#include <iostream>

struct Foo
{
  int a;
  int b;
  int c;
  double d;
  double e;
  int calc() { return static_cast<int>(d);}
};

int main() 
{ 
  Foo bar;

  // declare a double pointer to member of class Foo
  // initialize the variable to Foo's d
  double Foo::* p_member = &Foo::d;

  // declare a pointer to member function of class Foo that returns int and takes no arguments
  // initialize the variable to Foo's calc function
  int (Foo::* p_member_func)() = &Foo::calc;

  // assign a value to bar's member, pointed to by p_member
  bar.*p_member = 3.14;

  // call a member function on bar, member function is in the pointer to member function variable p_member_func
  std::cout << (bar.*p_member_func)() << std::endl;

  return 0;
}