FIX: You receive a C2004 error message when you initiate a class template that uses a function pointer as a template parameter in Visual C++ 6.0

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Article ID: 216722 - View products that this article applies to.
This article was previously published under Q216722
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When initiating a class template that uses a function pointer as a template parameter, you may receive the following error message:
error C2440: ''specialization'' : cannot convert from 'function prototype' to ''int (__cdecl *)( *)''


Microsoft has confirmed that this is a bug in the Microsoft products that are listed in the "Applies to" section. This bug was corrected in Visual Studio 6.0 Service Pack 3.

For more information about Visual Studio service packs, click the following article numbers to view the articles in the Microsoft Knowledge Base:
194022 Visual Studio 6.0 service packs, what, where, why
194295 How to tell that a Visual Studio service pack is installed


Steps to reproduce the behavior

Use the following sample code to recreate the error message.
template < class T, int (*pfn)(T *)>
class F
	int Test( T *pb ) {
    	return (*pfn)(	pb );

int Bar( int *pb ) {
	return *pb;

F<int,&Bar> f;


Article ID: 216722 - Last Review: February 21, 2014 - Revision: 3.0
  • Microsoft Visual C++ 6.0 Enterprise Edition
  • Microsoft Visual C++ 6.0 Professional Edition
  • Microsoft Visual C++, 32-bit Learning Edition 6.0
kbnosurvey kbarchive kbbug kbfix kbvc600fix kbcpponly kbcompiler kbvs600sp3fix KB216722

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