libcxx/include/__chrono/tzdb_list.h

   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 !defined(_LIBCPP_HAS_NO_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 // !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_TZDB)
 107
 108 #endif // _LIBCPP___CHRONO_TZDB_LIST_H