ferencd@0: #ifndef TZ_H
ferencd@0: #define TZ_H
ferencd@0: 
ferencd@0: // The MIT License (MIT)
ferencd@0: //
ferencd@0: // Copyright (c) 2015, 2016, 2017 Howard Hinnant
ferencd@0: // Copyright (c) 2017 Jiangang Zhuang
ferencd@0: // Copyright (c) 2017 Aaron Bishop
ferencd@0: // Copyright (c) 2017 Tomasz Kamiński
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: // Get more recent database at http://www.iana.org/time-zones
ferencd@0: 
ferencd@0: // The notion of "current timezone" is something the operating system is expected to "just
ferencd@0: // know". How it knows this is system specific. It's often a value set by the user at OS
ferencd@0: // installation time and recorded by the OS somewhere. On Linux and Mac systems the current
ferencd@0: // timezone name is obtained by looking at the name or contents of a particular file on
ferencd@0: // disk. On Windows the current timezone name comes from the registry. In either method,
ferencd@0: // there is no guarantee that the "native" current timezone name obtained will match any
ferencd@0: // of the "Standard" names in this library's "database". On Linux, the names usually do
ferencd@0: // seem to match so mapping functions to map from native to "Standard" are typically not
ferencd@0: // required. On Windows, the names are never "Standard" so mapping is always required.
ferencd@0: // Technically any OS may use the mapping process but currently only Windows does use it.
ferencd@0: 
ferencd@0: #ifndef USE_OS_TZDB
ferencd@0: #  define USE_OS_TZDB 0
ferencd@0: #endif
ferencd@0: 
ferencd@0: #ifndef HAS_REMOTE_API
ferencd@0: #  if USE_OS_TZDB == 0
ferencd@0: #    ifdef _WIN32
ferencd@0: #      define HAS_REMOTE_API 0
ferencd@0: #    else
ferencd@0: #      define HAS_REMOTE_API 1
ferencd@0: #    endif
ferencd@0: #  else  // HAS_REMOTE_API makes no since when using the OS timezone database
ferencd@0: #    define HAS_REMOTE_API 0
ferencd@0: #  endif
ferencd@0: #endif
ferencd@0: 
ferencd@0: #ifdef __clang__
ferencd@0: # pragma clang diagnostic push
ferencd@0: # pragma clang diagnostic ignored "-Wconstant-logical-operand"
ferencd@0: #endif
ferencd@0: 
ferencd@0: static_assert(!(USE_OS_TZDB && HAS_REMOTE_API),
ferencd@0:               "USE_OS_TZDB and HAS_REMOTE_API can not be used together");
ferencd@0: 
ferencd@0: #ifdef __clang__
ferencd@0: # pragma clang diagnostic pop
ferencd@0: #endif
ferencd@0: 
ferencd@0: #ifndef AUTO_DOWNLOAD
ferencd@0: #  define AUTO_DOWNLOAD HAS_REMOTE_API
ferencd@0: #endif
ferencd@0: 
ferencd@0: static_assert(HAS_REMOTE_API == 0 ? AUTO_DOWNLOAD == 0 : true,
ferencd@0:               "AUTO_DOWNLOAD can not be turned on without HAS_REMOTE_API");
ferencd@0: 
ferencd@0: #ifndef USE_SHELL_API
ferencd@0: #  define USE_SHELL_API 1
ferencd@0: #endif
ferencd@0: 
ferencd@0: #if USE_OS_TZDB
ferencd@0: #  ifdef _WIN32
ferencd@0: #    error "USE_OS_TZDB can not be used on Windows"
ferencd@0: #  endif
ferencd@0: #  ifndef MISSING_LEAP_SECONDS
ferencd@0: #    ifdef __APPLE__
ferencd@0: #      define MISSING_LEAP_SECONDS 1
ferencd@0: #    else
ferencd@0: #      define MISSING_LEAP_SECONDS 0
ferencd@0: #    endif
ferencd@0: #  endif
ferencd@0: #else
ferencd@0: #  define MISSING_LEAP_SECONDS 0
ferencd@0: #endif
ferencd@0: 
ferencd@0: #ifndef HAS_DEDUCTION_GUIDES
ferencd@0: #  if __cplusplus >= 201703
ferencd@0: #    define HAS_DEDUCTION_GUIDES 1
ferencd@0: #  else
ferencd@0: #    define HAS_DEDUCTION_GUIDES 0
ferencd@0: #  endif
ferencd@0: #endif  // HAS_DEDUCTION_GUIDES
ferencd@0: 
ferencd@0: #include "date.h"
ferencd@0: 
ferencd@0: #if defined(_MSC_VER) && (_MSC_VER < 1900)
ferencd@0: #include "tz_private.h"
ferencd@0: #endif
ferencd@0: 
ferencd@0: #include <algorithm>
ferencd@0: #include <atomic>
ferencd@0: #include <cassert>
ferencd@0: #include <chrono>
ferencd@0: #include <istream>
ferencd@0: #include <locale>
ferencd@0: #include <memory>
ferencd@0: #include <mutex>
ferencd@0: #include <ostream>
ferencd@0: #include <sstream>
ferencd@0: #include <stdexcept>
ferencd@0: #include <string>
ferencd@0: #include <type_traits>
ferencd@0: #include <utility>
ferencd@0: #include <vector>
ferencd@0: 
ferencd@0: #ifdef _WIN32
ferencd@0: #  ifdef DATE_BUILD_DLL
ferencd@0: #    define DATE_API __declspec(dllexport)
ferencd@0: #  elif defined(DATE_USE_DLL)
ferencd@0: #    define DATE_API __declspec(dllimport)
ferencd@0: #  else
ferencd@0: #    define DATE_API
ferencd@0: #  endif
ferencd@0: #else
ferencd@0: #  ifdef DATE_BUILD_DLL
ferencd@0: #    define DATE_API __attribute__ ((visibility ("default")))
ferencd@0: #  else
ferencd@0: #    define DATE_API
ferencd@0: #  endif
ferencd@0: #endif
ferencd@0: 
ferencd@0: namespace date
ferencd@0: {
ferencd@0: 
ferencd@0: enum class choose {earliest, latest};
ferencd@0: 
ferencd@0: namespace detail
ferencd@0: {
ferencd@0:     struct undocumented;
ferencd@0: 
ferencd@0:     template<typename T>
ferencd@0:     struct nodeduct
ferencd@0:     {
ferencd@0:        using type = T;
ferencd@0:     };
ferencd@0: 
ferencd@0:     template<typename T>
ferencd@0:     using nodeduct_t = typename nodeduct<T>::type;
ferencd@0: }
ferencd@0: 
ferencd@0: struct sys_info
ferencd@0: {
ferencd@0:     sys_seconds          begin;
ferencd@0:     sys_seconds          end;
ferencd@0:     std::chrono::seconds offset;
ferencd@0:     std::chrono::minutes save;
ferencd@0:     std::string          abbrev;
ferencd@0: };
ferencd@0: 
ferencd@0: template<class CharT, class Traits>
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: operator<<(std::basic_ostream<CharT, Traits>& os, const sys_info& r)
ferencd@0: {
ferencd@0:     os << r.begin << '\n';
ferencd@0:     os << r.end << '\n';
ferencd@0:     os << make_time(r.offset) << "\n";
ferencd@0:     os << make_time(r.save) << "\n";
ferencd@0:     os << r.abbrev << '\n';
ferencd@0:     return os;
ferencd@0: }
ferencd@0: 
ferencd@0: struct local_info
ferencd@0: {
ferencd@0:     enum {unique, nonexistent, ambiguous} result;
ferencd@0:     sys_info first;
ferencd@0:     sys_info second;
ferencd@0: };
ferencd@0: 
ferencd@0: template<class CharT, class Traits>
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: operator<<(std::basic_ostream<CharT, Traits>& os, const local_info& r)
ferencd@0: {
ferencd@0:     if (r.result == local_info::nonexistent)
ferencd@0:         os << "nonexistent between\n";
ferencd@0:     else if (r.result == local_info::ambiguous)
ferencd@0:         os << "ambiguous between\n";
ferencd@0:     os << r.first;
ferencd@0:     if (r.result != local_info::unique)
ferencd@0:     {
ferencd@0:         os << "and\n";
ferencd@0:         os << r.second;
ferencd@0:     }
ferencd@0:     return os;
ferencd@0: }
ferencd@0: 
ferencd@0: class nonexistent_local_time
ferencd@0:     : public std::runtime_error
ferencd@0: {
ferencd@0: public:
ferencd@0:     template <class Duration>
ferencd@0:         nonexistent_local_time(local_time<Duration> tp, const local_info& i);
ferencd@0: 
ferencd@0: private:
ferencd@0:     template <class Duration>
ferencd@0:     static
ferencd@0:     std::string
ferencd@0:     make_msg(local_time<Duration> tp, const local_info& i);
ferencd@0: };
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: nonexistent_local_time::nonexistent_local_time(local_time<Duration> tp,
ferencd@0:                                                const local_info& i)
ferencd@0:     : std::runtime_error(make_msg(tp, i))
ferencd@0: {
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: std::string
ferencd@0: nonexistent_local_time::make_msg(local_time<Duration> tp, const local_info& i)
ferencd@0: {
ferencd@0:     assert(i.result == local_info::nonexistent);
ferencd@0:     std::ostringstream os;
ferencd@0:     os << tp << " is in a gap between\n"
ferencd@0:        << local_seconds{i.first.end.time_since_epoch()} + i.first.offset << ' '
ferencd@0:        << i.first.abbrev << " and\n"
ferencd@0:        << local_seconds{i.second.begin.time_since_epoch()} + i.second.offset << ' '
ferencd@0:        << i.second.abbrev
ferencd@0:        << " which are both equivalent to\n"
ferencd@0:        << i.first.end << " UTC";
ferencd@0:     return os.str();
ferencd@0: }
ferencd@0: 
ferencd@0: class ambiguous_local_time
ferencd@0:     : public std::runtime_error
ferencd@0: {
ferencd@0: public:
ferencd@0:     template <class Duration>
ferencd@0:         ambiguous_local_time(local_time<Duration> tp, const local_info& i);
ferencd@0: 
ferencd@0: private:
ferencd@0:     template <class Duration>
ferencd@0:     static
ferencd@0:     std::string
ferencd@0:     make_msg(local_time<Duration> tp, const local_info& i);
ferencd@0: };
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: ambiguous_local_time::ambiguous_local_time(local_time<Duration> tp, const local_info& i)
ferencd@0:     : std::runtime_error(make_msg(tp, i))
ferencd@0: {
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: std::string
ferencd@0: ambiguous_local_time::make_msg(local_time<Duration> tp, const local_info& i)
ferencd@0: {
ferencd@0:     assert(i.result == local_info::ambiguous);
ferencd@0:     std::ostringstream os;
ferencd@0:     os << tp << " is ambiguous.  It could be\n"
ferencd@0:        << tp << ' ' << i.first.abbrev << " == "
ferencd@0:        << tp - i.first.offset << " UTC or\n"
ferencd@0:        << tp << ' ' << i.second.abbrev  << " == "
ferencd@0:        << tp - i.second.offset  << " UTC";
ferencd@0:     return os.str();
ferencd@0: }
ferencd@0: 
ferencd@0: class time_zone;
ferencd@0: 
ferencd@0: #if HAS_STRING_VIEW
ferencd@0: DATE_API const time_zone* locate_zone(std::string_view tz_name);
ferencd@0: #else
ferencd@0: DATE_API const time_zone* locate_zone(const std::string& tz_name);
ferencd@0: #endif
ferencd@0: 
ferencd@0: DATE_API const time_zone* current_zone();
ferencd@0: 
ferencd@0: template <class T>
ferencd@0: struct zoned_traits
ferencd@0: {
ferencd@0: };
ferencd@0: 
ferencd@0: template <>
ferencd@0: struct zoned_traits<const time_zone*>
ferencd@0: {
ferencd@0:     static
ferencd@0:     const time_zone*
ferencd@0:     default_zone()
ferencd@0:     {
ferencd@0:         return date::locate_zone("Etc/UTC");
ferencd@0:     }
ferencd@0: 
ferencd@0: #if HAS_STRING_VIEW
ferencd@0: 
ferencd@0:     static
ferencd@0:     const time_zone*
ferencd@0:     locate_zone(std::string_view name)
ferencd@0:     {
ferencd@0:         return date::locate_zone(name);
ferencd@0:     }
ferencd@0: 
ferencd@0: #else  // !HAS_STRING_VIEW
ferencd@0: 
ferencd@0:     static
ferencd@0:     const time_zone*
ferencd@0:     locate_zone(const std::string& name)
ferencd@0:     {
ferencd@0:         return date::locate_zone(name);
ferencd@0:     }
ferencd@0: 
ferencd@0:     static
ferencd@0:     const time_zone*
ferencd@0:     locate_zone(const char* name)
ferencd@0:     {
ferencd@0:         return date::locate_zone(name);
ferencd@0:     }
ferencd@0: 
ferencd@0: #endif  // !HAS_STRING_VIEW
ferencd@0: };
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: class zoned_time;
ferencd@0: 
ferencd@0: template <class Duration1, class Duration2, class TimeZonePtr>
ferencd@0: bool
ferencd@0: operator==(const zoned_time<Duration1, TimeZonePtr>& x,
ferencd@0:            const zoned_time<Duration2, TimeZonePtr>& y);
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr = const time_zone*>
ferencd@0: class zoned_time
ferencd@0: {
ferencd@0: public:
ferencd@0:     using duration = typename std::common_type<Duration, std::chrono::seconds>::type;
ferencd@0: 
ferencd@0: private:
ferencd@0:     TimeZonePtr        zone_;
ferencd@0:     sys_time<duration> tp_;
ferencd@0: 
ferencd@0: public:
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = decltype(zoned_traits<T>::default_zone())>
ferencd@0: #endif
ferencd@0:         zoned_time();
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = decltype(zoned_traits<T>::default_zone())>
ferencd@0: #endif
ferencd@0:         zoned_time(const sys_time<Duration>& st);
ferencd@0:     explicit zoned_time(TimeZonePtr z);
ferencd@0: 
ferencd@0: #if HAS_STRING_VIEW
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string_view()))
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0:         explicit zoned_time(std::string_view name);
ferencd@0: #else
ferencd@0: #  if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string()))
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0: #  endif
ferencd@0:         explicit zoned_time(const std::string& name);
ferencd@0: #endif
ferencd@0: 
ferencd@0:     template <class Duration2,
ferencd@0:               class = typename std::enable_if
ferencd@0:                       <
ferencd@0:                           std::is_convertible<sys_time<Duration2>,
ferencd@0:                                               sys_time<Duration>>::value
ferencd@0:                       >::type>
ferencd@0:         zoned_time(const zoned_time<Duration2, TimeZonePtr>& zt) NOEXCEPT;
ferencd@0: 
ferencd@0:     zoned_time(TimeZonePtr z, const sys_time<Duration>& st);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_convertible
