Question

How can I have generic function pointer. Consider following class.

#ifndef PERSON_HPP_
#define PERSON_HPP_

#include <string>

class Person {
public:
  Person() {
  }
  void SetName(std::string person_name) {
    m_name = person_name;
  }
  void setDept(std::string dept_name) {
    m_dept = dept_name;
  }
  void setAge(int person_age ) {
    m_age = person_age;
  }
  std::string getName() {
    return m_name;
  }
  std::string getDept() {
    return m_dept;
  }
  int getAge() {
    return m_age;
  }
private:
  std::string m_name;
  std::string m_dept;
  int m_age;
};

#endif

I want to store the function pointers in a std::vector for setName, setDept , constructor and so on ...

For normal function I could achieve this using following

#include <vector>


int mult(int a) { 
  return 2*a; 
}

int main()
{
    int b;

    std::vector<void *(*)(void *)> v;
    v.push_back((void *(*)(void *))mult);
    b = ((int (*)(int)) v[0])(2);        // The value of b is 2.

    return 0;
}

No Boost allowed in my case.

Answer 1

If you really need to cast the member pointers to a common type (like void*), you can do:

template <typename T>
void* castToVoidStar(T x) {
  return *reinterpret_cast<void**>(&x);
}

void *afterCast = castToVoidStar(&Person::getName)

However, I do not believe it is wise to do so. C++ has type safety for a reason.