template<class Iterator1, class Iterator2>
constexpr bool operator==(const move_iterator<Iterator1>& x,
const move_iterator<Iterator2>& y);
template<sentinel_for<Iterator> S>
friend constexpr bool operator==(const move_iterator& x,
const move_sentinel<S>& y);
template<class Iterator1, class Iterator2>
constexpr bool operator<(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template<class Iterator1, class Iterator2>
constexpr bool operator>(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template<class Iterator1, class Iterator2>
constexpr bool operator<=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template<class Iterator1, class Iterator2>
constexpr bool operator>=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);