ferencd@0: // The MIT License (MIT)
ferencd@0: //
ferencd@0: // Copyright (c) 2015, 2016, 2017 Howard Hinnant
ferencd@0: // Copyright (c) 2015 Ville Voutilainen
ferencd@0: // Copyright (c) 2016 Alexander Kormanovsky
ferencd@0: // Copyright (c) 2016, 2017 Jiangang Zhuang
ferencd@0: // Copyright (c) 2017 Nicolas Veloz Savino
ferencd@0: // Copyright (c) 2017 Florian Dang
ferencd@0: // Copyright (c) 2017 Aaron Bishop
ferencd@0: //
ferencd@0: // Permission is hereby granted, free of charge, to any person obtaining a copy
ferencd@0: // of this software and associated documentation files (the "Software"), to deal
ferencd@0: // in the Software without restriction, including without limitation the rights
ferencd@0: // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
ferencd@0: // copies of the Software, and to permit persons to whom the Software is
ferencd@0: // furnished to do so, subject to the following conditions:
ferencd@0: //
ferencd@0: // The above copyright notice and this permission notice shall be included in all
ferencd@0: // copies or substantial portions of the Software.
ferencd@0: //
ferencd@0: // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
ferencd@0: // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
ferencd@0: // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
ferencd@0: // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
ferencd@0: // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
ferencd@0: // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
ferencd@0: // SOFTWARE.
ferencd@0: //
ferencd@0: // Our apologies.  When the previous paragraph was written, lowercase had not yet
ferencd@0: // been invented (that would involve another several millennia of evolution).
ferencd@0: // We did not mean to shout.
ferencd@0: 
ferencd@0: #ifdef _WIN32
ferencd@0:    // windows.h will be included directly and indirectly (e.g. by curl).
ferencd@0:    // We need to define these macros to prevent windows.h bringing in
ferencd@0:    // more than we need and do it early so windows.h doesn't get included
ferencd@0:    // without these macros having been defined.
ferencd@0:    // min/max macros interfere with the C++ versions.
ferencd@0: #  ifndef NOMINMAX
ferencd@0: #    define NOMINMAX
ferencd@0: #  endif
ferencd@0:    // We don't need all that Windows has to offer.
ferencd@0: #  ifndef WIN32_LEAN_AND_MEAN
ferencd@0: #    define WIN32_LEAN_AND_MEAN
ferencd@0: #  endif
ferencd@0: 
ferencd@0:    // for wcstombs
ferencd@0: #  ifndef _CRT_SECURE_NO_WARNINGS
ferencd@0: #    define _CRT_SECURE_NO_WARNINGS
ferencd@0: #  endif
ferencd@0: 
ferencd@0:    // None of this happens with the MS SDK (at least VS14 which I tested), but:
ferencd@0:    // Compiling with mingw, we get "error: 'KF_FLAG_DEFAULT' was not declared in this scope."
ferencd@0:    // and error: 'SHGetKnownFolderPath' was not declared in this scope.".
ferencd@0:    // It seems when using mingw NTDDI_VERSION is undefined and that
ferencd@0:    // causes KNOWN_FOLDER_FLAG and the KF_ flags to not get defined.
ferencd@0:    // So we must define NTDDI_VERSION to get those flags on mingw.
ferencd@0:    // The docs say though here:
ferencd@0:    // https://msdn.microsoft.com/en-nz/library/windows/desktop/aa383745(v=vs.85).aspx
ferencd@0:    // that "If you define NTDDI_VERSION, you must also define _WIN32_WINNT."
ferencd@0:    // So we declare we require Vista or greater.
ferencd@0: #  ifdef __MINGW32__
ferencd@0: 
ferencd@0: #    ifndef NTDDI_VERSION
ferencd@0: #      define NTDDI_VERSION 0x06000000
ferencd@0: #      define _WIN32_WINNT _WIN32_WINNT_VISTA
ferencd@0: #    elif NTDDI_VERSION < 0x06000000
ferencd@0: #      warning "If this fails to compile NTDDI_VERSION may be to low. See comments above."
ferencd@0: #    endif
ferencd@0:      // But once we define the values above we then get this linker error:
ferencd@0:      // "tz.cpp:(.rdata$.refptr.FOLDERID_Downloads[.refptr.FOLDERID_Downloads]+0x0): "
ferencd@0:      //     "undefined reference to `FOLDERID_Downloads'"
ferencd@0:      // which #include <initguid.h> cures see:
ferencd@0:      // https://support.microsoft.com/en-us/kb/130869
ferencd@0: #    include <initguid.h>
ferencd@0:      // But with <initguid.h> included, the error moves on to:
ferencd@0:      // error: 'FOLDERID_Downloads' was not declared in this scope
ferencd@0:      // Which #include <knownfolders.h> cures.
ferencd@0: #    include <knownfolders.h>
ferencd@0: 
ferencd@0: #  endif  // __MINGW32__
ferencd@0: 
ferencd@0: #  include <windows.h>
ferencd@0: #endif  // _WIN32
ferencd@0: 
ferencd@0: #include "date/tz_private.h"
ferencd@0: 
ferencd@0: #ifdef __APPLE__
ferencd@0: #  include "date/ios.h"
ferencd@0: #else
ferencd@0: #  define TARGET_OS_IPHONE 0
ferencd@0: #endif
ferencd@0: 
ferencd@0: #if USE_OS_TZDB
ferencd@0: #  include <dirent.h>
ferencd@0: #endif
ferencd@0: #include <algorithm>
ferencd@0: #include <cctype>
ferencd@0: #include <cstdlib>
ferencd@0: #include <cstring>
ferencd@0: #include <cwchar>
ferencd@0: #include <exception>
ferencd@0: #include <fstream>
ferencd@0: #include <iostream>
ferencd@0: #include <iterator>
ferencd@0: #include <memory>
ferencd@0: #if USE_OS_TZDB
ferencd@0: #  include <queue>
ferencd@0: #endif
ferencd@0: #include <sstream>
ferencd@0: #include <string>
ferencd@0: #include <tuple>
ferencd@0: #include <vector>
ferencd@0: #include <sys/stat.h>
ferencd@0: 
ferencd@0: // unistd.h is used on some platforms as part of the the means to get
ferencd@0: // the current time zone. On Win32 windows.h provides a means to do it.
ferencd@0: // gcc/mingw supports unistd.h on Win32 but MSVC does not.
ferencd@0: 
ferencd@0: #ifdef _WIN32
ferencd@0: #  ifdef WINAPI_FAMILY
ferencd@0: #    include <winapifamily.h>
ferencd@0: #    if WINAPI_FAMILY != WINAPI_FAMILY_DESKTOP_APP
ferencd@0: #      define WINRT
ferencd@0: #      define INSTALL .
ferencd@0: #    endif
ferencd@0: #  endif
ferencd@0: 
ferencd@0: #  include <io.h> // _unlink etc.
ferencd@0: 
ferencd@0: #  if defined(__clang__)
ferencd@0:     struct IUnknown;    // fix for issue with static_cast<> in objbase.h
ferencd@0:                         //   (see https://github.com/philsquared/Catch/issues/690)
ferencd@0: #  endif
ferencd@0: 
ferencd@0: #  include <shlobj.h> // CoTaskFree, ShGetKnownFolderPath etc.
ferencd@0: #  if HAS_REMOTE_API
ferencd@0: #    include <direct.h> // _mkdir
ferencd@0: #    include <shellapi.h> // ShFileOperation etc.
ferencd@0: #  endif  // HAS_REMOTE_API
ferencd@0: #else   // !_WIN32
ferencd@0: #  include <unistd.h>
ferencd@0: #  if !USE_OS_TZDB
ferencd@0: #    include <wordexp.h>
ferencd@0: #  endif
ferencd@0: #  include <limits.h>
ferencd@0: #  include <string.h>
ferencd@0: #  if !USE_SHELL_API
ferencd@0: #    include <sys/stat.h>
ferencd@0: #    include <sys/fcntl.h>
ferencd@0: #    include <dirent.h>
ferencd@0: #    include <cstring>
ferencd@0: #    include <sys/wait.h>
ferencd@0: #    include <sys/types.h>
ferencd@0: #  endif //!USE_SHELL_API
ferencd@0: #endif  // !_WIN32
ferencd@0: 
ferencd@0: 
ferencd@0: #if HAS_REMOTE_API
ferencd@0:    // Note curl includes windows.h so we must include curl AFTER definitions of things
ferencd@0:    // that affect windows.h such as NOMINMAX.
ferencd@0: #if defined(_MSC_VER) && defined(SHORTENED_CURL_INCLUDE)
ferencd@0:    // For rmt_curl nuget package
ferencd@0: #  include <curl.h>
ferencd@0: #else
ferencd@0: #  include <curl/curl.h>
ferencd@0: #endif
ferencd@0: #endif
ferencd@0: 
ferencd@0: #ifdef _WIN32
ferencd@0: static CONSTDATA char folder_delimiter = '\\';
ferencd@0: #else   // !_WIN32
ferencd@0: static CONSTDATA char folder_delimiter = '/';
ferencd@0: #endif  // !_WIN32
ferencd@0: 
ferencd@0: #if defined(__GNUC__) && __GNUC__ < 5
ferencd@0:    // GCC 4.9 Bug 61489 Wrong warning with -Wmissing-field-initializers
ferencd@0: #  pragma GCC diagnostic push
ferencd@0: #  pragma GCC diagnostic ignored "-Wmissing-field-initializers"
ferencd@0: #endif  // defined(__GNUC__) && __GNUC__ < 5
ferencd@0: 
ferencd@0: #if !USE_OS_TZDB
ferencd@0: 
ferencd@0: #  ifdef _WIN32
ferencd@0: #    ifndef WINRT
ferencd@0: 
ferencd@0: namespace
ferencd@0: {
ferencd@0:     struct task_mem_deleter
ferencd@0:     {
ferencd@0:         void operator()(wchar_t buf[])
ferencd@0:         {
ferencd@0:             if (buf != nullptr)
ferencd@0:                 CoTaskMemFree(buf);
ferencd@0:         }
ferencd@0:     };
ferencd@0:     using co_task_mem_ptr = std::unique_ptr<wchar_t[], task_mem_deleter>;
ferencd@0: }
ferencd@0: 
ferencd@0: // We might need to know certain locations even if not using the remote API,
ferencd@0: // so keep these routines out of that block for now.
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_known_folder(const GUID& folderid)
ferencd@0: {
ferencd@0:     std::string folder;
ferencd@0:     PWSTR pfolder = nullptr;
ferencd@0:     HRESULT hr = SHGetKnownFolderPath(folderid, KF_FLAG_DEFAULT, nullptr, &pfolder);
ferencd@0:     if (SUCCEEDED(hr))
ferencd@0:     {
ferencd@0:         co_task_mem_ptr folder_ptr(pfolder);
ferencd@0:         const wchar_t* fptr = folder_ptr.get();
ferencd@0:         auto state = std::mbstate_t();
ferencd@0:         const auto required = std::wcsrtombs(nullptr, &fptr, 0, &state);
ferencd@0:         if (required != 0 && required != std::size_t(-1))
ferencd@0:         {
ferencd@0:             folder.resize(required);
ferencd@0:             std::wcsrtombs(&folder[0], &fptr, folder.size(), &state);
ferencd@0:         }
ferencd@0:     }
ferencd@0:     return folder;
ferencd@0: }
ferencd@0: 
ferencd@0: #      ifndef INSTALL
ferencd@0: 
ferencd@0: // Usually something like "c:\Users\username\Downloads".
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_download_folder()
ferencd@0: {
ferencd@0:     return get_known_folder(FOLDERID_Downloads);
ferencd@0: }
ferencd@0: 
ferencd@0: #      endif  // !INSTALL
ferencd@0: 
ferencd@0: #    endif // WINRT
ferencd@0: #  else // !_WIN32
ferencd@0: 
ferencd@0: #    if !defined(INSTALL)
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: expand_path(std::string path)
ferencd@0: {
ferencd@0: #      if TARGET_OS_IPHONE
ferencd@0:     return date::iOSUtils::get_tzdata_path();
ferencd@0: #      else  // !TARGET_OS_IPHONE
ferencd@0:     ::wordexp_t w{};
ferencd@0:     std::unique_ptr<::wordexp_t, void(*)(::wordexp_t*)> hold{&w, ::wordfree};
ferencd@0:     ::wordexp(path.c_str(), &w, 0);
ferencd@0:     if (w.we_wordc != 1)
ferencd@0:         throw std::runtime_error("Cannot expand path: " + path);
ferencd@0:     path = w.we_wordv[0];
ferencd@0:     return path;
ferencd@0: #      endif  // !TARGET_OS_IPHONE
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_download_folder()
ferencd@0: {
ferencd@0:     return expand_path("~/Downloads");
ferencd@0: }
ferencd@0: 
ferencd@0: #    endif // !defined(INSTALL)
ferencd@0: 
ferencd@0: #  endif  // !_WIN32
ferencd@0: 
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: namespace date
ferencd@0: {
ferencd@0: // +---------------------+
ferencd@0: // | Begin Configuration |
ferencd@0: // +---------------------+
ferencd@0: 
ferencd@0: using namespace detail;
ferencd@0: 
ferencd@0: #if !USE_OS_TZDB
ferencd@0: 
ferencd@0: static
ferencd@0: std::string&
ferencd@0: access_install()
ferencd@0: {
ferencd@0:     static std::string install
ferencd@0: #ifndef INSTALL
ferencd@0: 
ferencd@0:     = get_download_folder() + folder_delimiter + "tzdata";
ferencd@0: 
ferencd@0: #else   // !INSTALL
ferencd@0: 
ferencd@0: #  define STRINGIZEIMP(x) #x
ferencd@0: #  define STRINGIZE(x) STRINGIZEIMP(x)
ferencd@0: 
ferencd@0:     = STRINGIZE(INSTALL) + std::string(1, folder_delimiter) + "tzdata";
ferencd@0: 
ferencd@0:     #undef STRINGIZEIMP
ferencd@0:     #undef STRINGIZE
ferencd@0: #endif  // !INSTALL
ferencd@0: 
ferencd@0:     return install;
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: set_install(const std::string& s)
ferencd@0: {
ferencd@0:     access_install() = s;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: const std::string&
ferencd@0: get_install()
ferencd@0: {
ferencd@0:     static const std::string& ref = access_install();
ferencd@0:     return ref;
ferencd@0: }
ferencd@0: 
ferencd@0: #if HAS_REMOTE_API
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_download_gz_file(const std::string& version)
ferencd@0: {
ferencd@0:     auto file = get_install() + version + ".tar.gz";
ferencd@0:     return file;
ferencd@0: }
ferencd@0: #endif  // HAS_REMOTE_API
ferencd@0: 
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: // These can be used to reduce the range of the database to save memory
ferencd@0: CONSTDATA auto min_year = date::year::min();
ferencd@0: CONSTDATA auto max_year = date::year::max();
ferencd@0: 
ferencd@0: CONSTDATA auto min_day = date::January/1;
ferencd@0: CONSTDATA auto max_day = date::December/31;
ferencd@0: 
ferencd@0: #if USE_OS_TZDB
ferencd@0: 
ferencd@0: CONSTCD14 const sys_seconds min_seconds = sys_days(min_year/min_day);
ferencd@0: 
ferencd@0: #endif  // USE_OS_TZDB
ferencd@0: 
ferencd@0: #ifndef _WIN32
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: discover_tz_dir()
ferencd@0: {
ferencd@0:     struct stat sb;
ferencd@0:     using namespace std;
ferencd@0: #  ifndef __APPLE__
ferencd@0:     CONSTDATA auto tz_dir_default = "/usr/share/zoneinfo";
ferencd@0:     CONSTDATA auto tz_dir_buildroot = "/usr/share/zoneinfo/uclibc";
ferencd@0: 
ferencd@0:     // Check special path which is valid for buildroot with uclibc builds
ferencd@0:     if(stat(tz_dir_buildroot, &sb) == 0 && S_ISDIR(sb.st_mode))
ferencd@0:         return tz_dir_buildroot;
ferencd@0:     else if(stat(tz_dir_default, &sb) == 0 && S_ISDIR(sb.st_mode))
ferencd@0:         return tz_dir_default;
ferencd@0:     else
ferencd@0:         throw runtime_error("discover_tz_dir failed to find zoneinfo\n");
ferencd@0: #  else  // __APPLE__
ferencd@0: #      if TARGET_OS_IPHONE
ferencd@0:     return "/var/db/timezone/zoneinfo";
ferencd@0: #      else
ferencd@0:     CONSTDATA auto timezone = "/etc/localtime";
ferencd@0:     if (!(lstat(timezone, &sb) == 0 && S_ISLNK(sb.st_mode) && sb.st_size > 0))
ferencd@0:         throw runtime_error("discover_tz_dir failed\n");
ferencd@0:     string result;
ferencd@0:     char rp[PATH_MAX+1] = {};
ferencd@0:     if (readlink(timezone, rp, sizeof(rp)-1) > 0)
ferencd@0:         result = string(rp);
ferencd@0:     else
ferencd@0:         throw system_error(errno, system_category(), "readlink() failed");
ferencd@0:     auto i = result.find("zoneinfo");
ferencd@0:     if (i == string::npos)
ferencd@0:         throw runtime_error("discover_tz_dir failed to find zoneinfo\n");
ferencd@0:     i = result.find('/', i);
ferencd@0:     if (i == string::npos)
ferencd@0:         throw runtime_error("discover_tz_dir failed to find '/'\n");
ferencd@0:     return result.substr(0, i);
ferencd@0: #      endif
ferencd@0: #  endif  // __APPLE__
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: const std::string&
ferencd@0: get_tz_dir()
ferencd@0: {
ferencd@0:     static const std::string tz_dir = discover_tz_dir();
ferencd@0:     return tz_dir;
ferencd@0: }
ferencd@0: 
ferencd@0: #endif
ferencd@0: 
ferencd@0: // +-------------------+
ferencd@0: // | End Configuration |
ferencd@0: // +-------------------+
ferencd@0: 
ferencd@0: #ifndef _MSC_VER
ferencd@0: static_assert(min_year <= max_year, "Configuration error");
ferencd@0: #endif
ferencd@0: 
ferencd@0: static std::unique_ptr<tzdb> init_tzdb();
ferencd@0: 
ferencd@0: tzdb_list::~tzdb_list()
ferencd@0: {
ferencd@0:     const tzdb* ptr = head_;
ferencd@0:     head_ = nullptr;
ferencd@0:     while (ptr != nullptr)
ferencd@0:     {
ferencd@0:         auto next = ptr->next;
ferencd@0:         delete ptr;
ferencd@0:         ptr = next;
ferencd@0:     }
ferencd@0: }
ferencd@0: 
ferencd@0: tzdb_list::tzdb_list(tzdb_list&& x) noexcept
ferencd@0:    : head_{x.head_.exchange(nullptr)}
ferencd@0: {
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: tzdb_list::push_front(tzdb* tzdb) noexcept
ferencd@0: {
ferencd@0:     tzdb->next = head_;
ferencd@0:     head_ = tzdb;
ferencd@0: }
ferencd@0: 
ferencd@0: tzdb_list::const_iterator
ferencd@0: tzdb_list::erase_after(const_iterator p) noexcept
ferencd@0: {
ferencd@0:     auto t = p.p_->next;
ferencd@0:     p.p_->next = p.p_->next->next;
ferencd@0:     delete t;
ferencd@0:     return ++p;
ferencd@0: }
ferencd@0: 
ferencd@0: struct tzdb_list::undocumented_helper
ferencd@0: {
ferencd@0:     static void push_front(tzdb_list& db_list, tzdb* tzdb) noexcept
ferencd@0:     {
ferencd@0:         db_list.push_front(tzdb);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: static
ferencd@0: tzdb_list
ferencd@0: create_tzdb()
ferencd@0: {
ferencd@0:     tzdb_list tz_db;
ferencd@0:     tzdb_list::undocumented_helper::push_front(tz_db, init_tzdb().release());
ferencd@0:     return tz_db;
ferencd@0: }
ferencd@0: 
ferencd@0: tzdb_list&
ferencd@0: get_tzdb_list()
ferencd@0: {
ferencd@0:     static tzdb_list tz_db = create_tzdb();
ferencd@0:     return tz_db;
ferencd@0: }
ferencd@0: 
ferencd@0: #if !USE_OS_TZDB
ferencd@0: 
ferencd@0: #ifdef _WIN32
ferencd@0: 
ferencd@0: static
ferencd@0: void
ferencd@0: sort_zone_mappings(std::vector<date::detail::timezone_mapping>& mappings)
ferencd@0: {
ferencd@0:     std::sort(mappings.begin(), mappings.end(),
ferencd@0:         [](const date::detail::timezone_mapping& lhs,
ferencd@0:            const date::detail::timezone_mapping& rhs)->bool
ferencd@0:     {
ferencd@0:         auto other_result = lhs.other.compare(rhs.other);
ferencd@0:         if (other_result < 0)
ferencd@0:             return true;
ferencd@0:         else if (other_result == 0)
ferencd@0:         {
ferencd@0:             auto territory_result = lhs.territory.compare(rhs.territory);
ferencd@0:             if (territory_result < 0)
ferencd@0:                 return true;
ferencd@0:             else if (territory_result == 0)
ferencd@0:             {
ferencd@0:                 if (lhs.type < rhs.type)
ferencd@0:                     return true;
ferencd@0:             }
ferencd@0:         }
ferencd@0:         return false;
ferencd@0:     });
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: bool
ferencd@0: native_to_standard_timezone_name(const std::string& native_tz_name,
ferencd@0:                                  std::string& standard_tz_name)
ferencd@0: {
ferencd@0:     // TOOD! Need be a case insensitive compare?
