20 General utilities library [utilities]

20.17.2 Header <chrono> synopsis [time.syn]

namespace std {
  namespace chrono {
    // [time.duration], class template duration
    template <class Rep, class Period = ratio<1>> class duration;

    // [time.point], class template time_point
    template <class Clock, class Duration = typename Clock::duration> class time_point;
  }

  // [time.traits.specializations], common_type specializations
  template <class Rep1, class Period1, class Rep2, class Period2>
    struct common_type<chrono::duration<Rep1, Period1>,
                       chrono::duration<Rep2, Period2>>;

  template <class Clock, class Duration1, class Duration2>
    struct common_type<chrono::time_point<Clock, Duration1>,
                       chrono::time_point<Clock, Duration2>>;

  namespace chrono {
    // [time.traits], customization traits
    template <class Rep> struct treat_as_floating_point;
    template <class Rep> struct duration_values;
    template <class Rep> constexpr bool treat_as_floating_point_v
      = treat_as_floating_point<Rep>::value;

    // [time.duration.nonmember], duration arithmetic
    template <class Rep1, class Period1, class Rep2, class Period2>
      common_type_t<duration<Rep1, Period1>, duration<Rep2, Period2>>
      constexpr operator+(const duration<Rep1, Period1>& lhs,
                          const duration<Rep2, Period2>& rhs);
    template <class Rep1, class Period1, class Rep2, class Period2>
      common_type_t<duration<Rep1, Period1>, duration<Rep2, Period2>>
      constexpr operator-(const duration<Rep1, Period1>& lhs,
                          const duration<Rep2, Period2>& rhs);
    template <class Rep1, class Period, class Rep2>
      duration<common_type_t<Rep1, Rep2>, Period>
      constexpr operator*(const duration<Rep1, Period>& d, const Rep2& s);
    template <class Rep1, class Rep2, class Period>
      duration<common_type_t<Rep1, Rep2>, Period>
      constexpr operator*(const Rep1& s, const duration<Rep2, Period>& d);
    template <class Rep1, class Period, class Rep2>
      duration<common_type_t<Rep1, Rep2>, Period>
      constexpr operator/(const duration<Rep1, Period>& d, const Rep2& s);
    template <class Rep1, class Period1, class Rep2, class Period2>
      common_type_t<Rep1, Rep2>
      constexpr operator/(const duration<Rep1, Period1>& lhs,
                          const duration<Rep2, Period2>& rhs);
    template <class Rep1, class Period, class Rep2>
      duration<common_type_t<Rep1, Rep2>, Period>
      constexpr operator%(const duration<Rep1, Period>& d, const Rep2& s);
    template <class Rep1, class Period1, class Rep2, class Period2>
      common_type_t<duration<Rep1, Period1>, duration<Rep2, Period2>>
      constexpr operator%(const duration<Rep1, Period1>& lhs,
                          const duration<Rep2, Period2>& rhs);

    // [time.duration.comparisons], duration comparisons
    template <class Rep1, class Period1, class Rep2, class Period2>
      constexpr bool operator==(const duration<Rep1, Period1>& lhs,
                                const duration<Rep2, Period2>& rhs);
    template <class Rep1, class Period1, class Rep2, class Period2>
      constexpr bool operator!=(const duration<Rep1, Period1>& lhs,
                                const duration<Rep2, Period2>& rhs);
    template <class Rep1, class Period1, class Rep2, class Period2>
      constexpr bool operator< (const duration<Rep1, Period1>& lhs,
                                const duration<Rep2, Period2>& rhs);
    template <class Rep1, class Period1, class Rep2, class Period2>
      constexpr bool operator<=(const duration<Rep1, Period1>& lhs,
                                const duration<Rep2, Period2>& rhs);
    template <class Rep1, class Period1, class Rep2, class Period2>
      constexpr bool operator> (const duration<Rep1, Period1>& lhs,
                                const duration<Rep2, Period2>& rhs);
    template <class Rep1, class Period1, class Rep2, class Period2>
      constexpr bool operator>=(const duration<Rep1, Period1>& lhs,
                                const duration<Rep2, Period2>& rhs);

    // [time.duration.cast], duration_cast
    template <class ToDuration, class Rep, class Period>
      constexpr ToDuration duration_cast(const duration<Rep, Period>& d);
    template <class ToDuration, class Rep, class Period>
      constexpr ToDuration floor(const duration<Rep, Period>& d);
    template <class ToDuration, class Rep, class Period>
      constexpr ToDuration ceil(const duration<Rep, Period>& d);
    template <class ToDuration, class Rep, class Period>
      constexpr ToDuration round(const duration<Rep, Period>& d);

