Implement P0092R1 for C++1z

llvm-svn: 252195

libcxx/include/chrono

@@ -194,6 +194,13 @@ template <class Rep1, class Period1, class Rep2, class Period2>
 template <class ToDuration, class Rep, class Period>
   ToDuration duration_cast(const duration<Rep, Period>& d);
 
+template <class ToDuration, class Rep, class Period>
+    constexpr ToDuration floor(const duration<Rep, Period>& d);    // C++17
+template <class ToDuration, class Rep, class Period>
+    constexpr ToDuration ceil(const duration<Rep, Period>& d);     // C++17
+template <class ToDuration, class Rep, class Period>
+    constexpr ToDuration round(const duration<Rep, Period>& d);    // C++17
+
 // time_point arithmetic (all constexpr in C++14)
 template <class Clock, class Duration1, class Rep2, class Period2>
   time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
@@ -227,6 +234,20 @@ template <class Clock, class Duration1, class Duration2>
 template <class ToDuration, class Clock, class Duration>
   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);                  // C++17
+
+template <class ToDuration, class Clock, class Duration>
+    constexpr time_point<Clock, ToDuration>
+    ceil(const time_point<Clock, Duration>& tp);                   // C++17
+
+template <class ToDuration, class Clock, class Duration>
+    constexpr time_point<Clock, ToDuration>
+    round(const time_point<Clock, Duration>& tp);                  // C++17
+
+template <class Rep, class Period>
+    constexpr duration<Rep, Period> abs(duration<Rep, Period> d);  // C++17
 // Clocks
 
 class system_clock
@@ -401,6 +422,58 @@ public:
     _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep min()  {return numeric_limits<_Rep>::lowest();}
 };
 
+#if _LIBCPP_STD_VER > 14
+template <class _ToDuration, class _Rep, class _Period>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+typename enable_if
+<
+    __is_duration<_ToDuration>::value,
+    _ToDuration
+>::type
+floor(const duration<_Rep, _Period>& __d)
+{
+    _ToDuration __t = duration_cast<_ToDuration>(__d);
+    if (__t > __d)
+        __t = __t - _ToDuration{1};
+    return __t;
+}
+
+template <class _ToDuration, class _Rep, class _Period>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+typename enable_if
+<
+    __is_duration<_ToDuration>::value,
+    _ToDuration
+>::type
+ceil(const duration<_Rep, _Period>& __d)
+{
+    _ToDuration __t = duration_cast<_ToDuration>(__d);
+    if (__t < __d)
+        __t = __t + _ToDuration{1};
+    return __t;
+}
+
+template <class _ToDuration, class _Rep, class _Period>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+typename enable_if
+<
+    __is_duration<_ToDuration>::value,
+    _ToDuration
+>::type
+round(const duration<_Rep, _Period>& __d)
+{
+    _ToDuration __lower = floor<_ToDuration>(__d);
+    _ToDuration __upper = __lower + _ToDuration{1};
+    auto __lowerDiff = __d - __lower;
+    auto __upperDiff = __upper - __d;
+    if (__lowerDiff < __upperDiff)
+        return __lower;
+    if (__lowerDiff > __upperDiff)
+        return __upper;
+    return __lower.count() & 1 ? __upper : __lower;
+}
+#endif
+
 // duration
 
 template <class _Rep, class _Period>
@@ -807,6 +880,56 @@ time_point_cast(const time_point<_Clock, _Duration>& __t)
     return time_point<_Clock, _ToDuration>(_VSTD::chrono::duration_cast<_ToDuration>(__t.time_since_epoch()));
 }
 
