1// -*- C++ -*-
 2//===----------------------------------------------------------------------===//
 3//
 4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 5// See https://llvm.org/LICENSE.txt for license information.
 6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 7//
 8//===----------------------------------------------------------------------===//
 9
10// For information see https://libcxx.llvm.org/DesignDocs/TimeZone.html
11
12#ifndef _LIBCPP___CHRONO_TIME_ZONE_LINK_H
13#define _LIBCPP___CHRONO_TIME_ZONE_LINK_H
14
15#include <version>
16// Enable the contents of the header only when libc++ was built with experimental features enabled.
17#if _LIBCPP_HAS_EXPERIMENTAL_TZDB
18
19#  include <__compare/strong_order.h>
20#  include <__config>
21#  include <__utility/private_constructor_tag.h>
22#  include <string>
23#  include <string_view>
24
25#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
26#    pragma GCC system_header
27#  endif
28
29_LIBCPP_PUSH_MACROS
30#  include <__undef_macros>
31
32_LIBCPP_BEGIN_NAMESPACE_STD
33
34#  if _LIBCPP_STD_VER >= 20 && _LIBCPP_HAS_TIME_ZONE_DATABASE && _LIBCPP_HAS_FILESYSTEM && _LIBCPP_HAS_LOCALIZATION
35
36namespace chrono {
37
38class time_zone_link {
39public:
40  [[nodiscard]]
41  _LIBCPP_HIDE_FROM_ABI explicit time_zone_link(__private_constructor_tag, string_view __name, string_view __target)
42      : __name_{__name}, __target_{__target} {}
43
44  _LIBCPP_HIDE_FROM_ABI time_zone_link(time_zone_link&&)            = default;
45  _LIBCPP_HIDE_FROM_ABI time_zone_link& operator=(time_zone_link&&) = default;
46
47  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI string_view name() const noexcept { return __name_; }
48  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI string_view target() const noexcept { return __target_; }
49
50private:
51  string __name_;
52  // TODO TZDB instead of the name we can store the pointer to a zone. These
53  // pointers are immutable. This makes it possible to directly return a
54  // pointer in the time_zone in the 'locate_zone' function.
55  string __target_;
56};
57
58[[nodiscard]] _LIBCPP_AVAILABILITY_TZDB _LIBCPP_HIDE_FROM_ABI inline bool
59operator==(const time_zone_link& __x, const time_zone_link& __y) noexcept {
60  return __x.name() == __y.name();
61}
62
63[[nodiscard]] _LIBCPP_AVAILABILITY_TZDB _LIBCPP_HIDE_FROM_ABI inline strong_ordering
64operator<=>(const time_zone_link& __x, const time_zone_link& __y) noexcept {
65  return __x.name() <=> __y.name();
66}
67
68} // namespace chrono
69
70#  endif // _LIBCPP_STD_VER >= 20 && _LIBCPP_HAS_TIME_ZONE_DATABASE && _LIBCPP_HAS_FILESYSTEM &&
71         // _LIBCPP_HAS_LOCALIZATION
72
73_LIBCPP_END_NAMESPACE_STD
74
75_LIBCPP_POP_MACROS
76
77#endif // _LIBCPP_HAS_EXPERIMENTAL_TZDB
78
79#endif // _LIBCPP___CHRONO_TIME_ZONE_LINK_H