ferencd@0:     if (native_tz_name == "UTC")
ferencd@0:     {
ferencd@0:         standard_tz_name = "Etc/UTC";
ferencd@0:         return true;
ferencd@0:     }
ferencd@0:     standard_tz_name.clear();
ferencd@0:     // TODO! we can improve on linear search.
ferencd@0:     const auto& mappings = date::get_tzdb().mappings;
ferencd@0:     for (const auto& tzm : mappings)
ferencd@0:     {
ferencd@0:         if (tzm.other == native_tz_name)
ferencd@0:         {
ferencd@0:             standard_tz_name = tzm.type;
ferencd@0:             return true;
ferencd@0:         }
ferencd@0:     }
ferencd@0:     return false;
ferencd@0: }
ferencd@0: 
ferencd@0: // Parse this XML file:
ferencd@0: // https://raw.githubusercontent.com/unicode-org/cldr/master/common/supplemental/windowsZones.xml
ferencd@0: // The parsing method is designed to be simple and quick. It is not overly
ferencd@0: // forgiving of change but it should diagnose basic format issues.
ferencd@0: // See timezone_mapping structure for more info.
ferencd@0: static
ferencd@0: std::vector<detail::timezone_mapping>
ferencd@0: load_timezone_mappings_from_xml_file(const std::string& input_path)
ferencd@0: {
ferencd@0:     std::size_t line_num = 0;
ferencd@0:     std::vector<detail::timezone_mapping> mappings;
ferencd@0:     std::string line;
ferencd@0: 
ferencd@0:     std::ifstream is(input_path);
ferencd@0:     if (!is.is_open())
ferencd@0:     {
ferencd@0:         // We don't emit file exceptions because that's an implementation detail.
ferencd@0:         std::string msg = "Error opening time zone mapping file \"";
ferencd@0:         msg += input_path;
ferencd@0:         msg += "\".";
ferencd@0:         throw std::runtime_error(msg);
ferencd@0:     }
ferencd@0: 
ferencd@0:     auto error = [&input_path, &line_num](const char* info)
ferencd@0:     {
ferencd@0:         std::string msg = "Error loading time zone mapping file \"";
ferencd@0:         msg += input_path;
ferencd@0:         msg += "\" at line ";
ferencd@0:         msg += std::to_string(line_num);
ferencd@0:         msg += ": ";
ferencd@0:         msg += info;
ferencd@0:         throw std::runtime_error(msg);
ferencd@0:     };
ferencd@0:     // [optional space]a="b"
ferencd@0:     auto read_attribute = [&line, &error]
ferencd@0:                           (const char* name, std::string& value, std::size_t startPos)
ferencd@0:                           ->std::size_t
ferencd@0:     {
ferencd@0:         value.clear();
ferencd@0:         // Skip leading space before attribute name.
ferencd@0:         std::size_t spos = line.find_first_not_of(' ', startPos);
ferencd@0:         if (spos == std::string::npos)
ferencd@0:             spos = startPos;
ferencd@0:         // Assume everything up to next = is the attribute name
ferencd@0:         // and that an = will always delimit that.
ferencd@0:         std::size_t epos = line.find('=', spos);
ferencd@0:         if (epos == std::string::npos)
ferencd@0:             error("Expected \'=\' right after attribute name.");
ferencd@0:         std::size_t name_len = epos - spos;
ferencd@0:         // Expect the name we find matches the name we expect.
ferencd@0:         if (line.compare(spos, name_len, name) != 0)
ferencd@0:         {
ferencd@0:             std::string msg;
ferencd@0:             msg = "Expected attribute name \'";
ferencd@0:             msg += name;
ferencd@0:             msg += "\' around position ";
ferencd@0:             msg += std::to_string(spos);
ferencd@0:             msg += " but found something else.";
ferencd@0:             error(msg.c_str());
ferencd@0:         }
ferencd@0:         ++epos; // Skip the '=' that is after the attribute name.
ferencd@0:         spos = epos;
ferencd@0:         if (spos < line.length() && line[spos] == '\"')
ferencd@0:             ++spos; // Skip the quote that is before the attribute value.
ferencd@0:         else
ferencd@0:         {
ferencd@0:             std::string msg = "Expected '\"' to begin value of attribute \'";
ferencd@0:             msg += name;
ferencd@0:             msg += "\'.";
ferencd@0:             error(msg.c_str());
ferencd@0:         }
ferencd@0:         epos = line.find('\"', spos);
ferencd@0:         if (epos == std::string::npos)
ferencd@0:         {
ferencd@0:             std::string msg = "Expected '\"' to end value of attribute \'";
ferencd@0:             msg += name;
ferencd@0:             msg += "\'.";
ferencd@0:             error(msg.c_str());
ferencd@0:         }
ferencd@0:         // Extract everything in between the quotes. Note no escaping is done.
ferencd@0:         std::size_t value_len = epos - spos;
ferencd@0:         value.assign(line, spos, value_len);
ferencd@0:         ++epos; // Skip the quote that is after the attribute value;
ferencd@0:         return epos;
ferencd@0:     };
ferencd@0: 
ferencd@0:     // Quick but not overly forgiving XML mapping file processing.
ferencd@0:     bool mapTimezonesOpenTagFound = false;
ferencd@0:     bool mapTimezonesCloseTagFound = false;
ferencd@0:     std::size_t mapZonePos = std::string::npos;
ferencd@0:     std::size_t mapTimezonesPos = std::string::npos;
ferencd@0:     CONSTDATA char mapTimeZonesOpeningTag[] = { "<mapTimezones " };
ferencd@0:     CONSTDATA char mapZoneOpeningTag[] = { "<mapZone " };
ferencd@0:     CONSTDATA std::size_t mapZoneOpeningTagLen = sizeof(mapZoneOpeningTag) /
ferencd@0:                                                  sizeof(mapZoneOpeningTag[0]) - 1;
ferencd@0:     while (!mapTimezonesOpenTagFound)
ferencd@0:     {
ferencd@0:         std::getline(is, line);
ferencd@0:         ++line_num;
ferencd@0:         if (is.eof())
ferencd@0:         {
ferencd@0:             // If there is no mapTimezones tag is it an error?
ferencd@0:             // Perhaps if there are no mapZone mappings it might be ok for
ferencd@0:             // its parent mapTimezones element to be missing?
ferencd@0:             // We treat this as an error though on the assumption that if there
ferencd@0:             // really are no mappings we should still get a mapTimezones parent
ferencd@0:             // element but no mapZone elements inside. Assuming we must
ferencd@0:             // find something will hopefully at least catch more drastic formatting
ferencd@0:             // changes or errors than if we don't do this and assume nothing found.
ferencd@0:             error("Expected a mapTimezones opening tag.");
ferencd@0:         }
ferencd@0:         mapTimezonesPos = line.find(mapTimeZonesOpeningTag);
ferencd@0:         mapTimezonesOpenTagFound = (mapTimezonesPos != std::string::npos);
ferencd@0:     }
ferencd@0: 
ferencd@0:     // NOTE: We could extract the version info that follows the opening
ferencd@0:     // mapTimezones tag and compare that to the version of other data we have.
ferencd@0:     // I would have expected them to be kept in synch but testing has shown
ferencd@0:     // it typically does not match anyway. So what's the point?
ferencd@0:     while (!mapTimezonesCloseTagFound)
ferencd@0:     {
ferencd@0:         std::ws(is);
ferencd@0:         std::getline(is, line);
ferencd@0:         ++line_num;
ferencd@0:         if (is.eof())
ferencd@0:             error("Expected a mapTimezones closing tag.");
ferencd@0:         if (line.empty())
ferencd@0:             continue;
ferencd@0:         mapZonePos = line.find(mapZoneOpeningTag);
ferencd@0:         if (mapZonePos != std::string::npos)
ferencd@0:         {
ferencd@0:             mapZonePos += mapZoneOpeningTagLen;
ferencd@0:             detail::timezone_mapping zm{};
ferencd@0:             std::size_t pos = read_attribute("other", zm.other, mapZonePos);
ferencd@0:             pos = read_attribute("territory", zm.territory, pos);
ferencd@0:             read_attribute("type", zm.type, pos);
ferencd@0:             mappings.push_back(std::move(zm));
ferencd@0: 
ferencd@0:             continue;
ferencd@0:         }
ferencd@0:         mapTimezonesPos = line.find("</mapTimezones>");
ferencd@0:         mapTimezonesCloseTagFound = (mapTimezonesPos != std::string::npos);
ferencd@0:         if (!mapTimezonesCloseTagFound)
ferencd@0:         {
ferencd@0:             std::size_t commentPos = line.find("<!--");
ferencd@0:             if (commentPos == std::string::npos)
ferencd@0:                 error("Unexpected mapping record found. A xml mapZone or comment "
ferencd@0:                       "attribute or mapTimezones closing tag was expected.");
ferencd@0:         }
ferencd@0:     }
ferencd@0: 
ferencd@0:     is.close();
ferencd@0:     return mappings;
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // _WIN32
ferencd@0: 
ferencd@0: // Parsing helpers
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: parse3(std::istream& in)
ferencd@0: {
ferencd@0:     std::string r(3, ' ');
ferencd@0:     ws(in);
ferencd@0:     r[0] = static_cast<char>(in.get());
ferencd@0:     r[1] = static_cast<char>(in.get());
ferencd@0:     r[2] = static_cast<char>(in.get());
ferencd@0:     return r;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: unsigned
ferencd@0: parse_dow(std::istream& in)
ferencd@0: {
ferencd@0:     CONSTDATA char*const dow_names[] =
ferencd@0:         {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
ferencd@0:     auto s = parse3(in);
ferencd@0:     auto dow = std::find(std::begin(dow_names), std::end(dow_names), s) - dow_names;
ferencd@0:     if (dow >= std::end(dow_names) - std::begin(dow_names))
ferencd@0:         throw std::runtime_error("oops: bad dow name: " + s);
ferencd@0:     return static_cast<unsigned>(dow);
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: unsigned
ferencd@0: parse_month(std::istream& in)
ferencd@0: {
ferencd@0:     CONSTDATA char*const month_names[] =
ferencd@0:         {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
ferencd@0:          "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
ferencd@0:     auto s = parse3(in);
ferencd@0:     auto m = std::find(std::begin(month_names), std::end(month_names), s) - month_names;
ferencd@0:     if (m >= std::end(month_names) - std::begin(month_names))
ferencd@0:         throw std::runtime_error("oops: bad month name: " + s);
ferencd@0:     return static_cast<unsigned>(++m);
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::chrono::seconds
ferencd@0: parse_unsigned_time(std::istream& in)
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     int x;
ferencd@0:     in >> x;
ferencd@0:     auto r = seconds{hours{x}};
ferencd@0:     if (!in.eof() && in.peek() == ':')
ferencd@0:     {
ferencd@0:         in.get();
ferencd@0:         in >> x;
ferencd@0:         r += minutes{x};
ferencd@0:         if (!in.eof() && in.peek() == ':')
ferencd@0:         {
ferencd@0:             in.get();
ferencd@0:             in >> x;
ferencd@0:             r += seconds{x};
ferencd@0:         }
ferencd@0:     }
ferencd@0:     return r;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::chrono::seconds
ferencd@0: parse_signed_time(std::istream& in)
ferencd@0: {
ferencd@0:     ws(in);
ferencd@0:     auto sign = 1;
ferencd@0:     if (in.peek() == '-')
ferencd@0:     {
ferencd@0:         sign = -1;
ferencd@0:         in.get();
ferencd@0:     }
ferencd@0:     else if (in.peek() == '+')
ferencd@0:         in.get();
ferencd@0:     return sign * parse_unsigned_time(in);
ferencd@0: }
ferencd@0: 
ferencd@0: // MonthDayTime
ferencd@0: 
ferencd@0: detail::MonthDayTime::MonthDayTime(local_seconds tp, tz timezone)
ferencd@0:     : zone_(timezone)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     const auto dp = date::floor<days>(tp);
ferencd@0:     const auto hms = make_time(tp - dp);
ferencd@0:     const auto ymd = year_month_day(dp);
ferencd@0:     u = ymd.month() / ymd.day();
ferencd@0:     h_ = hms.hours();
ferencd@0:     m_ = hms.minutes();
ferencd@0:     s_ = hms.seconds();
ferencd@0: }
ferencd@0: 
ferencd@0: detail::MonthDayTime::MonthDayTime(const date::month_day& md, tz timezone)
ferencd@0:     : zone_(timezone)
ferencd@0: {
ferencd@0:     u = md;
ferencd@0: }
ferencd@0: 
ferencd@0: date::day
ferencd@0: detail::MonthDayTime::day() const
ferencd@0: {
ferencd@0:     switch (type_)
ferencd@0:     {
ferencd@0:     case month_day:
ferencd@0:         return u.month_day_.day();
ferencd@0:     case month_last_dow:
ferencd@0:         return date::day{31};
ferencd@0:     case lteq:
ferencd@0:     case gteq:
ferencd@0:         break;
ferencd@0:     }
ferencd@0:     return u.month_day_weekday_.month_day_.day();
ferencd@0: }
ferencd@0: 
ferencd@0: date::month
ferencd@0: detail::MonthDayTime::month() const
ferencd@0: {
ferencd@0:     switch (type_)
ferencd@0:     {
ferencd@0:     case month_day:
ferencd@0:         return u.month_day_.month();
ferencd@0:     case month_last_dow:
ferencd@0:         return u.month_weekday_last_.month();
ferencd@0:     case lteq:
ferencd@0:     case gteq:
ferencd@0:         break;
ferencd@0:     }
ferencd@0:     return u.month_day_weekday_.month_day_.month();
ferencd@0: }
ferencd@0: 
ferencd@0: int
ferencd@0: detail::MonthDayTime::compare(date::year y, const MonthDayTime& x, date::year yx,
ferencd@0:                       std::chrono::seconds offset, std::chrono::minutes prev_save) const
ferencd@0: {
ferencd@0:     if (zone_ != x.zone_)
ferencd@0:     {
ferencd@0:         auto dp0 = to_sys_days(y);
ferencd@0:         auto dp1 = x.to_sys_days(yx);
ferencd@0:         if (std::abs((dp0-dp1).count()) > 1)
ferencd@0:             return dp0 < dp1 ? -1 : 1;
ferencd@0:         if (zone_ == tz::local)
ferencd@0:         {
ferencd@0:             auto tp0 = to_time_point(y) - prev_save;
ferencd@0:             if (x.zone_ == tz::utc)
ferencd@0:                 tp0 -= offset;
ferencd@0:             auto tp1 = x.to_time_point(yx);
ferencd@0:             return tp0 < tp1 ? -1 : tp0 == tp1 ? 0 : 1;
ferencd@0:         }
ferencd@0:         else if (zone_ == tz::standard)
ferencd@0:         {
ferencd@0:             auto tp0 = to_time_point(y);
ferencd@0:             auto tp1 = x.to_time_point(yx);
ferencd@0:             if (x.zone_ == tz::local)
ferencd@0:                 tp1 -= prev_save;
ferencd@0:             else
ferencd@0:                 tp0 -= offset;
ferencd@0:             return tp0 < tp1 ? -1 : tp0 == tp1 ? 0 : 1;
ferencd@0:         }
ferencd@0:         // zone_ == tz::utc
ferencd@0:         auto tp0 = to_time_point(y);
ferencd@0:         auto tp1 = x.to_time_point(yx);
ferencd@0:         if (x.zone_ == tz::local)
ferencd@0:             tp1 -= offset + prev_save;
ferencd@0:         else
ferencd@0:             tp1 -= offset;
ferencd@0:         return tp0 < tp1 ? -1 : tp0 == tp1 ? 0 : 1;
ferencd@0:     }
ferencd@0:     auto const t0 = to_time_point(y);
ferencd@0:     auto const t1 = x.to_time_point(yx);
ferencd@0:     return t0 < t1 ? -1 : t0 == t1 ? 0 : 1;
ferencd@0: }
ferencd@0: 
ferencd@0: sys_seconds
ferencd@0: detail::MonthDayTime::to_sys(date::year y, std::chrono::seconds offset,
ferencd@0:                      std::chrono::seconds save) const
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     using namespace std::chrono;
ferencd@0:     auto until_utc = to_time_point(y);
ferencd@0:     if (zone_ == tz::standard)
ferencd@0:         until_utc -= offset;
ferencd@0:     else if (zone_ == tz::local)
ferencd@0:         until_utc -= offset + save;
ferencd@0:     return until_utc;
ferencd@0: }
ferencd@0: 
ferencd@0: detail::MonthDayTime::U&
ferencd@0: detail::MonthDayTime::U::operator=(const date::month_day& x)
ferencd@0: {
ferencd@0:     month_day_ = x;
ferencd@0:     return *this;
ferencd@0: }
ferencd@0: 
ferencd@0: detail::MonthDayTime::U&
ferencd@0: detail::MonthDayTime::U::operator=(const date::month_weekday_last& x)
ferencd@0: {
ferencd@0:     month_weekday_last_ = x;
ferencd@0:     return *this;
ferencd@0: }
ferencd@0: 
ferencd@0: detail::MonthDayTime::U&
ferencd@0: detail::MonthDayTime::U::operator=(const pair& x)
ferencd@0: {
ferencd@0:     month_day_weekday_ = x;
ferencd@0:     return *this;
ferencd@0: }
ferencd@0: 
ferencd@0: date::sys_days
ferencd@0: detail::MonthDayTime::to_sys_days(date::year y) const
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     using namespace date;
ferencd@0:     switch (type_)
ferencd@0:     {
ferencd@0:     case month_day:
ferencd@0:         return sys_days(y/u.month_day_);
ferencd@0:     case month_last_dow:
ferencd@0:         return sys_days(y/u.month_weekday_last_);
ferencd@0:     case lteq:
ferencd@0:         {
ferencd@0:             auto const x = y/u.month_day_weekday_.month_day_;
ferencd@0:             auto const wd1 = weekday(static_cast<sys_days>(x));
ferencd@0:             auto const wd0 = u.month_day_weekday_.weekday_;
ferencd@0:             return sys_days(x) - (wd1-wd0);
ferencd@0:         }
ferencd@0:     case gteq:
ferencd@0:         break;
ferencd@0:     }
ferencd@0:     auto const x = y/u.month_day_weekday_.month_day_;
ferencd@0:     auto const wd1 = u.month_day_weekday_.weekday_;
ferencd@0:     auto const wd0 = weekday(static_cast<sys_days>(x));
ferencd@0:     return sys_days(x) + (wd1-wd0);
ferencd@0: }
ferencd@0: 
ferencd@0: sys_seconds
ferencd@0: detail::MonthDayTime::to_time_point(date::year y) const
ferencd@0: {
ferencd@0:     // Add seconds first to promote to largest rep early to prevent overflow
ferencd@0:     return to_sys_days(y) + s_ + h_ + m_;
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: detail::MonthDayTime::canonicalize(date::year y)
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     using namespace date;
ferencd@0:     switch (type_)
ferencd@0:     {
ferencd@0:     case month_day:
ferencd@0:         return;
ferencd@0:     case month_last_dow:
ferencd@0:         {
ferencd@0:             auto const ymd = year_month_day(sys_days(y/u.month_weekday_last_));
ferencd@0:             u.month_day_ = ymd.month()/ymd.day();
ferencd@0:             type_ = month_day;
ferencd@0:             return;
ferencd@0:         }
ferencd@0:     case lteq:
ferencd@0:         {
ferencd@0:             auto const x = y/u.month_day_weekday_.month_day_;
ferencd@0:             auto const wd1 = weekday(static_cast<sys_days>(x));
ferencd@0:             auto const wd0 = u.month_day_weekday_.weekday_;
ferencd@0:             auto const ymd = year_month_day(sys_days(x) - (wd1-wd0));
ferencd@0:             u.month_day_ = ymd.month()/ymd.day();
ferencd@0:             type_ = month_day;
ferencd@0:             return;
ferencd@0:         }
ferencd@0:     case gteq:
ferencd@0:         {
ferencd@0:             auto const x = y/u.month_day_weekday_.month_day_;
ferencd@0:             auto const wd1 = u.month_day_weekday_.weekday_;
ferencd@0:             auto const wd0 = weekday(static_cast<sys_days>(x));
ferencd@0:             auto const ymd = year_month_day(sys_days(x) + (wd1-wd0));
ferencd@0:             u.month_day_ = ymd.month()/ymd.day();
ferencd@0:             type_ = month_day;
ferencd@0:             return;
ferencd@0:         }
ferencd@0:     }
ferencd@0: }
ferencd@0: 
ferencd@0: std::istream&
ferencd@0: detail::operator>>(std::istream& is, MonthDayTime& x)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     using namespace std::chrono;
ferencd@0:     assert(((std::ios::failbit | std::ios::badbit) & is.exceptions()) ==
ferencd@0:             (std::ios::failbit | std::ios::badbit));
ferencd@0:     x = MonthDayTime{};
ferencd@0:     if (!is.eof() && ws(is) && !is.eof() && is.peek() != '#')
ferencd@0:     {
ferencd@0:         auto m = parse_month(is);
ferencd@0:         if (!is.eof() && ws(is) && !is.eof() && is.peek() != '#')
ferencd@0:         {
ferencd@0:             if (is.peek() == 'l')
ferencd@0:             {
ferencd@0:                 for (int i = 0; i < 4; ++i)
ferencd@0:                     is.get();
ferencd@0:                 auto dow = parse_dow(is);
ferencd@0:                 x.type_ = MonthDayTime::month_last_dow;
ferencd@0:                 x.u = date::month(m)/weekday(dow)[last];
ferencd@0:             }
ferencd@0:             else if (std::isalpha(is.peek()))
ferencd@0:             {
ferencd@0:                 auto dow = parse_dow(is);
ferencd@0:                 char c{};
ferencd@0:                 is >> c;
