FIX: Exception Specification in Template causes C2961 Error

• The Microsoft C/C++ Compiler (CL.EXE) included with: - Microsoft Visual C++, 32-bit Edition, versions 2.0, 2.1, 2.2, 4.0, 4.1

SYMPTOMS

When you use an exception specification in a class or function template, the following error occurs:

   error C2961: syntax error : 'throw' : unexpected token in template
   declaration

RESOLUTION

Remove the exception specification from the function declaration and definition. By design, it is not supported.

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 use of exception specifications is not supported in this version of Microsoft C++. However, you would expect the compiler to generate the following warning instead of an error:

   warning C4290: C++ Exception Specification ignored

Sample Code to Generate Error C2961 and Demonstrate Problem

   /* Compile options needed: (none)
   */
   template <class T>
   class C1 {
   public:
        C1();
        void fn() throw();   // C2961 error - to work around, remove
        "throw()"
   };

   template <class T>
   void C1<T>::fn() throw()  // C2961 error - to work around, remove
   "throw()"
   {}

Sample Code to Generate Warning C4290 and Demonstrate Resolution

   /* Compile options needed: /W4
   */
   class C2 {
   public:
        C2();
        void fn() throw(); // compiler correctly generates C4290 warning
   };

   void C2::fn() throw()   // compiler correctly generates C4290 warning
   {}