Using cout in static object destructors

Given this shortened version of my code:

#include <iostream>

using namespace std;

struct S {
  S( ostream &os ) : os_( os ) { }
  ~S() { os_ << "The end.\n"; }         // line 7
  ostream &os_;
};

void f() {
  static S s( cout );
  (void)s;
}

int main() {
  f();
  return 0;
}

The program prints The end.however, as part of a larger program, it SEGFAULTS when trying to write to ostream.

I am trying to ensure that some text is always printed when the program ends. Am I trying to make legal use of iostreams? Would it be better to use atexit(3)?

I thought that since it coutwas built before my use, it will be destroyed after; therefore, it is not clear why code like the one above should always work.

Update

If I change line 7 to write directly to cout, and not through a link, it works fine. This is even weirder.