ferencd@0:                 if (c == '<' || c == '>')
ferencd@0:                 {
ferencd@0:                     char c2{};
ferencd@0:                     is >> c2;
ferencd@0:                     if (c2 != '=')
ferencd@0:                         throw std::runtime_error(std::string("bad operator: ") + c + c2);
ferencd@0:                     int d;
ferencd@0:                     is >> d;
ferencd@0:                     if (d < 1 || d > 31)
ferencd@0:                         throw std::runtime_error(std::string("bad operator: ") + c + c2
ferencd@0:                                  + std::to_string(d));
ferencd@0:                     x.type_ = c == '<' ? MonthDayTime::lteq : MonthDayTime::gteq;
ferencd@0:                     x.u = MonthDayTime::pair{ date::month(m) / d, date::weekday(dow) };
ferencd@0:                 }
ferencd@0:                 else
ferencd@0:                     throw std::runtime_error(std::string("bad operator: ") + c);
ferencd@0:             }
ferencd@0:             else  // if (std::isdigit(is.peek())
ferencd@0:             {
ferencd@0:                 int d;
ferencd@0:                 is >> d;
ferencd@0:                 if (d < 1 || d > 31)
ferencd@0:                     throw std::runtime_error(std::string("day of month: ")
ferencd@0:                              + std::to_string(d));
ferencd@0:                 x.type_ = MonthDayTime::month_day;
ferencd@0:                 x.u = date::month(m)/d;
ferencd@0:             }
ferencd@0:             if (!is.eof() && ws(is) && !is.eof() && is.peek() != '#')
ferencd@0:             {
ferencd@0:                 int t;
ferencd@0:                 is >> t;
ferencd@0:                 x.h_ = hours{t};
ferencd@0:                 if (!is.eof() && is.peek() == ':')
ferencd@0:                 {
ferencd@0:                     is.get();
ferencd@0:                     is >> t;
ferencd@0:                     x.m_ = minutes{t};
ferencd@0:                     if (!is.eof() && is.peek() == ':')
ferencd@0:                     {
ferencd@0:                         is.get();
ferencd@0:                         is >> t;
ferencd@0:                         x.s_ = seconds{t};
ferencd@0:                     }
ferencd@0:                 }
ferencd@0:                 if (!is.eof() && std::isalpha(is.peek()))
ferencd@0:                 {
ferencd@0:                     char c;
ferencd@0:                     is >> c;
ferencd@0:                     switch (c)
ferencd@0:                     {
ferencd@0:                     case 's':
ferencd@0:                         x.zone_ = tz::standard;
ferencd@0:                         break;
ferencd@0:                     case 'u':
ferencd@0:                         x.zone_ = tz::utc;
ferencd@0:                         break;
ferencd@0:                     }
ferencd@0:                 }
ferencd@0:             }
ferencd@0:         }
ferencd@0:         else
ferencd@0:         {
ferencd@0:             x.u = month{m}/1;
ferencd@0:         }
ferencd@0:     }
ferencd@0:     return is;
ferencd@0: }
ferencd@0: 
ferencd@0: std::ostream&
ferencd@0: detail::operator<<(std::ostream& os, const MonthDayTime& x)
ferencd@0: {
ferencd@0:     switch (x.type_)
ferencd@0:     {
ferencd@0:     case MonthDayTime::month_day:
ferencd@0:         os << x.u.month_day_ << "                  ";
ferencd@0:         break;
ferencd@0:     case MonthDayTime::month_last_dow:
ferencd@0:         os << x.u.month_weekday_last_ << "           ";
ferencd@0:         break;
ferencd@0:     case MonthDayTime::lteq:
ferencd@0:         os << x.u.month_day_weekday_.weekday_ << " on or before "
ferencd@0:            << x.u.month_day_weekday_.month_day_ << "  ";
ferencd@0:         break;
ferencd@0:     case MonthDayTime::gteq:
ferencd@0:         if ((static_cast<unsigned>(x.day()) - 1) % 7 == 0)
ferencd@0:         {
ferencd@0:             os << (x.u.month_day_weekday_.month_day_.month() /
ferencd@0:                    x.u.month_day_weekday_.weekday_[
ferencd@0:                        (static_cast<unsigned>(x.day()) - 1)/7+1]) << "              ";
ferencd@0:         }
ferencd@0:         else
ferencd@0:         {
ferencd@0:             os << x.u.month_day_weekday_.weekday_ << " on or after "
ferencd@0:                << x.u.month_day_weekday_.month_day_ << "  ";
ferencd@0:         }
ferencd@0:         break;
ferencd@0:     }
ferencd@0:     os << date::make_time(x.s_ + x.h_ + x.m_);
ferencd@0:     if (x.zone_ == tz::utc)
ferencd@0:         os << "UTC   ";
ferencd@0:     else if (x.zone_ == tz::standard)
ferencd@0:         os << "STD   ";
ferencd@0:     else
ferencd@0:         os << "      ";
ferencd@0:     return os;
ferencd@0: }
ferencd@0: 
ferencd@0: // Rule
ferencd@0: 
ferencd@0: detail::Rule::Rule(const std::string& s)
ferencd@0: {
ferencd@0:     try
ferencd@0:     {
ferencd@0:         using namespace date;
ferencd@0:         using namespace std::chrono;
ferencd@0:         std::istringstream in(s);
ferencd@0:         in.exceptions(std::ios::failbit | std::ios::badbit);
ferencd@0:         std::string word;
ferencd@0:         in >> word >> name_;
ferencd@0:         int x;
ferencd@0:         ws(in);
ferencd@0:         if (std::isalpha(in.peek()))
ferencd@0:         {
ferencd@0:             in >> word;
ferencd@0:             if (word == "min")
ferencd@0:             {
ferencd@0:                 starting_year_ = year::min();
ferencd@0:             }
ferencd@0:             else
ferencd@0:                 throw std::runtime_error("Didn't find expected word: " + word);
ferencd@0:         }
ferencd@0:         else
ferencd@0:         {
ferencd@0:             in >> x;
ferencd@0:             starting_year_ = year{x};
ferencd@0:         }
ferencd@0:         std::ws(in);
ferencd@0:         if (std::isalpha(in.peek()))
ferencd@0:         {
ferencd@0:             in >> word;
ferencd@0:             if (word == "only")
ferencd@0:             {
ferencd@0:                 ending_year_ = starting_year_;
ferencd@0:             }
ferencd@0:             else if (word == "max")
ferencd@0:             {
ferencd@0:                 ending_year_ = year::max();
ferencd@0:             }
ferencd@0:             else
ferencd@0:                 throw std::runtime_error("Didn't find expected word: " + word);
ferencd@0:         }
ferencd@0:         else
ferencd@0:         {
ferencd@0:             in >> x;
ferencd@0:             ending_year_ = year{x};
ferencd@0:         }
ferencd@0:         in >> word;  // TYPE (always "-")
ferencd@0:         assert(word == "-");
ferencd@0:         in >> starting_at_;
ferencd@0:         save_ = duration_cast<minutes>(parse_signed_time(in));
ferencd@0:         in >> abbrev_;
ferencd@0:         if (abbrev_ == "-")
ferencd@0:             abbrev_.clear();
ferencd@0:         assert(hours{-1} <= save_ && save_ <= hours{2});
ferencd@0:     }
ferencd@0:     catch (...)
ferencd@0:     {
ferencd@0:         std::cerr << s << '\n';
ferencd@0:         std::cerr << *this << '\n';
ferencd@0:         throw;
ferencd@0:     }
ferencd@0: }
ferencd@0: 
ferencd@0: detail::Rule::Rule(const Rule& r, date::year starting_year, date::year ending_year)
ferencd@0:     : name_(r.name_)
ferencd@0:     , starting_year_(starting_year)
ferencd@0:     , ending_year_(ending_year)
ferencd@0:     , starting_at_(r.starting_at_)
ferencd@0:     , save_(r.save_)
ferencd@0:     , abbrev_(r.abbrev_)
ferencd@0: {
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator==(const Rule& x, const Rule& y)
ferencd@0: {
ferencd@0:     if (std::tie(x.name_, x.save_, x.starting_year_, x.ending_year_) ==
ferencd@0:         std::tie(y.name_, y.save_, y.starting_year_, y.ending_year_))
ferencd@0:         return x.month() == y.month() && x.day() == y.day();
ferencd@0:     return false;
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator<(const Rule& x, const Rule& y)
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     auto const xm = x.month();
ferencd@0:     auto const ym = y.month();
ferencd@0:     if (std::tie(x.name_, x.starting_year_, xm, x.ending_year_) <
ferencd@0:         std::tie(y.name_, y.starting_year_, ym, y.ending_year_))
ferencd@0:         return true;
ferencd@0:     if (std::tie(x.name_, x.starting_year_, xm, x.ending_year_) >
ferencd@0:         std::tie(y.name_, y.starting_year_, ym, y.ending_year_))
ferencd@0:         return false;
ferencd@0:     return x.day() < y.day();
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator==(const Rule& x, const date::year& y)
ferencd@0: {
ferencd@0:     return x.starting_year_ <= y && y <= x.ending_year_;
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator<(const Rule& x, const date::year& y)
ferencd@0: {
ferencd@0:     return x.ending_year_ < y;
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator==(const date::year& x, const Rule& y)
ferencd@0: {
ferencd@0:     return y.starting_year_ <= x && x <= y.ending_year_;
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator<(const date::year& x, const Rule& y)
ferencd@0: {
ferencd@0:     return x < y.starting_year_;
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator==(const Rule& x, const std::string& y)
ferencd@0: {
ferencd@0:     return x.name() == y;
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator<(const Rule& x, const std::string& y)
ferencd@0: {
ferencd@0:     return x.name() < y;
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator==(const std::string& x, const Rule& y)
ferencd@0: {
ferencd@0:     return y.name() == x;
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::operator<(const std::string& x, const Rule& y)
ferencd@0: {
ferencd@0:     return x < y.name();
ferencd@0: }
ferencd@0: 
ferencd@0: std::ostream&
ferencd@0: detail::operator<<(std::ostream& os, const Rule& r)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     using namespace std::chrono;
ferencd@0:     detail::save_ostream<char> _(os);
ferencd@0:     os.fill(' ');
ferencd@0:     os.flags(std::ios::dec | std::ios::left);
ferencd@0:     os.width(15);
ferencd@0:     os << r.name_;
ferencd@0:     os << r.starting_year_ << "    " << r.ending_year_ << "    ";
ferencd@0:     os << r.starting_at_;
ferencd@0:     if (r.save_ >= minutes{0})
ferencd@0:         os << ' ';
ferencd@0:     os << date::make_time(r.save_) << "   ";
ferencd@0:     os << r.abbrev_;
ferencd@0:     return os;
ferencd@0: }
ferencd@0: 
ferencd@0: date::day
ferencd@0: detail::Rule::day() const
ferencd@0: {
ferencd@0:     return starting_at_.day();
ferencd@0: }
ferencd@0: 
ferencd@0: date::month
ferencd@0: detail::Rule::month() const
ferencd@0: {
ferencd@0:     return starting_at_.month();
ferencd@0: }
ferencd@0: 
ferencd@0: struct find_rule_by_name
ferencd@0: {
ferencd@0:     bool operator()(const Rule& x, const std::string& nm) const
ferencd@0:     {
ferencd@0:         return x.name() < nm;
ferencd@0:     }
ferencd@0: 
ferencd@0:     bool operator()(const std::string& nm, const Rule& x) const
ferencd@0:     {
ferencd@0:         return nm < x.name();
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: bool
ferencd@0: detail::Rule::overlaps(const Rule& x, const Rule& y)
ferencd@0: {
ferencd@0:     // assume x.starting_year_ <= y.starting_year_;
ferencd@0:     if (!(x.starting_year_ <= y.starting_year_))
ferencd@0:     {
ferencd@0:         std::cerr << x << '\n';
ferencd@0:         std::cerr << y << '\n';
ferencd@0:         assert(x.starting_year_ <= y.starting_year_);
ferencd@0:     }
ferencd@0:     if (y.starting_year_ > x.ending_year_)
ferencd@0:         return false;
ferencd@0:     return !(x.starting_year_ == y.starting_year_ && x.ending_year_ == y.ending_year_);
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: detail::Rule::split(std::vector<Rule>& rules, std::size_t i, std::size_t k, std::size_t& e)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     using difference_type = std::vector<Rule>::iterator::difference_type;
ferencd@0:     // rules[i].starting_year_ <= rules[k].starting_year_ &&
ferencd@0:     //     rules[i].ending_year_ >= rules[k].starting_year_ &&
ferencd@0:     //     (rules[i].starting_year_ != rules[k].starting_year_ ||
ferencd@0:     //      rules[i].ending_year_ != rules[k].ending_year_)
ferencd@0:     assert(rules[i].starting_year_ <= rules[k].starting_year_ &&
ferencd@0:            rules[i].ending_year_ >= rules[k].starting_year_ &&
ferencd@0:            (rules[i].starting_year_ != rules[k].starting_year_ ||
ferencd@0:             rules[i].ending_year_ != rules[k].ending_year_));
ferencd@0:     if (rules[i].starting_year_ == rules[k].starting_year_)
ferencd@0:     {
ferencd@0:         if (rules[k].ending_year_ < rules[i].ending_year_)
ferencd@0:         {
ferencd@0:             rules.insert(rules.begin() + static_cast<difference_type>(k+1),
ferencd@0:                          Rule(rules[i], rules[k].ending_year_ + years{1},
ferencd@0:                               std::move(rules[i].ending_year_)));
ferencd@0:             ++e;
ferencd@0:             rules[i].ending_year_ = rules[k].ending_year_;
ferencd@0:         }
ferencd@0:         else  // rules[k].ending_year_ > rules[i].ending_year_
ferencd@0:         {
ferencd@0:             rules.insert(rules.begin() + static_cast<difference_type>(k+1),
ferencd@0:                          Rule(rules[k], rules[i].ending_year_ + years{1},
ferencd@0:                               std::move(rules[k].ending_year_)));
ferencd@0:             ++e;
ferencd@0:             rules[k].ending_year_ = rules[i].ending_year_;
ferencd@0:         }
ferencd@0:     }
ferencd@0:     else  // rules[i].starting_year_ < rules[k].starting_year_
ferencd@0:     {
ferencd@0:         if (rules[k].ending_year_ < rules[i].ending_year_)
ferencd@0:         {
ferencd@0:             rules.insert(rules.begin() + static_cast<difference_type>(k),
ferencd@0:                          Rule(rules[i], rules[k].starting_year_, rules[k].ending_year_));
ferencd@0:             ++k;
ferencd@0:             rules.insert(rules.begin() + static_cast<difference_type>(k+1),
ferencd@0:                          Rule(rules[i], rules[k].ending_year_ + years{1},
ferencd@0:                               std::move(rules[i].ending_year_)));
ferencd@0:             rules[i].ending_year_ = rules[k].starting_year_ - years{1};
ferencd@0:             e += 2;
ferencd@0:         }
ferencd@0:         else if (rules[k].ending_year_ > rules[i].ending_year_)
ferencd@0:         {
ferencd@0:             rules.insert(rules.begin() + static_cast<difference_type>(k),
ferencd@0:                          Rule(rules[i], rules[k].starting_year_, rules[i].ending_year_));
ferencd@0:             ++k;
ferencd@0:             rules.insert(rules.begin() + static_cast<difference_type>(k+1),
ferencd@0:                          Rule(rules[k], rules[i].ending_year_ + years{1},
ferencd@0:                          std::move(rules[k].ending_year_)));
ferencd@0:             e += 2;
ferencd@0:             rules[k].ending_year_ = std::move(rules[i].ending_year_);
ferencd@0:             rules[i].ending_year_ = rules[k].starting_year_ - years{1};
ferencd@0:         }
ferencd@0:         else  // rules[k].ending_year_ == rules[i].ending_year_
ferencd@0:         {
ferencd@0:             rules.insert(rules.begin() + static_cast<difference_type>(k),
ferencd@0:                          Rule(rules[i], rules[k].starting_year_,
ferencd@0:                          std::move(rules[i].ending_year_)));
ferencd@0:             ++k;
ferencd@0:             ++e;
ferencd@0:             rules[i].ending_year_ = rules[k].starting_year_ - years{1};
ferencd@0:         }
ferencd@0:     }
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: detail::Rule::split_overlaps(std::vector<Rule>& rules, std::size_t i, std::size_t& e)
ferencd@0: {
ferencd@0:     using difference_type = std::vector<Rule>::iterator::difference_type;
ferencd@0:     auto j = i;
ferencd@0:     for (; i + 1 < e; ++i)
ferencd@0:     {
ferencd@0:         for (auto k = i + 1; k < e; ++k)
ferencd@0:         {
ferencd@0:             if (overlaps(rules[i], rules[k]))
ferencd@0:             {
ferencd@0:                 split(rules, i, k, e);
ferencd@0:                 std::sort(rules.begin() + static_cast<difference_type>(i),
ferencd@0:                           rules.begin() + static_cast<difference_type>(e));
ferencd@0:             }
ferencd@0:         }
ferencd@0:     }
ferencd@0:     for (; j < e; ++j)
ferencd@0:     {
ferencd@0:         if (rules[j].starting_year() == rules[j].ending_year())
ferencd@0:             rules[j].starting_at_.canonicalize(rules[j].starting_year());
ferencd@0:     }
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: detail::Rule::split_overlaps(std::vector<Rule>& rules)
ferencd@0: {
ferencd@0:     using difference_type = std::vector<Rule>::iterator::difference_type;
ferencd@0:     for (std::size_t i = 0; i < rules.size();)
ferencd@0:     {
ferencd@0:         auto e = static_cast<std::size_t>(std::upper_bound(
ferencd@0:             rules.cbegin()+static_cast<difference_type>(i), rules.cend(), rules[i].name(),
ferencd@0:             [](const std::string& nm, const Rule& x)
ferencd@0:             {
ferencd@0:                 return nm < x.name();
ferencd@0:             }) - rules.cbegin());
ferencd@0:         split_overlaps(rules, i, e);
ferencd@0:         auto first_rule = rules.begin() + static_cast<difference_type>(i);
ferencd@0:         auto last_rule = rules.begin() + static_cast<difference_type>(e);
ferencd@0:         auto t = std::lower_bound(first_rule, last_rule, min_year);
ferencd@0:         if (t > first_rule+1)
ferencd@0:         {
ferencd@0:             if (t == last_rule || t->starting_year() >= min_year)
ferencd@0:                 --t;
ferencd@0:             auto d = static_cast<std::size_t>(t - first_rule);
ferencd@0:             rules.erase(first_rule, t);
ferencd@0:             e -= d;
ferencd@0:         }
ferencd@0:         first_rule = rules.begin() + static_cast<difference_type>(i);
ferencd@0:         last_rule = rules.begin() + static_cast<difference_type>(e);
ferencd@0:         t = std::upper_bound(first_rule, last_rule, max_year);
ferencd@0:         if (t != last_rule)
ferencd@0:         {
ferencd@0:             auto d = static_cast<std::size_t>(last_rule - t);
ferencd@0:             rules.erase(t, last_rule);
ferencd@0:             e -= d;
ferencd@0:         }
ferencd@0:         i = e;
ferencd@0:     }
ferencd@0:     rules.shrink_to_fit();
ferencd@0: }
ferencd@0: 
ferencd@0: // Find the rule that comes chronologically before Rule r.  For multi-year rules,
ferencd@0: // y specifies which rules in r.  For single year rules, y is assumed to be equal
ferencd@0: // to the year specified by r.
ferencd@0: // Returns a pointer to the chronologically previous rule, and the year within
ferencd@0: // that rule.  If there is no previous rule, returns nullptr and year::min().
ferencd@0: // Preconditions:
ferencd@0: //     r->starting_year() <= y && y <= r->ending_year()
ferencd@0: static
ferencd@0: std::pair<const Rule*, date::year>
ferencd@0: find_previous_rule(const Rule* r, date::year y)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     auto const& rules = get_tzdb().rules;
ferencd@0:     if (y == r->starting_year())
ferencd@0:     {
ferencd@0:         if (r == &rules.front() || r->name() != r[-1].name())
ferencd@0:             std::terminate();  // never called with first rule
ferencd@0:         --r;
ferencd@0:         if (y == r->starting_year())
ferencd@0:             return {r, y};
ferencd@0:         return {r, r->ending_year()};
ferencd@0:     }
ferencd@0:     if (r == &rules.front() || r->name() != r[-1].name() ||
ferencd@0:         r[-1].starting_year() < r->starting_year())
ferencd@0:     {
ferencd@0:         while (r < &rules.back() && r->name() == r[1].name() &&
ferencd@0:                r->starting_year() == r[1].starting_year())
ferencd@0:             ++r;
ferencd@0:         return {r, --y};
ferencd@0:     }
ferencd@0:     --r;
ferencd@0:     return {r, y};
ferencd@0: }
ferencd@0: 
ferencd@0: // Find the rule that comes chronologically after Rule r.  For multi-year rules,
ferencd@0: // y specifies which rules in r.  For single year rules, y is assumed to be equal
ferencd@0: // to the year specified by r.
