xref: /freebsd-src/contrib/llvm-project/libcxx/include/__chrono/zoned_time.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1*0fca6ea1SDimitry Andric // -*- C++ -*-
2*0fca6ea1SDimitry Andric //===----------------------------------------------------------------------===//
3*0fca6ea1SDimitry Andric //
4*0fca6ea1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5*0fca6ea1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6*0fca6ea1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7*0fca6ea1SDimitry Andric //
8*0fca6ea1SDimitry Andric //===----------------------------------------------------------------------===//
9*0fca6ea1SDimitry Andric 
10*0fca6ea1SDimitry Andric // For information see https://libcxx.llvm.org/DesignDocs/TimeZone.html
11*0fca6ea1SDimitry Andric 
12*0fca6ea1SDimitry Andric #ifndef _LIBCPP___CHRONO_ZONED_TIME_H
13*0fca6ea1SDimitry Andric #define _LIBCPP___CHRONO_ZONED_TIME_H
14*0fca6ea1SDimitry Andric 
15*0fca6ea1SDimitry Andric #include <version>
16*0fca6ea1SDimitry Andric // Enable the contents of the header only when libc++ was built with experimental features enabled.
17*0fca6ea1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_TZDB)
18*0fca6ea1SDimitry Andric 
19*0fca6ea1SDimitry Andric #  include <__chrono/calendar.h>
20*0fca6ea1SDimitry Andric #  include <__chrono/duration.h>
21*0fca6ea1SDimitry Andric #  include <__chrono/sys_info.h>
22*0fca6ea1SDimitry Andric #  include <__chrono/system_clock.h>
23*0fca6ea1SDimitry Andric #  include <__chrono/time_zone.h>
24*0fca6ea1SDimitry Andric #  include <__chrono/tzdb_list.h>
25*0fca6ea1SDimitry Andric #  include <__config>
26*0fca6ea1SDimitry Andric #  include <__fwd/string_view.h>
27*0fca6ea1SDimitry Andric #  include <__type_traits/common_type.h>
28*0fca6ea1SDimitry Andric #  include <__type_traits/conditional.h>
29*0fca6ea1SDimitry Andric #  include <__type_traits/remove_cvref.h>
30*0fca6ea1SDimitry Andric #  include <__utility/move.h>
31*0fca6ea1SDimitry Andric 
32*0fca6ea1SDimitry Andric #  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
33*0fca6ea1SDimitry Andric #    pragma GCC system_header
34*0fca6ea1SDimitry Andric #  endif
35*0fca6ea1SDimitry Andric 
36*0fca6ea1SDimitry Andric _LIBCPP_PUSH_MACROS
37*0fca6ea1SDimitry Andric #  include <__undef_macros>
38*0fca6ea1SDimitry Andric 
39*0fca6ea1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
40*0fca6ea1SDimitry Andric 
41*0fca6ea1SDimitry Andric #  if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_TIME_ZONE_DATABASE) && !defined(_LIBCPP_HAS_NO_FILESYSTEM) &&   \
42*0fca6ea1SDimitry Andric       !defined(_LIBCPP_HAS_NO_LOCALIZATION)
43*0fca6ea1SDimitry Andric 
44*0fca6ea1SDimitry Andric namespace chrono {
45*0fca6ea1SDimitry Andric 
46*0fca6ea1SDimitry Andric template <class>
47*0fca6ea1SDimitry Andric struct zoned_traits {};
48*0fca6ea1SDimitry Andric 
49*0fca6ea1SDimitry Andric template <>
50*0fca6ea1SDimitry Andric struct zoned_traits<const time_zone*> {
51*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static const time_zone* default_zone() { return chrono::locate_zone("UTC"); }
52*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static const time_zone* locate_zone(string_view __name) {
53*0fca6ea1SDimitry Andric     return chrono::locate_zone(__name);
54*0fca6ea1SDimitry Andric   }
55*0fca6ea1SDimitry Andric };
56*0fca6ea1SDimitry Andric 
57*0fca6ea1SDimitry Andric template <class _Duration, class _TimeZonePtr = const time_zone*>
58*0fca6ea1SDimitry Andric class zoned_time {
59*0fca6ea1SDimitry Andric   // [time.zone.zonedtime.ctor]/2
60*0fca6ea1SDimitry Andric   static_assert(__is_duration<_Duration>::value,
61*0fca6ea1SDimitry Andric                 "the program is ill-formed since _Duration is not a specialization of std::chrono::duration");
62*0fca6ea1SDimitry Andric 
63*0fca6ea1SDimitry Andric   // The wording uses the constraints like
64*0fca6ea1SDimitry Andric   //   constructible_from<zoned_time, decltype(__traits::locate_zone(string_view{}))>
65*0fca6ea1SDimitry Andric   // Using these constraints in the code causes the compiler to give an
66*0fca6ea1SDimitry Andric   // error that the constraint depends on itself. To avoid that issue use
67*0fca6ea1SDimitry Andric   // the fact it is possible to create this object from a _TimeZonePtr.
