Output Iterators
- Specialized write_only forward iterator:
// no comparison logic
// write-only element access (lvalue only)
value_type& operator * (); // dereference operator
// motion
Iterator& operator ++ (); // prefix increment
Iterator& operator ++ (int); // postfix increment
// proper type
Iterator () // constructor
~Iterator () // destructor
Iterator (const Iterator& ); // copy constructor
// no assignment operator