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Q241940: BUG: C2954 Error When Using Class Template as Template-Parameter

Article: Q241940
Product(s): Microsoft C Compiler
Version(s): winnt:5.0,6.0
Operating System(s): 
Keyword(s): kbCompiler kbCPPonly kbLangCPP kbVC kbVC500 kbVC500bug kbVC600 kbVC600bug
Last Modified: 03-MAY-2001

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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 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 
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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

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