在 C++ 中从子类调用重载的父方法

Question

I'm trying to understand if is possible to call a parent's function member from a child class.

Basically I have the following code:

struct Parent
   {
   template<class... Args>
   void doFoo(Args&&... args)
     {
     std::cout << "parent doFoo";
     }

   template<class... Args>
   void foo(Args&&... args)
     {
     doFoo(args...);
     }
   };

 struct Child : Parent
   {
     template<class... Args>
     void doFoo(Args&&... args)
       {
       std::cout << "child doFoo";
       }
   };

   Child c;
   c.foo(); // This should invoke Child::doFoo()

Is there a simple way to obtain "child doFoo" as output without introducing overhead?

Answer 1

I don't know if it's an option but if you can afford to template the class instead of the method, you're allowed to make "doFoo" virtual and then it works as you expect.

#include <iostream>

template <typename ... Args>
struct Parent
   {
   virtual void doFoo(Args&&... args)
     {
     std::cout << "parent doFoo";
     }

   void foo(Args&&... args)
     {
     doFoo(args...);
     }
   };

template <typename ... Args>
 struct Child : Parent <Args...>
   {
     void doFoo(Args&&... args) override
       {
       std::cout << "child doFoo";
       }
   };

int main()
{
   Child<> c;
   c.foo(); // This should invoke Child::doFoo()
}