68*0fca6ea1SDimitry Andric   using __traits = zoned_traits<_TimeZonePtr>;
69*0fca6ea1SDimitry Andric 
70*0fca6ea1SDimitry Andric public:
71*0fca6ea1SDimitry Andric   using duration = common_type_t<_Duration, seconds>;
72*0fca6ea1SDimitry Andric 
73*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time()
74*0fca6ea1SDimitry Andric     requires requires { __traits::default_zone(); }
75*0fca6ea1SDimitry Andric       : __zone_{__traits::default_zone()}, __tp_{} {}
76*0fca6ea1SDimitry Andric 
77*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(const zoned_time&)            = default;
78*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time& operator=(const zoned_time&) = default;
79*0fca6ea1SDimitry Andric 
80*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(const sys_time<_Duration>& __tp)
81*0fca6ea1SDimitry Andric     requires requires { __traits::default_zone(); }
82*0fca6ea1SDimitry Andric       : __zone_{__traits::default_zone()}, __tp_{__tp} {}
83*0fca6ea1SDimitry Andric 
84*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI explicit zoned_time(_TimeZonePtr __zone) : __zone_{std::move(__zone)}, __tp_{} {}
85*0fca6ea1SDimitry Andric 
86*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI explicit zoned_time(string_view __name)
87*0fca6ea1SDimitry Andric     requires(requires { __traits::locate_zone(string_view{}); } &&
88*0fca6ea1SDimitry Andric              constructible_from<_TimeZonePtr, decltype(__traits::locate_zone(string_view{}))>)
89*0fca6ea1SDimitry Andric       : __zone_{__traits::locate_zone(__name)}, __tp_{} {}
90*0fca6ea1SDimitry Andric 
91*0fca6ea1SDimitry Andric   template <class _Duration2>
92*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(const zoned_time<_Duration2, _TimeZonePtr>& __zt)
93*0fca6ea1SDimitry Andric     requires is_convertible_v<sys_time<_Duration2>, sys_time<_Duration>>
94*0fca6ea1SDimitry Andric       : __zone_{__zt.get_time_zone()}, __tp_{__zt.get_sys_time()} {}
95*0fca6ea1SDimitry Andric 
96*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(_TimeZonePtr __zone, const sys_time<_Duration>& __tp)
97*0fca6ea1SDimitry Andric       : __zone_{std::move(__zone)}, __tp_{__tp} {}
98*0fca6ea1SDimitry Andric 
99*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(string_view __name, const sys_time<_Duration>& __tp)
100*0fca6ea1SDimitry Andric     requires requires { _TimeZonePtr{__traits::locate_zone(string_view{})}; }
101*0fca6ea1SDimitry Andric       : zoned_time{__traits::locate_zone(__name), __tp} {}
102*0fca6ea1SDimitry Andric 
103*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(_TimeZonePtr __zone, const local_time<_Duration>& __tp)
104*0fca6ea1SDimitry Andric     requires(is_convertible_v<decltype(std::declval<_TimeZonePtr&>() -> to_sys(local_time<_Duration>{})),
105*0fca6ea1SDimitry Andric                               sys_time<duration>>)
106*0fca6ea1SDimitry Andric       : __zone_{std::move(__zone)}, __tp_{__zone_->to_sys(__tp)} {}
107*0fca6ea1SDimitry Andric 
108*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(string_view __name, const local_time<_Duration>& __tp)
109*0fca6ea1SDimitry Andric     requires(requires {
110*0fca6ea1SDimitry Andric       _TimeZonePtr{__traits::locate_zone(string_view{})};
111*0fca6ea1SDimitry Andric     } && is_convertible_v<decltype(std::declval<_TimeZonePtr&>() -> to_sys(local_time<_Duration>{})),
112*0fca6ea1SDimitry Andric                           sys_time<duration>>)
113*0fca6ea1SDimitry Andric       : zoned_time{__traits::locate_zone(__name), __tp} {}
114*0fca6ea1SDimitry Andric 
115*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(_TimeZonePtr __zone, const local_time<_Duration>& __tp, choose __c)
116*0fca6ea1SDimitry Andric     requires(is_convertible_v<
