BUG: C2065: Undeclared Identifier Creating a STL Function Object

• Microsoft Visual C++, 32-bit Edition, version 5.0

SYMPTOMS

Creating the STL function object “binder2nd” causes the compiler to generate the following error C2065:

   'identifier' : undeclared identifier

RESOLUTION

One of the following methods can be used to work around this problem:

• Use the 'using namespace' directive instead of qualifying the function objects.

  -or-

• Pre-declaring an instance of std::multiplies<int> solves the problem.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft product listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The following sample demonstrates the problem and the first workaround.

Sample Code

   /*
   * Compiler Options: /GX
   */

   #include <algorithm>
   #include <functional>
   #include <iostream>

   #define BUG
   //Workaround: Comment the line above.
   //Uncomment the line below.
   //#define WORKAROUND

   #ifdef WORKAROUND
   using namespace std ;
   #endif

   int main()
   {

   #ifdef BUG
      std::binder2nd< std::multiplies<int> >
                     times_two(std::multiplies<int>(), 2);
   #endif

   #ifdef WORKAROUND
       binder2nd< multiplies<int> > times_two(multiplies<int>(), 2);
   #endif

      int n = times_two(4) ;
      std::cout << "n = " << n << std::endl ;
      return 0 ;
   }

Sample Code

   /*
   * Compiler Options: /GX
   */

   #include <algorithm>
   #include <functional>
   #include <iostream>

   #define BUG
   //Workaround: Comment the line above.
   //Uncomment the line below.
   //#define WORKAROUND

   int main()
   {

   #ifdef BUG
      std::binder2nd< std::multiplies<int> >
                     times_two(std::multiplies<int>(), 2);
   #endif

   #ifdef WORKAROUND
      std::multiplies<int> mi ;
      std::binder2nd< std::multiplies<int> > times_two(mi, 2);
   #endif

      int n = times_two(4) ;
      std::cout << "n = " << n << std::endl ;
      return 0 ;
   }

REFERENCES

Please see the following help topics in the Microsoft Visual C++ online documentation for more information on ”binder2nd”:

   TITLE: binder2nd
   URL:   mk:@ivt:vclang/STDLIBBLD/FUNCTIO2_BINDER2ND.HTM

   TITLE: Visual C++ 4.2 Standard Template Library Tutorial
   URL:   mk:@ivt:tatech/F1/DB/S4249.HTM#sec58

Keywords          : CPPIss CPPLngIss STLIss vcbuglist500 kbbuglist
Version           : WINNT:5.0
Platform          : winnt
Issue type        : kbbug
Solution Type     : kbfix