Re: more auto_ptr confusion

After reading all I could find about auto_ptr, I decided to write a
little program to test my comprehension:

#include <iostream>
#include <memory>

class A {
public:
  void say_hi() {
    std::cout << "hi!" << std::endl;
  }
  void say_ih() {
    std::cout << "!ih" << std::endl;
  }
};

void f(std::auto_ptr<A> fs_pa) {
  fs_pa->say_hi();
}

int main() {
  std::auto_ptr<A> pa(new A);
  pa->say_ih();
  f(pa);
  pa->say_ih();
}

This is what I expected would happen:
1. a new A is created, and its ownership is assumed by pa.

2. the say_ih() function is called with no problems

3. when f() is called, pa is copied into fs_pa, thereby transfering
ownership of the A object to fs_pa, and leaving pa with a null pointer

4. the A object's say_hi() function is called through fs_pa

5. fs_pa goes out of scope, and therefore runs its deconstructor,
which calls 'delete' on the chunk of memory which holds the A object

6. when we return to main(), pa now holds a null pointer, and
"pa->say_ih();" should cause a runtime error.