std::ostreambuf_iterator

template <class charT=char, class traits=char_traits<charT> >
  class ostreambuf_iterator :
    public iterator<output_iterator_tag, charT,
                    typename traits::off_type, charT*, charT&>
{
public:
  typedef charT char_type;
  typedef traits traits_type;
  typedef typename traits::int_type int_type;
  typedef basic_streambuf<charT,traits> streambuf_type;
  typedef basic_ostream<charT,traits> ostream_type;
  ostreambuf_iterator(ostream_type& s) throw(): sbuf_(s.rdbuf()) { }
  ostreambuf_iterator(streambuf_type* s) throw(): sbuf_(s) { }
  ostreambuf_iterator& operator= (charT c)
  { if (!failed()) last=sbuf_->sputc(c); return *this; }
  ostreambuf_iterator& operator*() { return *this; }
  ostreambuf_iterator& operator++() { return *this; }
  ostreambuf_iterator& operator++(int) { return *this;}
  bool failed() const throw() { return last==traits::eof(); }
private:
  streambuf_type* sbuf_;
  charT last;
  
};