Implement n3469 - constexpr for chrono

llvm-svn: 187517
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: a1d0d376c88d46c942dead9e0b664978d0a8d587
diff --git a/include/chrono b/include/chrono
index 219e20e..08c40b5 100644
--- a/include/chrono
+++ b/include/chrono
@@ -111,16 +111,16 @@
     duration d_;  // exposition only
 
 public:
-    time_point();  // has value "epoch"
-    explicit time_point(const duration& d);  // same as time_point() + d
+    time_point();  // has value "epoch" // constexpr in C++14
+    explicit time_point(const duration& d);  // same as time_point() + d // constexpr in C++14
 
     // conversions
     template <class Duration2>
-       time_point(const time_point<clock, Duration2>& t);
+       time_point(const time_point<clock, Duration2>& t); // constexpr in C++14
 
     // observer
 
-    duration time_since_epoch() const;
+    duration time_since_epoch() const; // constexpr in C++14
 
     // arithmetic
 
@@ -194,7 +194,7 @@
 template <class ToDuration, class Rep, class Period>
   ToDuration duration_cast(const duration<Rep, Period>& d);
 
-// time_point arithmetic
+// 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>
   operator+(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
@@ -208,7 +208,7 @@
   typename common_type<Duration1, Duration2>::type
   operator-(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
 
-// time_point comparisons
+// time_point comparisons (all constexpr in C++14)
 template <class Clock, class Duration1, class Duration2>
    bool operator==(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
 template <class Clock, class Duration1, class Duration2>
@@ -222,7 +222,7 @@
 template <class Clock, class Duration1, class Duration2>
    bool operator>=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
 
-// time_point_cast
+// time_point_cast (constexpr in C++14)
 
 template <class ToDuration, class Clock, class Duration>
   time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t);
@@ -236,7 +236,7 @@
     typedef duration::rep                    rep;
     typedef duration::period                 period;
     typedef chrono::time_point<system_clock> time_point;
-    static const bool is_steady =            false;
+    static const bool is_steady =            false; // constexpr in C++14
 
     static time_point now() noexcept;
     static time_t     to_time_t  (const time_point& __t) noexcept;
@@ -250,7 +250,7 @@
     typedef duration::rep                                 rep;
     typedef duration::period                              period;
     typedef chrono::time_point<steady_clock, duration>    time_point;
-    static const bool is_steady =                         true;
+    static const bool is_steady =                         true; // constexpr in C++14
 
     static time_point now() noexcept;
 };
@@ -416,7 +416,13 @@
     rep __rep_;
 public:
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR duration() {} // = default;
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+        duration() {}
+#else
+        duration() = default;
+#endif
+
     template <class _Rep2>
         _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
         explicit duration(const _Rep2& __r,
@@ -722,12 +728,12 @@
     duration __d_;
 
 public:
-    _LIBCPP_INLINE_VISIBILITY time_point() : __d_(duration::zero()) {}
-    _LIBCPP_INLINE_VISIBILITY explicit time_point(const duration& __d) : __d_(__d) {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 time_point() : __d_(duration::zero()) {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 explicit time_point(const duration& __d) : __d_(__d) {}
 
     // conversions
     template <class _Duration2>
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     time_point(const time_point<clock, _Duration2>& t,
         typename enable_if
         <
@@ -737,7 +743,7 @@
 
     // observer
 
-    _LIBCPP_INLINE_VISIBILITY duration time_since_epoch() const {return __d_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 duration time_since_epoch() const {return __d_;}
 
     // arithmetic
 
@@ -762,7 +768,7 @@
 namespace chrono {
 
 template <class _ToDuration, class _Clock, class _Duration>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 time_point<_Clock, _ToDuration>
 time_point_cast(const time_point<_Clock, _Duration>& __t)
 {
@@ -772,7 +778,7 @@
 // time_point ==
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator==(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -782,7 +788,7 @@
 // time_point !=
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator!=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -792,7 +798,7 @@
 // time_point <
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator<(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -802,7 +808,7 @@
 // time_point >
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator>(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -812,7 +818,7 @@
 // time_point <=
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator<=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -822,7 +828,7 @@
 // time_point >=
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator>=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -832,20 +838,18 @@
 // time_point operator+(time_point x, duration y);
 
 template <class _Clock, class _Duration1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
 operator+(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
 {
     typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Tr;
-    _Tr __r(__lhs.time_since_epoch());
-    __r += __rhs;
-    return __r;
+    return _Tr (__lhs.time_since_epoch() + __rhs);
 }
 
 // time_point operator+(duration x, time_point y);
 
 template <class _Rep1, class _Period1, class _Clock, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 time_point<_Clock, typename common_type<duration<_Rep1, _Period1>, _Duration2>::type>
 operator+(const duration<_Rep1, _Period1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -855,7 +859,7 @@
 // time_point operator-(time_point x, duration y);
 
 template <class _Clock, class _Duration1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
 operator-(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
 {
@@ -865,7 +869,7 @@
 // duration operator-(time_point x, time_point y);
 
 template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 typename common_type<_Duration1, _Duration2>::type
 operator-(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
 {
@@ -883,7 +887,7 @@
     typedef duration::rep                    rep;
     typedef duration::period                 period;
     typedef chrono::time_point<system_clock> time_point;
-    static const bool is_steady =            false;
+    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
 
     static time_point now() _NOEXCEPT;
     static time_t     to_time_t  (const time_point& __t) _NOEXCEPT;
@@ -897,7 +901,7 @@
     typedef duration::rep                                 rep;
     typedef duration::period                              period;
     typedef chrono::time_point<steady_clock, duration>    time_point;
-    static const bool is_steady =                         true;
+    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = true;
 
     static time_point now() _NOEXCEPT;
 };