23 Iterators library [iterators]

23.5 Iterator adaptors [predef.iterators]

23.5.3 Move iterators and sentinels [move.iterators]

23.5.3.2 Class template move_­iterator [move.iterator]

namespace std { template<class Iterator> class move_iterator { public: using iterator_type = Iterator; using iterator_concept = input_iterator_tag; using iterator_category = see below; // not always present using value_type = iter_value_t<Iterator>; using difference_type = iter_difference_t<Iterator>; using pointer = Iterator; using reference = iter_rvalue_reference_t<Iterator>; constexpr move_iterator(); constexpr explicit move_iterator(Iterator i); template<class U> constexpr move_iterator(const move_iterator<U>& u); template<class U> constexpr move_iterator& operator=(const move_iterator<U>& u); constexpr const Iterator& base() const & noexcept; constexpr Iterator base() &&; constexpr reference operator*() const; constexpr move_iterator& operator++(); constexpr auto operator++(int); constexpr move_iterator& operator--(); constexpr move_iterator operator--(int); constexpr move_iterator operator+(difference_type n) const; constexpr move_iterator& operator+=(difference_type n); constexpr move_iterator operator-(difference_type n) const; constexpr move_iterator& operator-=(difference_type n); constexpr reference operator[](difference_type n) const; template<sentinel_­for<Iterator> S> friend constexpr bool operator==(const move_iterator& x, const move_sentinel<S>& y); template<sized_­sentinel_­for<Iterator> S> friend constexpr iter_difference_t<Iterator> operator-(const move_sentinel<S>& x, const move_iterator& y); template<sized_­sentinel_­for<Iterator> S> friend constexpr iter_difference_t<Iterator> operator-(const move_iterator& x, const move_sentinel<S>& y); friend constexpr iter_rvalue_reference_t<Iterator> iter_move(const move_iterator& i) noexcept(noexcept(ranges::iter_move(i.current))); template<indirectly_­swappable<Iterator> Iterator2> friend constexpr void iter_swap(const move_iterator& x, const move_iterator<Iterator2>& y) noexcept(noexcept(ranges::iter_swap(x.current, y.current))); private: Iterator current; // exposition only }; }
The member typedef-name iterator_­category is defined if and only if the qualified-id iterator_­traits<Iterator>​::​iterator_­category is valid and denotes a type.
In that case, iterator_­category denotes
  • random_­access_­iterator_­tag if the type iterator_­traits<​Iterator>​::​iterator_­category models derived_­from<random_­access_­iterator_­tag>, and
  • iterator_­traits<​Iterator>​::​iterator_­category otherwise.