+#if _LIBCPP_STD_VER > 14
+template <class _ToDuration, class _Clock, class _Duration>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+typename enable_if
+<
+    __is_duration<_ToDuration>::value,
+    time_point<_Clock, _ToDuration>
+>::type
+floor(const time_point<_Clock, _Duration>& __t)
+{
+    return time_point<_Clock, _ToDuration>{floor<_ToDuration>(__t.time_since_epoch())};
+}
+
+template <class _ToDuration, class _Clock, class _Duration>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+typename enable_if
+<
+    __is_duration<_ToDuration>::value,
+    time_point<_Clock, _ToDuration>
+>::type
+ceil(const time_point<_Clock, _Duration>& __t)
+{
+    return time_point<_Clock, _ToDuration>{ceil<_ToDuration>(__t.time_since_epoch())};
+}
+
+template <class _ToDuration, class _Clock, class _Duration>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+typename enable_if
+<
+    __is_duration<_ToDuration>::value,
+    time_point<_Clock, _ToDuration>
+>::type
+round(const time_point<_Clock, _Duration>& __t)
+{
+    return time_point<_Clock, _ToDuration>{round<_ToDuration>(__t.time_since_epoch())};
+}
+
+template <class _Rep, class _Period>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+typename enable_if
+<
+    numeric_limits<_Rep>::is_signed,
+    duration<_Rep, _Period>
+>::type
+abs(duration<_Rep, _Period> __d)
+{
+    return __d >= __d.zero() ? __d : -__d;
+}
+#endif
+
 // time_point ==
 
 template <class _Clock, class _Duration1, class _Duration2>

libcxx/test/std/utilities/time/time.duration/time.duration.alg/abs.fail.cpp

@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// ceil
+
+// template <class Rep, class Period>
+//   constexpr duration<Rep, Period> abs(duration<Rep, Period> d)
+
+// This function shall not participate in overload resolution unless numeric_limits<Rep>::is_signed is true.
+
+#include <chrono>
+
+typedef std::chrono::duration<unsigned> unsigned_secs;
+
+int main()
+{
+    std::chrono::abs(unsigned_secs(0));
+}

libcxx/test/std/utilities/time/time.duration/time.duration.alg/abs.pass.cpp

@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <chrono>
+
+// abs
+
+// template <class Rep, class Period>
+//   constexpr duration<Rep, Period> abs(duration<Rep, Period> d)
+
+#include <chrono>
+#include <type_traits>
+#include <cassert>
+
+template <class Duration>
+void
+test(const Duration& f, const Duration& d)
+{
+    {
+    typedef decltype(std::chrono::abs(f)) R;
+    static_assert((std::is_same<R, Duration>::value), "");
+    assert(std::chrono::abs(f) == d);
+    }
+}
+
+int main()
+{
+//  7290000ms is 2 hours, 1 minute, and 30 seconds
+    test(std::chrono::milliseconds( 7290000), std::chrono::milliseconds( 7290000));
+    test(std::chrono::milliseconds(-7290000), std::chrono::milliseconds( 7290000));
+    test(std::chrono::minutes( 122), std::chrono::minutes( 122));
+    test(std::chrono::minutes(-122), std::chrono::minutes( 122));
+    test(std::chrono::hours(0), std::chrono::hours(0));
+
+    {
+//  9000000ms is 2 hours and 30 minutes
+    constexpr std::chrono::hours h1 = std::chrono::abs(std::chrono::hours(-3));
+    static_assert(h1.count() == 3, "");
+    constexpr std::chrono::hours h2 = std::chrono::abs(std::chrono::hours(3));
+    static_assert(h2.count() == 3, "");
+    }
+}

libcxx/test/std/utilities/time/time.duration/time.duration.cast/ceil.fail.cpp

@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// ceil
+
+// template <class ToDuration, class Rep, class Period>
+//   ToDuration
+//   ceil(const duration<Rep, Period>& d);
+
+// ToDuration shall be an instantiation of duration.
+
+#include <chrono>
+
+int main()
+{
+    std::chrono::ceil<int>(std::chrono::milliseconds(3));
+}

