How to store methods as function pointers in a map container?

Question

I want to be able to call functions based on the data I read from file. So for each item type, I want to call the desired reader method. I wrote this code, but it does not compile where I want to add function pointers to the map. What is wrong?

#include <vector>
#include <map>
#include <iostream>
class reader
{

  std::map< std::string, void(*)()> functionCallMap; // function pointer
  void readA(){ std::cout << "reading A\n";};
  void readB(){ std::cout << "reading B\n";};;
public:
  reader()
  {
    *functionCallMap["A"] = &reader::readA;*
    *functionCallMap["B"] = &reader::readB;*
  }

  void read()
  {
   auto (*f) = functionCallMap["A"];
   (*f)();
  }



};

I am filling the map at Constructor.

Answer 1

You can use std::function with a lambda or std::bind :

class reader
{
    std::map<std::string, std::function<void()>> functionCallMap;

    void readA() { std::cout << "reading A\n"; };
    void readB() { std::cout << "reading B\n"; };

public:
    reader()
    {
        functionCallMap["A"] = [this]() { readA(); };
        functionCallMap["B"] = std::bind(&reader::readB, this);
    }

    void read()
    {
        functionCallMap["A"]();
        functionCallMap["B"]();
    }
};