ferencd@0:                   <
ferencd@0:                       decltype(std::declval<T&>()->to_sys(local_time<Duration>{})),
ferencd@0:                       sys_time<duration>
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0: #endif
ferencd@0:         zoned_time(TimeZonePtr z, const local_time<Duration>& tp);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_convertible
ferencd@0:                   <
ferencd@0:                       decltype(std::declval<T&>()->to_sys(local_time<Duration>{},
ferencd@0:                                                           choose::earliest)),
ferencd@0:                       sys_time<duration>
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0: #endif
ferencd@0:         zoned_time(TimeZonePtr z, const local_time<Duration>& tp, choose c);
ferencd@0: 
ferencd@0:     template <class Duration2, class TimeZonePtr2,
ferencd@0:               class = typename std::enable_if
ferencd@0:                       <
ferencd@0:                           std::is_convertible<sys_time<Duration2>,
ferencd@0:                                               sys_time<Duration>>::value
ferencd@0:                       >::type>
ferencd@0:         zoned_time(TimeZonePtr z, const zoned_time<Duration2, TimeZonePtr2>& zt);
ferencd@0: 
ferencd@0:     template <class Duration2, class TimeZonePtr2,
ferencd@0:               class = typename std::enable_if
ferencd@0:                       <
ferencd@0:                           std::is_convertible<sys_time<Duration2>,
ferencd@0:                                               sys_time<Duration>>::value
ferencd@0:                       >::type>
ferencd@0:         zoned_time(TimeZonePtr z, const zoned_time<Duration2, TimeZonePtr2>& zt, choose);
ferencd@0: 
ferencd@0: #if HAS_STRING_VIEW
ferencd@0: 
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string_view())),
ferencd@0:                       sys_time<Duration>
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0:         zoned_time(std::string_view name, detail::nodeduct_t<const sys_time<Duration>&> st);
ferencd@0: 
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string_view())),
ferencd@0:                       local_time<Duration>
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0:         zoned_time(std::string_view name, detail::nodeduct_t<const local_time<Duration>&> tp);
ferencd@0: 
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string_view())),
ferencd@0:                       local_time<Duration>,
ferencd@0:                       choose
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0:         zoned_time(std::string_view name, detail::nodeduct_t<const local_time<Duration>&> tp, choose c);
ferencd@0: 
ferencd@0:     template <class Duration2, class TimeZonePtr2, class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:                       <
ferencd@0:                           std::is_convertible<sys_time<Duration2>,
ferencd@0:                                               sys_time<Duration>>::value &&
ferencd@0:                           std::is_constructible
ferencd@0:                           <
ferencd@0:                               zoned_time,
ferencd@0:                               decltype(zoned_traits<T>::locate_zone(std::string_view())),
ferencd@0:                               zoned_time
ferencd@0:                           >::value
ferencd@0:                       >::type>
ferencd@0:         zoned_time(std::string_view name, const zoned_time<Duration2, TimeZonePtr2>& zt);
ferencd@0: 
ferencd@0:     template <class Duration2, class TimeZonePtr2, class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:                       <
ferencd@0:                           std::is_convertible<sys_time<Duration2>,
ferencd@0:                                               sys_time<Duration>>::value &&
ferencd@0:                           std::is_constructible
ferencd@0:                           <
ferencd@0:                               zoned_time,
ferencd@0:                               decltype(zoned_traits<T>::locate_zone(std::string_view())),
ferencd@0:                               zoned_time,
ferencd@0:                               choose
ferencd@0:                           >::value
ferencd@0:                       >::type>
ferencd@0:         zoned_time(std::string_view name, const zoned_time<Duration2, TimeZonePtr2>& zt, choose);
ferencd@0: 
ferencd@0: #else  // !HAS_STRING_VIEW
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                       sys_time<Duration>
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0: #endif
ferencd@0:         zoned_time(const std::string& name, const sys_time<Duration>& st);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                       sys_time<Duration>
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0: #endif
ferencd@0:         zoned_time(const char* name, const sys_time<Duration>& st);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                       local_time<Duration>
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0: #endif
ferencd@0:         zoned_time(const std::string& name, const local_time<Duration>& tp);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                       local_time<Duration>
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0: #endif
ferencd@0:         zoned_time(const char* name, const local_time<Duration>& tp);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                       local_time<Duration>,
ferencd@0:                       choose
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0: #endif
ferencd@0:         zoned_time(const std::string& name, const local_time<Duration>& tp, choose c);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:               <
ferencd@0:                   std::is_constructible
ferencd@0:                   <
ferencd@0:                       zoned_time,
ferencd@0:                       decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                       local_time<Duration>,
ferencd@0:                       choose
ferencd@0:                   >::value
ferencd@0:               >::type>
ferencd@0: #endif
ferencd@0:         zoned_time(const char* name, const local_time<Duration>& tp, choose c);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class Duration2, class TimeZonePtr2, class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:                       <
ferencd@0:                           std::is_convertible<sys_time<Duration2>,
ferencd@0:                                               sys_time<Duration>>::value &&
ferencd@0:                           std::is_constructible
ferencd@0:                           <
ferencd@0:                               zoned_time,
ferencd@0:                               decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                               zoned_time
ferencd@0:                           >::value
ferencd@0:                       >::type>
ferencd@0: #else
ferencd@0:     template <class Duration2, class TimeZonePtr2>
ferencd@0: #endif
ferencd@0:         zoned_time(const std::string& name, const zoned_time<Duration2, TimeZonePtr2>& zt);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class Duration2, class TimeZonePtr2, class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:                       <
ferencd@0:                           std::is_convertible<sys_time<Duration2>,
ferencd@0:                                               sys_time<Duration>>::value &&
ferencd@0:                           std::is_constructible
ferencd@0:                           <
ferencd@0:                               zoned_time,
ferencd@0:                               decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                               zoned_time
ferencd@0:                           >::value
ferencd@0:                       >::type>
ferencd@0: #else
ferencd@0:     template <class Duration2, class TimeZonePtr2>
ferencd@0: #endif
ferencd@0:         zoned_time(const char* name, const zoned_time<Duration2, TimeZonePtr2>& zt);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class Duration2, class TimeZonePtr2, class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:                       <
ferencd@0:                           std::is_convertible<sys_time<Duration2>,
ferencd@0:                                               sys_time<Duration>>::value &&
ferencd@0:                           std::is_constructible
ferencd@0:                           <
ferencd@0:                               zoned_time,
ferencd@0:                               decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                               zoned_time,
ferencd@0:                               choose
ferencd@0:                           >::value
ferencd@0:                       >::type>
ferencd@0: #else
ferencd@0:     template <class Duration2, class TimeZonePtr2>
ferencd@0: #endif
ferencd@0:         zoned_time(const std::string& name, const zoned_time<Duration2, TimeZonePtr2>& zt,
ferencd@0:                    choose);
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:     template <class Duration2, class TimeZonePtr2, class T = TimeZonePtr,
ferencd@0:               class = typename std::enable_if
ferencd@0:                       <
ferencd@0:                           std::is_convertible<sys_time<Duration2>,
ferencd@0:                                               sys_time<Duration>>::value &&
ferencd@0:                           std::is_constructible
ferencd@0:                           <
ferencd@0:                               zoned_time,
ferencd@0:                               decltype(zoned_traits<T>::locate_zone(std::string())),
ferencd@0:                               zoned_time,
ferencd@0:                               choose
ferencd@0:                           >::value
ferencd@0:                       >::type>
ferencd@0: #else
ferencd@0:     template <class Duration2, class TimeZonePtr2>
ferencd@0: #endif
ferencd@0:         zoned_time(const char* name, const zoned_time<Duration2, TimeZonePtr2>& zt,
ferencd@0:                    choose);
ferencd@0: 
ferencd@0: #endif  // !HAS_STRING_VIEW
ferencd@0: 
ferencd@0:     zoned_time& operator=(const sys_time<Duration>& st);
ferencd@0:     zoned_time& operator=(const local_time<Duration>& ut);
ferencd@0: 
ferencd@0:     explicit operator sys_time<duration>() const;
ferencd@0:     explicit operator local_time<duration>() const;
ferencd@0: 
ferencd@0:     TimeZonePtr          get_time_zone() const;
ferencd@0:     local_time<duration> get_local_time() const;
ferencd@0:     sys_time<duration>   get_sys_time() const;
ferencd@0:     sys_info             get_info() const;
ferencd@0: 
ferencd@0:     template <class Duration1, class Duration2, class TimeZonePtr1>
ferencd@0:     friend
ferencd@0:     bool
ferencd@0:     operator==(const zoned_time<Duration1, TimeZonePtr1>& x,
ferencd@0:                const zoned_time<Duration2, TimeZonePtr1>& y);
ferencd@0: 
ferencd@0:     template <class CharT, class Traits, class Duration1, class TimeZonePtr1>
ferencd@0:     friend
ferencd@0:     std::basic_ostream<CharT, Traits>&
ferencd@0:     operator<<(std::basic_ostream<CharT, Traits>& os,
ferencd@0:                const zoned_time<Duration1, TimeZonePtr1>& t);
ferencd@0: 
ferencd@0: private:
ferencd@0:     template <class D, class T> friend class zoned_time;
ferencd@0: };
ferencd@0: 
ferencd@0: using zoned_seconds = zoned_time<std::chrono::seconds>;
ferencd@0: 
ferencd@0: #if HAS_DEDUCTION_GUIDES
ferencd@0: 
ferencd@0: namespace detail
ferencd@0: {
ferencd@0:    template<typename TimeZonePtrOrName>
ferencd@0:    using time_zone_representation =
ferencd@0:        std::conditional_t
ferencd@0:        <
ferencd@0:            std::is_convertible<TimeZonePtrOrName, std::string_view>::value,
ferencd@0:            time_zone const*,
ferencd@0:            std::remove_cv_t<std::remove_reference_t<TimeZonePtrOrName>>
ferencd@0:        >;
ferencd@0: }
ferencd@0: 
ferencd@0: zoned_time()
ferencd@0:     -> zoned_time<std::chrono::seconds>;
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: zoned_time(sys_time<Duration>)
ferencd@0:     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>>;
ferencd@0: 
ferencd@0: template <class TimeZonePtrOrName>
ferencd@0: zoned_time(TimeZonePtrOrName&&)
ferencd@0:     -> zoned_time<std::chrono::seconds, detail::time_zone_representation<TimeZonePtrOrName>>;
ferencd@0: 
ferencd@0: template <class TimeZonePtrOrName, class Duration>
ferencd@0: zoned_time(TimeZonePtrOrName&&, sys_time<Duration>)
ferencd@0:     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>, detail::time_zone_representation<TimeZonePtrOrName>>;
ferencd@0: 
ferencd@0: template <class TimeZonePtrOrName, class Duration>
ferencd@0: zoned_time(TimeZonePtrOrName&&, local_time<Duration>, choose = choose::earliest)
ferencd@0:     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>, detail::time_zone_representation<TimeZonePtrOrName>>;
