Создание меню с использованием указателей на метод класса

void file::menu ()
{
    file F;
    F.initialisation(F.FILE_S,1024,300);
    char *labels [] = {"1. New blocks.", "2. Free blocks.", "3. Write.", "4. Read.", "5. Start transaction.", "6. Commit.", "7. Rollback.", "8. Information.", "9. Exit"};
    typedef void (file::*f_ptr)();
    int len = sizeof(labels)/sizeof(labels[0]), position;
    f_ptr interface [] = {&file::new_blocks_menu,&file::free_blocks_menu,&file::write_menu,&file::read_menu,&file::start_transaction_menu,&file::commit_menu,&file::rollback_menu,&file::get_infomation,&file::exit_menu};
 
    while (1)
    {
        for (int i = 0; i < len; i++)
            cout<<labels[i]<<endl;
        cout<<"Enter number of action - ";
        cin>>position;
        if (position < 1 || position > len)
        {
            cout<<"Wrong value."<<endl;
        }
        else
            F.*(interface[position-1])();
    }
}

#include <iostream>
 
class Class
{
public:
  void f1() { std::cout << "f1" << std::endl; }
  void f2() { std::cout << "f2" << std::endl; }
};
 
int main()
{
  typedef void (Class::*MethodPtr)();
  MethodPtr methods[] = {&Class::f1, &Class::f2};
 
  Class c;
  (c.*methods[0])();
  (c.*methods[1])();
 
  return 0;
}