FIX: Classview Cannot Find Template Member Function Definition

• Microsoft Visual C++, 32-bit Edition, versions 4.0, 4.1, 4.2

SYMPTOMS

Classview pops up the message "Cannot find the definition for this function" for some member functions of a template class. This happens for those member functions that return a template class, or a reference or pointer to a template class. The function must also be defined outside of the class. The sample code in the More Information section below demonstrates this problem.

RESOLUTION

The only workaround is to define the function inline by moving its body inside the class declaration. Note that defining the function outside the class declaration with the inline keyword will not solve the problem. Also note that projects with this problem will still build and run correctly; only the convenience of finding a function's definition via the class view is lost.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug was corrected in Visual C++ version 5.0.

MORE INFORMATION

The following sample code will reproduce the problem. To reproduce, right click on "mult_by_scalar" while in the class view and select Go To Definition.

Sample Code

   /* Compile options needed:none
   */

   template<class T>
   class SimpleArray {

   public:

       SimpleArray();
       ~SimpleArray();

       SimpleArray<T>& mult_by_scalar(T);// Cannot find the definition

       int Numelem();

   private:
       int num_elts;
       T* ptr_to_data;

   };

   template <class T>
   SimpleArray<T>::SimpleArray() {
       num_elts=0;
       ptr_to_data = 0;
   }

   template <class T>
   SimpleArray<T>::~SimpleArray() {
       delete [] ptr_to_data;
   }

   template <class T>
   SimpleArray<T>& SimpleArray<T>::mult_by_scalar(T rm) {

        return *this;
   }

   template <class T>
   int SimpleArray<T>::Numelem(){

       return  num_elts;
   }