23 Iterators library [iterators]

23.6 Stream iterators [stream.iterators]

23.6.3 Class template ostream_­iterator [ostream.iterator]

23.6.3.1 General [ostream.iterator.general]

ostream_­iterator writes (using operator<<) successive elements onto the output stream from which it was constructed.
If it was constructed with charT* as a constructor argument, this string, called a delimiter string, is written to the stream after every T is written.
namespace std { template<class T, class charT = char, class traits = char_traits<charT>> class ostream_iterator { public: using iterator_category = output_iterator_tag; using value_type = void; using difference_type = ptrdiff_t; using pointer = void; using reference = void; using char_type = charT; using traits_type = traits; using ostream_type = basic_ostream<charT,traits>; ostream_iterator(ostream_type& s); ostream_iterator(ostream_type& s, const charT* delimiter); ostream_iterator(const ostream_iterator& x); ~ostream_iterator(); ostream_iterator& operator=(const ostream_iterator&) = default; ostream_iterator& operator=(const T& value); ostream_iterator& operator*(); ostream_iterator& operator++(); ostream_iterator& operator++(int); private: basic_ostream<charT,traits>* out_stream; // exposition only const charT* delim; // exposition only }; }

23.6.3.2 Constructors and destructor [ostream.iterator.cons.des]

ostream_iterator(ostream_type& s);
Effects: Initializes out_­stream with addressof(s) and delim with nullptr.
ostream_iterator(ostream_type& s, const charT* delimiter);
Effects: Initializes out_­stream with addressof(s) and delim with delimiter.

23.6.3.3 Operations [ostream.iterator.ops]

ostream_iterator& operator=(const T& value);
Effects: As if by: *out_stream << value; if (delim) *out_stream << delim; return *this;
ostream_iterator& operator*();
Returns: *this.
ostream_iterator& operator++(); ostream_iterator& operator++(int);
Returns: *this.