In addition to being available via inclusion of the <iterator> header, the function templates in [iterator.range] are available when any of the following headers are included: <array>, <deque>, <forward_list>, <list>, <map>, <regex>, <set>, <string>, <string_view>, <unordered_map>, <unordered_set>, and <vector>.
template <class C> constexpr auto begin(C& c) -> decltype(c.begin());
template <class C> constexpr auto begin(const C& c) -> decltype(c.begin());
template <class C> constexpr auto end(C& c) -> decltype(c.end());
template <class C> constexpr auto end(const C& c) -> decltype(c.end());
template <class T, size_t N> constexpr T* begin(T (&array)[N]) noexcept;
template <class T, size_t N> constexpr T* end(T (&array)[N]) noexcept;
template <class C> constexpr auto cbegin(const C& c) noexcept(noexcept(std::begin(c)))
-> decltype(std::begin(c));
template <class C> constexpr auto cend(const C& c) noexcept(noexcept(std::end(c)))
-> decltype(std::end(c));
template <class C> constexpr auto rbegin(C& c) -> decltype(c.rbegin());
template <class C> constexpr auto rbegin(const C& c) -> decltype(c.rbegin());
template <class C> constexpr auto rend(C& c) -> decltype(c.rend());
template <class C> constexpr auto rend(const C& c) -> decltype(c.rend());
template <class T, size_t N> constexpr reverse_iterator<T*> rbegin(T (&array)[N]);
template <class T, size_t N> constexpr reverse_iterator<T*> rend(T (&array)[N]);
template <class E> constexpr reverse_iterator<const E*> rbegin(initializer_list<E> il);
template <class E> constexpr reverse_iterator<const E*> rend(initializer_list<E> il);
template <class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin(c));
template <class C> constexpr auto crend(const C& c) -> decltype(std::rend(c));