional Edition, version 6.0 
    - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

The following error message may appear if you try to use a class template as a
template-parameter:

   error C2954: template definitions cannot nest
   error C2951: template declarations are only permitted at global or namespace
   scope
   error C2226: syntax error : unexpected type 'C'
   error C2143: syntax error : missing '>' before '{'
   error C2059: syntax error : '<end Parse>'

CAUSE
=====

The compiler does not support template template-parameters as specified in the
C++ Standard.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

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

Steps to Reproduce Behavior
---------------------------

The following sample code demonstrates the error:

   //test.cpp
   // compiler option needed: none

   template<class T> class myarray { /* ... */ };
   template<class K, class V, template<class T> class C = myarray>
   class Map {
   	C<K> key;
   	C<V> value;
   	};

Additional query words:

======================================================================
Keywords          : kbCompiler kbCPPonly kbLangCPP kbVC kbVC500 kbVC500bug kbVC600 kbVC600bug 
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : winnt:5.0,6.0
Issue type        : kbbug

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

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 2001.