117*0fca6ea1SDimitry Andric                 decltype(std::declval<_TimeZonePtr&>() -> to_sys(local_time<_Duration>{}, choose::earliest)),
118*0fca6ea1SDimitry Andric                 sys_time<duration>>)
119*0fca6ea1SDimitry Andric       : __zone_{std::move(__zone)}, __tp_{__zone_->to_sys(__tp, __c)} {}
120*0fca6ea1SDimitry Andric 
121*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(string_view __name, const local_time<_Duration>& __tp, choose __c)
122*0fca6ea1SDimitry Andric     requires(requires {
123*0fca6ea1SDimitry Andric       _TimeZonePtr{__traits::locate_zone(string_view{})};
124*0fca6ea1SDimitry Andric     } && is_convertible_v<decltype(std::declval<_TimeZonePtr&>() -> to_sys(local_time<_Duration>{}, choose::earliest)),
125*0fca6ea1SDimitry Andric                           sys_time<duration>>)
126*0fca6ea1SDimitry Andric       : zoned_time{__traits::locate_zone(__name), __tp, __c} {}
127*0fca6ea1SDimitry Andric 
128*0fca6ea1SDimitry Andric   template <class _Duration2, class _TimeZonePtr2>
129*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(_TimeZonePtr __zone, const zoned_time<_Duration2, _TimeZonePtr2>& __zt)
130*0fca6ea1SDimitry Andric     requires is_convertible_v<sys_time<_Duration2>, sys_time<_Duration>>
131*0fca6ea1SDimitry Andric       : __zone_{std::move(__zone)}, __tp_{__zt.get_sys_time()} {}
132*0fca6ea1SDimitry Andric 
133*0fca6ea1SDimitry Andric   // per wording choose has no effect
134*0fca6ea1SDimitry Andric   template <class _Duration2, class _TimeZonePtr2>
135*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(_TimeZonePtr __zone, const zoned_time<_Duration2, _TimeZonePtr2>& __zt, choose)
136*0fca6ea1SDimitry Andric     requires is_convertible_v<sys_time<_Duration2>, sys_time<_Duration>>
137*0fca6ea1SDimitry Andric       : __zone_{std::move(__zone)}, __tp_{__zt.get_sys_time()} {}
138*0fca6ea1SDimitry Andric 
139*0fca6ea1SDimitry Andric   template <class _Duration2, class _TimeZonePtr2>
140*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(string_view __name, const zoned_time<_Duration2, _TimeZonePtr2>& __zt)
141*0fca6ea1SDimitry Andric     requires(requires {
142*0fca6ea1SDimitry Andric       _TimeZonePtr{__traits::locate_zone(string_view{})};
143*0fca6ea1SDimitry Andric     } && is_convertible_v<sys_time<_Duration2>, sys_time<_Duration>>)
144*0fca6ea1SDimitry Andric       : zoned_time{__traits::locate_zone(__name), __zt} {}
145*0fca6ea1SDimitry Andric 
146*0fca6ea1SDimitry Andric   template <class _Duration2, class _TimeZonePtr2>
147*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time(string_view __name, const zoned_time<_Duration2, _TimeZonePtr2>& __zt, choose __c)
148*0fca6ea1SDimitry Andric     requires(requires {
149*0fca6ea1SDimitry Andric       _TimeZonePtr{__traits::locate_zone(string_view{})};
150*0fca6ea1SDimitry Andric     } && is_convertible_v<sys_time<_Duration2>, sys_time<_Duration>>)
151*0fca6ea1SDimitry Andric       : zoned_time{__traits::locate_zone(__name), __zt, __c} {}
152*0fca6ea1SDimitry Andric 
153*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time& operator=(const sys_time<_Duration>& __tp) {
154*0fca6ea1SDimitry Andric     __tp_ = __tp;
155*0fca6ea1SDimitry Andric     return *this;
156*0fca6ea1SDimitry Andric   }
157*0fca6ea1SDimitry Andric 
158*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI zoned_time& operator=(const local_time<_Duration>& __tp) {
159*0fca6ea1SDimitry Andric     // TODO TZDB This seems wrong.
160*0fca6ea1SDimitry Andric     // Assigning a non-existent or ambiguous time will throw and not satisfy
161*0fca6ea1SDimitry Andric     // the post condition. This seems quite odd; I constructed an object with
162*0fca6ea1SDimitry Andric     // choose::earliest and that choice is not respected.
163*0fca6ea1SDimitry Andric     // what did LEWG do with this.
