73     cpp20_iterator& operator+=(difference_type n)  in operator +=()
76         my_ptr += n;  in operator +=()
80     cpp20_iterator& operator-=(difference_type n)  in operator -=()
83         my_ptr -= n;  in operator -=()
87     T& operator[](difference_type n) const  in operator []()
90         return my_ptr[n];  in operator []()
98     friend cpp20_iterator operator+(cpp20_iterator i, difference_type n)  in operator +()  argument
101         return cpp20_iterator(i.my_ptr + n);  in operator +()
104     friend cpp20_iterator operator+(difference_type n, cpp20_iterator i)  in operator +()  argument
107         return i + n;  in operator +()
110     friend cpp20_iterator operator-(cpp20_iterator i, difference_type n)  in operator -()  argument
113         return cpp20_iterator(i.my_ptr - n);  in operator -()
291     constexpr std::size_t n = 1'000'000;  in test_with_cpp20_iterator()  local
293     std::vector<no_copy_move> elements(n);  in test_with_cpp20_iterator()
296     cpp20_iterator<no_copy_move, Category> end(elements.data() + n);  in test_with_cpp20_iterator()
302     for (std::size_t index = 0; index < n; ++index) {  in test_with_cpp20_iterator()