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtrOrName, class TimeZonePtr2>
ferencd@0: zoned_time(TimeZonePtrOrName&&, zoned_time<Duration, TimeZonePtr2>, choose = choose::earliest)
ferencd@0:     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>, detail::time_zone_representation<TimeZonePtrOrName>>;
ferencd@0: 
ferencd@0: #endif  // HAS_DEDUCTION_GUIDES
ferencd@0: 
ferencd@0: template <class Duration1, class Duration2, class TimeZonePtr>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator==(const zoned_time<Duration1, TimeZonePtr>& x,
ferencd@0:            const zoned_time<Duration2, TimeZonePtr>& y)
ferencd@0: {
ferencd@0:     return x.zone_ == y.zone_ && x.tp_ == y.tp_;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration1, class Duration2, class TimeZonePtr>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator!=(const zoned_time<Duration1, TimeZonePtr>& x,
ferencd@0:            const zoned_time<Duration2, TimeZonePtr>& y)
ferencd@0: {
ferencd@0:     return !(x == y);
ferencd@0: }
ferencd@0: 
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER >= 1900)
ferencd@0: 
ferencd@0: namespace detail
ferencd@0: {
ferencd@0: #  if USE_OS_TZDB
ferencd@0:     struct transition;
ferencd@0:     struct expanded_ttinfo;
ferencd@0: #  else  // !USE_OS_TZDB
ferencd@0:     struct zonelet;
ferencd@0:     class Rule;
ferencd@0: #  endif  // !USE_OS_TZDB
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !defined(_MSC_VER) || (_MSC_VER >= 1900)
ferencd@0: 
ferencd@0: class time_zone
ferencd@0: {
ferencd@0: private:
ferencd@0:     std::string                          name_;
ferencd@0: #if USE_OS_TZDB
ferencd@0:     std::vector<detail::transition>      transitions_;
ferencd@0:     std::vector<detail::expanded_ttinfo> ttinfos_;
ferencd@0: #else  // !USE_OS_TZDB
ferencd@0:     std::vector<detail::zonelet>         zonelets_;
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0:     std::unique_ptr<std::once_flag>      adjusted_;
ferencd@0: 
ferencd@0: public:
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER >= 1900)
ferencd@0:     time_zone(time_zone&&) = default;
ferencd@0:     time_zone& operator=(time_zone&&) = default;
ferencd@0: #else   // defined(_MSC_VER) && (_MSC_VER < 1900)
ferencd@0:     time_zone(time_zone&& src);
ferencd@0:     time_zone& operator=(time_zone&& src);
ferencd@0: #endif  // defined(_MSC_VER) && (_MSC_VER < 1900)
ferencd@0: 
ferencd@0:     DATE_API explicit time_zone(const std::string& s, detail::undocumented);
ferencd@0: 
ferencd@0:     const std::string& name() const NOEXCEPT;
ferencd@0: 
ferencd@0:     template <class Duration> sys_info   get_info(sys_time<Duration> st) const;
ferencd@0:     template <class Duration> local_info get_info(local_time<Duration> tp) const;
ferencd@0: 
ferencd@0:     template <class Duration>
ferencd@0:         sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:         to_sys(local_time<Duration> tp) const;
ferencd@0: 
ferencd@0:     template <class Duration>
ferencd@0:         sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:         to_sys(local_time<Duration> tp, choose z) const;
ferencd@0: 
ferencd@0:     template <class Duration>
ferencd@0:         local_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:         to_local(sys_time<Duration> tp) const;
ferencd@0: 
ferencd@0:     friend bool operator==(const time_zone& x, const time_zone& y) NOEXCEPT;
ferencd@0:     friend bool operator< (const time_zone& x, const time_zone& y) NOEXCEPT;
ferencd@0:     friend DATE_API std::ostream& operator<<(std::ostream& os, const time_zone& z);
ferencd@0: 
ferencd@0: #if !USE_OS_TZDB
ferencd@0:     DATE_API void add(const std::string& s);
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: private:
ferencd@0:     DATE_API sys_info   get_info_impl(sys_seconds tp) const;
ferencd@0:     DATE_API local_info get_info_impl(local_seconds tp) const;
ferencd@0: 
ferencd@0:     template <class Duration>
ferencd@0:         sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:         to_sys_impl(local_time<Duration> tp, choose z, std::false_type) const;
ferencd@0:     template <class Duration>
ferencd@0:         sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:         to_sys_impl(local_time<Duration> tp, choose, std::true_type) const;
ferencd@0: 
ferencd@0: #if USE_OS_TZDB
ferencd@0:     DATE_API void init() const;
ferencd@0:     DATE_API void init_impl();
ferencd@0:     DATE_API sys_info
ferencd@0:         load_sys_info(std::vector<detail::transition>::const_iterator i) const;
ferencd@0: 
ferencd@0:     template <class TimeType>
ferencd@0:     DATE_API void
ferencd@0:     load_data(std::istream& inf, std::int32_t tzh_leapcnt, std::int32_t tzh_timecnt,
ferencd@0:                                  std::int32_t tzh_typecnt, std::int32_t tzh_charcnt);
ferencd@0: #else  // !USE_OS_TZDB
ferencd@0:     DATE_API sys_info   get_info_impl(sys_seconds tp, int timezone) const;
ferencd@0:     DATE_API void adjust_infos(const std::vector<detail::Rule>& rules);
ferencd@0:     DATE_API void parse_info(std::istream& in);
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: };
ferencd@0: 
ferencd@0: #if defined(_MSC_VER) && (_MSC_VER < 1900)
ferencd@0: 
ferencd@0: inline
ferencd@0: time_zone::time_zone(time_zone&& src)
ferencd@0:     : name_(std::move(src.name_))
ferencd@0:     , zonelets_(std::move(src.zonelets_))
ferencd@0:     , adjusted_(std::move(src.adjusted_))
ferencd@0:     {}
ferencd@0: 
ferencd@0: inline
ferencd@0: time_zone&
ferencd@0: time_zone::operator=(time_zone&& src)
ferencd@0: {
ferencd@0:     name_ = std::move(src.name_);
ferencd@0:     zonelets_ = std::move(src.zonelets_);
ferencd@0:     adjusted_ = std::move(src.adjusted_);
ferencd@0:     return *this;
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // defined(_MSC_VER) && (_MSC_VER < 1900)
ferencd@0: 
ferencd@0: inline
ferencd@0: const std::string&
ferencd@0: time_zone::name() const NOEXCEPT
ferencd@0: {
ferencd@0:     return name_;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: sys_info
ferencd@0: time_zone::get_info(sys_time<Duration> st) const
ferencd@0: {
ferencd@0:     return get_info_impl(date::floor<std::chrono::seconds>(st));
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: local_info
ferencd@0: time_zone::get_info(local_time<Duration> tp) const
ferencd@0: {
ferencd@0:     return get_info_impl(date::floor<std::chrono::seconds>(tp));
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: time_zone::to_sys(local_time<Duration> tp) const
ferencd@0: {
ferencd@0:     return to_sys_impl(tp, choose{}, std::true_type{});
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: time_zone::to_sys(local_time<Duration> tp, choose z) const
ferencd@0: {
ferencd@0:     return to_sys_impl(tp, z, std::false_type{});
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: local_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: time_zone::to_local(sys_time<Duration> tp) const
ferencd@0: {
ferencd@0:     using LT = local_time<typename std::common_type<Duration, std::chrono::seconds>::type>;
ferencd@0:     auto i = get_info(tp);
ferencd@0:     return LT{(tp + i.offset).time_since_epoch()};
ferencd@0: }
ferencd@0: 
ferencd@0: inline bool operator==(const time_zone& x, const time_zone& y) NOEXCEPT {return x.name_ == y.name_;}
ferencd@0: inline bool operator< (const time_zone& x, const time_zone& y) NOEXCEPT {return x.name_ < y.name_;}
ferencd@0: 
ferencd@0: inline bool operator!=(const time_zone& x, const time_zone& y) NOEXCEPT {return !(x == y);}
ferencd@0: inline bool operator> (const time_zone& x, const time_zone& y) NOEXCEPT {return   y < x;}
ferencd@0: inline bool operator<=(const time_zone& x, const time_zone& y) NOEXCEPT {return !(y < x);}
ferencd@0: inline bool operator>=(const time_zone& x, const time_zone& y) NOEXCEPT {return !(x < y);}
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: time_zone::to_sys_impl(local_time<Duration> tp, choose z, std::false_type) const
ferencd@0: {
ferencd@0:     auto i = get_info(tp);
ferencd@0:     if (i.result == local_info::nonexistent)
ferencd@0:     {
ferencd@0:         return i.first.end;
ferencd@0:     }
ferencd@0:     else if (i.result == local_info::ambiguous)
ferencd@0:     {
ferencd@0:         if (z == choose::latest)
ferencd@0:             return sys_time<Duration>{tp.time_since_epoch()} - i.second.offset;
ferencd@0:     }
ferencd@0:     return sys_time<Duration>{tp.time_since_epoch()} - i.first.offset;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: time_zone::to_sys_impl(local_time<Duration> tp, choose, std::true_type) const
ferencd@0: {
ferencd@0:     auto i = get_info(tp);
ferencd@0:     if (i.result == local_info::nonexistent)
ferencd@0:         throw nonexistent_local_time(tp, i);
ferencd@0:     else if (i.result == local_info::ambiguous)
ferencd@0:         throw ambiguous_local_time(tp, i);
ferencd@0:     return sys_time<Duration>{tp.time_since_epoch()} - i.first.offset;
ferencd@0: }
ferencd@0: 
ferencd@0: #if !USE_OS_TZDB
ferencd@0: 
ferencd@0: class link
ferencd@0: {
ferencd@0: private:
ferencd@0:     std::string name_;
ferencd@0:     std::string target_;
ferencd@0: public:
ferencd@0:     DATE_API explicit link(const std::string& s);
ferencd@0: 
ferencd@0:     const std::string& name() const {return name_;}
ferencd@0:     const std::string& target() const {return target_;}
ferencd@0: 
ferencd@0:     friend bool operator==(const link& x, const link& y) {return x.name_ == y.name_;}
ferencd@0:     friend bool operator< (const link& x, const link& y) {return x.name_ < y.name_;}
ferencd@0: 
ferencd@0:     friend DATE_API std::ostream& operator<<(std::ostream& os, const link& x);
ferencd@0: };
ferencd@0: 
ferencd@0: inline bool operator!=(const link& x, const link& y) {return !(x == y);}
ferencd@0: inline bool operator> (const link& x, const link& y) {return   y < x;}
ferencd@0: inline bool operator<=(const link& x, const link& y) {return !(y < x);}
ferencd@0: inline bool operator>=(const link& x, const link& y) {return !(x < y);}
ferencd@0: 
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: #if !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: class leap
ferencd@0: {
ferencd@0: private:
ferencd@0:     sys_seconds date_;
ferencd@0: 
ferencd@0: public:
ferencd@0: #if USE_OS_TZDB
ferencd@0:     DATE_API explicit leap(const sys_seconds& s, detail::undocumented);
ferencd@0: #else
ferencd@0:     DATE_API explicit leap(const std::string& s, detail::undocumented);
ferencd@0: #endif
ferencd@0: 
ferencd@0:     sys_seconds date() const {return date_;}
ferencd@0: 
ferencd@0:     friend bool operator==(const leap& x, const leap& y) {return x.date_ == y.date_;}
ferencd@0:     friend bool operator< (const leap& x, const leap& y) {return x.date_ < y.date_;}
ferencd@0: 
ferencd@0:     template <class Duration>
ferencd@0:     friend
ferencd@0:     bool
ferencd@0:     operator==(const leap& x, const sys_time<Duration>& y)
ferencd@0:     {
ferencd@0:         return x.date_ == y;
ferencd@0:     }
ferencd@0: 
ferencd@0:     template <class Duration>
ferencd@0:     friend
ferencd@0:     bool
ferencd@0:     operator< (const leap& x, const sys_time<Duration>& y)
ferencd@0:     {
ferencd@0:         return x.date_ < y;
ferencd@0:     }
ferencd@0: 
ferencd@0:     template <class Duration>
ferencd@0:     friend
ferencd@0:     bool
ferencd@0:     operator< (const sys_time<Duration>& x, const leap& y)
ferencd@0:     {
ferencd@0:         return x < y.date_;
ferencd@0:     }
ferencd@0: 
ferencd@0:     friend DATE_API std::ostream& operator<<(std::ostream& os, const leap& x);
ferencd@0: };
ferencd@0: 
ferencd@0: inline bool operator!=(const leap& x, const leap& y) {return !(x == y);}
ferencd@0: inline bool operator> (const leap& x, const leap& y) {return   y < x;}
ferencd@0: inline bool operator<=(const leap& x, const leap& y) {return !(y < x);}
ferencd@0: inline bool operator>=(const leap& x, const leap& y) {return !(x < y);}
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator==(const sys_time<Duration>& x, const leap& y)
ferencd@0: {
ferencd@0:     return y == x;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator!=(const leap& x, const sys_time<Duration>& y)
ferencd@0: {
ferencd@0:     return !(x == y);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator!=(const sys_time<Duration>& x, const leap& y)
ferencd@0: {
ferencd@0:     return !(x == y);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator> (const leap& x, const sys_time<Duration>& y)
ferencd@0: {
ferencd@0:     return y < x;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator> (const sys_time<Duration>& x, const leap& y)
ferencd@0: {
ferencd@0:     return y < x;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator<=(const leap& x, const sys_time<Duration>& y)
ferencd@0: {
ferencd@0:     return !(y < x);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator<=(const sys_time<Duration>& x, const leap& y)
