Question

Consider the following class template:

template <class T>
class MyClass
{
   void MyFunc();
};

template <class T>
void MyClass<T>::MyFunc()
{
  //...implementation goes here
}

I need to add another function template MyFunc2 which accepts a template argument T2
i.e.,

template <class T>
class MyClass
{
   void MyFunc();

   template <class T2>
   static void MyFunc2(T2* data);
};

template <class T>
void MyClass<T>::MyFunc()
{
  //...implementation goes here
}

template <class T, class T2>
void MyClass<T>::MyFunc2(T2* pData)  // error here
{
  //...implementation goes here
}

I am using VS 2008 compiler. I am getting the error:

error C2244: unable to match function definition to an existing declaration

What should the function’s definition and declaration look like in this case?

Answer 1

template <class T>
template <class T2> 
void MyClass<T>::MyFunc2(T2* pData) 
{ 
  //...implementation goes here 
}

$14.5.2/1 – "A template can be
declared within a class or class
template; such a template is called a
member template. A member template can
be defined within or outside its class
definition or class template
definition. A member template of a
class template that is defined outside
of its class template definition shall
be specified with the
template-parameters of the class
template followed by the
template-parameters of the member
template."