ferencd@0: // Returns a pointer to the chronologically next rule, and the year within
ferencd@0: // that rule.  If there is no next rule, return a pointer to a defaulted rule
ferencd@0: // and y+1.
ferencd@0: // Preconditions:
ferencd@0: //     first <= r && r < last && r->starting_year() <= y && y <= r->ending_year()
ferencd@0: //     [first, last) all have the same name
ferencd@0: static
ferencd@0: std::pair<const Rule*, date::year>
ferencd@0: find_next_rule(const Rule* first_rule, const Rule* last_rule, const Rule* r, date::year y)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     if (y == r->ending_year())
ferencd@0:     {
ferencd@0:         if (r == last_rule-1)
ferencd@0:             return {nullptr, year::max()};
ferencd@0:         ++r;
ferencd@0:         if (y == r->ending_year())
ferencd@0:             return {r, y};
ferencd@0:         return {r, r->starting_year()};
ferencd@0:     }
ferencd@0:     if (r == last_rule-1 || r->ending_year() < r[1].ending_year())
ferencd@0:     {
ferencd@0:         while (r > first_rule && r->starting_year() == r[-1].starting_year())
ferencd@0:             --r;
ferencd@0:         return {r, ++y};
ferencd@0:     }
ferencd@0:     ++r;
ferencd@0:     return {r, y};
ferencd@0: }
ferencd@0: 
ferencd@0: // Find the rule that comes chronologically after Rule r.  For multi-year rules,
ferencd@0: // y specifies which rules in r.  For single year rules, y is assumed to be equal
ferencd@0: // to the year specified by r.
ferencd@0: // Returns a pointer to the chronologically next rule, and the year within
ferencd@0: // that rule.  If there is no next rule, return nullptr and year::max().
ferencd@0: // Preconditions:
ferencd@0: //     r->starting_year() <= y && y <= r->ending_year()
ferencd@0: static
ferencd@0: std::pair<const Rule*, date::year>
ferencd@0: find_next_rule(const Rule* r, date::year y)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     auto const& rules = get_tzdb().rules;
ferencd@0:     if (y == r->ending_year())
ferencd@0:     {
ferencd@0:         if (r == &rules.back() || r->name() != r[1].name())
ferencd@0:             return {nullptr, year::max()};
ferencd@0:         ++r;
ferencd@0:         if (y == r->ending_year())
ferencd@0:             return {r, y};
ferencd@0:         return {r, r->starting_year()};
ferencd@0:     }
ferencd@0:     if (r == &rules.back() || r->name() != r[1].name() ||
ferencd@0:         r->ending_year() < r[1].ending_year())
ferencd@0:     {
ferencd@0:         while (r > &rules.front() && r->name() == r[-1].name() &&
ferencd@0:                r->starting_year() == r[-1].starting_year())
ferencd@0:             --r;
ferencd@0:         return {r, ++y};
ferencd@0:     }
ferencd@0:     ++r;
ferencd@0:     return {r, y};
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: const Rule*
ferencd@0: find_first_std_rule(const std::pair<const Rule*, const Rule*>& eqr)
ferencd@0: {
ferencd@0:     auto r = eqr.first;
ferencd@0:     auto ry = r->starting_year();
ferencd@0:     while (r->save() != std::chrono::minutes{0})
ferencd@0:     {
ferencd@0:         std::tie(r, ry) = find_next_rule(eqr.first, eqr.second, r, ry);
ferencd@0:         if (r == nullptr)
ferencd@0:             throw std::runtime_error("Could not find standard offset in rule "
ferencd@0:                                      + eqr.first->name());
ferencd@0:     }
ferencd@0:     return r;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::pair<const Rule*, date::year>
ferencd@0: find_rule_for_zone(const std::pair<const Rule*, const Rule*>& eqr,
ferencd@0:                    const date::year& y, const std::chrono::seconds& offset,
ferencd@0:                    const MonthDayTime& mdt)
ferencd@0: {
ferencd@0:     assert(eqr.first != nullptr);
ferencd@0:     assert(eqr.second != nullptr);
ferencd@0: 
ferencd@0:     using namespace std::chrono;
ferencd@0:     using namespace date;
ferencd@0:     auto r = eqr.first;
ferencd@0:     auto ry = r->starting_year();
ferencd@0:     auto prev_save = minutes{0};
ferencd@0:     auto prev_year = year::min();
ferencd@0:     const Rule* prev_rule = nullptr;
ferencd@0:     while (r != nullptr)
ferencd@0:     {
ferencd@0:         if (mdt.compare(y, r->mdt(), ry, offset, prev_save) <= 0)
ferencd@0:             break;
ferencd@0:         prev_rule = r;
ferencd@0:         prev_year = ry;
ferencd@0:         prev_save = prev_rule->save();
ferencd@0:         std::tie(r, ry) = find_next_rule(eqr.first, eqr.second, r, ry);
ferencd@0:     }
ferencd@0:     return {prev_rule, prev_year};
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::pair<const Rule*, date::year>
ferencd@0: find_rule_for_zone(const std::pair<const Rule*, const Rule*>& eqr,
ferencd@0:                    const sys_seconds& tp_utc,
ferencd@0:                    const local_seconds& tp_std,
ferencd@0:                    const local_seconds& tp_loc)
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     using namespace date;
ferencd@0:     auto r = eqr.first;
ferencd@0:     auto ry = r->starting_year();
ferencd@0:     auto prev_save = minutes{0};
ferencd@0:     auto prev_year = year::min();
ferencd@0:     const Rule* prev_rule = nullptr;
ferencd@0:     while (r != nullptr)
ferencd@0:     {
ferencd@0:         bool found = false;
ferencd@0:         switch (r->mdt().zone())
ferencd@0:         {
ferencd@0:         case tz::utc:
ferencd@0:             found = tp_utc < r->mdt().to_time_point(ry);
ferencd@0:             break;
ferencd@0:         case tz::standard:
ferencd@0:             found = sys_seconds{tp_std.time_since_epoch()} < r->mdt().to_time_point(ry);
ferencd@0:             break;
ferencd@0:         case tz::local:
ferencd@0:             found = sys_seconds{tp_loc.time_since_epoch()} < r->mdt().to_time_point(ry);
ferencd@0:             break;
ferencd@0:         }
ferencd@0:         if (found)
ferencd@0:             break;
ferencd@0:         prev_rule = r;
ferencd@0:         prev_year = ry;
ferencd@0:         prev_save = prev_rule->save();
ferencd@0:         std::tie(r, ry) = find_next_rule(eqr.first, eqr.second, r, ry);
ferencd@0:     }
ferencd@0:     return {prev_rule, prev_year};
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: sys_info
ferencd@0: find_rule(const std::pair<const Rule*, date::year>& first_rule,
ferencd@0:           const std::pair<const Rule*, date::year>& last_rule,
ferencd@0:           const date::year& y, const std::chrono::seconds& offset,
ferencd@0:           const MonthDayTime& mdt, const std::chrono::minutes& initial_save,
ferencd@0:           const std::string& initial_abbrev)
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     using namespace date;
ferencd@0:     auto r = first_rule.first;
ferencd@0:     auto ry = first_rule.second;
ferencd@0:     sys_info x{sys_days(year::min()/min_day), sys_days(year::max()/max_day),
ferencd@0:                seconds{0}, initial_save, initial_abbrev};
ferencd@0:     while (r != nullptr)
ferencd@0:     {
ferencd@0:         auto tr = r->mdt().to_sys(ry, offset, x.save);
ferencd@0:         auto tx = mdt.to_sys(y, offset, x.save);
ferencd@0:         // Find last rule where tx >= tr
ferencd@0:         if (tx <= tr || (r == last_rule.first && ry == last_rule.second))
ferencd@0:         {
ferencd@0:             if (tx < tr && r == first_rule.first && ry == first_rule.second)
ferencd@0:             {
ferencd@0:                 x.end = r->mdt().to_sys(ry, offset, x.save);
ferencd@0:                 break;
ferencd@0:             }
ferencd@0:             if (tx < tr)
ferencd@0:             {
ferencd@0:                 std::tie(r, ry) = find_previous_rule(r, ry);  // can't return nullptr for r
ferencd@0:                 assert(r != nullptr);
ferencd@0:             }
ferencd@0:             // r != nullptr && tx >= tr (if tr were to be recomputed)
ferencd@0:             auto prev_save = initial_save;
ferencd@0:             if (!(r == first_rule.first && ry == first_rule.second))
ferencd@0:                 prev_save = find_previous_rule(r, ry).first->save();
ferencd@0:             x.begin = r->mdt().to_sys(ry, offset, prev_save);
ferencd@0:             x.save = r->save();
ferencd@0:             x.abbrev = r->abbrev();
ferencd@0:             if (!(r == last_rule.first && ry == last_rule.second))
ferencd@0:             {
ferencd@0:                 std::tie(r, ry) = find_next_rule(r, ry);  // can't return nullptr for r
ferencd@0:                 assert(r != nullptr);
ferencd@0:                 x.end = r->mdt().to_sys(ry, offset, x.save);
ferencd@0:             }
ferencd@0:             else
ferencd@0:                 x.end = sys_days(year::max()/max_day);
ferencd@0:             break;
ferencd@0:         }
ferencd@0:         x.save = r->save();
ferencd@0:         std::tie(r, ry) = find_next_rule(r, ry);  // Can't return nullptr for r
ferencd@0:         assert(r != nullptr);
ferencd@0:     }
ferencd@0:     return x;
ferencd@0: }
ferencd@0: 
ferencd@0: // zonelet
ferencd@0: 
ferencd@0: detail::zonelet::~zonelet()
ferencd@0: {
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER >= 1900)
ferencd@0:     using minutes = std::chrono::minutes;
ferencd@0:     using string = std::string;
ferencd@0:     if (tag_ == has_save)
ferencd@0:         u.save_.~minutes();
ferencd@0:     else
ferencd@0:         u.rule_.~string();
ferencd@0: #endif
ferencd@0: }
ferencd@0: 
ferencd@0: detail::zonelet::zonelet()
ferencd@0: {
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER >= 1900)
ferencd@0:     ::new(&u.rule_) std::string();
ferencd@0: #endif
ferencd@0: }
ferencd@0: 
ferencd@0: detail::zonelet::zonelet(const zonelet& i)
ferencd@0:     : gmtoff_(i.gmtoff_)
ferencd@0:     , tag_(i.tag_)
ferencd@0:     , format_(i.format_)
ferencd@0:     , until_year_(i.until_year_)
ferencd@0:     , until_date_(i.until_date_)
ferencd@0:     , until_utc_(i.until_utc_)
ferencd@0:     , until_std_(i.until_std_)
ferencd@0:     , until_loc_(i.until_loc_)
ferencd@0:     , initial_save_(i.initial_save_)
ferencd@0:     , initial_abbrev_(i.initial_abbrev_)
ferencd@0:     , first_rule_(i.first_rule_)
ferencd@0:     , last_rule_(i.last_rule_)
ferencd@0: {
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER >= 1900)
ferencd@0:     if (tag_ == has_save)
ferencd@0:         ::new(&u.save_) std::chrono::minutes(i.u.save_);
ferencd@0:     else
ferencd@0:         ::new(&u.rule_) std::string(i.u.rule_);
ferencd@0: #else
ferencd@0:     if (tag_ == has_save)
ferencd@0:         u.save_ = i.u.save_;
ferencd@0:     else
ferencd@0:         u.rule_ = i.u.rule_;
ferencd@0: #endif
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: // time_zone
ferencd@0: 
ferencd@0: #if USE_OS_TZDB
ferencd@0: 
ferencd@0: time_zone::time_zone(const std::string& s, detail::undocumented)
ferencd@0:     : name_(s)
ferencd@0:     , adjusted_(new std::once_flag{})
ferencd@0: {
ferencd@0: }
ferencd@0: 
ferencd@0: enum class endian
ferencd@0: {
ferencd@0:     native = __BYTE_ORDER__,
ferencd@0:     little = __ORDER_LITTLE_ENDIAN__,
ferencd@0:     big    = __ORDER_BIG_ENDIAN__
ferencd@0: };
ferencd@0: 
ferencd@0: static
ferencd@0: inline
ferencd@0: std::uint32_t
ferencd@0: reverse_bytes(std::uint32_t i)
ferencd@0: {
ferencd@0:     return
ferencd@0:         (i & 0xff000000u) >> 24 |
ferencd@0:         (i & 0x00ff0000u) >> 8 |
ferencd@0:         (i & 0x0000ff00u) << 8 |
ferencd@0:         (i & 0x000000ffu) << 24;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: inline
ferencd@0: std::uint64_t
ferencd@0: reverse_bytes(std::uint64_t i)
ferencd@0: {
ferencd@0:     return
ferencd@0:         (i & 0xff00000000000000ull) >> 56 |
ferencd@0:         (i & 0x00ff000000000000ull) >> 40 |
ferencd@0:         (i & 0x0000ff0000000000ull) >> 24 |
ferencd@0:         (i & 0x000000ff00000000ull) >> 8 |
ferencd@0:         (i & 0x00000000ff000000ull) << 8 |
ferencd@0:         (i & 0x0000000000ff0000ull) << 24 |
ferencd@0:         (i & 0x000000000000ff00ull) << 40 |
ferencd@0:         (i & 0x00000000000000ffull) << 56;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class T>
ferencd@0: static
ferencd@0: inline
ferencd@0: void
ferencd@0: maybe_reverse_bytes(T&, std::false_type)
ferencd@0: {
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: inline
ferencd@0: void
ferencd@0: maybe_reverse_bytes(std::int32_t& t, std::true_type)
ferencd@0: {
ferencd@0:     t = static_cast<std::int32_t>(reverse_bytes(static_cast<std::uint32_t>(t)));
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: inline
ferencd@0: void
ferencd@0: maybe_reverse_bytes(std::int64_t& t, std::true_type)
ferencd@0: {
ferencd@0:     t = static_cast<std::int64_t>(reverse_bytes(static_cast<std::uint64_t>(t)));
ferencd@0: }
ferencd@0: 
ferencd@0: template <class T>
ferencd@0: static
ferencd@0: inline
ferencd@0: void
ferencd@0: maybe_reverse_bytes(T& t)
ferencd@0: {
ferencd@0:     maybe_reverse_bytes(t, std::integral_constant<bool,
ferencd@0:                                                   endian::native == endian::little>{});
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: void
ferencd@0: load_header(std::istream& inf)
ferencd@0: {
ferencd@0:     // Read TZif
ferencd@0:     auto t = inf.get();
ferencd@0:     auto z = inf.get();
ferencd@0:     auto i = inf.get();
ferencd@0:     auto f = inf.get();
ferencd@0: #ifndef NDEBUG
ferencd@0:     assert(t == 'T');
ferencd@0:     assert(z == 'Z');
ferencd@0:     assert(i == 'i');
ferencd@0:     assert(f == 'f');
ferencd@0: #else
ferencd@0:     (void)t;
ferencd@0:     (void)z;
ferencd@0:     (void)i;
ferencd@0:     (void)f;
ferencd@0: #endif
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: unsigned char
ferencd@0: load_version(std::istream& inf)
ferencd@0: {
ferencd@0:     // Read version
ferencd@0:     auto v = inf.get();
ferencd@0:     assert(v != EOF);
ferencd@0:     return static_cast<unsigned char>(v);
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: void
ferencd@0: skip_reserve(std::istream& inf)
ferencd@0: {
ferencd@0:     inf.ignore(15);
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: void
ferencd@0: load_counts(std::istream& inf,
ferencd@0:             std::int32_t& tzh_ttisgmtcnt, std::int32_t& tzh_ttisstdcnt,
ferencd@0:             std::int32_t& tzh_leapcnt,    std::int32_t& tzh_timecnt,
ferencd@0:             std::int32_t& tzh_typecnt,    std::int32_t& tzh_charcnt)
ferencd@0: {
ferencd@0:     // Read counts;
ferencd@0:     inf.read(reinterpret_cast<char*>(&tzh_ttisgmtcnt), 4);
ferencd@0:     maybe_reverse_bytes(tzh_ttisgmtcnt);
ferencd@0:     inf.read(reinterpret_cast<char*>(&tzh_ttisstdcnt), 4);
ferencd@0:     maybe_reverse_bytes(tzh_ttisstdcnt);
ferencd@0:     inf.read(reinterpret_cast<char*>(&tzh_leapcnt), 4);
ferencd@0:     maybe_reverse_bytes(tzh_leapcnt);
ferencd@0:     inf.read(reinterpret_cast<char*>(&tzh_timecnt), 4);
ferencd@0:     maybe_reverse_bytes(tzh_timecnt);
ferencd@0:     inf.read(reinterpret_cast<char*>(&tzh_typecnt), 4);
ferencd@0:     maybe_reverse_bytes(tzh_typecnt);
ferencd@0:     inf.read(reinterpret_cast<char*>(&tzh_charcnt), 4);
ferencd@0:     maybe_reverse_bytes(tzh_charcnt);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class TimeType>
ferencd@0: static
ferencd@0: std::vector<detail::transition>
ferencd@0: load_transitions(std::istream& inf, std::int32_t tzh_timecnt)
ferencd@0: {
ferencd@0:     // Read transitions
ferencd@0:     using namespace std::chrono;
ferencd@0:     std::vector<detail::transition> transitions;
ferencd@0:     transitions.reserve(static_cast<unsigned>(tzh_timecnt));
ferencd@0:     for (std::int32_t i = 0; i < tzh_timecnt; ++i)
ferencd@0:     {
ferencd@0:         TimeType t;
ferencd@0:         inf.read(reinterpret_cast<char*>(&t), sizeof(t));
ferencd@0:         maybe_reverse_bytes(t);
ferencd@0:         transitions.emplace_back(sys_seconds{seconds{t}});
ferencd@0:         if (transitions.back().timepoint < min_seconds)
ferencd@0:             transitions.back().timepoint = min_seconds;
ferencd@0:     }
ferencd@0:     return transitions;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::vector<std::uint8_t>
ferencd@0: load_indices(std::istream& inf, std::int32_t tzh_timecnt)
ferencd@0: {
ferencd@0:     // Read indices
ferencd@0:     std::vector<std::uint8_t> indices;
ferencd@0:     indices.reserve(static_cast<unsigned>(tzh_timecnt));
ferencd@0:     for (std::int32_t i = 0; i < tzh_timecnt; ++i)
ferencd@0:     {
ferencd@0:         std::uint8_t t;
ferencd@0:         inf.read(reinterpret_cast<char*>(&t), sizeof(t));
ferencd@0:         indices.emplace_back(t);
ferencd@0:     }
ferencd@0:     return indices;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::vector<ttinfo>
ferencd@0: load_ttinfo(std::istream& inf, std::int32_t tzh_typecnt)
ferencd@0: {
ferencd@0:     // Read ttinfo
ferencd@0:     std::vector<ttinfo> ttinfos;
ferencd@0:     ttinfos.reserve(static_cast<unsigned>(tzh_typecnt));
ferencd@0:     for (std::int32_t i = 0; i < tzh_typecnt; ++i)
ferencd@0:     {
ferencd@0:         ttinfo t;
ferencd@0:         inf.read(reinterpret_cast<char*>(&t), 6);
ferencd@0:         maybe_reverse_bytes(t.tt_gmtoff);
ferencd@0:         ttinfos.emplace_back(t);
ferencd@0:     }
ferencd@0:     return ttinfos;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: load_abbreviations(std::istream& inf, std::int32_t tzh_charcnt)
ferencd@0: {
ferencd@0:     // Read abbreviations
ferencd@0:     std::string abbrev;
ferencd@0:     abbrev.resize(static_cast<unsigned>(tzh_charcnt), '\0');
ferencd@0:     inf.read(&abbrev[0], tzh_charcnt);
ferencd@0:     return abbrev;
ferencd@0: }
ferencd@0: 
ferencd@0: #if !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: template <class TimeType>
ferencd@0: static
ferencd@0: std::vector<leap>
ferencd@0: load_leaps(std::istream& inf, std::int32_t tzh_leapcnt)
ferencd@0: {
ferencd@0:     // Read tzh_leapcnt pairs
ferencd@0:     using namespace std::chrono;
ferencd@0:     std::vector<leap> leap_seconds;
ferencd@0:     leap_seconds.reserve(static_cast<std::size_t>(tzh_leapcnt));
ferencd@0:     for (std::int32_t i = 0; i < tzh_leapcnt; ++i)
ferencd@0:     {
ferencd@0:         TimeType     t0;
ferencd@0:         std::int32_t t1;