ferencd@0: {
ferencd@0:     return !(y < x);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator>=(const leap& x, const sys_time<Duration>& y)
ferencd@0: {
ferencd@0:     return !(x < y);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: bool
ferencd@0: operator>=(const sys_time<Duration>& x, const leap& y)
ferencd@0: {
ferencd@0:     return !(x < y);
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: #ifdef _WIN32
ferencd@0: 
ferencd@0: namespace detail
ferencd@0: {
ferencd@0: 
ferencd@0: // The time zone mapping is modelled after this data file:
ferencd@0: // http://unicode.org/repos/cldr/trunk/common/supplemental/windowsZones.xml
ferencd@0: // and the field names match the element names from the mapZone element
ferencd@0: // of windowsZones.xml.
ferencd@0: // The website displays this file here:
ferencd@0: // http://www.unicode.org/cldr/charts/latest/supplemental/zone_tzid.html
ferencd@0: // The html view is sorted before being displayed but is otherwise the same
ferencd@0: // There is a mapping between the os centric view (in this case windows)
ferencd@0: // the html displays uses and the generic view the xml file.
ferencd@0: // That mapping is this:
ferencd@0: // display column "windows" -> xml field "other".
ferencd@0: // display column "region"  -> xml field "territory".
ferencd@0: // display column "tzid"    -> xml field "type".
ferencd@0: // This structure uses the generic terminology because it could be
ferencd@0: // used to to support other os/native name conversions, not just windows,
ferencd@0: // and using the same generic names helps retain the connection to the
ferencd@0: // origin of the data that we are using.
ferencd@0: struct timezone_mapping
ferencd@0: {
ferencd@0:     timezone_mapping(const char* other, const char* territory, const char* type)
ferencd@0:         : other(other), territory(territory), type(type)
ferencd@0:     {
ferencd@0:     }
ferencd@0:     timezone_mapping() = default;
ferencd@0:     std::string other;
ferencd@0:     std::string territory;
ferencd@0:     std::string type;
ferencd@0: };
ferencd@0: 
ferencd@0: }  // detail
ferencd@0: 
ferencd@0: #endif  // _WIN32
ferencd@0: 
ferencd@0: struct tzdb
ferencd@0: {
ferencd@0:     std::string               version = "unknown";
ferencd@0:     std::vector<time_zone>    zones;
ferencd@0: #if !USE_OS_TZDB
ferencd@0:     std::vector<link>         links;
ferencd@0: #endif
ferencd@0: #if !MISSING_LEAP_SECONDS
ferencd@0:     std::vector<leap>         leaps;
ferencd@0: #endif
ferencd@0: #if !USE_OS_TZDB
ferencd@0:     std::vector<detail::Rule> rules;
ferencd@0: #endif
ferencd@0: #ifdef _WIN32
ferencd@0:     std::vector<detail::timezone_mapping> mappings;
ferencd@0: #endif
ferencd@0:     tzdb* next = nullptr;
ferencd@0: 
ferencd@0:     tzdb() = default;
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER >= 1900)
ferencd@0:     tzdb(tzdb&&) = default;
ferencd@0:     tzdb& operator=(tzdb&&) = default;
ferencd@0: #else  // defined(_MSC_VER) && (_MSC_VER < 1900)
ferencd@0:     tzdb(tzdb&& src)
ferencd@0:         : version(std::move(src.version))
ferencd@0:         , zones(std::move(src.zones))
ferencd@0:         , links(std::move(src.links))
ferencd@0:         , leaps(std::move(src.leaps))
ferencd@0:         , rules(std::move(src.rules))
ferencd@0:         , mappings(std::move(src.mappings))
ferencd@0:     {}
ferencd@0: 
ferencd@0:     tzdb& operator=(tzdb&& src)
ferencd@0:     {
ferencd@0:         version = std::move(src.version);
ferencd@0:         zones = std::move(src.zones);
ferencd@0:         links = std::move(src.links);
ferencd@0:         leaps = std::move(src.leaps);
ferencd@0:         rules = std::move(src.rules);
ferencd@0:         mappings = std::move(src.mappings);
ferencd@0:         return *this;
ferencd@0:     }
ferencd@0: #endif  // defined(_MSC_VER) && (_MSC_VER < 1900)
ferencd@0: 
ferencd@0: #if HAS_STRING_VIEW
ferencd@0:     const time_zone* locate_zone(std::string_view tz_name) const;
ferencd@0: #else
ferencd@0:     const time_zone* locate_zone(const std::string& tz_name) const;
ferencd@0: #endif
ferencd@0:     const time_zone* current_zone() const;
ferencd@0: };
ferencd@0: 
ferencd@0: using TZ_DB = tzdb;
ferencd@0: 
ferencd@0: DATE_API std::ostream&
ferencd@0: operator<<(std::ostream& os, const tzdb& db);
ferencd@0: 
ferencd@0: DATE_API const tzdb& get_tzdb();
ferencd@0: 
ferencd@0: class tzdb_list
ferencd@0: {
ferencd@0:     std::atomic<tzdb*> head_{nullptr};
ferencd@0: 
ferencd@0: public:
ferencd@0:     ~tzdb_list();
ferencd@0:     tzdb_list() = default;
ferencd@0:     tzdb_list(tzdb_list&& x) noexcept;
ferencd@0: 
ferencd@0:     const tzdb& front() const noexcept {return *head_;}
ferencd@0:           tzdb& front()       noexcept {return *head_;}
ferencd@0: 
ferencd@0:     class const_iterator;
ferencd@0: 
ferencd@0:     const_iterator begin() const noexcept;
ferencd@0:     const_iterator end() const noexcept;
ferencd@0: 
ferencd@0:     const_iterator cbegin() const noexcept;
ferencd@0:     const_iterator cend() const noexcept;
ferencd@0: 
ferencd@0:     const_iterator erase_after(const_iterator p) noexcept;
ferencd@0: 
ferencd@0:     struct undocumented_helper;
ferencd@0: private:
ferencd@0:     void push_front(tzdb* tzdb) noexcept;
ferencd@0: };
ferencd@0: 
ferencd@0: class tzdb_list::const_iterator
ferencd@0: {
ferencd@0:     tzdb* p_ = nullptr;
ferencd@0: 
ferencd@0:     explicit const_iterator(tzdb* p) noexcept : p_{p} {}
ferencd@0: public:
ferencd@0:     const_iterator() = default;
ferencd@0: 
ferencd@0:     using iterator_category = std::forward_iterator_tag;
ferencd@0:     using value_type        = tzdb;
ferencd@0:     using reference         = const value_type&;
ferencd@0:     using pointer           = const value_type*;
ferencd@0:     using difference_type   = std::ptrdiff_t;
ferencd@0: 
ferencd@0:     reference operator*() const noexcept {return *p_;}
ferencd@0:     pointer  operator->() const noexcept {return p_;}
ferencd@0: 
ferencd@0:     const_iterator& operator++() noexcept {p_ = p_->next; return *this;}
ferencd@0:     const_iterator  operator++(int) noexcept {auto t = *this; ++(*this); return t;}
ferencd@0: 
ferencd@0:     friend
ferencd@0:     bool
ferencd@0:     operator==(const const_iterator& x, const const_iterator& y) noexcept
ferencd@0:         {return x.p_ == y.p_;}
ferencd@0: 
ferencd@0:     friend
ferencd@0:     bool
ferencd@0:     operator!=(const const_iterator& x, const const_iterator& y) noexcept
ferencd@0:         {return !(x == y);}
ferencd@0: 
ferencd@0:     friend class tzdb_list;
ferencd@0: };
ferencd@0: 
ferencd@0: inline
ferencd@0: tzdb_list::const_iterator
ferencd@0: tzdb_list::begin() const noexcept
ferencd@0: {
ferencd@0:     return const_iterator{head_};
ferencd@0: }
ferencd@0: 
ferencd@0: inline
ferencd@0: tzdb_list::const_iterator
ferencd@0: tzdb_list::end() const noexcept
ferencd@0: {
ferencd@0:     return const_iterator{nullptr};
ferencd@0: }
ferencd@0: 
ferencd@0: inline
ferencd@0: tzdb_list::const_iterator
ferencd@0: tzdb_list::cbegin() const noexcept
ferencd@0: {
ferencd@0:     return begin();
ferencd@0: }
ferencd@0: 
ferencd@0: inline
ferencd@0: tzdb_list::const_iterator
ferencd@0: tzdb_list::cend() const noexcept
ferencd@0: {
ferencd@0:     return end();
ferencd@0: }
ferencd@0: 
ferencd@0: DATE_API tzdb_list& get_tzdb_list();
ferencd@0: 
ferencd@0: #if !USE_OS_TZDB
ferencd@0: 
ferencd@0: DATE_API const tzdb& reload_tzdb();
ferencd@0: DATE_API void        set_install(const std::string& install);
ferencd@0: 
ferencd@0: #endif  // !USE_OS_TZDB
ferencd@0: 
ferencd@0: #if HAS_REMOTE_API
ferencd@0: 
ferencd@0: DATE_API std::string remote_version();
ferencd@0: DATE_API bool        remote_download(const std::string& version);
ferencd@0: DATE_API bool        remote_install(const std::string& version);
ferencd@0: 
ferencd@0: #endif
ferencd@0: 
ferencd@0: // zoned_time
ferencd@0: 
ferencd@0: namespace detail
ferencd@0: {
ferencd@0: 
ferencd@0: template <class T>
ferencd@0: inline
ferencd@0: T*
ferencd@0: to_raw_pointer(T* p) noexcept
ferencd@0: {
ferencd@0:     return p;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Pointer>
ferencd@0: inline
ferencd@0: auto
ferencd@0: to_raw_pointer(Pointer p) noexcept
ferencd@0:     -> decltype(detail::to_raw_pointer(p.operator->()))
ferencd@0: {
ferencd@0:     return detail::to_raw_pointer(p.operator->());
ferencd@0: }
ferencd@0: 
ferencd@0: }  // namespace detail
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time()
ferencd@0:     : zone_(zoned_traits<TimeZonePtr>::default_zone())
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const sys_time<Duration>& st)
ferencd@0:     : zone_(zoned_traits<TimeZonePtr>::default_zone())
ferencd@0:     , tp_(st)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z)
ferencd@0:     : zone_(std::move(z))
ferencd@0:     {assert(detail::to_raw_pointer(zone_) != nullptr);}
ferencd@0: 
ferencd@0: #if HAS_STRING_VIEW
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: template <class T, class>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name))
ferencd@0:     {}
ferencd@0: 
ferencd@0: #else  // !HAS_STRING_VIEW
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name))
ferencd@0:     {}
ferencd@0: 
ferencd@0: #endif  // !HAS_STRING_VIEW
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: template <class Duration2, class>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const zoned_time<Duration2, TimeZonePtr>& zt) NOEXCEPT
ferencd@0:     : zone_(zt.zone_)
ferencd@0:     , tp_(zt.tp_)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z, const sys_time<Duration>& st)
ferencd@0:     : zone_(std::move(z))
ferencd@0:     , tp_(st)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z, const local_time<Duration>& t)
ferencd@0:     : zone_(std::move(z))
ferencd@0:     , tp_(zone_->to_sys(t))
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z, const local_time<Duration>& t,
ferencd@0:                                               choose c)
ferencd@0:     : zone_(std::move(z))
ferencd@0:     , tp_(zone_->to_sys(t, c))
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: template <class Duration2, class TimeZonePtr2, class>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z,
ferencd@0:                                               const zoned_time<Duration2, TimeZonePtr2>& zt)
ferencd@0:     : zone_(std::move(z))
ferencd@0:     , tp_(zt.tp_)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: template <class Duration2, class TimeZonePtr2, class>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z,
ferencd@0:                                       const zoned_time<Duration2, TimeZonePtr2>& zt, choose)
ferencd@0:     : zoned_time(std::move(z), zt)
ferencd@0:     {}
ferencd@0: 
ferencd@0: #if HAS_STRING_VIEW
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: template <class T, class>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name,
ferencd@0:                                               detail::nodeduct_t<const sys_time<Duration>&> st)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), st)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: template <class T, class>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name,
ferencd@0:                                               detail::nodeduct_t<const local_time<Duration>&> t)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), t)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: template <class T, class>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name,
ferencd@0:                                               detail::nodeduct_t<const local_time<Duration>&> t, choose c)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), t, c)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: template <class Duration2, class TimeZonePtr2, class, class>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name,
ferencd@0:                                               const zoned_time<Duration2, TimeZonePtr2>& zt)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), zt)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: template <class Duration2, class TimeZonePtr2, class, class>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name,
ferencd@0:                                               const zoned_time<Duration2, TimeZonePtr2>& zt,
ferencd@0:                                               choose c)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), zt, c)
ferencd@0:     {}
ferencd@0: 
ferencd@0: #else  // !HAS_STRING_VIEW
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name,
ferencd@0:                                               const sys_time<Duration>& st)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), st)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name,
ferencd@0:                                               const sys_time<Duration>& st)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), st)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name,
