25 Time library [time]

25.7 Clocks [time.clock]

25.7.7 Class high_­resolution_­clock [time.clock.hires]

namespace std::chrono {
  class high_resolution_clock {
  public:
    using rep        = unspecified;
    using period     = ratio<unspecified, unspecified>;
    using duration   = chrono::duration<rep, period>;
    using time_point = chrono::time_point<unspecified, duration>;
    static constexpr bool is_steady = unspecified;

    static time_point now() noexcept;
  };
}