libcxx/test/std/utilities/time/time.duration/time.duration.cast/ceil.pass.cpp

@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <chrono>
+
+// ceil
+
+// template <class ToDuration, class Rep, class Period>
+//   constexpr
+//   ToDuration
+//   ceil(const duration<Rep, Period>& d);
+
+#include <chrono>
+#include <type_traits>
+#include <cassert>
+
+template <class ToDuration, class FromDuration>
+void
+test(const FromDuration& f, const ToDuration& d)
+{
+    {
+    typedef decltype(std::chrono::ceil<ToDuration>(f)) R;
+    static_assert((std::is_same<R, ToDuration>::value), "");
+    assert(std::chrono::ceil<ToDuration>(f) == d);
+    }
+}
+
+int main()
+{
+//  7290000ms is 2 hours, 1 minute, and 30 seconds
+    test(std::chrono::milliseconds( 7290000), std::chrono::hours( 3));
+    test(std::chrono::milliseconds(-7290000), std::chrono::hours(-2));
+    test(std::chrono::milliseconds( 7290000), std::chrono::minutes( 122));
+    test(std::chrono::milliseconds(-7290000), std::chrono::minutes(-121));
+
+    {
+//  9000000ms is 2 hours and 30 minutes
+    constexpr std::chrono::hours h1 = std::chrono::ceil<std::chrono::hours>(std::chrono::milliseconds(9000000));
+    static_assert(h1.count() == 3, "");
+    constexpr std::chrono::hours h2 = std::chrono::ceil<std::chrono::hours>(std::chrono::milliseconds(-9000000));
+    static_assert(h2.count() == -2, "");
+    }
+}

libcxx/test/std/utilities/time/time.duration/time.duration.cast/floor.fail.cpp

@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// floor
+
+// template <class ToDuration, class Rep, class Period>
+//   ToDuration
+//   floor(const duration<Rep, Period>& d);
+
+// ToDuration shall be an instantiation of duration.
+
+#include <chrono>
+
+int main()
+{
+    std::chrono::floor<int>(std::chrono::milliseconds(3));
+}

libcxx/test/std/utilities/time/time.duration/time.duration.cast/floor.pass.cpp

@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// floor
+
+// template <class ToDuration, class Rep, class Period>
+//   constexpr
+//   ToDuration
+//   floor(const duration<Rep, Period>& d);
+
+#include <chrono>
+#include <type_traits>
+#include <cassert>
+
+template <class ToDuration, class FromDuration>
+void
+test(const FromDuration& f, const ToDuration& d)
+{
+    {
+    typedef decltype(std::chrono::floor<ToDuration>(f)) R;
+    static_assert((std::is_same<R, ToDuration>::value), "");
+    assert(std::chrono::floor<ToDuration>(f) == d);
+    }
+}
+
+int main()
+{
+//  7290000ms is 2 hours, 1 minute, and 30 seconds
+    test(std::chrono::milliseconds( 7290000), std::chrono::hours( 2));
+    test(std::chrono::milliseconds(-7290000), std::chrono::hours(-3));
+    test(std::chrono::milliseconds( 7290000), std::chrono::minutes( 121));
+    test(std::chrono::milliseconds(-7290000), std::chrono::minutes(-122));
+
+    {
+//  9000000ms is 2 hours and 30 minutes
+    constexpr std::chrono::hours h1 = std::chrono::floor<std::chrono::hours>(std::chrono::milliseconds(9000000));
+    static_assert(h1.count() == 2, "");
+    constexpr std::chrono::hours h2 = std::chrono::floor<std::chrono::hours>(std::chrono::milliseconds(-9000000));
+    static_assert(h2.count() == -3, "");
+    }
+}

libcxx/test/std/utilities/time/time.duration/time.duration.cast/round.fail.cpp

@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// round
+
+// template <class ToDuration, class Rep, class Period>
+//   ToDuration
+//   round(const duration<Rep, Period>& d);
+
+// ToDuration shall be an instantiation of duration.
+
+#include <chrono>
+
+int main()
+{
+    std::chrono::round<int>(std::chrono::milliseconds(3));
+}

