class member function pointer

main.cpp

#include <iostream>
#include <functional>
using namespace std;

struct Foo
{
  Foo (int num):num_ (num)
  {
  }
  void print_add (int i) const
  {
    std::cout << num_ + i << '\n';
  }
  int num_;
};

template < typename T, typename F > void
bar (T obj, F f, int i)
{
  (obj.*f) (i);
}

int
main ()
{
  const Foo foo (314159);
  std::function < int (Foo const &) > f_num = &Foo::num_;
  std::cout << "num_: " << f_num (foo) << '\n';

  bar (foo, &Foo::print_add, 10);


  foo.Foo::print_add (20);
  cout << "Hello World";

  return 0;
}