33 struct cpp20_iterator {  struct
42     cpp20_iterator() = default;  argument
43     explicit cpp20_iterator(T* ptr) : my_ptr(ptr) {}  in cpp20_iterator()  argument
47     cpp20_iterator& operator++() {  in operator ++()  argument
52     cpp20_iterator operator++(int) {  in operator ++()  argument
58     cpp20_iterator& operator--()  in operator --()  argument
65     cpp20_iterator operator--(int)  in operator --()  argument
73     cpp20_iterator& operator+=(difference_type n)  in operator +=()  argument
80     cpp20_iterator& operator-=(difference_type n)  in operator -=()  argument
93     friend bool operator==(const cpp20_iterator&, const cpp20_iterator&) = default;  argument
95     friend auto operator<=>(const cpp20_iterator&, const cpp20_iterator&)
98     friend cpp20_iterator operator+(cpp20_iterator i, difference_type n)  in operator +()
101         return cpp20_iterator(i.my_ptr + n);  in operator +()
104     friend cpp20_iterator operator+(difference_type n, cpp20_iterator i)  in operator +()
110     friend cpp20_iterator operator-(cpp20_iterator i, difference_type n)  in operator -()
113         return cpp20_iterator(i.my_ptr - n);  in operator -()
116     friend difference_type operator-(const cpp20_iterator& x, const cpp20_iterator& y) {  in operator -()
295     cpp20_iterator<no_copy_move, Category> begin(elements.data());  in test_with_cpp20_iterator()
296     cpp20_iterator<no_copy_move, Category> end(elements.data() + n);  in test_with_cpp20_iterator()
318     using cpp20_forward_iterator = cpp20_iterator<int, std::forward_iterator_tag>;
319     using cpp20_bidirectional_iterator = cpp20_iterator<int, std::bidirectional_iterator_tag>;
320     using cpp20_random_access_iterator = cpp20_iterator<int, std::random_access_iterator_tag>;