libcxx/test/std/utilities/time/time.duration/time.duration.cast/round.pass.cpp

@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// round
+
+// template <class ToDuration, class Rep, class Period>
+//   constexpr
+//   ToDuration
+//   ceil(const duration<Rep, Period>& d);
+
+#include <chrono>
+#include <type_traits>
+#include <cassert>
+
+template <class ToDuration, class FromDuration>
+void
+test(const FromDuration& f, const ToDuration& d)
+{
+    {
+    typedef decltype(std::chrono::round<ToDuration>(f)) R;
+    static_assert((std::is_same<R, ToDuration>::value), "");
+    assert(std::chrono::round<ToDuration>(f) == d);
+    }
+}
+
+int main()
+{
+//  7290000ms is 2 hours, 1 minute, and 30 seconds
+    test(std::chrono::milliseconds( 7290000), std::chrono::hours( 2));
+    test(std::chrono::milliseconds(-7290000), std::chrono::hours(-2));
+    test(std::chrono::milliseconds( 7290000), std::chrono::minutes( 122));
+    test(std::chrono::milliseconds(-7290000), std::chrono::minutes(-122));
+
+    {
+//  9000000ms is 2 hours and 30 minutes
+    constexpr std::chrono::hours h1 = std::chrono::round<std::chrono::hours>(std::chrono::milliseconds(9000000));
+    static_assert(h1.count() == 2, "");
+    constexpr std::chrono::hours h2 = std::chrono::round<std::chrono::hours>(std::chrono::milliseconds(-9000000));
+    static_assert(h2.count() == -2, "");
+    }
+}

libcxx/test/std/utilities/time/time.point/time.point.cast/ceil.fail.cpp

@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// ceil
+
+// template <class ToDuration, class Clock, class Duration>
+//   time_point<Clock, ToDuration>
+//   ceil(const time_point<Clock, Duration>& t);
+
+// ToDuration shall be an instantiation of duration.
+
+#include <chrono>
+
+int main()
+{
+    std::chrono::ceil<int>(std::chrono::system_clock::now());
+}

libcxx/test/std/utilities/time/time.point/time.point.cast/ceil.pass.cpp

@@ -0,0 +1,69 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// ceil
+
+// template <class ToDuration, class Clock, class Duration>
+//   time_point<Clock, ToDuration>
+//   ceil(const time_point<Clock, Duration>& t);
+
+#include <chrono>
+#include <type_traits>
+#include <cassert>
+
+template <class FromDuration, class ToDuration>
+void
+test(const FromDuration& df, const ToDuration& d)
+{
+    typedef std::chrono::system_clock Clock;
+    typedef std::chrono::time_point<Clock, FromDuration> FromTimePoint;
+    typedef std::chrono::time_point<Clock, ToDuration> ToTimePoint;
+    {
+    FromTimePoint f(df);
+    ToTimePoint t(d);
+    typedef decltype(std::chrono::ceil<ToDuration>(f)) R;
+    static_assert((std::is_same<R, ToTimePoint>::value), "");
+    assert(std::chrono::ceil<ToDuration>(f) == t);
+    }
+}
+
+template<class FromDuration, long long From, class ToDuration, long long To>
+void test_constexpr ()
+{
+    typedef std::chrono::system_clock Clock;
+    typedef std::chrono::time_point<Clock, FromDuration> FromTimePoint;
+    typedef std::chrono::time_point<Clock, ToDuration> ToTimePoint;
+    {
+    constexpr FromTimePoint f{FromDuration{From}};
+    constexpr ToTimePoint   t{ToDuration{To}};
+    static_assert(std::chrono::ceil<ToDuration>(f) == t, "");
+    }
+}
+
+
+int main()
+{
+//  7290000ms is 2 hours, 1 minute, and 30 seconds
+    test(std::chrono::milliseconds( 7290000), std::chrono::hours( 3));
+    test(std::chrono::milliseconds(-7290000), std::chrono::hours(-2));
+    test(std::chrono::milliseconds( 7290000), std::chrono::minutes( 122));
+    test(std::chrono::milliseconds(-7290000), std::chrono::minutes(-121));
+
+//  9000000ms is 2 hours and 30 minutes
+    test_constexpr<std::chrono::milliseconds, 9000000, std::chrono::hours,    3> ();
+    test_constexpr<std::chrono::milliseconds,-9000000, std::chrono::hours,   -2> ();
+    test_constexpr<std::chrono::milliseconds, 9000001, std::chrono::minutes, 151> ();
+    test_constexpr<std::chrono::milliseconds,-9000001, std::chrono::minutes,-150> ();
+
+    test_constexpr<std::chrono::milliseconds, 9000000, std::chrono::seconds, 9000> ();
+    test_constexpr<std::chrono::milliseconds,-9000000, std::chrono::seconds,-9000> ();
+}

