Dynamic function calling with C++

class.hpp

class Class
{
  public:
    int a (int a, short b)
    {
      return a + b;
    }
    
    int (Class::*PointerToA())(int, short)
    {
      return &Class::a;
    }
};

function.hpp

int function(int a, short b)
{
  return a + b;
}

main.cpp

#include <iostream>
#include "function.hpp"
#include "class.hpp"

int main(int argc, char** argv)
{
  int (*p2func) (int, short) = NULL;
  
  p2func = &function;
  
  Class* instance = new Class;
  
  std::cout << "p2func(5, 8);" << std::endl << p2func(5, 8) << std::endl;
  std::cout << "(instance->*(instance->PointerToA()))(5, 8);" << std::endl << (instance->*(instance->PointerToA()))(5, 8) << std::endl;
  
  delete instance;
  return 0;
}