ferencd@0:         inf.read(reinterpret_cast<char*>(&t0), sizeof(t0));
ferencd@0:         inf.read(reinterpret_cast<char*>(&t1), sizeof(t1));
ferencd@0:         maybe_reverse_bytes(t0);
ferencd@0:         maybe_reverse_bytes(t1);
ferencd@0:         leap_seconds.emplace_back(sys_seconds{seconds{t0 - (t1-1)}},
ferencd@0:                                   detail::undocumented{});
ferencd@0:     }
ferencd@0:     return leap_seconds;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class TimeType>
ferencd@0: static
ferencd@0: std::vector<leap>
ferencd@0: load_leap_data(std::istream& inf,
ferencd@0:                std::int32_t tzh_leapcnt, std::int32_t tzh_timecnt,
ferencd@0:                std::int32_t tzh_typecnt, std::int32_t tzh_charcnt)
ferencd@0: {
ferencd@0:     inf.ignore(tzh_timecnt*static_cast<std::int32_t>(sizeof(TimeType)) + tzh_timecnt +
ferencd@0:                tzh_typecnt*6 + tzh_charcnt);
ferencd@0:     return load_leaps<TimeType>(inf, tzh_leapcnt);
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::vector<leap>
ferencd@0: load_just_leaps(std::istream& inf)
ferencd@0: {
ferencd@0:     // Read tzh_leapcnt pairs
ferencd@0:     using namespace std::chrono;
ferencd@0:     load_header(inf);
ferencd@0:     auto v = load_version(inf);
ferencd@0:     std::int32_t tzh_ttisgmtcnt, tzh_ttisstdcnt, tzh_leapcnt,
ferencd@0:                  tzh_timecnt,    tzh_typecnt,    tzh_charcnt;
ferencd@0:     skip_reserve(inf);
ferencd@0:     load_counts(inf, tzh_ttisgmtcnt, tzh_ttisstdcnt, tzh_leapcnt,
ferencd@0:                      tzh_timecnt,    tzh_typecnt,    tzh_charcnt);
ferencd@0:     if (v == 0)
ferencd@0:         return load_leap_data<int32_t>(inf, tzh_leapcnt, tzh_timecnt, tzh_typecnt,
ferencd@0:                                        tzh_charcnt);
ferencd@0: #if !defined(NDEBUG)
ferencd@0:     inf.ignore((4+1)*tzh_timecnt + 6*tzh_typecnt + tzh_charcnt + 8*tzh_leapcnt +
ferencd@0:                tzh_ttisstdcnt + tzh_ttisgmtcnt);
ferencd@0:     load_header(inf);
ferencd@0:     auto v2 = load_version(inf);
ferencd@0:     assert(v == v2);
ferencd@0:     skip_reserve(inf);
ferencd@0: #else  // defined(NDEBUG)
ferencd@0:     inf.ignore((4+1)*tzh_timecnt + 6*tzh_typecnt + tzh_charcnt + 8*tzh_leapcnt +
ferencd@0:                tzh_ttisstdcnt + tzh_ttisgmtcnt + (4+1+15));
ferencd@0: #endif  // defined(NDEBUG)
ferencd@0:     load_counts(inf, tzh_ttisgmtcnt, tzh_ttisstdcnt, tzh_leapcnt,
ferencd@0:                      tzh_timecnt,    tzh_typecnt,    tzh_charcnt);
ferencd@0:     return load_leap_data<int64_t>(inf, tzh_leapcnt, tzh_timecnt, tzh_typecnt,
ferencd@0:                                    tzh_charcnt);
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: template <class TimeType>
ferencd@0: void
ferencd@0: time_zone::load_data(std::istream& inf,
ferencd@0:                      std::int32_t tzh_leapcnt, std::int32_t tzh_timecnt,
ferencd@0:                      std::int32_t tzh_typecnt, std::int32_t tzh_charcnt)
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     transitions_ = load_transitions<TimeType>(inf, tzh_timecnt);
ferencd@0:     auto indices = load_indices(inf, tzh_timecnt);
ferencd@0:     auto infos = load_ttinfo(inf, tzh_typecnt);
ferencd@0:     auto abbrev = load_abbreviations(inf, tzh_charcnt);
ferencd@0: #if !MISSING_LEAP_SECONDS
ferencd@0:     auto& leap_seconds = get_tzdb_list().front().leaps;
ferencd@0:     if (leap_seconds.empty() && tzh_leapcnt > 0)
ferencd@0:         leap_seconds = load_leaps<TimeType>(inf, tzh_leapcnt);
ferencd@0: #endif
ferencd@0:     ttinfos_.reserve(infos.size());
ferencd@0:     for (auto& info : infos)
ferencd@0:     {
ferencd@0:         ttinfos_.push_back({seconds{info.tt_gmtoff},
ferencd@0:                             abbrev.c_str() + info.tt_abbrind,
ferencd@0:                             info.tt_isdst != 0});
ferencd@0:     }
ferencd@0:     auto i = 0u;
ferencd@0:     if (transitions_.empty() || transitions_.front().timepoint != min_seconds)
ferencd@0:     {
ferencd@0:         transitions_.emplace(transitions_.begin(), min_seconds);
ferencd@0:         auto tf = std::find_if(ttinfos_.begin(), ttinfos_.end(),
ferencd@0:                                [](const expanded_ttinfo& ti)
ferencd@0:                                    {return ti.is_dst == 0;});
ferencd@0:         if (tf == ttinfos_.end())
ferencd@0:             tf = ttinfos_.begin();
ferencd@0:         transitions_[i].info = &*tf;
ferencd@0:         ++i;
ferencd@0:     }
ferencd@0:     for (auto j = 0u; i < transitions_.size(); ++i, ++j)
ferencd@0:         transitions_[i].info = ttinfos_.data() + indices[j];
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: time_zone::init_impl()
ferencd@0: {
ferencd@0:     using namespace std;
ferencd@0:     using namespace std::chrono;
ferencd@0:     auto name = get_tz_dir() + ('/' + name_);
ferencd@0:     std::ifstream inf(name);
ferencd@0:     if (!inf.is_open())
ferencd@0:         throw std::runtime_error{"Unable to open " + name};
ferencd@0:     inf.exceptions(std::ios::failbit | std::ios::badbit);
ferencd@0:     load_header(inf);
ferencd@0:     auto v = load_version(inf);
ferencd@0:     std::int32_t tzh_ttisgmtcnt, tzh_ttisstdcnt, tzh_leapcnt,
ferencd@0:                  tzh_timecnt,    tzh_typecnt,    tzh_charcnt;
ferencd@0:     skip_reserve(inf);
ferencd@0:     load_counts(inf, tzh_ttisgmtcnt, tzh_ttisstdcnt, tzh_leapcnt,
ferencd@0:                      tzh_timecnt,    tzh_typecnt,    tzh_charcnt);
ferencd@0:     if (v == 0)
ferencd@0:     {
ferencd@0:         load_data<int32_t>(inf, tzh_leapcnt, tzh_timecnt, tzh_typecnt, tzh_charcnt);
ferencd@0:     }
ferencd@0:     else
ferencd@0:     {
ferencd@0: #if !defined(NDEBUG)
ferencd@0:         inf.ignore((4+1)*tzh_timecnt + 6*tzh_typecnt + tzh_charcnt + 8*tzh_leapcnt +
ferencd@0:                    tzh_ttisstdcnt + tzh_ttisgmtcnt);
ferencd@0:         load_header(inf);
ferencd@0:         auto v2 = load_version(inf);
ferencd@0:         assert(v == v2);
ferencd@0:         skip_reserve(inf);
ferencd@0: #else  // defined(NDEBUG)
ferencd@0:         inf.ignore((4+1)*tzh_timecnt + 6*tzh_typecnt + tzh_charcnt + 8*tzh_leapcnt +
ferencd@0:                    tzh_ttisstdcnt + tzh_ttisgmtcnt + (4+1+15));
ferencd@0: #endif  // defined(NDEBUG)
ferencd@0:         load_counts(inf, tzh_ttisgmtcnt, tzh_ttisstdcnt, tzh_leapcnt,
ferencd@0:                          tzh_timecnt,    tzh_typecnt,    tzh_charcnt);
ferencd@0:         load_data<int64_t>(inf, tzh_leapcnt, tzh_timecnt, tzh_typecnt, tzh_charcnt);
ferencd@0:     }
ferencd@0: #if !MISSING_LEAP_SECONDS
ferencd@0:     if (tzh_leapcnt > 0)
ferencd@0:     {
ferencd@0:         auto& leap_seconds = get_tzdb_list().front().leaps;
ferencd@0:         auto itr = leap_seconds.begin();
ferencd@0:         auto l = itr->date();
ferencd@0:         seconds leap_count{0};
ferencd@0:         for (auto t = std::upper_bound(transitions_.begin(), transitions_.end(), l,
ferencd@0:                                        [](const sys_seconds& x, const transition& ct)
ferencd@0:                                        {
ferencd@0:                                            return x < ct.timepoint;
ferencd@0:                                        });
ferencd@0:                   t != transitions_.end(); ++t)
ferencd@0:         {
ferencd@0:             while (t->timepoint >= l)
ferencd@0:             {
ferencd@0:                 ++leap_count;
ferencd@0:                 if (++itr == leap_seconds.end())
ferencd@0:                     l = sys_days(max_year/max_day);
ferencd@0:                 else
ferencd@0:                     l = itr->date() + leap_count;
ferencd@0:             }
ferencd@0:             t->timepoint -= leap_count;
ferencd@0:         }
ferencd@0:     }
ferencd@0: #endif  // !MISSING_LEAP_SECONDS
ferencd@0:     auto b = transitions_.begin();
ferencd@0:     auto i = transitions_.end();
ferencd@0:     if (i != b)
ferencd@0:     {
ferencd@0:         for (--i; i != b; --i)
ferencd@0:         {
ferencd@0:             if (i->info->offset == i[-1].info->offset &&
ferencd@0:                 i->info->abbrev == i[-1].info->abbrev &&
ferencd@0:                 i->info->is_dst == i[-1].info->is_dst)
ferencd@0:                 i = transitions_.erase(i);
ferencd@0:         }
ferencd@0:     }
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: time_zone::init() const
ferencd@0: {
ferencd@0:     std::call_once(*adjusted_, [this]() {const_cast<time_zone*>(this)->init_impl();});
ferencd@0: }
ferencd@0: 
ferencd@0: sys_info
ferencd@0: time_zone::load_sys_info(std::vector<detail::transition>::const_iterator i) const
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     assert(!transitions_.empty());
ferencd@0:     assert(i != transitions_.begin());
ferencd@0:     sys_info r;
ferencd@0:     r.begin = i[-1].timepoint;
ferencd@0:     r.end = i != transitions_.end() ? i->timepoint :
ferencd@0:                                       sys_seconds(sys_days(year::max()/max_day));
ferencd@0:     r.offset = i[-1].info->offset;
ferencd@0:     r.save = i[-1].info->is_dst ? minutes{1} : minutes{0};
ferencd@0:     r.abbrev = i[-1].info->abbrev;
ferencd@0:     return r;
ferencd@0: }
ferencd@0: 
ferencd@0: sys_info
ferencd@0: time_zone::get_info_impl(sys_seconds tp) const
ferencd@0: {
ferencd@0:     using namespace std;
ferencd@0:     init();
ferencd@0:     return load_sys_info(upper_bound(transitions_.begin(), transitions_.end(), tp,
ferencd@0:                                      [](const sys_seconds& x, const transition& t)
ferencd@0:                                      {
ferencd@0:                                          return x < t.timepoint;
ferencd@0:                                      }));
ferencd@0: }
ferencd@0: 
ferencd@0: local_info
ferencd@0: time_zone::get_info_impl(local_seconds tp) const
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     init();
ferencd@0:     local_info i;
ferencd@0:     i.result = local_info::unique;
ferencd@0:     auto tr = upper_bound(transitions_.begin(), transitions_.end(), tp,
ferencd@0:                           [](const local_seconds& x, const transition& t)
ferencd@0:                           {
ferencd@0:                               return sys_seconds{x.time_since_epoch()} -
ferencd@0:                                                          t.info->offset < t.timepoint;
ferencd@0:                           });
ferencd@0:     i.first = load_sys_info(tr);
ferencd@0:     auto tps = sys_seconds{(tp - i.first.offset).time_since_epoch()};
ferencd@0:     if (tps < i.first.begin + days{1} && tr != transitions_.begin())
ferencd@0:     {
ferencd@0:         i.second = load_sys_info(--tr);
ferencd@0:         tps = sys_seconds{(tp - i.second.offset).time_since_epoch()};
ferencd@0:         if (tps < i.second.end)
ferencd@0:         {
ferencd@0:            i.result = local_info::ambiguous;
ferencd@0:            std::swap(i.first, i.second);
ferencd@0:         }
ferencd@0:         else
ferencd@0:         {
ferencd@0:             i.second = {};
ferencd@0:         }
ferencd@0:     }
ferencd@0:     else if (tps >= i.first.end && tr != transitions_.end())
ferencd@0:     {
ferencd@0:         i.second = load_sys_info(++tr);
ferencd@0:         tps = sys_seconds{(tp - i.second.offset).time_since_epoch()};
ferencd@0:         if (tps < i.second.begin)
ferencd@0:             i.result = local_info::nonexistent;
ferencd@0:         else
ferencd@0:             i.second = {};
ferencd@0:     }
ferencd@0:     return i;
ferencd@0: }
ferencd@0: 
ferencd@0: std::ostream&
ferencd@0: operator<<(std::ostream& os, const time_zone& z)
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     z.init();
ferencd@0:     os << z.name_ << '\n';
ferencd@0:     os << "Initially:           ";
ferencd@0:     auto const& t = z.transitions_.front();
ferencd@0:     if (t.info->offset >= seconds{0})
ferencd@0:         os << '+';
ferencd@0:     os << make_time(t.info->offset);
ferencd@0:     if (t.info->is_dst > 0)
ferencd@0:         os << " daylight ";
ferencd@0:     else
ferencd@0:         os << " standard ";
ferencd@0:     os << t.info->abbrev << '\n';
ferencd@0:     for (auto i = std::next(z.transitions_.cbegin()); i < z.transitions_.cend(); ++i)
ferencd@0:         os << *i << '\n';
ferencd@0:     return os;
ferencd@0: }
ferencd@0: 
ferencd@0: #if !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: leap::leap(const sys_seconds& s, detail::undocumented)
ferencd@0:     : date_(s)
ferencd@0: {
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: #else  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: time_zone::time_zone(const std::string& s, detail::undocumented)
ferencd@0:     : adjusted_(new std::once_flag{})
ferencd@0: {
ferencd@0:     try
ferencd@0:     {
ferencd@0:         using namespace date;
ferencd@0:         std::istringstream in(s);
ferencd@0:         in.exceptions(std::ios::failbit | std::ios::badbit);
ferencd@0:         std::string word;
ferencd@0:         in >> word >> name_;
ferencd@0:         parse_info(in);
ferencd@0:     }
ferencd@0:     catch (...)
ferencd@0:     {
ferencd@0:         std::cerr << s << '\n';
ferencd@0:         std::cerr << *this << '\n';
ferencd@0:         zonelets_.pop_back();
ferencd@0:         throw;
ferencd@0:     }
ferencd@0: }
ferencd@0: 
ferencd@0: sys_info
ferencd@0: time_zone::get_info_impl(sys_seconds tp) const
ferencd@0: {
ferencd@0:     return get_info_impl(tp, static_cast<int>(tz::utc));
ferencd@0: }
ferencd@0: 
ferencd@0: local_info
ferencd@0: time_zone::get_info_impl(local_seconds tp) const
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     local_info i{};
ferencd@0:     i.first = get_info_impl(sys_seconds{tp.time_since_epoch()}, static_cast<int>(tz::local));
ferencd@0:     auto tps = sys_seconds{(tp - i.first.offset).time_since_epoch()};
ferencd@0:     if (tps < i.first.begin)
ferencd@0:     {
ferencd@0:         i.second = std::move(i.first);
ferencd@0:         i.first = get_info_impl(i.second.begin - seconds{1}, static_cast<int>(tz::utc));
ferencd@0:         i.result = local_info::nonexistent;
ferencd@0:     }
ferencd@0:     else if (i.first.end - tps <= days{1})
ferencd@0:     {
ferencd@0:         i.second = get_info_impl(i.first.end, static_cast<int>(tz::utc));
ferencd@0:         tps = sys_seconds{(tp - i.second.offset).time_since_epoch()};
ferencd@0:         if (tps >= i.second.begin)
ferencd@0:             i.result = local_info::ambiguous;
ferencd@0:         else
ferencd@0:             i.second = {};
ferencd@0:     }
ferencd@0:     return i;
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: time_zone::add(const std::string& s)
ferencd@0: {
ferencd@0:     try
ferencd@0:     {
ferencd@0:         std::istringstream in(s);
ferencd@0:         in.exceptions(std::ios::failbit | std::ios::badbit);
ferencd@0:         ws(in);
ferencd@0:         if (!in.eof() && in.peek() != '#')
ferencd@0:             parse_info(in);
ferencd@0:     }
ferencd@0:     catch (...)
ferencd@0:     {
ferencd@0:         std::cerr << s << '\n';
ferencd@0:         std::cerr << *this << '\n';
ferencd@0:         zonelets_.pop_back();
ferencd@0:         throw;
ferencd@0:     }
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: time_zone::parse_info(std::istream& in)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     using namespace std::chrono;
ferencd@0:     zonelets_.emplace_back();
ferencd@0:     auto& zonelet = zonelets_.back();
ferencd@0:     zonelet.gmtoff_ = parse_signed_time(in);
ferencd@0:     in >> zonelet.u.rule_;
ferencd@0:     if (zonelet.u.rule_ == "-")
ferencd@0:         zonelet.u.rule_.clear();
ferencd@0:     in >> zonelet.format_;
ferencd@0:     if (!in.eof())
ferencd@0:         ws(in);
ferencd@0:     if (in.eof() || in.peek() == '#')
ferencd@0:     {
ferencd@0:         zonelet.until_year_ = year::max();
ferencd@0:         zonelet.until_date_ = MonthDayTime(max_day, tz::utc);
ferencd@0:     }
ferencd@0:     else
ferencd@0:     {
ferencd@0:         int y;
ferencd@0:         in >> y;
ferencd@0:         zonelet.until_year_ = year{y};
ferencd@0:         in >> zonelet.until_date_;
ferencd@0:         zonelet.until_date_.canonicalize(zonelet.until_year_);
ferencd@0:     }
ferencd@0:     if ((zonelet.until_year_ < min_year) ||
ferencd@0:             (zonelets_.size() > 1 && zonelets_.end()[-2].until_year_ > max_year))
ferencd@0:         zonelets_.pop_back();
ferencd@0: }
ferencd@0: 
ferencd@0: void
ferencd@0: time_zone::adjust_infos(const std::vector<Rule>& rules)
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     using namespace date;
ferencd@0:     const zonelet* prev_zonelet = nullptr;
ferencd@0:     for (auto& z : zonelets_)
ferencd@0:     {
ferencd@0:         std::pair<const Rule*, const Rule*> eqr{};
ferencd@0:         std::istringstream in;
ferencd@0:         in.exceptions(std::ios::failbit | std::ios::badbit);
ferencd@0:         // Classify info as rule-based, has save, or neither
ferencd@0:         if (!z.u.rule_.empty())
ferencd@0:         {
ferencd@0:             // Find out if this zonelet has a rule or a save
ferencd@0:             eqr = std::equal_range(rules.data(), rules.data() + rules.size(), z.u.rule_);
ferencd@0:             if (eqr.first == eqr.second)
ferencd@0:             {
ferencd@0:                 // The rule doesn't exist.  Assume this is a save
ferencd@0:                 try
ferencd@0:                 {
ferencd@0:                     using namespace std::chrono;
ferencd@0:                     using string = std::string;
ferencd@0:                     in.str(z.u.rule_);
ferencd@0:                     auto tmp = duration_cast<minutes>(parse_signed_time(in));
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER >= 1900)
ferencd@0:                     z.u.rule_.~string();
ferencd@0:                     z.tag_ = zonelet::has_save;
ferencd@0:                     ::new(&z.u.save_) minutes(tmp);
ferencd@0: #else
ferencd@0:                     z.u.rule_.clear();
ferencd@0:                     z.tag_ = zonelet::has_save;
ferencd@0:                     z.u.save_ = tmp;
ferencd@0: #endif
ferencd@0:                 }
ferencd@0:                 catch (...)
