Iterators library

Header <experimental/iterator> synopsis

#include <iterator>

namespace std::experimental::inline fundamentals_v3 {

  
  template <class DelimT, class charT = char, class traits = char_traits<charT>>
      class ostream_joiner;
  template <class charT, class traits, class DelimT>
    ostream_joiner<decay_t<DelimT>, charT, traits>
    make_ostream_joiner(basic_ostream<charT, traits>& os, DelimT&& delimiter);

} // namespace std::experimental::inline fundamentals_v3

Class template ostream_joiner

Overview

ostream_joiner writes (using operator<<) successive elements onto the output stream from which it was constructed. The delimiter that it was constructed with is written to the stream between every two Ts that are written. It is not possible to get a value out of the output iterator. Its only use is as an output iterator in situations like 

while (first != last)
  *result++ = *first++;

ostream_joiner is defined as 

namespace std::experimental::inline fundamentals_v3 {

  template <class DelimT, class charT = char, class traits = char_traits<charT>>
  class ostream_joiner {
  public:
    using char_type = charT;
    using traits_type = traits;
    using ostream_type = basic_ostream<charT, traits>;
    using iterator_category = output_iterator_tag;
    using value_type = void;
    using difference_type = void;
    using pointer = void;
    using reference = void;

    ostream_joiner(ostream_type& s, const DelimT& delimiter);
    ostream_joiner(ostream_type& s, DelimT&& delimiter);
    template<typename T>
    ostream_joiner& operator=(const T& value);
    ostream_joiner& operator*() noexcept;
    ostream_joiner& operator++() noexcept;
    ostream_joiner& operator++(int) noexcept;

  private:
    ostream_type* out_stream; // exposition only
    DelimT delim;             // exposition only
    bool first_element;       // exposition only
  };

} // namespace std::experimental::inline fundamentals_v3

Constructor

ostream_joiner(ostream_type& s, const DelimT& delimiter); Initializes out_stream with std::addressof(s), delim with delimiter, and first_element with true. ostream_joiner(ostream_type& s, DelimT&& delimiter); Initializes out_stream with std::addressof(s), delim with move(delimiter), and first_element with true.

Operations

template<typename T> ostream_joiner& operator=(const T& value); 
if (!first_element)
  *out_stream << delim;
first_element = false;
*out_stream << value;
return *this;
 ostream_joiner& operator*() noexcept; *this. ostream_joiner& operator++() noexcept; ostream_joiner& operator++(int) noexcept; *this.

Creation function

template <class charT, class traits, class DelimT> ostream_joiner<decay_t<DelimT>, charT, traits> make_ostream_joiner(basic_ostream<charT, traits>& os, DelimT&& delimiter); ostream_joiner<decay_t<DelimT>, charT, traits>(os, forward<DelimT>(delimiter));