成员函数指针和模板的继承

Question

I have two classes:

class A {
   public:
      bool funA();
};
class B : public A {
   pubic:
      bool funB();
};

and a templated function that takes a function pointer and then calls it against a list of B's:

template <typename T>
std::vector<T> getFunc(T (B::func*)()) {
 ....iterator through list of B's calling func....
}

If I try to call getFunc(B::funA) I get a compile error that "no getFunc(A::funA) exists..."

I can solve the problem by simply creating a second getFunc that takes A::func* instead of B::, but now I have two functions doing the exact same thing. Is there a way for me to only end up with one implementation of getFunc ?

EDIT: I need a pre C++11 solution.

Answer 1

Simply deduce the entire parameter and extract its return type:

template<class F,class R=std::result_of_t<F(B&)>>
std::vector<R> getFunc(F&&){return{};}

std::result_of_t is C++14, for a C++11 compatible solution, use typename std::result_of<F(B&)>::type .

For a C++03 solution, simply deduce the class type:

template <typename T, typename C>
std::vector<T> getFunc(T (C::*func)());

Answer 2

&B::funA has type bool (A::*)() , not bool (B::*)() . You will need to perform a static_cast : static_cast<bool (B::*)()>(&B::funA) .