ostreambuf_iterator(ostream_type& s) noexcept;
ostreambuf_iterator(streambuf_type* s) noexcept;
ostreambuf_iterator& operator=(charT c);
ostreambuf_iterator& operator*();
ostreambuf_iterator& operator++();
ostreambuf_iterator& operator++(int);
bool failed() const noexcept;