23 Iterators library [iterators]

23.5 Iterator adaptors [predef.iterators]

23.5.2 Insert iterators [insert.iterators]

23.5.2.3 Class template insert_­iterator [insert.iterator]

namespace std {
  template<class Container>
  class insert_iterator {
  protected:
    Container* container = nullptr;
    iterator_t<Container> iter = iterator_t<Container>();

  public:
    using iterator_category = output_iterator_tag;
    using value_type        = void;
    using difference_type   = ptrdiff_t;
    using pointer           = void;
    using reference         = void;
    using container_type    = Container;

    insert_iterator() = default;
    constexpr insert_iterator(Container& x, iterator_t<Container> i);
    constexpr insert_iterator& operator=(const typename Container::value_type& value);
    constexpr insert_iterator& operator=(typename Container::value_type&& value);

    constexpr insert_iterator& operator*();
    constexpr insert_iterator& operator++();
    constexpr insert_iterator& operator++(int);
  };
}

23.5.2.3.1 Operations [insert.iter.ops]

constexpr insert_iterator(Container& x, iterator_t<Container> i);
Effects: Initializes container with addressof(x) and iter with i.
constexpr insert_iterator& operator=(const typename Container::value_type& value);
Effects: As if by:
iter = container->insert(iter, value);
++iter;
Returns: *this.
constexpr insert_iterator& operator=(typename Container::value_type&& value);
Effects: As if by:
iter = container->insert(iter, std::move(value));
++iter;
Returns: *this.
constexpr insert_iterator& operator*();
Returns: *this.
constexpr insert_iterator& operator++(); constexpr insert_iterator& operator++(int);
Returns: *this.

23.5.2.3.2 inserter [inserter]

template<class Container> constexpr insert_iterator<Container> inserter(Container& x, iterator_t<Container> i);
Returns: insert_­iterator<Container>(x, i).