v1/__chrono/steady_clock.h

0001 // -*- C++ -*-
0002 //===----------------------------------------------------------------------===//
0003 //
0004 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0005 // See https://llvm.org/LICENSE.txt for license information.
0006 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0007 //
0008 //===----------------------------------------------------------------------===//
0009
0010 #ifndef _LIBCPP___CHRONO_STEADY_CLOCK_H
0011 #define _LIBCPP___CHRONO_STEADY_CLOCK_H
0012
0013 #include <__chrono/duration.h>
0014 #include <__chrono/time_point.h>
0015 #include <__config>
0016
0017 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0018 #  pragma GCC system_header
0019 #endif
0020
0021 _LIBCPP_BEGIN_NAMESPACE_STD
0022
0023 namespace chrono {
0024
0025 #if _LIBCPP_HAS_MONOTONIC_CLOCK
0026 class _LIBCPP_EXPORTED_FROM_ABI steady_clock {
0027 public:
0028   typedef nanoseconds duration;
0029   typedef duration::rep rep;
0030   typedef duration::period period;
0031   typedef chrono::time_point<steady_clock, duration> time_point;
0032   static _LIBCPP_CONSTEXPR_SINCE_CXX14 const bool is_steady = true;
0033
0034   static time_point now() _NOEXCEPT;
0035 };
0036 #endif
0037
0038 } // namespace chrono
0039
0040 _LIBCPP_END_NAMESPACE_STD
0041
0042 #endif // _LIBCPP___CHRONO_STEADY_CLOCK_H