ferencd@0:                                               const local_time<Duration>& t)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), t)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name,
ferencd@0:                                               const local_time<Duration>& t)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), t)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name,
ferencd@0:                                               const local_time<Duration>& t, choose c)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), t, c)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class T, class>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name,
ferencd@0:                                               const local_time<Duration>& t, choose c)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), t, c)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class Duration2, class TimeZonePtr2, class, class>
ferencd@0: #else
ferencd@0: template <class Duration2, class TimeZonePtr2>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name,
ferencd@0:                                               const zoned_time<Duration2, TimeZonePtr2>& zt)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), zt)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class Duration2, class TimeZonePtr2, class, class>
ferencd@0: #else
ferencd@0: template <class Duration2, class TimeZonePtr2>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name,
ferencd@0:                                               const zoned_time<Duration2, TimeZonePtr2>& zt)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), zt)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class Duration2, class TimeZonePtr2, class, class>
ferencd@0: #else
ferencd@0: template <class Duration2, class TimeZonePtr2>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name,
ferencd@0:                                               const zoned_time<Duration2, TimeZonePtr2>& zt,
ferencd@0:                                               choose c)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), zt, c)
ferencd@0:     {}
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0: template <class Duration2, class TimeZonePtr2, class, class>
ferencd@0: #else
ferencd@0: template <class Duration2, class TimeZonePtr2>
ferencd@0: #endif
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name,
ferencd@0:                                               const zoned_time<Duration2, TimeZonePtr2>& zt,
ferencd@0:                                               choose c)
ferencd@0:     : zoned_time(zoned_traits<TimeZonePtr>::locate_zone(name), zt, c)
ferencd@0:     {}
ferencd@0: 
ferencd@0: #endif  // HAS_STRING_VIEW
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>&
ferencd@0: zoned_time<Duration, TimeZonePtr>::operator=(const sys_time<Duration>& st)
ferencd@0: {
ferencd@0:     tp_ = st;
ferencd@0:     return *this;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>&
ferencd@0: zoned_time<Duration, TimeZonePtr>::operator=(const local_time<Duration>& ut)
ferencd@0: {
ferencd@0:     tp_ = zone_->to_sys(ut);
ferencd@0:     return *this;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::operator local_time<typename zoned_time<Duration, TimeZonePtr>::duration>() const
ferencd@0: {
ferencd@0:     return get_local_time();
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>::operator sys_time<typename zoned_time<Duration, TimeZonePtr>::duration>() const
ferencd@0: {
ferencd@0:     return get_sys_time();
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: TimeZonePtr
ferencd@0: zoned_time<Duration, TimeZonePtr>::get_time_zone() const
ferencd@0: {
ferencd@0:     return zone_;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: local_time<typename zoned_time<Duration, TimeZonePtr>::duration>
ferencd@0: zoned_time<Duration, TimeZonePtr>::get_local_time() const
ferencd@0: {
ferencd@0:     return zone_->to_local(tp_);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: sys_time<typename zoned_time<Duration, TimeZonePtr>::duration>
ferencd@0: zoned_time<Duration, TimeZonePtr>::get_sys_time() const
ferencd@0: {
ferencd@0:     return tp_;
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: sys_info
ferencd@0: zoned_time<Duration, TimeZonePtr>::get_info() const
ferencd@0: {
ferencd@0:     return zone_->get_info(tp_);
ferencd@0: }
ferencd@0: 
ferencd@0: // make_zoned_time
ferencd@0: 
ferencd@0: inline
ferencd@0: zoned_time<std::chrono::seconds>
ferencd@0: make_zoned()
ferencd@0: {
ferencd@0:     return zoned_time<std::chrono::seconds>();
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: make_zoned(const sys_time<Duration>& tp)
ferencd@0: {
ferencd@0:     return zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>(tp);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class TimeZonePtr
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:           , class = typename std::enable_if
ferencd@0:           <
ferencd@0:             std::is_class
ferencd@0:             <
ferencd@0:                 typename std::decay
ferencd@0:                 <
ferencd@0:                     decltype(*detail::to_raw_pointer(std::declval<TimeZonePtr&>()))
ferencd@0:                 >::type
ferencd@0:             >{}
ferencd@0:           >::type
ferencd@0: #endif
ferencd@0:          >
ferencd@0: inline
ferencd@0: zoned_time<std::chrono::seconds, TimeZonePtr>
ferencd@0: make_zoned(TimeZonePtr z)
ferencd@0: {
ferencd@0:     return zoned_time<std::chrono::seconds, TimeZonePtr>(std::move(z));
ferencd@0: }
ferencd@0: 
ferencd@0: inline
ferencd@0: zoned_seconds
ferencd@0: make_zoned(const std::string& name)
ferencd@0: {
ferencd@0:     return zoned_seconds(name);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:           , class = typename std::enable_if
ferencd@0:           <
ferencd@0:             std::is_class<typename std::decay<decltype(*std::declval<TimeZonePtr&>())>::type>{}
ferencd@0:           >::type
ferencd@0: #endif
ferencd@0:          >
ferencd@0: inline
ferencd@0: zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type, TimeZonePtr>
ferencd@0: make_zoned(TimeZonePtr zone, const local_time<Duration>& tp)
ferencd@0: {
ferencd@0:     return zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type,
ferencd@0:                       TimeZonePtr>(std::move(zone), tp);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:           , class = typename std::enable_if
ferencd@0:           <
ferencd@0:             std::is_class<typename std::decay<decltype(*std::declval<TimeZonePtr&>())>::type>{}
ferencd@0:           >::type
ferencd@0: #endif
ferencd@0:          >
ferencd@0: inline
ferencd@0: zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type, TimeZonePtr>
ferencd@0: make_zoned(TimeZonePtr zone, const local_time<Duration>& tp, choose c)
ferencd@0: {
ferencd@0:     return zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type,
ferencd@0:                       TimeZonePtr>(std::move(zone), tp, c);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: make_zoned(const std::string& name, const local_time<Duration>& tp)
ferencd@0: {
ferencd@0:     return zoned_time<typename std::common_type<Duration,
ferencd@0:                       std::chrono::seconds>::type>(name, tp);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: make_zoned(const std::string& name, const local_time<Duration>& tp, choose c)
ferencd@0: {
ferencd@0:     return zoned_time<typename std::common_type<Duration,
ferencd@0:                       std::chrono::seconds>::type>(name, tp, c);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>
ferencd@0: make_zoned(TimeZonePtr zone, const zoned_time<Duration, TimeZonePtr>& zt)
ferencd@0: {
ferencd@0:     return zoned_time<Duration, TimeZonePtr>(std::move(zone), zt);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>
ferencd@0: make_zoned(const std::string& name, const zoned_time<Duration, TimeZonePtr>& zt)
ferencd@0: {
ferencd@0:     return zoned_time<Duration, TimeZonePtr>(name, zt);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>
ferencd@0: make_zoned(TimeZonePtr zone, const zoned_time<Duration, TimeZonePtr>& zt, choose c)
ferencd@0: {
ferencd@0:     return zoned_time<Duration, TimeZonePtr>(std::move(zone), zt, c);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: zoned_time<Duration, TimeZonePtr>
ferencd@0: make_zoned(const std::string& name, const zoned_time<Duration, TimeZonePtr>& zt, choose c)
ferencd@0: {
ferencd@0:     return zoned_time<Duration, TimeZonePtr>(name, zt, c);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class TimeZonePtr
ferencd@0: #if !defined(_MSC_VER) || (_MSC_VER > 1900)
ferencd@0:           , class = typename std::enable_if
ferencd@0:           <
ferencd@0:             std::is_class<typename std::decay<decltype(*std::declval<TimeZonePtr&>())>::type>{}
ferencd@0:           >::type
ferencd@0: #endif
ferencd@0:          >
ferencd@0: inline
ferencd@0: zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type, TimeZonePtr>
ferencd@0: make_zoned(TimeZonePtr zone, const sys_time<Duration>& st)
ferencd@0: {
ferencd@0:     return zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type,
ferencd@0:                       TimeZonePtr>(std::move(zone), st);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: make_zoned(const std::string& name, const sys_time<Duration>& st)
ferencd@0: {
ferencd@0:     return zoned_time<typename std::common_type<Duration,
ferencd@0:                       std::chrono::seconds>::type>(name, st);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class CharT, class Traits, class Duration, class TimeZonePtr>
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: to_stream(std::basic_ostream<CharT, Traits>& os, const CharT* fmt,
ferencd@0:           const zoned_time<Duration, TimeZonePtr>& tp)
ferencd@0: {
ferencd@0:     using duration = typename zoned_time<Duration, TimeZonePtr>::duration;
ferencd@0:     using LT = local_time<duration>;
ferencd@0:     auto const st = tp.get_sys_time();
ferencd@0:     auto const info = tp.get_time_zone()->get_info(st);
ferencd@0:     return to_stream(os, fmt, LT{(st+info.offset).time_since_epoch()},
ferencd@0:                      &info.abbrev, &info.offset);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class CharT, class Traits, class Duration, class TimeZonePtr>
ferencd@0: inline
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: operator<<(std::basic_ostream<CharT, Traits>& os, const zoned_time<Duration, TimeZonePtr>& t)
ferencd@0: {
ferencd@0:     const CharT fmt[] = {'%', 'F', ' ', '%', 'T', ' ', '%', 'Z', CharT{}};
ferencd@0:     return to_stream(os, fmt, t);
ferencd@0: }
ferencd@0: 
ferencd@0: #if !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: class utc_clock
ferencd@0: {
ferencd@0: public:
ferencd@0:     using duration                  = std::chrono::system_clock::duration;
ferencd@0:     using rep                       = duration::rep;
ferencd@0:     using period                    = duration::period;
ferencd@0:     using time_point                = std::chrono::time_point<utc_clock>;
ferencd@0:     static CONSTDATA bool is_steady = false;
ferencd@0: 
ferencd@0:     static time_point now();
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<std::chrono::system_clock, typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     to_sys(const std::chrono::time_point<utc_clock, Duration>&);
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<utc_clock, typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     from_sys(const std::chrono::time_point<std::chrono::system_clock, Duration>&);
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<local_t, typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     to_local(const std::chrono::time_point<utc_clock, Duration>&);
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<utc_clock, typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     from_local(const std::chrono::time_point<local_t, Duration>&);
ferencd@0: };
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0:     using utc_time = std::chrono::time_point<utc_clock, Duration>;
ferencd@0: 
ferencd@0: using utc_seconds = utc_time<std::chrono::seconds>;
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: utc_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: utc_clock::from_sys(const sys_time<Duration>& st)
ferencd@0: {
ferencd@0:     using std::chrono::seconds;
ferencd@0:     using CD = typename std::common_type<Duration, seconds>::type;
ferencd@0:     auto const& leaps = get_tzdb().leaps;
ferencd@0:     auto const lt = std::upper_bound(leaps.begin(), leaps.end(), st);
ferencd@0:     return utc_time<CD>{st.time_since_epoch() + seconds{lt-leaps.begin()}};
ferencd@0: }
ferencd@0: 
ferencd@0: // Return pair<is_leap_second, seconds{number_of_leap_seconds_since_1970}>
ferencd@0: // first is true if ut is during a leap second insertion, otherwise false.