ferencd@0:                 {
ferencd@0:                     std::cerr << name_ << " : " << z.u.rule_ << '\n';
ferencd@0:                     throw;
ferencd@0:                 }
ferencd@0:             }
ferencd@0:         }
ferencd@0:         else
ferencd@0:         {
ferencd@0:             // This zone::zonelet has no rule and no save
ferencd@0:             z.tag_ = zonelet::is_empty;
ferencd@0:         }
ferencd@0: 
ferencd@0:         minutes final_save{0};
ferencd@0:         if (z.tag_ == zonelet::has_save)
ferencd@0:         {
ferencd@0:             final_save = z.u.save_;
ferencd@0:         }
ferencd@0:         else if (z.tag_ == zonelet::has_rule)
ferencd@0:         {
ferencd@0:             z.last_rule_ = find_rule_for_zone(eqr, z.until_year_, z.gmtoff_,
ferencd@0:                                               z.until_date_);
ferencd@0:             if (z.last_rule_.first != nullptr)
ferencd@0:                 final_save = z.last_rule_.first->save();
ferencd@0:         }
ferencd@0:         z.until_utc_ = z.until_date_.to_sys(z.until_year_, z.gmtoff_, final_save);
ferencd@0:         z.until_std_ = local_seconds{z.until_utc_.time_since_epoch()} + z.gmtoff_;
ferencd@0:         z.until_loc_ = z.until_std_ + final_save;
ferencd@0: 
ferencd@0:         if (z.tag_ == zonelet::has_rule)
ferencd@0:         {
ferencd@0:             if (prev_zonelet != nullptr)
ferencd@0:             {
ferencd@0:                 z.first_rule_ = find_rule_for_zone(eqr, prev_zonelet->until_utc_,
ferencd@0:                                                         prev_zonelet->until_std_,
ferencd@0:                                                         prev_zonelet->until_loc_);
ferencd@0:                 if (z.first_rule_.first != nullptr)
ferencd@0:                 {
ferencd@0:                     z.initial_save_ = z.first_rule_.first->save();
ferencd@0:                     z.initial_abbrev_ = z.first_rule_.first->abbrev();
ferencd@0:                     if (z.first_rule_ != z.last_rule_)
ferencd@0:                     {
ferencd@0:                         z.first_rule_ = find_next_rule(eqr.first, eqr.second,
ferencd@0:                                                        z.first_rule_.first,
ferencd@0:                                                        z.first_rule_.second);
ferencd@0:                     }
ferencd@0:                     else
ferencd@0:                     {
ferencd@0:                         z.first_rule_ = std::make_pair(nullptr, year::min());
ferencd@0:                         z.last_rule_ = std::make_pair(nullptr, year::max());
ferencd@0:                     }
ferencd@0:                 }
ferencd@0:             }
ferencd@0:             if (z.first_rule_.first == nullptr && z.last_rule_.first != nullptr)
ferencd@0:             {
ferencd@0:                 z.first_rule_ = std::make_pair(eqr.first, eqr.first->starting_year());
ferencd@0:                 z.initial_abbrev_ = find_first_std_rule(eqr)->abbrev();
ferencd@0:             }
ferencd@0:         }
ferencd@0: 
ferencd@0: #ifndef NDEBUG
ferencd@0:         if (z.first_rule_.first == nullptr)
ferencd@0:         {
ferencd@0:             assert(z.first_rule_.second == year::min());
ferencd@0:             assert(z.last_rule_.first == nullptr);
ferencd@0:             assert(z.last_rule_.second == year::max());
ferencd@0:         }
ferencd@0:         else
ferencd@0:         {
ferencd@0:             assert(z.last_rule_.first != nullptr);
ferencd@0:         }
ferencd@0: #endif
ferencd@0:         prev_zonelet = &z;
ferencd@0:     }
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: format_abbrev(std::string format, const std::string& variable, std::chrono::seconds off,
ferencd@0:                                                                std::chrono::minutes save)
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     auto k = format.find("%s");
ferencd@0:     if (k != std::string::npos)
ferencd@0:     {
ferencd@0:         format.replace(k, 2, variable);
ferencd@0:     }
ferencd@0:     else
ferencd@0:     {
ferencd@0:         k = format.find('/');
ferencd@0:         if (k != std::string::npos)
ferencd@0:         {
ferencd@0:             if (save == minutes{0})
ferencd@0:                 format.erase(k);
ferencd@0:             else
ferencd@0:                 format.erase(0, k+1);
ferencd@0:         }
ferencd@0:         else
ferencd@0:         {
ferencd@0:             k = format.find("%z");
ferencd@0:             if (k != std::string::npos)
ferencd@0:             {
ferencd@0:                 std::string temp;
ferencd@0:                 if (off < seconds{0})
ferencd@0:                 {
ferencd@0:                     temp = '-';
ferencd@0:                     off = -off;
ferencd@0:                 }
ferencd@0:                 else
ferencd@0:                     temp = '+';
ferencd@0:                 auto h = date::floor<hours>(off);
ferencd@0:                 off -= h;
ferencd@0:                 if (h < hours{10})
ferencd@0:                     temp += '0';
ferencd@0:                 temp += std::to_string(h.count());
ferencd@0:                 if (off > seconds{0})
ferencd@0:                 {
ferencd@0:                     auto m = date::floor<minutes>(off);
ferencd@0:                     off -= m;
ferencd@0:                     if (m < minutes{10})
ferencd@0:                         temp += '0';
ferencd@0:                     temp += std::to_string(m.count());
ferencd@0:                     if (off > seconds{0})
ferencd@0:                     {
ferencd@0:                         if (off < seconds{10})
ferencd@0:                             temp += '0';
ferencd@0:                         temp += std::to_string(off.count());
ferencd@0:                     }
ferencd@0:                 }
ferencd@0:                 format.replace(k, 2, temp);
ferencd@0:             }
ferencd@0:         }
ferencd@0:     }
ferencd@0:     return format;
ferencd@0: }
ferencd@0: 
ferencd@0: sys_info
ferencd@0: time_zone::get_info_impl(sys_seconds tp, int tz_int) const
ferencd@0: {
ferencd@0:     using namespace std::chrono;
ferencd@0:     using namespace date;
ferencd@0:     tz timezone = static_cast<tz>(tz_int);
ferencd@0:     assert(timezone != tz::standard);
ferencd@0:     auto y = year_month_day(floor<days>(tp)).year();
ferencd@0:     if (y < min_year || y > max_year)
ferencd@0:         throw std::runtime_error("The year " + std::to_string(static_cast<int>(y)) +
ferencd@0:             " is out of range:[" + std::to_string(static_cast<int>(min_year)) + ", "
ferencd@0:                                  + std::to_string(static_cast<int>(max_year)) + "]");
ferencd@0:     std::call_once(*adjusted_,
ferencd@0:                    [this]()
ferencd@0:                    {
ferencd@0:                        const_cast<time_zone*>(this)->adjust_infos(get_tzdb().rules);
ferencd@0:                    });
ferencd@0:     auto i = std::upper_bound(zonelets_.begin(), zonelets_.end(), tp,
ferencd@0:         [timezone](sys_seconds t, const zonelet& zl)
ferencd@0:         {
ferencd@0:             return timezone == tz::utc ? t < zl.until_utc_ :
ferencd@0:                                          t < sys_seconds{zl.until_loc_.time_since_epoch()};
ferencd@0:         });
ferencd@0: 
ferencd@0:     sys_info r{};
ferencd@0:     if (i != zonelets_.end())
ferencd@0:     {
ferencd@0:         if (i->tag_ == zonelet::has_save)
ferencd@0:         {
ferencd@0:             if (i != zonelets_.begin())
ferencd@0:                 r.begin = i[-1].until_utc_;
ferencd@0:             else
ferencd@0:                 r.begin = sys_days(year::min()/min_day);
ferencd@0:             r.end = i->until_utc_;
ferencd@0:             r.offset = i->gmtoff_ + i->u.save_;
ferencd@0:             r.save = i->u.save_;
ferencd@0:         }
ferencd@0:         else if (i->u.rule_.empty())
ferencd@0:         {
ferencd@0:             if (i != zonelets_.begin())
ferencd@0:                 r.begin = i[-1].until_utc_;
ferencd@0:             else
ferencd@0:                 r.begin = sys_days(year::min()/min_day);
ferencd@0:             r.end = i->until_utc_;
ferencd@0:             r.offset = i->gmtoff_;
ferencd@0:         }
ferencd@0:         else
ferencd@0:         {
ferencd@0:             r = find_rule(i->first_rule_, i->last_rule_, y, i->gmtoff_,
ferencd@0:                           MonthDayTime(local_seconds{tp.time_since_epoch()}, timezone),
ferencd@0:                           i->initial_save_, i->initial_abbrev_);
ferencd@0:             r.offset = i->gmtoff_ + r.save;
ferencd@0:             if (i != zonelets_.begin() && r.begin < i[-1].until_utc_)
ferencd@0:                 r.begin = i[-1].until_utc_;
ferencd@0:             if (r.end > i->until_utc_)
ferencd@0:                 r.end = i->until_utc_;
ferencd@0:         }
ferencd@0:         r.abbrev = format_abbrev(i->format_, r.abbrev, r.offset, r.save);
ferencd@0:         assert(r.begin < r.end);
ferencd@0:     }
ferencd@0:     return r;
ferencd@0: }
ferencd@0: 
ferencd@0: std::ostream&
ferencd@0: operator<<(std::ostream& os, const time_zone& z)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     using namespace std::chrono;
ferencd@0:     detail::save_ostream<char> _(os);
ferencd@0:     os.fill(' ');
ferencd@0:     os.flags(std::ios::dec | std::ios::left);
ferencd@0:     std::call_once(*z.adjusted_,
ferencd@0:                    [&z]()
ferencd@0:                    {
ferencd@0:                        const_cast<time_zone&>(z).adjust_infos(get_tzdb().rules);
ferencd@0:                    });
ferencd@0:     os.width(35);
ferencd@0:     os << z.name_;
ferencd@0:     std::string indent;
ferencd@0:     for (auto const& s : z.zonelets_)
ferencd@0:     {
ferencd@0:         os << indent;
ferencd@0:         if (s.gmtoff_ >= seconds{0})
ferencd@0:             os << ' ';
ferencd@0:         os << make_time(s.gmtoff_) << "   ";
ferencd@0:         os.width(15);
ferencd@0:         if (s.tag_ != zonelet::has_save)
ferencd@0:             os << s.u.rule_;
ferencd@0:         else
ferencd@0:         {
ferencd@0:             std::ostringstream tmp;
ferencd@0:             tmp << make_time(s.u.save_);
ferencd@0:             os <<  tmp.str();
ferencd@0:         }
ferencd@0:         os.width(8);
ferencd@0:         os << s.format_ << "   ";
ferencd@0:         os << s.until_year_ << ' ' << s.until_date_;
ferencd@0:         os << "   " << s.until_utc_ << " UTC";
ferencd@0:         os << "   " << s.until_std_ << " STD";
ferencd@0:         os << "   " << s.until_loc_;
ferencd@0:         os << "   " << make_time(s.initial_save_);
ferencd@0:         os << "   " << s.initial_abbrev_;
ferencd@0:         if (s.first_rule_.first != nullptr)
ferencd@0:             os << "   {" << *s.first_rule_.first << ", " << s.first_rule_.second << '}';
ferencd@0:         else
ferencd@0:             os << "   {" << "nullptr" << ", " << s.first_rule_.second << '}';
ferencd@0:         if (s.last_rule_.first != nullptr)
ferencd@0:             os << "   {" << *s.last_rule_.first << ", " << s.last_rule_.second << '}';
ferencd@0:         else
ferencd@0:             os << "   {" << "nullptr" << ", " << s.last_rule_.second << '}';
ferencd@0:         os << '\n';
ferencd@0:         if (indent.empty())
ferencd@0:             indent = std::string(35, ' ');
ferencd@0:     }
ferencd@0:     return os;
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: #if !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: std::ostream&
ferencd@0: operator<<(std::ostream& os, const leap& x)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     return os << x.date_ << "  +";
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: #if USE_OS_TZDB
ferencd@0: 
ferencd@0: # ifdef __APPLE__
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_version()
ferencd@0: {
ferencd@0:     using namespace std;
ferencd@0:     auto path = get_tz_dir() + string("/+VERSION");
ferencd@0:     ifstream in{path};
ferencd@0:     string version;
ferencd@0:     in >> version;
ferencd@0:     if (in.fail())
ferencd@0:         throw std::runtime_error("Unable to get Timezone database version from " + path);
ferencd@0:     return version;
ferencd@0: }
ferencd@0: # endif
ferencd@0: 
ferencd@0: static
ferencd@0: std::unique_ptr<tzdb>
ferencd@0: init_tzdb()
ferencd@0: {
ferencd@0:     std::unique_ptr<tzdb> db(new tzdb);
ferencd@0: 
ferencd@0:     //Iterate through folders
ferencd@0:     std::queue<std::string> subfolders;
ferencd@0:     subfolders.emplace(get_tz_dir());
ferencd@0:     struct dirent* d;
ferencd@0:     struct stat s;
ferencd@0:     while (!subfolders.empty())
ferencd@0:     {
ferencd@0:         auto dirname = std::move(subfolders.front());
ferencd@0:         subfolders.pop();
ferencd@0:         auto dir = opendir(dirname.c_str());
ferencd@0:         if (!dir)
ferencd@0:             continue;
ferencd@0:         while ((d = readdir(dir)) != nullptr)
ferencd@0:         {
ferencd@0:             // Ignore these files:
ferencd@0:             if (d->d_name[0]                      == '.'    || // curdir, prevdir, hidden
ferencd@0:                 memcmp(d->d_name, "posix", 5)     == 0      || // starts with posix
ferencd@0:                 strcmp(d->d_name, "Factory")      == 0      ||
ferencd@0:                 strcmp(d->d_name, "iso3166.tab")  == 0      ||
ferencd@0:                 strcmp(d->d_name, "right")        == 0      ||
ferencd@0:                 strcmp(d->d_name, "+VERSION")     == 0      ||
ferencd@0:                 strcmp(d->d_name, "zone.tab")     == 0      ||
ferencd@0:                 strcmp(d->d_name, "zone1970.tab") == 0      ||
ferencd@0:                 strcmp(d->d_name, "tzdata.zi")    == 0      ||
ferencd@0:                 strcmp(d->d_name, "leapseconds")  == 0      ||
ferencd@0:                 strcmp(d->d_name, "leap-seconds.list") == 0   )
ferencd@0:                 continue;
ferencd@0:             auto subname = dirname + folder_delimiter + d->d_name;
ferencd@0:             if(stat(subname.c_str(), &s) == 0)
ferencd@0:             {
ferencd@0:                 if(S_ISDIR(s.st_mode))
ferencd@0:                 {
ferencd@0:                     if(!S_ISLNK(s.st_mode))
ferencd@0:                     {
ferencd@0:                         subfolders.push(subname);
ferencd@0:                     }
ferencd@0:                 }
ferencd@0:                 else
ferencd@0:                 {
ferencd@0:                     db->zones.emplace_back(subname.substr(get_tz_dir().size()+1),
ferencd@0:                                            detail::undocumented{});
ferencd@0:                 }
ferencd@0:             }
ferencd@0:         }
ferencd@0:         closedir(dir);
ferencd@0:     }
ferencd@0:     db->zones.shrink_to_fit();
ferencd@0:     std::sort(db->zones.begin(), db->zones.end());
ferencd@0: #  if !MISSING_LEAP_SECONDS
ferencd@0:     std::ifstream in(get_tz_dir() + std::string(1, folder_delimiter) + "right/UTC",
ferencd@0:                      std::ios_base::binary);
ferencd@0:     if (in)
ferencd@0:     {
ferencd@0:         in.exceptions(std::ios::failbit | std::ios::badbit);
ferencd@0:         db->leaps = load_just_leaps(in);
ferencd@0:     }
ferencd@0:     else
ferencd@0:     {
ferencd@0:         in.clear();
ferencd@0:         in.open(get_tz_dir() + std::string(1, folder_delimiter) +
ferencd@0:                 "UTC", std::ios_base::binary);
ferencd@0:         if (!in)
ferencd@0:             throw std::runtime_error("Unable to extract leap second information");
ferencd@0:         in.exceptions(std::ios::failbit | std::ios::badbit);
ferencd@0:         db->leaps = load_just_leaps(in);
ferencd@0:     }
ferencd@0: #  endif  // !MISSING_LEAP_SECONDS
ferencd@0: #  ifdef __APPLE__
ferencd@0:     db->version = get_version();
ferencd@0: #  endif
ferencd@0:     return db;
ferencd@0: }
ferencd@0: 
ferencd@0: #else  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: // link
ferencd@0: 
ferencd@0: link::link(const std::string& s)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     std::istringstream in(s);
ferencd@0:     in.exceptions(std::ios::failbit | std::ios::badbit);
ferencd@0:     std::string word;
ferencd@0:     in >> word >> target_ >> name_;
ferencd@0: }
ferencd@0: 
ferencd@0: std::ostream&
ferencd@0: operator<<(std::ostream& os, const link& x)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     detail::save_ostream<char> _(os);
ferencd@0:     os.fill(' ');
ferencd@0:     os.flags(std::ios::dec | std::ios::left);
ferencd@0:     os.width(35);
ferencd@0:     return os << x.name_ << " --> " << x.target_;
ferencd@0: }
ferencd@0: 
ferencd@0: // leap
ferencd@0: 
ferencd@0: leap::leap(const std::string& s, detail::undocumented)
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     std::istringstream in(s);
ferencd@0:     in.exceptions(std::ios::failbit | std::ios::badbit);
ferencd@0:     std::string word;
ferencd@0:     int y;
ferencd@0:     MonthDayTime date;
ferencd@0:     in >> word >> y >> date;
ferencd@0:     date_ = date.to_time_point(year(y));
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: bool
ferencd@0: file_exists(const std::string& filename)
ferencd@0: {
ferencd@0: #ifdef _WIN32
ferencd@0:     return ::_access(filename.c_str(), 0) == 0;
ferencd@0: #else
ferencd@0:     return ::access(filename.c_str(), F_OK) == 0;
ferencd@0: #endif
ferencd@0: }
ferencd@0: 
ferencd@0: #if HAS_REMOTE_API
ferencd@0: 
ferencd@0: // CURL tools
ferencd@0: 
ferencd@0: static
ferencd@0: int
ferencd@0: curl_global()
ferencd@0: {
ferencd@0:     if (::curl_global_init(CURL_GLOBAL_DEFAULT) != 0)
ferencd@0:         throw std::runtime_error("CURL global initialization failed");
ferencd@0:     return 0;
ferencd@0: }
ferencd@0: 
ferencd@0: namespace
ferencd@0: {
ferencd@0: 
ferencd@0: struct curl_deleter
ferencd@0: {
ferencd@0:     void operator()(CURL* p) const
ferencd@0:     {
ferencd@0:         ::curl_easy_cleanup(p);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: }  // unnamed namespace
ferencd@0: 
ferencd@0: static
ferencd@0: std::unique_ptr<CURL, curl_deleter>
ferencd@0: curl_init()
ferencd@0: {
ferencd@0:     static const auto curl_is_now_initiailized = curl_global();
ferencd@0:     (void)curl_is_now_initiailized;
ferencd@0:     return std::unique_ptr<CURL, curl_deleter>{::curl_easy_init()};
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: bool
ferencd@0: download_to_string(const std::string& url, std::string& str)
ferencd@0: {
ferencd@0:     str.clear();
ferencd@0:     auto curl = curl_init();
ferencd@0:     if (!curl)
ferencd@0:         return false;
ferencd@0:     std::string version;
ferencd@0:     curl_easy_setopt(curl.get(), CURLOPT_USERAGENT, "curl");
ferencd@0:     curl_easy_setopt(curl.get(), CURLOPT_URL, url.c_str());
ferencd@0:     curl_write_callback write_cb = [](char* contents, std::size_t size, std::size_t nmemb,
ferencd@0:                                       void* userp) -> std::size_t
ferencd@0:     {
ferencd@0:         auto& userstr = *static_cast<std::string*>(userp);
ferencd@0:         auto realsize = size * nmemb;
ferencd@0:         userstr.append(contents, realsize);
ferencd@0:         return realsize;
ferencd@0:     };
ferencd@0:     curl_easy_setopt(curl.get(), CURLOPT_WRITEFUNCTION, write_cb);
ferencd@0:     curl_easy_setopt(curl.get(), CURLOPT_WRITEDATA, &str);
ferencd@0:     curl_easy_setopt(curl.get(), CURLOPT_SSL_VERIFYPEER, false);
ferencd@0:     auto res = curl_easy_perform(curl.get());
ferencd@0:     return (res == CURLE_OK);
ferencd@0: }
ferencd@0: 
ferencd@0: namespace
ferencd@0: {
ferencd@0:     enum class download_file_options { binary, text };
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: bool
ferencd@0: download_to_file(const std::string& url, const std::string& local_filename,
ferencd@0:                  download_file_options opts)
ferencd@0: {
ferencd@0:     auto curl = curl_init();
ferencd@0:     if (!curl)
ferencd@0:         return false;
ferencd@0:     curl_easy_setopt(curl.get(), CURLOPT_URL, url.c_str());
ferencd@0:     curl_easy_setopt(curl.get(), CURLOPT_SSL_VERIFYPEER, false);
ferencd@0:     curl_write_callback write_cb = [](char* contents, std::size_t size, std::size_t nmemb,
ferencd@0:                                       void* userp) -> std::size_t
ferencd@0:     {
ferencd@0:         auto& of = *static_cast<std::ofstream*>(userp);
ferencd@0:         auto realsize = size * nmemb;
ferencd@0:         of.write(contents, static_cast<std::streamsize>(realsize));
ferencd@0:         return realsize;
ferencd@0:     };
ferencd@0:     curl_easy_setopt(curl.get(), CURLOPT_WRITEFUNCTION, write_cb);
ferencd@0:     decltype(curl_easy_perform(curl.get())) res;
ferencd@0:     {
ferencd@0:         std::ofstream of(local_filename,
ferencd@0:                          opts == download_file_options::binary ?
