c++ pass child class method to base class method in argument

Question

I have a base class which has a method that takes a method pointer (class function pointer) as an argument. I derive a child class from this base class. I then want to pass a method of the child class to the method of the base class.

An example:

    class Base1
    {
        public:
             void BaseMethod(void (Base1::*basemth)(/*arguments list A*/), 
                             double a)){/*definition*/}
    };
    class Derived1 : public Base1
    {
        public: 
             void ChildMethod(/*arguments list A*/)

             void ChildMethod2()
             {
                double double_a = 1.0;
                void (Derived1::*pntr)(/*arguments list A*/);
                pntr = &Derived1::ChildMethod;
                BaseMethod(pntr, double_a); //<---- this fails
             }

    };

I get "error: no matching function for call to...".

Is this possible? If it is, what am I doing wrong? Any help will be appreciated. I have looked at child class method pointer to method parent argument c++ but following R Sahu's method does not seem to work, while Slava's answer does not seem relevant (I am not calling a child method from a parent instance).

Answer 1

Is this possible?

It is possible and should work ok if you use a virtual member function. If you use a non-virtual member function, it won't work.

Example program:

#include <iostream>

class Base1
{
   public:

      void BaseMethod(void (Base1::*basemth)(), double a)
      {
         (this->*basemth)();
      }

      virtual void Method2() = 0;

};

class Derived1 : public Base1
{
   public: 

      void Method2()
      {
         std::cout << "In Derived1::Method2()\n";
      }

      void ChildMethod2()
      {
         double double_a = 1.0;
         BaseMethod(&Base1::Method2, double_a);
      }

};

int main()
{
   Derived1 d;
   d.ChildMethod2();
}

Output:

In Derived1::Method2()