DOCUMENT:Q165803  04-MAY-2001  [visualc]
TITLE   :FIX: Error C2783 - Cannot Deduce Non-Type Template Parameter
PRODUCT :Microsoft C Compiler
PROD/VER:winnt:5.0
OPER/SYS:
KEYWORDS:kbVC500bug kbVC600fix kbVS600sp2kbbuglist

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

 - The C/C++ Compiler (CL.EXE), used with:
    - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
    - Microsoft Visual C++, 32-bit Professional Edition, version 5.0 
    - Microsoft Visual Studio 6.0, SP2 
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SYMPTOMS
========

The sample code in the MORE INFORMATION section causes the compiler error
C2783:

   'declaration' : could not deduce template argument for 'identifier'

RESOLUTION
==========

The workaround is to avoid argument deduction by specifying the
template-parameter-list when calling the function template.

STATUS
======

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

This problem was corrected in Microsoft Visual C++ version 6.0.

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

The following sample code demonstrates the problem and the workaround:

SAMPLE
------

         /* Compile options needed: none
         */ 

         template <int I>
         struct C
         {
             int a[I] ;
         };

         template <int I>
         int F(C<I> a)
         {
             return I ;
         }

         int main ()
         {
             int i;
             C<4>  CObj ;

             i  = F(CObj);

             // Workaround: Comment the line above.
             // Uncomment the following line
             // i = F<4>(CObj);

             return 0 ;
         }

Additional query words:

======================================================================
Keywords          : kbVC500bug kbVC600fix kbVS600sp2 kbbuglist
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : winnt:5.0
Issue type        : kbbug
Solution Type     : kbfix

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

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Copyright Microsoft Corporation 2001.