xref: /llvm-project/libcxx/include/__chrono/tzdb_list.h (revision 24e70e3930724ce499ad05d669bfbc4423c542e0)
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_TZDB_LIST_H
13 #define _LIBCPP___CHRONO_TZDB_LIST_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 <__chrono/time_zone.h>
20 #  include <__chrono/tzdb.h>
21 #  include <__config>
22 #  include <__fwd/string.h>
23 #  include <forward_list>
24 #  include <string_view>
25 
26 #  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
27 #    pragma GCC system_header
28 #  endif
29 
30 _LIBCPP_BEGIN_NAMESPACE_STD
31 
32 #  if _LIBCPP_STD_VER >= 20 && _LIBCPP_HAS_TIME_ZONE_DATABASE && _LIBCPP_HAS_FILESYSTEM && _LIBCPP_HAS_LOCALIZATION
33 
34 namespace chrono {
35 
36 // TODO TZDB
37 // Libc++ recently switched to only export __ugly_names from the dylib.
38 // Since the library is still experimental the functions in this header
39 // should be adapted to this new style. The other tzdb headers should be
40 // evaluated too.
41 
42 class _LIBCPP_AVAILABILITY_TZDB tzdb_list {
43 public:
44   class __impl; // public to allow construction in dylib
45   _LIBCPP_HIDE_FROM_ABI explicit tzdb_list(__impl* __p) : __impl_(__p) {
46     _LIBCPP_ASSERT_NON_NULL(__impl_ != nullptr, "initialized time_zone without a valid pimpl object");
47   }
48   _LIBCPP_EXPORTED_FROM_ABI ~tzdb_list();
49 
50   tzdb_list(const tzdb_list&)            = delete;
51   tzdb_list& operator=(const tzdb_list&) = delete;
52 
53   using const_iterator = forward_list<tzdb>::const_iterator;
54 
55   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI const tzdb& front() const noexcept { return __front(); }
56 
57   _LIBCPP_HIDE_FROM_ABI const_iterator erase_after(const_iterator __p) { return __erase_after(__p); }
58 
59   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI const_iterator begin() const noexcept { return __begin(); }
60   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI const_iterator end() const noexcept { return __end(); }
61 
62   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const noexcept { return __cbegin(); }
63   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI const_iterator cend() const noexcept { return __cend(); }
64 
65   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI __impl& __implementation() { return *__impl_; }
66 
67 private:
68   [[nodiscard]] _LIBCPP_EXPORTED_FROM_ABI const tzdb& __front() const noexcept;
69 
70   _LIBCPP_EXPORTED_FROM_ABI const_iterator __erase_after(const_iterator __p);
71 
72   [[nodiscard]] _LIBCPP_EXPORTED_FROM_ABI const_iterator __begin() const noexcept;
73   [[nodiscard]] _LIBCPP_EXPORTED_FROM_ABI const_iterator __end() const noexcept;
74 
75   [[nodiscard]] _LIBCPP_EXPORTED_FROM_ABI const_iterator __cbegin() const noexcept;
76   [[nodiscard]] _LIBCPP_EXPORTED_FROM_ABI const_iterator __cend() const noexcept;
77 
78   __impl* __impl_;
79 };
80 
81 [[nodiscard]] _LIBCPP_AVAILABILITY_TZDB _LIBCPP_EXPORTED_FROM_ABI tzdb_list& get_tzdb_list();
82 
83 [[nodiscard]] _LIBCPP_AVAILABILITY_TZDB _LIBCPP_HIDE_FROM_ABI inline const tzdb& get_tzdb() {
84   return get_tzdb_list().front();
85 }
86 
87 [[nodiscard]] _LIBCPP_AVAILABILITY_TZDB _LIBCPP_HIDE_FROM_ABI inline const time_zone* locate_zone(string_view __name) {
88   return get_tzdb().locate_zone(__name);
89 }
90 
91 [[nodiscard]] _LIBCPP_AVAILABILITY_TZDB _LIBCPP_HIDE_FROM_ABI inline const time_zone* current_zone() {
92   return get_tzdb().current_zone();
93 }
94 
95 _LIBCPP_AVAILABILITY_TZDB _LIBCPP_EXPORTED_FROM_ABI const tzdb& reload_tzdb();
96 
97 [[nodiscard]] _LIBCPP_AVAILABILITY_TZDB _LIBCPP_EXPORTED_FROM_ABI string remote_version();
98 
99 } // namespace chrono
100 
101 #  endif // _LIBCPP_STD_VER >= 20 && _LIBCPP_HAS_TIME_ZONE_DATABASE && _LIBCPP_HAS_FILESYSTEM &&
102          // _LIBCPP_HAS_LOCALIZATION
103 
104 _LIBCPP_END_NAMESPACE_STD
105 
106 #endif // _LIBCPP_HAS_EXPERIMENTAL_TZDB
107 
108 #endif // _LIBCPP___CHRONO_TZDB_LIST_H
109