ferencd@0: // If ut is during a leap second insertion, that leap second is included in the count
ferencd@0: template <class Duration>
ferencd@0: std::pair<bool, std::chrono::seconds>
ferencd@0: is_leap_second(date::utc_time<Duration> const& ut)
ferencd@0: {
ferencd@0:     using std::chrono::seconds;
ferencd@0:     using duration = typename std::common_type<Duration, seconds>::type;
ferencd@0:     auto const& leaps = get_tzdb().leaps;
ferencd@0:     auto tp = sys_time<duration>{ut.time_since_epoch()};
ferencd@0:     auto const lt = std::upper_bound(leaps.begin(), leaps.end(), tp);
ferencd@0:     auto ds = seconds{lt-leaps.begin()};
ferencd@0:     tp -= ds;
ferencd@0:     auto ls = false;
ferencd@0:     if (lt > leaps.begin())
ferencd@0:     {
ferencd@0:         if (tp < lt[-1])
ferencd@0:         {
ferencd@0:             if (tp >= lt[-1].date() - seconds{1})
ferencd@0:                 ls = true;
ferencd@0:             else
ferencd@0:                 --ds;
ferencd@0:         }
ferencd@0:     }
ferencd@0:     return {ls, ds};
ferencd@0: }
ferencd@0: 
ferencd@0: struct leap_second_info
ferencd@0: {
ferencd@0:     bool is_leap_second;
ferencd@0:     std::chrono::seconds elapsed;
ferencd@0: };
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: leap_second_info
ferencd@0: get_leap_second_info(date::utc_time<Duration> const& ut)
ferencd@0: {
ferencd@0:     auto p = is_leap_second(ut);
ferencd@0:     return {p.first, p.second};
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: utc_clock::to_sys(const utc_time<Duration>& ut)
ferencd@0: {
ferencd@0:     using std::chrono::seconds;
ferencd@0:     using CD = typename std::common_type<Duration, seconds>::type;
ferencd@0:     auto ls = is_leap_second(ut);
ferencd@0:     auto tp = sys_time<CD>{ut.time_since_epoch() - ls.second};
ferencd@0:     if (ls.first)
ferencd@0:         tp = floor<seconds>(tp) + seconds{1} - CD{1};
ferencd@0:     return tp;
ferencd@0: }
ferencd@0: 
ferencd@0: inline
ferencd@0: utc_clock::time_point
ferencd@0: utc_clock::now()
ferencd@0: {
ferencd@0:     return from_sys(std::chrono::system_clock::now());
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: utc_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: utc_clock::from_local(const local_time<Duration>& st)
ferencd@0: {
ferencd@0:     return from_sys(sys_time<Duration>{st.time_since_epoch()});
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: local_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: utc_clock::to_local(const utc_time<Duration>& ut)
ferencd@0: {
ferencd@0:     using CD = typename std::common_type<Duration, std::chrono::seconds>::type;
ferencd@0:     return local_time<CD>{to_sys(ut).time_since_epoch()};
ferencd@0: }
ferencd@0: 
ferencd@0: template <class CharT, class Traits, class Duration>
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: to_stream(std::basic_ostream<CharT, Traits>& os, const CharT* fmt,
ferencd@0:           const utc_time<Duration>& t)
ferencd@0: {
ferencd@0:     using std::chrono::seconds;
ferencd@0:     using CT = typename std::common_type<Duration, seconds>::type;
ferencd@0:     const std::string abbrev("UTC");
ferencd@0:     CONSTDATA seconds offset{0};
ferencd@0:     auto ls = is_leap_second(t);
ferencd@0:     auto tp = sys_time<CT>{t.time_since_epoch() - ls.second};
ferencd@0:     auto const sd = floor<days>(tp);
ferencd@0:     year_month_day ymd = sd;
ferencd@0:     auto time = make_time(tp - sys_seconds{sd});
ferencd@0:     time.seconds(detail::undocumented{}) += seconds{ls.first};
ferencd@0:     fields<CT> fds{ymd, time};
ferencd@0:     return to_stream(os, fmt, fds, &abbrev, &offset);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class CharT, class Traits, class Duration>
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: operator<<(std::basic_ostream<CharT, Traits>& os, const utc_time<Duration>& t)
ferencd@0: {
ferencd@0:     const CharT fmt[] = {'%', 'F', ' ', '%', 'T', CharT{}};
ferencd@0:     return to_stream(os, fmt, t);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class CharT, class Traits, class Alloc = std::allocator<CharT>>
ferencd@0: std::basic_istream<CharT, Traits>&
ferencd@0: from_stream(std::basic_istream<CharT, Traits>& is, const CharT* fmt,
ferencd@0:             utc_time<Duration>& tp, std::basic_string<CharT, Traits, Alloc>* abbrev = nullptr,
ferencd@0:             std::chrono::minutes* offset = nullptr)
ferencd@0: {
ferencd@0:     using std::chrono::seconds;
ferencd@0:     using std::chrono::minutes;
ferencd@0:     using CT = typename std::common_type<Duration, seconds>::type;
ferencd@0:     minutes offset_local{};
ferencd@0:     auto offptr = offset ? offset : &offset_local;
ferencd@0:     fields<CT> fds{};
ferencd@0:     fds.has_tod = true;
ferencd@0:     from_stream(is, fmt, fds, abbrev, offptr);
ferencd@0:     if (!fds.ymd.ok())
ferencd@0:         is.setstate(std::ios::failbit);
ferencd@0:     if (!is.fail())
ferencd@0:     {
ferencd@0:         bool is_60_sec = fds.tod.seconds() == seconds{60};
ferencd@0:         if (is_60_sec)
ferencd@0:             fds.tod.seconds(detail::undocumented{}) -= seconds{1};
ferencd@0:         auto tmp = utc_clock::from_sys(sys_days(fds.ymd) - *offptr + fds.tod.to_duration());
ferencd@0:         if (is_60_sec)
ferencd@0:             tmp += seconds{1};
ferencd@0:         if (is_60_sec != is_leap_second(tmp).first || !fds.tod.in_conventional_range())
ferencd@0:         {
ferencd@0:             is.setstate(std::ios::failbit);
ferencd@0:             return is;
ferencd@0:         }
ferencd@0:         tp = std::chrono::time_point_cast<Duration>(tmp);
ferencd@0:     }
ferencd@0:     return is;
ferencd@0: }
ferencd@0: 
ferencd@0: // tai_clock
ferencd@0: 
ferencd@0: class tai_clock
ferencd@0: {
ferencd@0: public:
ferencd@0:     using duration                  = std::chrono::system_clock::duration;
ferencd@0:     using rep                       = duration::rep;
ferencd@0:     using period                    = duration::period;
ferencd@0:     using time_point                = std::chrono::time_point<tai_clock>;
ferencd@0:     static const bool is_steady     = false;
ferencd@0: 
ferencd@0:     static time_point now();
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<utc_clock, typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     to_utc(const std::chrono::time_point<tai_clock, Duration>&) NOEXCEPT;
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<tai_clock, typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     from_utc(const std::chrono::time_point<utc_clock, Duration>&) NOEXCEPT;
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<local_t, typename std::common_type<Duration, date::days>::type>
ferencd@0:     to_local(const std::chrono::time_point<tai_clock, Duration>&) NOEXCEPT;
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<tai_clock, typename std::common_type<Duration, date::days>::type>
ferencd@0:     from_local(const std::chrono::time_point<local_t, Duration>&) NOEXCEPT;
ferencd@0: };
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0:     using tai_time = std::chrono::time_point<tai_clock, Duration>;
ferencd@0: 
ferencd@0: using tai_seconds = tai_time<std::chrono::seconds>;
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: utc_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: tai_clock::to_utc(const tai_time<Duration>& t) NOEXCEPT
ferencd@0: {
ferencd@0:     using std::chrono::seconds;
ferencd@0:     using CD = typename std::common_type<Duration, seconds>::type;
ferencd@0:     return utc_time<CD>{t.time_since_epoch()} -
ferencd@0:             (sys_days(year{1970}/January/1) - sys_days(year{1958}/January/1) + seconds{10});
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: tai_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: tai_clock::from_utc(const utc_time<Duration>& t) NOEXCEPT
ferencd@0: {
ferencd@0:     using std::chrono::seconds;
ferencd@0:     using CD = typename std::common_type<Duration, seconds>::type;
ferencd@0:     return tai_time<CD>{t.time_since_epoch()} +
ferencd@0:             (sys_days(year{1970}/January/1) - sys_days(year{1958}/January/1) + seconds{10});
ferencd@0: }
ferencd@0: 
ferencd@0: inline
ferencd@0: tai_clock::time_point
ferencd@0: tai_clock::now()
ferencd@0: {
ferencd@0:     return from_utc(utc_clock::now());
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: local_time<typename std::common_type<Duration, date::days>::type>
ferencd@0: tai_clock::to_local(const tai_time<Duration>& t) NOEXCEPT
ferencd@0: {
ferencd@0:     using CD = typename std::common_type<Duration, date::days>::type;
ferencd@0:     return local_time<CD>{t.time_since_epoch()} -
ferencd@0:            (local_days(year{1970}/January/1) - local_days(year{1958}/January/1));
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: tai_time<typename std::common_type<Duration, date::days>::type>
ferencd@0: tai_clock::from_local(const local_time<Duration>& t) NOEXCEPT
ferencd@0: {
ferencd@0:     using CD = typename std::common_type<Duration, date::days>::type;
ferencd@0:     return tai_time<CD>{t.time_since_epoch()} +
ferencd@0:             (local_days(year{1970}/January/1) - local_days(year{1958}/January/1));
ferencd@0: }
ferencd@0: 
ferencd@0: template <class CharT, class Traits, class Duration>
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: to_stream(std::basic_ostream<CharT, Traits>& os, const CharT* fmt,
ferencd@0:           const tai_time<Duration>& t)
ferencd@0: {
ferencd@0:     const std::string abbrev("TAI");
ferencd@0:     CONSTDATA std::chrono::seconds offset{0};
ferencd@0:     return to_stream(os, fmt, tai_clock::to_local(t), &abbrev, &offset);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class CharT, class Traits, class Duration>
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: operator<<(std::basic_ostream<CharT, Traits>& os, const tai_time<Duration>& t)
ferencd@0: {
ferencd@0:     const CharT fmt[] = {'%', 'F', ' ', '%', 'T', CharT{}};
ferencd@0:     return to_stream(os, fmt, t);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class CharT, class Traits, class Alloc = std::allocator<CharT>>
ferencd@0: std::basic_istream<CharT, Traits>&
ferencd@0: from_stream(std::basic_istream<CharT, Traits>& is, const CharT* fmt,
