C++ code - 11 lines

Link:

C++, pasted on Feb 2:

struct Example {
private:
  struct iterator {};
public:
  iterator begin();
};

int main() {
  Example e;
  Example::iterator x = e.begin();
}

Output:

1
2
3

In function 'int main()':
Line 3: error: 'struct Example::iterator' is private
compilation terminated due to -Wfatal-errors.