    // convenience typedefs
    using nanoseconds  = duration<signed integer type of at least 64 bits, nano>;
    using microseconds = duration<signed integer type of at least 55 bits, micro>;
    using milliseconds = duration<signed integer type of at least 45 bits, milli>;
    using seconds      = duration<signed integer type of at least 35 bits>;
    using minutes      = duration<signed integer type of at least 29 bits, ratio<  60>>;
    using hours        = duration<signed integer type of at least 23 bits, ratio<3600>>;

    // [time.point.nonmember], time_point arithmetic
    template <class Clock, class Duration1, class Rep2, class Period2>
      constexpr time_point<Clock, common_type_t<Duration1, duration<Rep2, Period2>>>
      operator+(const time_point<Clock, Duration1>& lhs,
                const duration<Rep2, Period2>& rhs);
    template <class Rep1, class Period1, class Clock, class Duration2>
      constexpr time_point<Clock, common_type_t<duration<Rep1, Period1>, Duration2>>
      operator+(const duration<Rep1, Period1>& lhs,
                const time_point<Clock, Duration2>& rhs);
    template <class Clock, class Duration1, class Rep2, class Period2>
      constexpr time_point<Clock, common_type_t<Duration1, duration<Rep2, Period2>>>
      operator-(const time_point<Clock, Duration1>& lhs,
                const duration<Rep2, Period2>& rhs);
    template <class Clock, class Duration1, class Duration2>
      constexpr common_type_t<Duration1, Duration2>
      operator-(const time_point<Clock, Duration1>& lhs,
                const time_point<Clock, Duration2>& rhs);

    // [time.point.comparisons], time_point comparisons
    template <class Clock, class Duration1, class Duration2>
       constexpr bool operator==(const time_point<Clock, Duration1>& lhs,
                                 const time_point<Clock, Duration2>& rhs);
    template <class Clock, class Duration1, class Duration2>
       constexpr bool operator!=(const time_point<Clock, Duration1>& lhs,
                                 const time_point<Clock, Duration2>& rhs);
    template <class Clock, class Duration1, class Duration2>
       constexpr bool operator< (const time_point<Clock, Duration1>& lhs,
                                 const time_point<Clock, Duration2>& rhs);
    template <class Clock, class Duration1, class Duration2>
       constexpr bool operator<=(const time_point<Clock, Duration1>& lhs,
                                 const time_point<Clock, Duration2>& rhs);
    template <class Clock, class Duration1, class Duration2>
       constexpr bool operator> (const time_point<Clock, Duration1>& lhs,
                                 const time_point<Clock, Duration2>& rhs);
    template <class Clock, class Duration1, class Duration2>
       constexpr bool operator>=(const time_point<Clock, Duration1>& lhs,
                                 const time_point<Clock, Duration2>& rhs);

    // [time.point.cast], time_point_cast
    template <class ToDuration, class Clock, class Duration>
      constexpr time_point<Clock, ToDuration>
      time_point_cast(const time_point<Clock, Duration>& t);
    template <class ToDuration, class Clock, class Duration>
      constexpr time_point<Clock, ToDuration>
      floor(const time_point<Clock, Duration>& tp);
    template <class ToDuration, class Clock, class Duration>
      constexpr time_point<Clock, ToDuration>
      ceil(const time_point<Clock, Duration>& tp);
    template <class ToDuration, class Clock, class Duration>
      constexpr time_point<Clock, ToDuration>
      round(const time_point<Clock, Duration>& tp);

    // [time.duration.alg], specialized algorithms
    template <class Rep, class Period>
      constexpr duration<Rep, Period> abs(duration<Rep, Period> d);

    // [time.clock], clocks
    class system_clock;
    class steady_clock;
    class high_resolution_clock;
  }

  inline namespace literals {
    inline namespace chrono_literals {
      //  [time.duration.literals], suffixes for duration literals
      constexpr chrono::hours                                operator "" h(unsigned long long);
      constexpr chrono::duration<unspecified, ratio<3600,1>> operator "" h(long double);
      constexpr chrono::minutes                              operator "" min(unsigned long long);
      constexpr chrono::duration<unspecified, ratio<60,1>>   operator "" min(long double);
      constexpr chrono::seconds                              operator "" s(unsigned long long);
      constexpr chrono::duration<unspecified>                operator "" s(long double);
      constexpr chrono::milliseconds                         operator "" ms(unsigned long long);
      constexpr chrono::duration<unspecified, milli>          operator "" ms(long double);
      constexpr chrono::microseconds                         operator "" us(unsigned long long);
      constexpr chrono::duration<unspecified, micro>         operator "" us(long double);
      constexpr chrono::nanoseconds                          operator "" ns(unsigned long long);
      constexpr chrono::duration<unspecified, nano>          operator "" ns(long double);
    }
  }

  namespace chrono {
    using namespace literals::chrono_literals;
  }
}