ferencd@0:             tai_time<Duration>& tp,
ferencd@0:             std::basic_string<CharT, Traits, Alloc>* abbrev = nullptr,
ferencd@0:             std::chrono::minutes* offset = nullptr)
ferencd@0: {
ferencd@0:     local_time<Duration> lp;
ferencd@0:     from_stream(is, fmt, lp, abbrev, offset);
ferencd@0:     if (!is.fail())
ferencd@0:         tp = tai_clock::from_local(lp);
ferencd@0:     return is;
ferencd@0: }
ferencd@0: 
ferencd@0: // gps_clock
ferencd@0: 
ferencd@0: class gps_clock
ferencd@0: {
ferencd@0: public:
ferencd@0:     using duration                  = std::chrono::system_clock::duration;
ferencd@0:     using rep                       = duration::rep;
ferencd@0:     using period                    = duration::period;
ferencd@0:     using time_point                = std::chrono::time_point<gps_clock>;
ferencd@0:     static const bool is_steady     = false;
ferencd@0: 
ferencd@0:     static time_point now();
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<utc_clock, typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     to_utc(const std::chrono::time_point<gps_clock, Duration>&) NOEXCEPT;
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<gps_clock, typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     from_utc(const std::chrono::time_point<utc_clock, Duration>&) NOEXCEPT;
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<local_t, typename std::common_type<Duration, date::days>::type>
ferencd@0:     to_local(const std::chrono::time_point<gps_clock, Duration>&) NOEXCEPT;
ferencd@0: 
ferencd@0:     template<typename Duration>
ferencd@0:     static
ferencd@0:     std::chrono::time_point<gps_clock, typename std::common_type<Duration, date::days>::type>
ferencd@0:     from_local(const std::chrono::time_point<local_t, Duration>&) NOEXCEPT;
ferencd@0: };
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0:     using gps_time = std::chrono::time_point<gps_clock, Duration>;
ferencd@0: 
ferencd@0: using gps_seconds = gps_time<std::chrono::seconds>;
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: utc_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: gps_clock::to_utc(const gps_time<Duration>& t) NOEXCEPT
ferencd@0: {
ferencd@0:     using std::chrono::seconds;
ferencd@0:     using CD = typename std::common_type<Duration, seconds>::type;
ferencd@0:     return utc_time<CD>{t.time_since_epoch()} +
ferencd@0:             (sys_days(year{1980}/January/Sunday[1]) - sys_days(year{1970}/January/1) +
ferencd@0:              seconds{9});
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: gps_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: gps_clock::from_utc(const utc_time<Duration>& t) NOEXCEPT
ferencd@0: {
ferencd@0:     using std::chrono::seconds;
ferencd@0:     using CD = typename std::common_type<Duration, seconds>::type;
ferencd@0:     return gps_time<CD>{t.time_since_epoch()} -
ferencd@0:             (sys_days(year{1980}/January/Sunday[1]) - sys_days(year{1970}/January/1) +
ferencd@0:              seconds{9});
ferencd@0: }
ferencd@0: 
ferencd@0: inline
ferencd@0: gps_clock::time_point
ferencd@0: gps_clock::now()
ferencd@0: {
ferencd@0:     return from_utc(utc_clock::now());
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: local_time<typename std::common_type<Duration, date::days>::type>
ferencd@0: gps_clock::to_local(const gps_time<Duration>& t) NOEXCEPT
ferencd@0: {
ferencd@0:     using CD = typename std::common_type<Duration, date::days>::type;
ferencd@0:     return local_time<CD>{t.time_since_epoch()} +
ferencd@0:             (local_days(year{1980}/January/Sunday[1]) - local_days(year{1970}/January/1));
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: gps_time<typename std::common_type<Duration, date::days>::type>
ferencd@0: gps_clock::from_local(const local_time<Duration>& t) NOEXCEPT
ferencd@0: {
ferencd@0:     using CD = typename std::common_type<Duration, date::days>::type;
ferencd@0:     return gps_time<CD>{t.time_since_epoch()} -
ferencd@0:             (local_days(year{1980}/January/Sunday[1]) - local_days(year{1970}/January/1));
ferencd@0: }
ferencd@0: 
ferencd@0: 
ferencd@0: template <class CharT, class Traits, class Duration>
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: to_stream(std::basic_ostream<CharT, Traits>& os, const CharT* fmt,
ferencd@0:           const gps_time<Duration>& t)
ferencd@0: {
ferencd@0:     const std::string abbrev("GPS");
ferencd@0:     CONSTDATA std::chrono::seconds offset{0};
ferencd@0:     return to_stream(os, fmt, gps_clock::to_local(t), &abbrev, &offset);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class CharT, class Traits, class Duration>
ferencd@0: std::basic_ostream<CharT, Traits>&
ferencd@0: operator<<(std::basic_ostream<CharT, Traits>& os, const gps_time<Duration>& t)
ferencd@0: {
ferencd@0:     const CharT fmt[] = {'%', 'F', ' ', '%', 'T', CharT{}};
ferencd@0:     return to_stream(os, fmt, t);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration, class CharT, class Traits, class Alloc = std::allocator<CharT>>
ferencd@0: std::basic_istream<CharT, Traits>&
ferencd@0: from_stream(std::basic_istream<CharT, Traits>& is, const CharT* fmt,
ferencd@0:             gps_time<Duration>& tp,
ferencd@0:             std::basic_string<CharT, Traits, Alloc>* abbrev = nullptr,
ferencd@0:             std::chrono::minutes* offset = nullptr)
ferencd@0: {
ferencd@0:     local_time<Duration> lp;
ferencd@0:     from_stream(is, fmt, lp, abbrev, offset);
ferencd@0:     if (!is.fail())
ferencd@0:         tp = gps_clock::from_local(lp);
ferencd@0:     return is;
ferencd@0: }
ferencd@0: 
ferencd@0: // clock_time_conversion
ferencd@0: 
ferencd@0: template <class DstClock, class SrcClock>
ferencd@0: struct clock_time_conversion
ferencd@0: {};
ferencd@0: 
ferencd@0: template <>
ferencd@0: struct clock_time_conversion<std::chrono::system_clock, std::chrono::system_clock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     sys_time<Duration>
ferencd@0:     operator()(const sys_time<Duration>& st) const
ferencd@0:     {
ferencd@0:         return st;
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template <>
ferencd@0: struct clock_time_conversion<utc_clock, utc_clock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     utc_time<Duration>
ferencd@0:     operator()(const utc_time<Duration>& ut) const
ferencd@0:     {
ferencd@0:         return ut;
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template<>
ferencd@0: struct clock_time_conversion<local_t, local_t>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     local_time<Duration>
ferencd@0:     operator()(const local_time<Duration>& lt) const
ferencd@0:     {
ferencd@0:         return lt;
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template <>
ferencd@0: struct clock_time_conversion<utc_clock, std::chrono::system_clock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     utc_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     operator()(const sys_time<Duration>& st) const
ferencd@0:     {
ferencd@0:         return utc_clock::from_sys(st);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template <>
ferencd@0: struct clock_time_conversion<std::chrono::system_clock, utc_clock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     operator()(const utc_time<Duration>& ut) const
ferencd@0:     {
ferencd@0:         return utc_clock::to_sys(ut);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template<>
ferencd@0: struct clock_time_conversion<local_t, std::chrono::system_clock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     local_time<Duration>
ferencd@0:     operator()(const sys_time<Duration>& st) const
ferencd@0:     {
ferencd@0:        return local_time<Duration>{st.time_since_epoch()};
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template<>
ferencd@0: struct clock_time_conversion<std::chrono::system_clock, local_t>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     sys_time<Duration>
ferencd@0:     operator()(const local_time<Duration>& lt) const
ferencd@0:     {
ferencd@0:         return sys_time<Duration>{lt.time_since_epoch()};
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template<>
ferencd@0: struct clock_time_conversion<utc_clock, local_t>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     utc_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     operator()(const local_time<Duration>& lt) const
ferencd@0:     {
ferencd@0:        return utc_clock::from_local(lt);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template<>
ferencd@0: struct clock_time_conversion<local_t, utc_clock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     local_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0:     operator()(const utc_time<Duration>& ut) const
ferencd@0:     {
ferencd@0:        return utc_clock::to_local(ut);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template<typename Clock>
ferencd@0: struct clock_time_conversion<Clock, Clock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     std::chrono::time_point<Clock, Duration>
ferencd@0:     operator()(const std::chrono::time_point<Clock, Duration>& tp) const
ferencd@0:     {
ferencd@0:         return tp;
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: namespace ctc_detail
ferencd@0: {
ferencd@0: 
ferencd@0: template <class Clock, class Duration>
ferencd@0:     using time_point = std::chrono::time_point<Clock, Duration>;
ferencd@0: 
ferencd@0: using std::declval;
ferencd@0: using std::chrono::system_clock;
ferencd@0: 
ferencd@0: //Check if TimePoint is time for given clock,
ferencd@0: //if not emits hard error
ferencd@0: template <class Clock, class TimePoint>
ferencd@0: struct return_clock_time
ferencd@0: {
ferencd@0:     using clock_time_point = time_point<Clock, typename TimePoint::duration>;
ferencd@0:     using type             = TimePoint;
ferencd@0: 
ferencd@0:     static_assert(std::is_same<TimePoint, clock_time_point>::value,
ferencd@0:                   "time point with appropariate clock shall be returned");
ferencd@0: };
ferencd@0: 
ferencd@0: // Check if Clock has to_sys method accepting TimePoint with given duration const& and
ferencd@0: // returning sys_time. If so has nested type member equal to return type to_sys.
