namespace std::chrono {
class year {
short y_; // exposition only
public:
year() = default;
constexpr explicit year(int y) noexcept;
constexpr year& operator++() noexcept;
constexpr year operator++(int) noexcept;
constexpr year& operator--() noexcept;
constexpr year operator--(int) noexcept;
constexpr year& operator+=(const years& y) noexcept;
constexpr year& operator-=(const years& y) noexcept;
constexpr year operator+() const noexcept;
constexpr year operator-() const noexcept;
constexpr bool is_leap() const noexcept;
constexpr explicit operator int() const noexcept;
constexpr bool ok() const noexcept;
static constexpr year min() noexcept;
static constexpr year max() noexcept;
};
}