ferencd@0:                              std::ofstream::out | std::ofstream::binary :
ferencd@0:                              std::ofstream::out);
ferencd@0:         of.exceptions(std::ios::badbit);
ferencd@0:         curl_easy_setopt(curl.get(), CURLOPT_WRITEDATA, &of);
ferencd@0:         res = curl_easy_perform(curl.get());
ferencd@0:     }
ferencd@0:     return res == CURLE_OK;
ferencd@0: }
ferencd@0: 
ferencd@0: std::string
ferencd@0: remote_version()
ferencd@0: {
ferencd@0:     std::string version;
ferencd@0:     std::string str;
ferencd@0:     if (download_to_string("https://www.iana.org/time-zones", str))
ferencd@0:     {
ferencd@0:         CONSTDATA char db[] = "/time-zones/releases/tzdata";
ferencd@0:         CONSTDATA auto db_size = sizeof(db) - 1;
ferencd@0:         auto p = str.find(db, 0, db_size);
ferencd@0:         const int ver_str_len = 5;
ferencd@0:         if (p != std::string::npos && p + (db_size + ver_str_len) <= str.size())
ferencd@0:             version = str.substr(p + db_size, ver_str_len);
ferencd@0:     }
ferencd@0:     return version;
ferencd@0: }
ferencd@0: 
ferencd@0: 
ferencd@0: // TODO! Using system() create a process and a console window.
ferencd@0: // This is useful to see what errors may occur but is slow and distracting.
ferencd@0: // Consider implementing this functionality more directly, such as
ferencd@0: // using _mkdir and CreateProcess etc.
ferencd@0: // But use the current means now as matches Unix implementations and while
ferencd@0: // in proof of concept / testing phase.
ferencd@0: // TODO! Use <filesystem> eventually.
ferencd@0: static
ferencd@0: bool
ferencd@0: remove_folder_and_subfolders(const std::string& folder)
ferencd@0: {
ferencd@0: #  ifdef _WIN32
ferencd@0: #    if USE_SHELL_API
ferencd@0:     // Delete the folder contents by deleting the folder.
ferencd@0:     std::string cmd = "rd /s /q \"";
ferencd@0:     cmd += folder;
ferencd@0:     cmd += '\"';
ferencd@0:     return std::system(cmd.c_str()) == EXIT_SUCCESS;
ferencd@0: #    else  // !USE_SHELL_API
ferencd@0:     // Create a buffer containing the path to delete. It must be terminated
ferencd@0:     // by two nuls. Who designs these API's...
ferencd@0:     std::vector<char> from;
ferencd@0:     from.assign(folder.begin(), folder.end());
ferencd@0:     from.push_back('\0');
ferencd@0:     from.push_back('\0');
ferencd@0:     SHFILEOPSTRUCT fo{}; // Zero initialize.
ferencd@0:     fo.wFunc = FO_DELETE;
ferencd@0:     fo.pFrom = from.data();
ferencd@0:     fo.fFlags = FOF_NO_UI;
ferencd@0:     int ret = SHFileOperation(&fo);
ferencd@0:     if (ret == 0 && !fo.fAnyOperationsAborted)
ferencd@0:         return true;
ferencd@0:     return false;
ferencd@0: #    endif  // !USE_SHELL_API
ferencd@0: #  else   // !_WIN32
ferencd@0: #    if USE_SHELL_API
ferencd@0:     return std::system(("rm -R " + folder).c_str()) == EXIT_SUCCESS;
ferencd@0: #    else // !USE_SHELL_API
ferencd@0:     struct dir_deleter {
ferencd@0:         dir_deleter() {}
ferencd@0:         void operator()(DIR* d) const
ferencd@0:         {
ferencd@0:             if (d != nullptr)
ferencd@0:             {
ferencd@0:                 int result = closedir(d);
ferencd@0:                 assert(result == 0);
ferencd@0:             }
ferencd@0:         }
ferencd@0:     };
ferencd@0:     using closedir_ptr = std::unique_ptr<DIR, dir_deleter>;
ferencd@0: 
ferencd@0:     std::string filename;
ferencd@0:     struct stat statbuf;
ferencd@0:     std::size_t folder_len = folder.length();
ferencd@0:     struct dirent* p = nullptr;
ferencd@0: 
ferencd@0:     closedir_ptr d(opendir(folder.c_str()));
ferencd@0:     bool r = d.get() != nullptr;
ferencd@0:     while (r && (p=readdir(d.get())) != nullptr)
ferencd@0:     {
ferencd@0:         if (strcmp(p->d_name, ".") == 0 || strcmp(p->d_name, "..") == 0)
ferencd@0:            continue;
ferencd@0: 
ferencd@0:         // + 2 for path delimiter and nul terminator.
ferencd@0:         std::size_t buf_len = folder_len + strlen(p->d_name) + 2;
ferencd@0:         filename.resize(buf_len);
ferencd@0:         std::size_t path_len = static_cast<std::size_t>(
ferencd@0:             snprintf(&filename[0], buf_len, "%s/%s", folder.c_str(), p->d_name));
ferencd@0:         assert(path_len == buf_len - 1);
ferencd@0:         filename.resize(path_len);
ferencd@0: 
ferencd@0:         if (stat(filename.c_str(), &statbuf) == 0)
ferencd@0:             r = S_ISDIR(statbuf.st_mode)
ferencd@0:               ? remove_folder_and_subfolders(filename)
ferencd@0:               : unlink(filename.c_str()) == 0;
ferencd@0:     }
ferencd@0:     d.reset();
ferencd@0: 
ferencd@0:     if (r)
ferencd@0:         r = rmdir(folder.c_str()) == 0;
ferencd@0: 
ferencd@0:     return r;
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0: #  endif  // !_WIN32
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: bool
ferencd@0: make_directory(const std::string& folder)
ferencd@0: {
ferencd@0: #  ifdef _WIN32
ferencd@0: #    if USE_SHELL_API
ferencd@0:     // Re-create the folder.
ferencd@0:     std::string cmd = "mkdir \"";
ferencd@0:     cmd += folder;
ferencd@0:     cmd += '\"';
ferencd@0:     return std::system(cmd.c_str()) == EXIT_SUCCESS;
ferencd@0: #    else  // !USE_SHELL_API
ferencd@0:     return _mkdir(folder.c_str()) == 0;
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0: #  else  // !_WIN32
ferencd@0: #    if USE_SHELL_API
ferencd@0:     return std::system(("mkdir -p " + folder).c_str()) == EXIT_SUCCESS;
ferencd@0: #    else  // !USE_SHELL_API
ferencd@0:     return mkdir(folder.c_str(), 0777) == 0;
ferencd@0: #    endif  // !USE_SHELL_API
ferencd@0: #  endif  // !_WIN32
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: bool
ferencd@0: delete_file(const std::string& file)
ferencd@0: {
ferencd@0: #  ifdef _WIN32
ferencd@0: #    if USE_SHELL_API
ferencd@0:     std::string cmd = "del \"";
ferencd@0:     cmd += file;
ferencd@0:     cmd += '\"';
ferencd@0:     return std::system(cmd.c_str()) == 0;
ferencd@0: #    else  // !USE_SHELL_API
ferencd@0:     return _unlink(file.c_str()) == 0;
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0: #  else  // !_WIN32
ferencd@0: #    if USE_SHELL_API
ferencd@0:     return std::system(("rm " + file).c_str()) == EXIT_SUCCESS;
ferencd@0: #    else // !USE_SHELL_API
ferencd@0:     return unlink(file.c_str()) == 0;
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0: #  endif  // !_WIN32
ferencd@0: }
ferencd@0: 
ferencd@0: #  ifdef _WIN32
ferencd@0: 
ferencd@0: static
ferencd@0: bool
ferencd@0: move_file(const std::string& from, const std::string& to)
ferencd@0: {
ferencd@0: #    if USE_SHELL_API
ferencd@0:     std::string cmd = "move \"";
ferencd@0:     cmd += from;
ferencd@0:     cmd += "\" \"";
ferencd@0:     cmd += to;
ferencd@0:     cmd += '\"';
ferencd@0:     return std::system(cmd.c_str()) == EXIT_SUCCESS;
ferencd@0: #    else  // !USE_SHELL_API
ferencd@0:     return !!::MoveFile(from.c_str(), to.c_str());
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0: }
ferencd@0: 
ferencd@0: // Usually something like "c:\Program Files".
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_program_folder()
ferencd@0: {
ferencd@0:     return get_known_folder(FOLDERID_ProgramFiles);
ferencd@0: }
ferencd@0: 
ferencd@0: // Note folder can and usually does contain spaces.
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_unzip_program()
ferencd@0: {
ferencd@0:     std::string path;
ferencd@0: 
ferencd@0:     // 7-Zip appears to note its location in the registry.
ferencd@0:     // If that doesn't work, fall through and take a guess, but it will likely be wrong.
ferencd@0:     HKEY hKey = nullptr;
ferencd@0:     if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, "SOFTWARE\\7-Zip", 0, KEY_READ, &hKey) == ERROR_SUCCESS)
ferencd@0:     {
ferencd@0:         char value_buffer[MAX_PATH + 1]; // fyi 260 at time of writing.
ferencd@0:         // in/out parameter. Documentation say that size is a count of bytes not chars.
ferencd@0:         DWORD size = sizeof(value_buffer) - sizeof(value_buffer[0]);
ferencd@0:         DWORD tzi_type = REG_SZ;
ferencd@0:         // Testing shows Path key value is "C:\Program Files\7-Zip\" i.e. always with trailing \.
ferencd@0:         bool got_value = (RegQueryValueExA(hKey, "Path", nullptr, &tzi_type,
ferencd@0:             reinterpret_cast<LPBYTE>(value_buffer), &size) == ERROR_SUCCESS);
ferencd@0:         RegCloseKey(hKey); // Close now incase of throw later.
ferencd@0:         if (got_value)
ferencd@0:         {
ferencd@0:             // Function does not guarantee to null terminate.
ferencd@0:             value_buffer[size / sizeof(value_buffer[0])] = '\0';
ferencd@0:             path = value_buffer;
ferencd@0:             if (!path.empty())
ferencd@0:             {
ferencd@0:                 path += "7z.exe";
ferencd@0:                 return path;
ferencd@0:             }
ferencd@0:         }
ferencd@0:     }
ferencd@0:     path += get_program_folder();
ferencd@0:     path += folder_delimiter;
ferencd@0:     path += "7-Zip\\7z.exe";
ferencd@0:     return path;
ferencd@0: }
ferencd@0: 
ferencd@0: #    if !USE_SHELL_API
ferencd@0: static
ferencd@0: int
ferencd@0: run_program(const std::string& command)
ferencd@0: {
ferencd@0:     STARTUPINFO si{};
ferencd@0:     si.cb = sizeof(si);
ferencd@0:     PROCESS_INFORMATION pi{};
ferencd@0: 
ferencd@0:     // Allegedly CreateProcess overwrites the command line. Ugh.
ferencd@0:     std::string mutable_command(command);
ferencd@0:     if (CreateProcess(nullptr, &mutable_command[0],
ferencd@0:         nullptr, nullptr, FALSE, CREATE_NO_WINDOW, nullptr, nullptr, &si, &pi))
ferencd@0:     {
ferencd@0:         WaitForSingleObject(pi.hProcess, INFINITE);
ferencd@0:         DWORD exit_code;
ferencd@0:         bool got_exit_code = !!GetExitCodeProcess(pi.hProcess, &exit_code);
ferencd@0:         CloseHandle(pi.hProcess);
ferencd@0:         CloseHandle(pi.hThread);
ferencd@0:         // Not 100% sure about this still active thing is correct,
ferencd@0:         // but I'm going with it because I *think* WaitForSingleObject might
ferencd@0:         // return in some cases without INFINITE-ly waiting.
ferencd@0:         // But why/wouldn't GetExitCodeProcess return false in that case?
ferencd@0:         if (got_exit_code && exit_code != STILL_ACTIVE)
ferencd@0:             return static_cast<int>(exit_code);
ferencd@0:     }
ferencd@0:     return EXIT_FAILURE;
ferencd@0: }
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_download_tar_file(const std::string& version)
ferencd@0: {
ferencd@0:     auto file = get_install();
ferencd@0:     file += folder_delimiter;
ferencd@0:     file += "tzdata";
ferencd@0:     file += version;
ferencd@0:     file += ".tar";
ferencd@0:     return file;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: bool
ferencd@0: extract_gz_file(const std::string& version, const std::string& gz_file,
ferencd@0:                 const std::string& dest_folder)
ferencd@0: {
ferencd@0:     auto unzip_prog = get_unzip_program();
ferencd@0:     bool unzip_result = false;
ferencd@0:     // Use the unzip program to extract the tar file from the archive.
ferencd@0: 
ferencd@0:     // Aim to create a string like:
ferencd@0:     // "C:\Program Files\7-Zip\7z.exe" x "C:\Users\SomeUser\Downloads\tzdata2016d.tar.gz"
ferencd@0:     //     -o"C:\Users\SomeUser\Downloads\tzdata"
ferencd@0:     std::string cmd;
ferencd@0:     cmd = '\"';
ferencd@0:     cmd += unzip_prog;
ferencd@0:     cmd += "\" x \"";
ferencd@0:     cmd += gz_file;
ferencd@0:     cmd += "\" -o\"";
ferencd@0:     cmd += dest_folder;
ferencd@0:     cmd += '\"';
ferencd@0: 
ferencd@0: #    if USE_SHELL_API
ferencd@0:     // When using shelling out with std::system() extra quotes are required around the
ferencd@0:     // whole command. It's weird but necessary it seems, see:
ferencd@0:     // http://stackoverflow.com/q/27975969/576911
ferencd@0: 
ferencd@0:     cmd = "\"" + cmd + "\"";
ferencd@0:     if (std::system(cmd.c_str()) == EXIT_SUCCESS)
ferencd@0:         unzip_result = true;
ferencd@0: #    else  // !USE_SHELL_API
ferencd@0:     if (run_program(cmd) == EXIT_SUCCESS)
ferencd@0:         unzip_result = true;
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0:     if (unzip_result)
ferencd@0:         delete_file(gz_file);
ferencd@0: 
ferencd@0:     // Use the unzip program extract the data from the tar file that was
ferencd@0:     // just extracted from the archive.
ferencd@0:     auto tar_file = get_download_tar_file(version);
ferencd@0:     cmd = '\"';
ferencd@0:     cmd += unzip_prog;
ferencd@0:     cmd += "\" x \"";
ferencd@0:     cmd += tar_file;
ferencd@0:     cmd += "\" -o\"";
ferencd@0:     cmd += get_install();
ferencd@0:     cmd += '\"';
ferencd@0: #    if USE_SHELL_API
ferencd@0:     cmd = "\"" + cmd + "\"";
ferencd@0:     if (std::system(cmd.c_str()) == EXIT_SUCCESS)
ferencd@0:         unzip_result = true;
ferencd@0: #    else  // !USE_SHELL_API
ferencd@0:     if (run_program(cmd) == EXIT_SUCCESS)
ferencd@0:         unzip_result = true;
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0: 
ferencd@0:     if (unzip_result)
ferencd@0:         delete_file(tar_file);
ferencd@0: 
ferencd@0:     return unzip_result;
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_download_mapping_file(const std::string& version)
ferencd@0: {
ferencd@0:     auto file = get_install() + version + "windowsZones.xml";
ferencd@0:     return file;
ferencd@0: }
ferencd@0: 
ferencd@0: #  else  // !_WIN32
ferencd@0: 
ferencd@0: #    if !USE_SHELL_API
ferencd@0: static
ferencd@0: int
ferencd@0: run_program(const char* prog, const char*const args[])
ferencd@0: {
ferencd@0:     pid_t pid = fork();
ferencd@0:     if (pid == -1) // Child failed to start.
ferencd@0:         return EXIT_FAILURE;
ferencd@0: 
ferencd@0:     if (pid != 0)
ferencd@0:     {
ferencd@0:         // We are in the parent. Child started. Wait for it.
ferencd@0:         pid_t ret;
ferencd@0:         int status;
ferencd@0:         while ((ret = waitpid(pid, &status, 0)) == -1)
ferencd@0:         {
ferencd@0:             if (errno != EINTR)
ferencd@0:                 break;
ferencd@0:         }
ferencd@0:         if (ret != -1)
ferencd@0:         {
ferencd@0:             if (WIFEXITED(status))
ferencd@0:                 return WEXITSTATUS(status);
ferencd@0:         }
ferencd@0:         printf("Child issues!\n");
ferencd@0: 
ferencd@0:         return EXIT_FAILURE; // Not sure what status of child is.
ferencd@0:     }
ferencd@0:     else // We are in the child process. Start the program the parent wants to run.
ferencd@0:     {
ferencd@0: 
ferencd@0:         if (execv(prog, const_cast<char**>(args)) == -1) // Does not return.
ferencd@0:         {
ferencd@0:             perror("unreachable 0\n");
ferencd@0:             _Exit(127);
ferencd@0:         }
ferencd@0:         printf("unreachable 2\n");
ferencd@0:     }
ferencd@0:     printf("unreachable 2\n");
ferencd@0:     // Unreachable.