ferencd@0: template <class Clock, class Duration, class = void>
ferencd@0: struct return_to_sys
ferencd@0: {};
ferencd@0: 
ferencd@0: template <class Clock, class Duration>
ferencd@0: struct return_to_sys
ferencd@0:        <
ferencd@0:            Clock, Duration,
ferencd@0:            decltype(Clock::to_sys(declval<time_point<Clock, Duration> const&>()), void())
ferencd@0:        >
ferencd@0:     : return_clock_time
ferencd@0:       <
ferencd@0:           system_clock,
ferencd@0:           decltype(Clock::to_sys(declval<time_point<Clock, Duration> const&>()))
ferencd@0:       >
ferencd@0: {};
ferencd@0: 
ferencd@0: // Similiar to above
ferencd@0: template <class Clock, class Duration, class = void>
ferencd@0: struct return_from_sys
ferencd@0: {};
ferencd@0: 
ferencd@0: template <class Clock, class Duration>
ferencd@0: struct return_from_sys
ferencd@0:        <
ferencd@0:            Clock, Duration,
ferencd@0:            decltype(Clock::from_sys(declval<time_point<system_clock, Duration> const&>()),
ferencd@0:                     void())
ferencd@0:        >
ferencd@0:     : return_clock_time
ferencd@0:       <
ferencd@0:           Clock,
ferencd@0:           decltype(Clock::from_sys(declval<time_point<system_clock, Duration> const&>()))
ferencd@0:       >
ferencd@0: {};
ferencd@0: 
ferencd@0: // Similiar to above
ferencd@0: template <class Clock, class Duration, class = void>
ferencd@0: struct return_to_utc
ferencd@0: {};
ferencd@0: 
ferencd@0: template <class Clock, class Duration>
ferencd@0: struct return_to_utc
ferencd@0:        <
ferencd@0:            Clock, Duration,
ferencd@0:            decltype(Clock::to_utc(declval<time_point<Clock, Duration> const&>()), void())
ferencd@0:        >
ferencd@0:     : return_clock_time
ferencd@0:       <
ferencd@0:           utc_clock,
ferencd@0:           decltype(Clock::to_utc(declval<time_point<Clock, Duration> const&>()))>
ferencd@0: {};
ferencd@0: 
ferencd@0: // Similiar to above
ferencd@0: template <class Clock, class Duration, class = void>
ferencd@0: struct return_from_utc
ferencd@0: {};
ferencd@0: 
ferencd@0: template <class Clock, class Duration>
ferencd@0: struct return_from_utc
ferencd@0:        <
ferencd@0:            Clock, Duration,
ferencd@0:            decltype(Clock::from_utc(declval<time_point<utc_clock, Duration> const&>()),
ferencd@0:                     void())
ferencd@0:        >
ferencd@0:     : return_clock_time
ferencd@0:       <
ferencd@0:           Clock,
ferencd@0:           decltype(Clock::from_utc(declval<time_point<utc_clock, Duration> const&>()))
ferencd@0:       >
ferencd@0: {};
ferencd@0: 
ferencd@0: // Similiar to above
ferencd@0: template<typename Clock, typename Duration, typename = void>
ferencd@0: struct return_to_local
ferencd@0: {};
ferencd@0: 
ferencd@0: template<typename Clock, typename Duration>
ferencd@0: struct return_to_local
ferencd@0:        <
ferencd@0:           Clock, Duration,
ferencd@0:           decltype(Clock::to_local(declval<time_point<Clock, Duration> const&>()),
ferencd@0:                    void())
ferencd@0:        >
ferencd@0:      : return_clock_time
ferencd@0:        <
ferencd@0:            local_t,
ferencd@0:            decltype(Clock::to_local(declval<time_point<Clock, Duration> const&>()))
ferencd@0:        >
ferencd@0: {};
ferencd@0: 
ferencd@0: // Similiar to above
ferencd@0: template<typename Clock, typename Duration, typename = void>
ferencd@0: struct return_from_local
ferencd@0: {};
ferencd@0: 
ferencd@0: template<typename Clock, typename Duration>
ferencd@0: struct return_from_local
ferencd@0:        <
ferencd@0:            Clock, Duration,
ferencd@0:            decltype(Clock::from_local(declval<time_point<local_t, Duration> const&>()),
ferencd@0:                     void())
ferencd@0:        >
ferencd@0:      : return_clock_time
ferencd@0:        <
ferencd@0:            Clock,
ferencd@0:            decltype(Clock::from_local(declval<time_point<local_t, Duration> const&>()))
ferencd@0:        >
ferencd@0: {};
ferencd@0: 
ferencd@0: }  // namespace ctc_detail
ferencd@0: 
ferencd@0: template <class SrcClock>
ferencd@0: struct clock_time_conversion<std::chrono::system_clock, SrcClock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     typename ctc_detail::return_to_sys<SrcClock, Duration>::type
ferencd@0:     operator()(const std::chrono::time_point<SrcClock, Duration>& tp) const
ferencd@0:     {
ferencd@0:         return SrcClock::to_sys(tp);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template <class DstClock>
ferencd@0: struct clock_time_conversion<DstClock, std::chrono::system_clock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     typename ctc_detail::return_from_sys<DstClock, Duration>::type
ferencd@0:     operator()(const sys_time<Duration>& st) const
ferencd@0:     {
ferencd@0:         return DstClock::from_sys(st);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template <class SrcClock>
ferencd@0: struct clock_time_conversion<utc_clock, SrcClock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     typename ctc_detail::return_to_utc<SrcClock, Duration>::type
ferencd@0:     operator()(const std::chrono::time_point<SrcClock, Duration>& tp) const
ferencd@0:     {
ferencd@0:         return SrcClock::to_utc(tp);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template <class DstClock>
ferencd@0: struct clock_time_conversion<DstClock, utc_clock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     typename ctc_detail::return_from_utc<DstClock, Duration>::type
ferencd@0:     operator()(const utc_time<Duration>& ut) const
ferencd@0:     {
ferencd@0:         return DstClock::from_utc(ut);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template<typename SrcClock>
ferencd@0: struct clock_time_conversion<local_t, SrcClock>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     typename ctc_detail::return_to_local<SrcClock, Duration>::type
ferencd@0:     operator()(const std::chrono::time_point<SrcClock, Duration>& tp) const
ferencd@0:     {
ferencd@0:         return SrcClock::to_local(tp);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: template<typename DstClock>
ferencd@0: struct clock_time_conversion<DstClock, local_t>
ferencd@0: {
ferencd@0:     template <class Duration>
ferencd@0:     typename ctc_detail::return_from_local<DstClock, Duration>::type
ferencd@0:     operator()(const local_time<Duration>& lt) const
ferencd@0:     {
ferencd@0:         return DstClock::from_local(lt);
ferencd@0:     }
ferencd@0: };
ferencd@0: 
ferencd@0: namespace clock_cast_detail
ferencd@0: {
ferencd@0: 
ferencd@0: template <class Clock, class Duration>
ferencd@0:     using time_point = std::chrono::time_point<Clock, Duration>;
ferencd@0: using std::chrono::system_clock;
ferencd@0: 
ferencd@0: template <class DstClock, class SrcClock, class Duration>
ferencd@0: auto
ferencd@0: conv_clock(const time_point<SrcClock, Duration>& t)
ferencd@0:     -> decltype(std::declval<clock_time_conversion<DstClock, SrcClock>>()(t))
ferencd@0: {
ferencd@0:     return clock_time_conversion<DstClock, SrcClock>{}(t);
ferencd@0: }
ferencd@0: 
ferencd@0: //direct trait conversion, 1st candidate
ferencd@0: template <class DstClock, class SrcClock, class Duration>
ferencd@0: auto
ferencd@0: cc_impl(const time_point<SrcClock, Duration>& t, const time_point<SrcClock, Duration>*)
ferencd@0:     -> decltype(conv_clock<DstClock>(t))
ferencd@0: {
ferencd@0:     return conv_clock<DstClock>(t);
ferencd@0: }
ferencd@0: 
ferencd@0: //conversion through sys, 2nd candidate
ferencd@0: template <class DstClock, class SrcClock, class Duration>
ferencd@0: auto
ferencd@0: cc_impl(const time_point<SrcClock, Duration>& t, const void*)
ferencd@0:     -> decltype(conv_clock<DstClock>(conv_clock<system_clock>(t)))
ferencd@0: {
ferencd@0:     return conv_clock<DstClock>(conv_clock<system_clock>(t));
ferencd@0: }
ferencd@0: 
ferencd@0: //conversion through utc, 2nd candidate
ferencd@0: template <class DstClock, class SrcClock, class Duration>
ferencd@0: auto
ferencd@0: cc_impl(const time_point<SrcClock, Duration>& t, const void*)
ferencd@0:     -> decltype(0,  // MSVC_WORKAROUND
ferencd@0:                 conv_clock<DstClock>(conv_clock<utc_clock>(t)))
ferencd@0: {
ferencd@0:     return conv_clock<DstClock>(conv_clock<utc_clock>(t));
ferencd@0: }
ferencd@0: 
ferencd@0: //conversion through sys and utc, 3rd candidate
ferencd@0: template <class DstClock, class SrcClock, class Duration>
ferencd@0: auto
ferencd@0: cc_impl(const time_point<SrcClock, Duration>& t, ...)
ferencd@0:     -> decltype(conv_clock<DstClock>(conv_clock<utc_clock>(conv_clock<system_clock>(t))))
ferencd@0: {
ferencd@0:     return conv_clock<DstClock>(conv_clock<utc_clock>(conv_clock<system_clock>(t)));
ferencd@0: }
ferencd@0: 
ferencd@0: //conversion through utc and sys, 3rd candidate
ferencd@0: template <class DstClock, class SrcClock, class Duration>
ferencd@0: auto
ferencd@0: cc_impl(const time_point<SrcClock, Duration>& t, ...)
ferencd@0:     -> decltype(0,  // MSVC_WORKAROUND
ferencd@0:                 conv_clock<DstClock>(conv_clock<system_clock>(conv_clock<utc_clock>(t))))
ferencd@0: {
ferencd@0:     return conv_clock<DstClock>(conv_clock<system_clock>(conv_clock<utc_clock>(t)));
ferencd@0: }
ferencd@0: 
ferencd@0: }  // namespace clock_cast_detail
ferencd@0: 
ferencd@0: template <class DstClock, class SrcClock, class Duration>
ferencd@0: auto
ferencd@0: clock_cast(const std::chrono::time_point<SrcClock, Duration>& tp)
ferencd@0:     -> decltype(clock_cast_detail::cc_impl<DstClock>(tp, &tp))
ferencd@0: {
ferencd@0:     return clock_cast_detail::cc_impl<DstClock>(tp, &tp);
ferencd@0: }
ferencd@0: 
ferencd@0: // Deprecated API
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_sys_time(const utc_time<Duration>& t)
ferencd@0: {
ferencd@0:     return utc_clock::to_sys(t);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_sys_time(const tai_time<Duration>& t)
ferencd@0: {
ferencd@0:     return utc_clock::to_sys(tai_clock::to_utc(t));
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: sys_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_sys_time(const gps_time<Duration>& t)
ferencd@0: {
ferencd@0:     return utc_clock::to_sys(gps_clock::to_utc(t));
ferencd@0: }
ferencd@0: 
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: utc_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_utc_time(const sys_time<Duration>& t)
ferencd@0: {
ferencd@0:     return utc_clock::from_sys(t);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: utc_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_utc_time(const tai_time<Duration>& t)
ferencd@0: {
ferencd@0:     return tai_clock::to_utc(t);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: utc_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_utc_time(const gps_time<Duration>& t)
ferencd@0: {
ferencd@0:     return gps_clock::to_utc(t);
ferencd@0: }
ferencd@0: 
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: tai_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_tai_time(const sys_time<Duration>& t)
ferencd@0: {
ferencd@0:     return tai_clock::from_utc(utc_clock::from_sys(t));
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: tai_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_tai_time(const utc_time<Duration>& t)
ferencd@0: {
ferencd@0:     return tai_clock::from_utc(t);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: tai_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_tai_time(const gps_time<Duration>& t)
ferencd@0: {
ferencd@0:     return tai_clock::from_utc(gps_clock::to_utc(t));
ferencd@0: }
ferencd@0: 
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: gps_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_gps_time(const sys_time<Duration>& t)
ferencd@0: {
ferencd@0:     return gps_clock::from_utc(utc_clock::from_sys(t));
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: gps_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_gps_time(const utc_time<Duration>& t)
ferencd@0: {
ferencd@0:     return gps_clock::from_utc(t);
ferencd@0: }
ferencd@0: 
ferencd@0: template <class Duration>
ferencd@0: inline
ferencd@0: gps_time<typename std::common_type<Duration, std::chrono::seconds>::type>
ferencd@0: to_gps_time(const tai_time<Duration>& t)
ferencd@0: {
ferencd@0:     return gps_clock::from_utc(tai_clock::to_utc(t));
ferencd@0: }
ferencd@0: 
ferencd@0: #endif  // !MISSING_LEAP_SECONDS
ferencd@0: 
ferencd@0: }  // namespace date
ferencd@0: 
ferencd@0: #endif  // TZ_H