libcxx/test/std/utilities/time/time.point/time.point.cast/floor.fail.cpp

@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// floor
+
+// template <class ToDuration, class Clock, class Duration>
+//   time_point<Clock, ToDuration>
+//   floor(const time_point<Clock, Duration>& t);
+
+// ToDuration shall be an instantiation of duration.
+
+#include <chrono>
+
+int main()
+{
+    std::chrono::floor<int>(std::chrono::system_clock::now());
+}

libcxx/test/std/utilities/time/time.point/time.point.cast/floor.pass.cpp

@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// floor
+
+// template <class ToDuration, class Clock, class Duration>
+//   time_point<Clock, ToDuration>
+//   floor(const time_point<Clock, Duration>& t);
+
+#include <chrono>
+#include <type_traits>
+#include <cassert>
+
+template <class FromDuration, class ToDuration>
+void
+test(const FromDuration& df, const ToDuration& d)
+{
+    typedef std::chrono::system_clock Clock;
+    typedef std::chrono::time_point<Clock, FromDuration> FromTimePoint;
+    typedef std::chrono::time_point<Clock, ToDuration> ToTimePoint;
+    {
+    FromTimePoint f(df);
+    ToTimePoint t(d);
+    typedef decltype(std::chrono::floor<ToDuration>(f)) R;
+    static_assert((std::is_same<R, ToTimePoint>::value), "");
+    assert(std::chrono::floor<ToDuration>(f) == t);
+    }
+}
+
+template<class FromDuration, long long From, class ToDuration, long long To>
+void test_constexpr ()
+{
+    typedef std::chrono::system_clock Clock;
+    typedef std::chrono::time_point<Clock, FromDuration> FromTimePoint;
+    typedef std::chrono::time_point<Clock, ToDuration> ToTimePoint;
+    {
+    constexpr FromTimePoint f{FromDuration{From}};
+    constexpr ToTimePoint   t{ToDuration{To}};
+    static_assert(std::chrono::floor<ToDuration>(f) == t, "");
+    }
+}
+
+int main()
+{
+//  7290000ms is 2 hours, 1 minute, and 30 seconds
+    test(std::chrono::milliseconds( 7290000), std::chrono::hours( 2));
+    test(std::chrono::milliseconds(-7290000), std::chrono::hours(-3));
+    test(std::chrono::milliseconds( 7290000), std::chrono::minutes( 121));
+    test(std::chrono::milliseconds(-7290000), std::chrono::minutes(-122));
+
+//  9000000ms is 2 hours and 30 minutes
+    test_constexpr<std::chrono::milliseconds, 9000000, std::chrono::hours,    2> ();
+    test_constexpr<std::chrono::milliseconds,-9000000, std::chrono::hours,   -3> ();
+    test_constexpr<std::chrono::milliseconds, 9000001, std::chrono::minutes, 150> ();
+    test_constexpr<std::chrono::milliseconds,-9000001, std::chrono::minutes,-151> ();
+
+    test_constexpr<std::chrono::milliseconds, 9000000, std::chrono::seconds, 9000> ();
+    test_constexpr<std::chrono::milliseconds,-9000000, std::chrono::seconds,-9000> ();
+}

libcxx/test/std/utilities/time/time.point/time.point.cast/round.fail.cpp

@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// round
+
+// template <class ToDuration, class Clock, class Duration>
+//   time_point<Clock, ToDuration>
+//   round(const time_point<Clock, Duration>& t);
+
+// ToDuration shall be an instantiation of duration.
+
+#include <chrono>
+
+int main()
+{
+    std::chrono::round<int>(std::chrono::system_clock::now());
+}

