namespace std {
template<class T, class Container = deque<T>>
class stack {
public:
using value_type = typename Container::value_type;
using reference = typename Container::reference;
using const_reference = typename Container::const_reference;
using size_type = typename Container::size_type;
using container_type = Container;
protected:
Container c;
public:
constexpr stack() : stack(Container()) {}
constexpr explicit stack(const Container&);
constexpr explicit stack(Container&&);
template<class InputIterator> constexpr stack(InputIterator first, InputIterator last);
template<container-compatible-range<T> R>
constexpr stack(from_range_t, R&& rg);
template<class Alloc> constexpr explicit stack(const Alloc&);
template<class Alloc> constexpr stack(const Container&, const Alloc&);
template<class Alloc> constexpr stack(Container&&, const Alloc&);
template<class Alloc> constexpr stack(const stack&, const Alloc&);
template<class Alloc> constexpr stack(stack&&, const Alloc&);
template<class InputIterator, class Alloc>
constexpr stack(InputIterator first, InputIterator last, const Alloc&);
template<container-compatible-range<T> R, class Alloc>
constexpr stack(from_range_t, R&& rg, const Alloc&);
constexpr bool empty() const { return c.empty(); }
constexpr size_type size() const { return c.size(); }
constexpr reference top() { return c.back(); }
constexpr const_reference top() const { return c.back(); }
constexpr void push(const value_type& x) { c.push_back(x); }
constexpr void push(value_type&& x) { c.push_back(std::move(x)); }
template<container-compatible-range<T> R>
constexpr void push_range(R&& rg);
template<class... Args>
constexpr decltype(auto) emplace(Args&&... args)
{ return c.emplace_back(std::forward<Args>(args)...); }
constexpr void pop() { c.pop_back(); }
constexpr void swap(stack& s) noexcept(is_nothrow_swappable_v<Container>)
{ using std::swap; swap(c, s.c); }
};
template<class Container>
stack(Container) -> stack<typename Container::value_type, Container>;
template<class InputIterator>
stack(InputIterator, InputIterator) -> stack<iter-value-type<InputIterator>>;
template<ranges::input_range R>
stack(from_range_t, R&&) -> stack<ranges::range_value_t<R>>;
template<class Container, class Allocator>
stack(Container, Allocator) -> stack<typename Container::value_type, Container>;
template<class InputIterator, class Allocator>
stack(InputIterator, InputIterator, Allocator)
-> stack<iter-value-type<InputIterator>, deque<iter-value-type<InputIterator>,
Allocator>>;
template<ranges::input_range R, class Allocator>
stack(from_range_t, R&&, Allocator)
-> stack<ranges::range_value_t<R>, deque<ranges::range_value_t<R>, Allocator>>;
template<class T, class Container, class Alloc>
struct uses_allocator<stack<T, Container>, Alloc>
: uses_allocator<Container, Alloc>::type { };
}