constexpr reverse_iterator();
Effects: Value-initializes
current. constexpr explicit reverse_iterator(Iterator x);
Effects: Initializes
current
with
x. template<class U> constexpr reverse_iterator(const reverse_iterator<U>& u);
Constraints:
is_same_v<U, Iterator> is
false and
const U& models
convertible_to<Iterator>. Effects: Initializes
current
with
u.current. template<class U>
constexpr reverse_iterator&
operator=(const reverse_iterator<U>& u);