libcxx/test/std/utilities/time/time.point/time.point.cast/round.pass.cpp

@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+// <chrono>
+
+// round
+
+// template <class ToDuration, class Clock, class Duration>
+//   time_point<Clock, ToDuration>
+//   round(const time_point<Clock, Duration>& t);
+
+#include <chrono>
+#include <type_traits>
+#include <cassert>
+
+template <class FromDuration, class ToDuration>
+void
+test(const FromDuration& df, const ToDuration& d)
+{
+    typedef std::chrono::system_clock Clock;
+    typedef std::chrono::time_point<Clock, FromDuration> FromTimePoint;
+    typedef std::chrono::time_point<Clock, ToDuration> ToTimePoint;
+    {
+    FromTimePoint f(df);
+    ToTimePoint t(d);
+    typedef decltype(std::chrono::round<ToDuration>(f)) R;
+    static_assert((std::is_same<R, ToTimePoint>::value), "");
+    assert(std::chrono::round<ToDuration>(f) == t);
+    }
+}
+
+template<class FromDuration, long long From, class ToDuration, long long To>
+void test_constexpr ()
+{
+    typedef std::chrono::system_clock Clock;
+    typedef std::chrono::time_point<Clock, FromDuration> FromTimePoint;
+    typedef std::chrono::time_point<Clock, ToDuration> ToTimePoint;
+    {
+    constexpr FromTimePoint f{FromDuration{From}};
+    constexpr ToTimePoint   t{ToDuration{To}};
+    static_assert(std::chrono::round<ToDuration>(f) == t, "");
+    }
+}
+
+int main()
+{
+//  7290000ms is 2 hours, 1 minute, and 30 seconds
+    test(std::chrono::milliseconds( 7290000), std::chrono::hours( 2));
+    test(std::chrono::milliseconds(-7290000), std::chrono::hours(-2));
+    test(std::chrono::milliseconds( 7290000), std::chrono::minutes( 122));
+    test(std::chrono::milliseconds(-7290000), std::chrono::minutes(-122));
+
+//  9000000ms is 2 hours and 30 minutes
+    test_constexpr<std::chrono::milliseconds, 9000000, std::chrono::hours,    2> ();
+    test_constexpr<std::chrono::milliseconds,-9000000, std::chrono::hours,   -2> ();
+    test_constexpr<std::chrono::milliseconds, 9000001, std::chrono::minutes, 150> ();
+    test_constexpr<std::chrono::milliseconds,-9000001, std::chrono::minutes,-150> ();
+
+    test_constexpr<std::chrono::milliseconds, 9000000, std::chrono::seconds, 9000> ();
+    test_constexpr<std::chrono::milliseconds,-9000000, std::chrono::seconds,-9000> ();
+}

libcxx/www/cxx1z_status.html

@@ -72,7 +72,7 @@
   	<tr><td></td><td></td><td></td><td></td><td></td><td></td></tr>
 	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0004R1.html">P0004R1</a></td><td>LWG</td><td>Remove Deprecated iostreams aliases.</td><td>Kona</td><td>Complete</td><td>3.8</td></tr>
 	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0006R0.html">P0006R0</a></td><td>LWG</td><td>Adopt Type Traits Variable Templates for C++17.</td><td>Kona</td><td>In progress</td><td></td></tr>
-	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0092R1.html">P0092R1</a></td><td>LWG</td><td>Polishing &lt;chrono&gt;</td><td>Kona</td><td></td><td></td></tr>
+	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0092R1.html">P0092R1</a></td><td>LWG</td><td>Polishing &lt;chrono&gt;</td><td>Kona</td><td>Complete</td><td>3.8</td></tr>
 	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0007R1.html">P0007R1</a></td><td>LWG</td><td>Constant View: A proposal for a <tt>std::as_const</tt> helper function template.</td><td>Kona</td><td>In progress</td><td></td></tr>
 	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0156R0.htm" >P0156R0</a></td><td>LWG</td><td>Variadic lock_guard(rev 3).</td><td>Kona</td><td></td><td></td></tr>
 	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0074R0.html">P0074R0</a></td><td>LWG</td><td>Making <tt>std::owner_less</tt> more flexible</td><td>Kona</td><td></td><td></td></tr>