Question

I’ve encountered a problem(error C2761) while writing specializations for a class. My classes are as follows:

class Print{
public:
    typedef class fontA;
    typedef class fontB;
    typedef class fontC;
    typedef class fontD;

    template<class T>
    void startPrint(void) { return; };
    virtual bool isValidDoc(void) = 0;
};

I have a class QuickPrint which inherits the Print class:

class QuickPrint : public Print {
       ...
};

The error occurs when I try to write specializations for the startPrint method:

template<>        // <= C2716 error given here
void QuickPrint::startPrint<fontA>(void)
{
      /// implementation
}

template<>        // <= C2716 error given here
void QuickPrint::startPrint<fontB>(void)
{
     /// implementation
}

The error appears for the remaining specializations as well.

Answer 1

QuickPrint does not have a template member function named startPrint, so specializing QuickPrint::startPrint is an error. If you repeat the template definition in QuickPrint the specializations are okay:

class QuickPrint : public Print {
   template<class T>
    void startPrint(void) { return; };
 };

template<>        // <= C2716 error given here
void QuickPrint::startPrint<Print::fontA>(void)
{
      /// implementation
}

But if the goal here is to be able to call into QuickPrint polymorphically, you’re in trouble, because the template function in Print can’t be marked virtual.