164*0fca6ea1SDimitry Andric     // MSVC STL and libstdc++ behave the same
165*0fca6ea1SDimitry Andric     __tp_ = __zone_->to_sys(__tp);
166*0fca6ea1SDimitry Andric     return *this;
167*0fca6ea1SDimitry Andric   }
168*0fca6ea1SDimitry Andric 
169*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI operator sys_time<duration>() const { return get_sys_time(); }
170*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit operator local_time<duration>() const { return get_local_time(); }
171*0fca6ea1SDimitry Andric 
172*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI _TimeZonePtr get_time_zone() const { return __zone_; }
173*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI local_time<duration> get_local_time() const { return __zone_->to_local(__tp_); }
174*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI sys_time<duration> get_sys_time() const { return __tp_; }
175*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI sys_info get_info() const { return __zone_->get_info(__tp_); }
176*0fca6ea1SDimitry Andric 
177*0fca6ea1SDimitry Andric private:
178*0fca6ea1SDimitry Andric   _TimeZonePtr __zone_;
179*0fca6ea1SDimitry Andric   sys_time<duration> __tp_;
180*0fca6ea1SDimitry Andric };
181*0fca6ea1SDimitry Andric 
182*0fca6ea1SDimitry Andric zoned_time() -> zoned_time<seconds>;
183*0fca6ea1SDimitry Andric 
184*0fca6ea1SDimitry Andric template <class _Duration>
185*0fca6ea1SDimitry Andric zoned_time(sys_time<_Duration>) -> zoned_time<common_type_t<_Duration, seconds>>;
186*0fca6ea1SDimitry Andric 
187*0fca6ea1SDimitry Andric template <class _TimeZonePtrOrName>
188*0fca6ea1SDimitry Andric using __time_zone_representation =
189*0fca6ea1SDimitry Andric     conditional_t<is_convertible_v<_TimeZonePtrOrName, string_view>,
190*0fca6ea1SDimitry Andric                   const time_zone*,
191*0fca6ea1SDimitry Andric                   remove_cvref_t<_TimeZonePtrOrName>>;
192*0fca6ea1SDimitry Andric 
193*0fca6ea1SDimitry Andric template <class _TimeZonePtrOrName>
194*0fca6ea1SDimitry Andric zoned_time(_TimeZonePtrOrName&&) -> zoned_time<seconds, __time_zone_representation<_TimeZonePtrOrName>>;
195*0fca6ea1SDimitry Andric 
196*0fca6ea1SDimitry Andric template <class _TimeZonePtrOrName, class _Duration>
197*0fca6ea1SDimitry Andric zoned_time(_TimeZonePtrOrName&&, sys_time<_Duration>)
198*0fca6ea1SDimitry Andric     -> zoned_time<common_type_t<_Duration, seconds>, __time_zone_representation<_TimeZonePtrOrName>>;
199*0fca6ea1SDimitry Andric 
200*0fca6ea1SDimitry Andric template <class _TimeZonePtrOrName, class _Duration>
201*0fca6ea1SDimitry Andric zoned_time(_TimeZonePtrOrName&&, local_time<_Duration>, choose = choose::earliest)
202*0fca6ea1SDimitry Andric     -> zoned_time<common_type_t<_Duration, seconds>, __time_zone_representation<_TimeZonePtrOrName>>;
203*0fca6ea1SDimitry Andric 
204*0fca6ea1SDimitry Andric template <class _Duration, class _TimeZonePtrOrName, class TimeZonePtr2>
205*0fca6ea1SDimitry Andric zoned_time(_TimeZonePtrOrName&&, zoned_time<_Duration, TimeZonePtr2>, choose = choose::earliest)
206*0fca6ea1SDimitry Andric     -> zoned_time<common_type_t<_Duration, seconds>, __time_zone_representation<_TimeZonePtrOrName>>;
207*0fca6ea1SDimitry Andric 
208*0fca6ea1SDimitry Andric using zoned_seconds = zoned_time<seconds>;
209*0fca6ea1SDimitry Andric 
210*0fca6ea1SDimitry Andric template <class _Duration1, class _Duration2, class _TimeZonePtr>
211*0fca6ea1SDimitry Andric _LIBCPP_HIDE_FROM_ABI bool
212*0fca6ea1SDimitry Andric operator==(const zoned_time<_Duration1, _TimeZonePtr>& __lhs, const zoned_time<_Duration2, _TimeZonePtr>& __rhs) {
213*0fca6ea1SDimitry Andric   return __lhs.get_time_zone() == __rhs.get_time_zone() && __lhs.get_sys_time() == __rhs.get_sys_time();
214*0fca6ea1SDimitry Andric }
215*0fca6ea1SDimitry Andric 
216*0fca6ea1SDimitry Andric } // namespace chrono
217*0fca6ea1SDimitry Andric 
218*0fca6ea1SDimitry Andric #  endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_TIME_ZONE_DATABASE) && !defined(_LIBCPP_HAS_NO_FILESYSTEM)
219*0fca6ea1SDimitry Andric          // && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
220*0fca6ea1SDimitry Andric 
221*0fca6ea1SDimitry Andric _LIBCPP_END_NAMESPACE_STD
222*0fca6ea1SDimitry Andric 
223*0fca6ea1SDimitry Andric _LIBCPP_POP_MACROS
224*0fca6ea1SDimitry Andric 
225*0fca6ea1SDimitry Andric #endif // !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_TZDB)
226*0fca6ea1SDimitry Andric 
227*0fca6ea1SDimitry Andric #endif // _LIBCPP___CHRONO_ZONED_TIME_H
228