ferencd@0:     assert(false);
ferencd@0:     exit(EXIT_FAILURE);
ferencd@0:     return EXIT_FAILURE;
ferencd@0: }
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0: 
ferencd@0: static
ferencd@0: bool
ferencd@0: extract_gz_file(const std::string&, const std::string& gz_file, const std::string&)
ferencd@0: {
ferencd@0: #    if USE_SHELL_API
ferencd@0:     bool unzipped = std::system(("tar -xzf " + gz_file + " -C " + get_install()).c_str()) == EXIT_SUCCESS;
ferencd@0: #    else  // !USE_SHELL_API
ferencd@0:     const char prog[] = {"/usr/bin/tar"};
ferencd@0:     const char*const args[] =
ferencd@0:     {
ferencd@0:         prog, "-xzf", gz_file.c_str(), "-C", get_install().c_str(), nullptr
ferencd@0:     };
ferencd@0:     bool unzipped = (run_program(prog, args) == EXIT_SUCCESS);
ferencd@0: #    endif // !USE_SHELL_API
ferencd@0:     if (unzipped)
ferencd@0:     {
ferencd@0:         delete_file(gz_file);
ferencd@0:         return true;
ferencd@0:     }
ferencd@0:     return false;
ferencd@0: }
ferencd@0: 
ferencd@0: #  endif // !_WIN32
ferencd@0: 
ferencd@0: bool
ferencd@0: remote_download(const std::string& version)
ferencd@0: {
ferencd@0:     assert(!version.empty());
ferencd@0: 
ferencd@0: #  ifdef _WIN32
ferencd@0:     // Download folder should be always available for Windows
ferencd@0: #  else  // !_WIN32
ferencd@0:     // Create download folder if it does not exist on UNIX system
ferencd@0:     auto download_folder = get_install();
ferencd@0:     if (!file_exists(download_folder))
ferencd@0:     {
ferencd@0:         if (!make_directory(download_folder))
ferencd@0:             return false;
ferencd@0:     }
ferencd@0: #  endif  // _WIN32
ferencd@0: 
ferencd@0:     auto url = "https://data.iana.org/time-zones/releases/tzdata" + version +
ferencd@0:                ".tar.gz";
ferencd@0:     bool result = download_to_file(url, get_download_gz_file(version),
ferencd@0:                                    download_file_options::binary);
ferencd@0: #  ifdef _WIN32
ferencd@0:     if (result)
ferencd@0:     {
ferencd@0:         auto mapping_file = get_download_mapping_file(version);
ferencd@0:         result = download_to_file(
ferencd@0: 			"https://raw.githubusercontent.com/unicode-org/cldr/master/"
ferencd@0: 			"common/supplemental/windowsZones.xml",
ferencd@0:             mapping_file, download_file_options::text);
ferencd@0:     }
ferencd@0: #  endif  // _WIN32
ferencd@0:     return result;
ferencd@0: }
ferencd@0: 
ferencd@0: bool
ferencd@0: remote_install(const std::string& version)
ferencd@0: {
ferencd@0:     auto success = false;
ferencd@0:     assert(!version.empty());
ferencd@0: 
ferencd@0:     std::string install = get_install();
ferencd@0:     auto gz_file = get_download_gz_file(version);
ferencd@0:     if (file_exists(gz_file))
ferencd@0:     {
ferencd@0:         if (file_exists(install))
ferencd@0:             remove_folder_and_subfolders(install);
ferencd@0:         if (make_directory(install))
ferencd@0:         {
ferencd@0:             if (extract_gz_file(version, gz_file, install))
ferencd@0:                 success = true;
ferencd@0: #  ifdef _WIN32
ferencd@0:             auto mapping_file_source = get_download_mapping_file(version);
ferencd@0:             auto mapping_file_dest = get_install();
ferencd@0:             mapping_file_dest += folder_delimiter;
ferencd@0:             mapping_file_dest += "windowsZones.xml";
ferencd@0:             if (!move_file(mapping_file_source, mapping_file_dest))
ferencd@0:                 success = false;
ferencd@0: #  endif  // _WIN32
ferencd@0:         }
ferencd@0:     }
ferencd@0:     return success;
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // HAS_REMOTE_API
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: get_version(const std::string& path)
ferencd@0: {
ferencd@0:     std::string version;
ferencd@0:     std::ifstream infile(path + "version");
ferencd@0:     if (infile.is_open())
ferencd@0:     {
ferencd@0:         infile >> version;
ferencd@0:         if (!infile.fail())
ferencd@0:             return version;
ferencd@0:     }
ferencd@0:     else
ferencd@0:     {
ferencd@0:         infile.open(path + "NEWS");
ferencd@0:         while (infile)
ferencd@0:         {
ferencd@0:             infile >> version;
ferencd@0:             if (version == "Release")
ferencd@0:             {
ferencd@0:                 infile >> version;
ferencd@0:                 return version;
ferencd@0:             }
ferencd@0:         }
ferencd@0:     }
ferencd@0:     throw std::runtime_error("Unable to get Timezone database version from " + path);
ferencd@0: }
ferencd@0: 
ferencd@0: static
ferencd@0: std::unique_ptr<tzdb>
ferencd@0: init_tzdb()
ferencd@0: {
ferencd@0:     using namespace date;
ferencd@0:     const std::string install = get_install();
ferencd@0:     const std::string path = install + folder_delimiter;
ferencd@0:     std::string line;
ferencd@0:     bool continue_zone = false;
ferencd@0:     std::unique_ptr<tzdb> db(new tzdb);
ferencd@0: 
ferencd@0: #if AUTO_DOWNLOAD
ferencd@0:     if (!file_exists(install))
ferencd@0:     {
ferencd@0:         auto rv = remote_version();
ferencd@0:         if (!rv.empty() && remote_download(rv))
ferencd@0:         {
ferencd@0:             if (!remote_install(rv))
ferencd@0:             {
ferencd@0:                 std::string msg = "Timezone database version \"";
ferencd@0:                 msg += rv;
ferencd@0:                 msg += "\" did not install correctly to \"";
ferencd@0:                 msg += install;
ferencd@0:                 msg += "\"";
ferencd@0:                 throw std::runtime_error(msg);
ferencd@0:             }
ferencd@0:         }
ferencd@0:         if (!file_exists(install))
ferencd@0:         {
ferencd@0:             std::string msg = "Timezone database not found at \"";
ferencd@0:             msg += install;
ferencd@0:             msg += "\"";
ferencd@0:             throw std::runtime_error(msg);
ferencd@0:         }
ferencd@0:         db->version = get_version(path);
ferencd@0:     }
ferencd@0:     else
ferencd@0:     {
ferencd@0:         db->version = get_version(path);
ferencd@0:         auto rv = remote_version();
ferencd@0:         if (!rv.empty() && db->version != rv)
ferencd@0:         {
ferencd@0:             if (remote_download(rv))
ferencd@0:             {
ferencd@0:                 remote_install(rv);
ferencd@0:                 db->version = get_version(path);
ferencd@0:             }
ferencd@0:         }
ferencd@0:     }
ferencd@0: #else  // !AUTO_DOWNLOAD
ferencd@0:     if (!file_exists(install))
ferencd@0:     {
ferencd@0:         std::string msg = "Timezone database not found at \"";
ferencd@0:         msg += install;
ferencd@0:         msg += "\"";
ferencd@0:         throw std::runtime_error(msg);
ferencd@0:     }
ferencd@0:     db->version = get_version(path);
ferencd@0: #endif  // !AUTO_DOWNLOAD
ferencd@0: 
ferencd@0:     CONSTDATA char*const files[] =
ferencd@0:     {
ferencd@0:         "africa", "antarctica", "asia", "australasia", "backward", "etcetera", "europe",
ferencd@0:         "pacificnew", "northamerica", "southamerica", "systemv", "leapseconds"
ferencd@0:     };
ferencd@0: 
ferencd@0:     for (const auto& filename : files)
ferencd@0:     {
ferencd@0:         std::ifstream infile(path + filename);
ferencd@0:         while (infile)
ferencd@0:         {
ferencd@0:             std::getline(infile, line);
ferencd@0:             if (!line.empty() && line[0] != '#')
ferencd@0:             {
ferencd@0:                 std::istringstream in(line);
ferencd@0:                 std::string word;
ferencd@0:                 in >> word;
ferencd@0:                 if (word == "Rule")
ferencd@0:                 {
ferencd@0:                     db->rules.push_back(Rule(line));
ferencd@0:                     continue_zone = false;
ferencd@0:                 }
ferencd@0:                 else if (word == "Link")
ferencd@0:                 {
ferencd@0:                     db->links.push_back(link(line));
ferencd@0:                     continue_zone = false;
ferencd@0:                 }
ferencd@0:                 else if (word == "Leap")
ferencd@0:                 {
ferencd@0:                     db->leaps.push_back(leap(line, detail::undocumented{}));
ferencd@0:                     continue_zone = false;
ferencd@0:                 }
ferencd@0:                 else if (word == "Zone")
ferencd@0:                 {
ferencd@0:                     db->zones.push_back(time_zone(line, detail::undocumented{}));
ferencd@0:                     continue_zone = true;
ferencd@0:                 }
ferencd@0:                 else if (line[0] == '\t' && continue_zone)
ferencd@0:                 {
ferencd@0:                     db->zones.back().add(line);
ferencd@0:                 }
ferencd@0:                 else
ferencd@0:                 {
ferencd@0:                     std::cerr << line << '\n';
ferencd@0:                 }
ferencd@0:             }
ferencd@0:         }
ferencd@0:     }
ferencd@0:     std::sort(db->rules.begin(), db->rules.end());
ferencd@0:     Rule::split_overlaps(db->rules);
ferencd@0:     std::sort(db->zones.begin(), db->zones.end());
ferencd@0:     db->zones.shrink_to_fit();
ferencd@0:     std::sort(db->links.begin(), db->links.end());
ferencd@0:     db->links.shrink_to_fit();
ferencd@0:     std::sort(db->leaps.begin(), db->leaps.end());
ferencd@0:     db->leaps.shrink_to_fit();
ferencd@0: 
ferencd@0: #ifdef _WIN32
ferencd@0:     std::string mapping_file = get_install() + folder_delimiter + "windowsZones.xml";
ferencd@0:     db->mappings = load_timezone_mappings_from_xml_file(mapping_file);
ferencd@0:     sort_zone_mappings(db->mappings);
ferencd@0: #endif // _WIN32
ferencd@0: 
ferencd@0:     return db;
ferencd@0: }
ferencd@0: 
ferencd@0: const tzdb&
ferencd@0: reload_tzdb()
ferencd@0: {
ferencd@0: #if AUTO_DOWNLOAD
ferencd@0:     auto const& v = get_tzdb_list().front().version;
ferencd@0:     if (!v.empty() && v == remote_version())
ferencd@0:         return get_tzdb_list().front();
ferencd@0: #endif  // AUTO_DOWNLOAD
ferencd@0:     tzdb_list::undocumented_helper::push_front(get_tzdb_list(), init_tzdb().release());
ferencd@0:     return get_tzdb_list().front();
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: const tzdb&
ferencd@0: get_tzdb()
ferencd@0: {
ferencd@0:     return get_tzdb_list().front();
ferencd@0: }
ferencd@0: 
ferencd@0: const time_zone*
ferencd@0: #if HAS_STRING_VIEW
ferencd@0: tzdb::locate_zone(std::string_view tz_name) const
ferencd@0: #else
ferencd@0: tzdb::locate_zone(const std::string& tz_name) const
ferencd@0: #endif
ferencd@0: {
ferencd@0:     auto zi = std::lower_bound(zones.begin(), zones.end(), tz_name,
ferencd@0: #if HAS_STRING_VIEW
ferencd@0:         [](const time_zone& z, const std::string_view& nm)
ferencd@0: #else
ferencd@0:         [](const time_zone& z, const std::string& nm)
ferencd@0: #endif
ferencd@0:         {
ferencd@0:             return z.name() < nm;
ferencd@0:         });
ferencd@0:     if (zi == zones.end() || zi->name() != tz_name)
ferencd@0:     {
ferencd@0: #if !USE_OS_TZDB
ferencd@0:         auto li = std::lower_bound(links.begin(), links.end(), tz_name,
ferencd@0: #if HAS_STRING_VIEW
ferencd@0:         [](const link& z, const std::string_view& nm)
ferencd@0: #else
ferencd@0:         [](const link& z, const std::string& nm)
ferencd@0: #endif
ferencd@0:         {
ferencd@0:             return z.name() < nm;
ferencd@0:         });
ferencd@0:         if (li != links.end() && li->name() == tz_name)
ferencd@0:         {
ferencd@0:             zi = std::lower_bound(zones.begin(), zones.end(), li->target(),
ferencd@0:                 [](const time_zone& z, const std::string& nm)
ferencd@0:                 {
ferencd@0:                     return z.name() < nm;
ferencd@0:                 });
ferencd@0:             if (zi != zones.end() && zi->name() == li->target())
ferencd@0:                 return &*zi;
ferencd@0:         }
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0:         throw std::runtime_error(std::string(tz_name) + " not found in timezone database");
ferencd@0:     }
ferencd@0:     return &*zi;
ferencd@0: }
ferencd@0: 
ferencd@0: const time_zone*
ferencd@0: #if HAS_STRING_VIEW
ferencd@0: locate_zone(std::string_view tz_name)
ferencd@0: #else
ferencd@0: locate_zone(const std::string& tz_name)
ferencd@0: #endif
ferencd@0: {
ferencd@0:     return get_tzdb().locate_zone(tz_name);
ferencd@0: }
ferencd@0: 
ferencd@0: #if USE_OS_TZDB
ferencd@0: 
ferencd@0: std::ostream&
ferencd@0: operator<<(std::ostream& os, const tzdb& db)
ferencd@0: {
ferencd@0:     os << "Version: " << db.version << "\n\n";
ferencd@0:     for (const auto& x : db.zones)
ferencd@0:         os << x << '\n';
ferencd@0: #if !MISSING_LEAP_SECONDS
ferencd@0:     os << '\n';
ferencd@0:     for (const auto& x : db.leaps)
ferencd@0:         os << x << '\n';
ferencd@0: #endif  // !MISSING_LEAP_SECONDS
ferencd@0:     return os;
ferencd@0: }
ferencd@0: 
ferencd@0: #else  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: std::ostream&
ferencd@0: operator<<(std::ostream& os, const tzdb& db)
ferencd@0: {
ferencd@0:     os << "Version: " << db.version << '\n';
ferencd@0:     std::string title("--------------------------------------------"
ferencd@0:                       "--------------------------------------------\n"
ferencd@0:                       "Name           ""Start Y ""End Y   "
ferencd@0:                       "Beginning                              ""Offset  "
ferencd@0:                       "Designator\n"
ferencd@0:                       "--------------------------------------------"
ferencd@0:                       "--------------------------------------------\n");
ferencd@0:     int count = 0;
ferencd@0:     for (const auto& x : db.rules)
ferencd@0:     {
ferencd@0:         if (count++ % 50 == 0)
ferencd@0:             os << title;
ferencd@0:         os << x << '\n';
ferencd@0:     }
ferencd@0:     os << '\n';
ferencd@0:     title = std::string("---------------------------------------------------------"
ferencd@0:                         "--------------------------------------------------------\n"
ferencd@0:                         "Name                               ""Offset      "
ferencd@0:                         "Rule           ""Abrev      ""Until\n"
ferencd@0:                         "---------------------------------------------------------"
ferencd@0:                         "--------------------------------------------------------\n");
ferencd@0:     count = 0;
ferencd@0:     for (const auto& x : db.zones)
ferencd@0:     {
ferencd@0:         if (count++ % 10 == 0)
ferencd@0:             os << title;
ferencd@0:         os << x << '\n';
ferencd@0:     }
ferencd@0:     os << '\n';
ferencd@0:     title = std::string("---------------------------------------------------------"
ferencd@0:                         "--------------------------------------------------------\n"
ferencd@0:                         "Alias                                   ""To\n"
ferencd@0:                         "---------------------------------------------------------"
ferencd@0:                         "--------------------------------------------------------\n");
ferencd@0:     count = 0;
ferencd@0:     for (const auto& x : db.links)
ferencd@0:     {
ferencd@0:         if (count++ % 45 == 0)
ferencd@0:             os << title;
ferencd@0:         os << x << '\n';
ferencd@0:     }
ferencd@0:     os << '\n';
ferencd@0:     title = std::string("---------------------------------------------------------"
ferencd@0:                         "--------------------------------------------------------\n"
ferencd@0:                         "Leap second on\n"
ferencd@0:                         "---------------------------------------------------------"
ferencd@0:                         "--------------------------------------------------------\n");
ferencd@0:     os << title;
ferencd@0:     for (const auto& x : db.leaps)
ferencd@0:         os << x << '\n';
ferencd@0:     return os;
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: // -----------------------
ferencd@0: 
ferencd@0: #ifdef _WIN32
ferencd@0: 
ferencd@0: static
ferencd@0: std::string
ferencd@0: getTimeZoneKeyName()
ferencd@0: {
ferencd@0:     DYNAMIC_TIME_ZONE_INFORMATION dtzi{};
ferencd@0:     auto result = GetDynamicTimeZoneInformation(&dtzi);
ferencd@0:     if (result == TIME_ZONE_ID_INVALID)
ferencd@0:         throw std::runtime_error("current_zone(): GetDynamicTimeZoneInformation()"
ferencd@0:                                  " reported TIME_ZONE_ID_INVALID.");
ferencd@0:     auto wlen = wcslen(dtzi.TimeZoneKeyName);
ferencd@0:     char buf[128] = {};
ferencd@0:     assert(sizeof(buf) >= wlen+1);
ferencd@0:     wcstombs(buf, dtzi.TimeZoneKeyName, wlen);
ferencd@0:     if (strcmp(buf, "Coordinated Universal Time") == 0)
ferencd@0:         return "UTC";
ferencd@0:     return buf;
ferencd@0: }
ferencd@0: 
ferencd@0: const time_zone*
ferencd@0: tzdb::current_zone() const
ferencd@0: {
ferencd@0:     std::string win_tzid = getTimeZoneKeyName();
ferencd@0:     std::string standard_tzid;
ferencd@0:     if (!native_to_standard_timezone_name(win_tzid, standard_tzid))
ferencd@0:     {
ferencd@0:         std::string msg;
ferencd@0:         msg = "current_zone() failed: A mapping from the Windows Time Zone id \"";
ferencd@0:         msg += win_tzid;
ferencd@0:         msg += "\" was not found in the time zone mapping database.";
ferencd@0:         throw std::runtime_error(msg);
ferencd@0:     }
ferencd@0:     return locate_zone(standard_tzid);
ferencd@0: }
ferencd@0: 
ferencd@0: #else  // !_WIN32
ferencd@0: 
ferencd@0: const time_zone*
ferencd@0: tzdb::current_zone() const
ferencd@0: {
ferencd@0:     // On some OS's a file called /etc/localtime may
ferencd@0:     // exist and it may be either a real file
ferencd@0:     // containing time zone details or a symlink to such a file.
ferencd@0:     // On MacOS and BSD Unix if this file is a symlink it
ferencd@0:     // might resolve to a path like this:
ferencd@0:     // "/usr/share/zoneinfo/America/Los_Angeles"
ferencd@0:     // If it does, we try to determine the current
ferencd@0:     // timezone from the remainder of the path by removing the prefix
ferencd@0:     // and hoping the rest resolves to a valid timezone.
ferencd@0:     // It may not always work though. If it doesn't then an
ferencd@0:     // exception will be thrown by local_timezone.
ferencd@0:     // The path may also take a relative form:
ferencd@0:     // "../usr/share/zoneinfo/America/Los_Angeles".
ferencd@0:     {
ferencd@0:         struct stat sb;
ferencd@0:         CONSTDATA auto timezone = "/etc/localtime";
ferencd@0:         if (lstat(timezone, &sb) == 0 && S_ISLNK(sb.st_mode) && sb.st_size > 0) {
ferencd@0:             using namespace std;
ferencd@0:             char rp[PATH_MAX+1] = {};
ferencd@0:             if (realpath(timezone, rp) == nullptr)
ferencd@0:                 throw system_error(errno, system_category(), "realpath() failed");
ferencd@0: #if HAS_STRING_VIEW
ferencd@0:             string_view result = rp;
ferencd@0:             CONSTDATA string_view zoneinfo = "/zoneinfo/";
ferencd@0:             const size_t pos = result.rfind(zoneinfo);
ferencd@0:             if (pos == result.npos)
ferencd@0:                 throw runtime_error(
ferencd@0:                     "current_zone() failed to find \"/zoneinfo/\" in " + string(result));
ferencd@0:             result.remove_prefix(pos + zoneinfo.size());
ferencd@0: #else
ferencd@0:             string result = rp;
ferencd@0:             CONSTDATA char zoneinfo[] = "/zoneinfo/";
ferencd@0:             const size_t pos = result.rfind(zoneinfo);
ferencd@0:             if (pos == result.npos)
ferencd@0:                 throw runtime_error(
ferencd@0:                     "current_zone() failed to find \"/zoneinfo/\" in " + result);
ferencd@0:             result.erase(0, pos + sizeof(zoneinfo) - 1);
ferencd@0: #endif
ferencd@0:             return locate_zone(result);
ferencd@0:         }
ferencd@0:     }
ferencd@0:     // On embedded systems e.g. buildroot with uclibc the timezone is linked
ferencd@0:     // into /etc/TZ which is a symlink to path like this:
ferencd@0:     // "/usr/share/zoneinfo/uclibc/America/Los_Angeles"
ferencd@0:     // If it does, we try to determine the current
ferencd@0:     // timezone from the remainder of the path by removing the prefix
ferencd@0:     // and hoping the rest resolves to valid timezone.
ferencd@0:     // It may not always work though. If it doesn't then an
ferencd@0:     // exception will be thrown by local_timezone.
ferencd@0:     // The path may also take a relative form:
ferencd@0:     // "../usr/share/zoneinfo/uclibc/America/Los_Angeles".
ferencd@0:     {
ferencd@0:         struct stat sb;
ferencd@0:         CONSTDATA auto timezone = "/etc/TZ";
ferencd@0:         if (lstat(timezone, &sb) == 0 && S_ISLNK(sb.st_mode) && sb.st_size > 0) {
ferencd@0:             using namespace std;
ferencd@0:             string result;
ferencd@0:             char rp[PATH_MAX+1] = {};
ferencd@0:             if (readlink(timezone, rp, sizeof(rp)-1) > 0)
ferencd@0:                 result = string(rp);
ferencd@0:             else
ferencd@0:                 throw system_error(errno, system_category(), "readlink() failed");
ferencd@0: 
ferencd@0:             const size_t pos = result.find(get_tz_dir());
ferencd@0:             if (pos != result.npos)
ferencd@0:                 result.erase(0, get_tz_dir().size() + 1 + pos);
ferencd@0:             return locate_zone(result);
ferencd@0:         }
ferencd@0:     }
ferencd@0:     {
ferencd@0:     // On some versions of some linux distro's (e.g. Ubuntu),
ferencd@0:     // the current timezone might be in the first line of
ferencd@0:     // the /etc/timezone file.
ferencd@0:         std::ifstream timezone_file("/etc/timezone");
ferencd@0:         if (timezone_file.is_open())
ferencd@0:         {
ferencd@0:             std::string result;
ferencd@0:             std::getline(timezone_file, result);
ferencd@0:             if (!result.empty())
ferencd@0:                 return locate_zone(result);
ferencd@0:         }
ferencd@0:         // Fall through to try other means.
ferencd@0:     }
ferencd@0:     {
ferencd@0:     // On some versions of some bsd distro's (e.g. FreeBSD),
ferencd@0:     // the current timezone might be in the first line of
ferencd@0:     // the /var/db/zoneinfo file.
ferencd@0:         std::ifstream timezone_file("/var/db/zoneinfo");
ferencd@0:         if (timezone_file.is_open())
ferencd@0:         {
ferencd@0:             std::string result;
ferencd@0:             std::getline(timezone_file, result);
ferencd@0:             if (!result.empty())
ferencd@0:                 return locate_zone(result);
ferencd@0:         }
ferencd@0:         // Fall through to try other means.
ferencd@0:     }
ferencd@0:     {
ferencd@0:     // On some versions of some bsd distro's (e.g. iOS),
ferencd@0:     // it is not possible to use file based approach,
ferencd@0:     // we switch to system API, calling functions in
ferencd@0:     // CoreFoundation framework.
ferencd@0: #if TARGET_OS_IPHONE
ferencd@0:         std::string result = date::iOSUtils::get_current_timezone();
ferencd@0:         if (!result.empty())
ferencd@0:             return locate_zone(result);
ferencd@0: #endif
ferencd@0:     // Fall through to try other means.
ferencd@0:     }
ferencd@0:     {
ferencd@0:     // On some versions of some linux distro's (e.g. Red Hat),
ferencd@0:     // the current timezone might be in the first line of
ferencd@0:     // the /etc/sysconfig/clock file as:
ferencd@0:     // ZONE="US/Eastern"
ferencd@0:         std::ifstream timezone_file("/etc/sysconfig/clock");
ferencd@0:         std::string result;
ferencd@0:         while (timezone_file)
ferencd@0:         {
ferencd@0:             std::getline(timezone_file, result);
ferencd@0:             auto p = result.find("ZONE=\"");
ferencd@0:             if (p != std::string::npos)
ferencd@0:             {
ferencd@0:                 result.erase(p, p+6);
ferencd@0:                 result.erase(result.rfind('"'));
ferencd@0:                 return locate_zone(result);
ferencd@0:             }
ferencd@0:         }
ferencd@0:         // Fall through to try other means.
ferencd@0:     }
ferencd@0:     throw std::runtime_error("Could not get current timezone");
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !_WIN32
ferencd@0: 
ferencd@0: const time_zone*
ferencd@0: current_zone()
ferencd@0: {
ferencd@0:     return get_tzdb().current_zone();
ferencd@0: }
ferencd@0: 
ferencd@0: }  // namespace date
ferencd@0: 
ferencd@0: #if defined(__GNUC__) && __GNUC__ < 5
ferencd@0: # pragma GCC diagnostic pop
ferencd@0: #endif