Template zoned_time on TimeZonePtr

* TimeZonePtr defaults to const time_zone*.
* Adjust template deduction guides and make_zoned.
* Add HAS_STRING_VIEW

tz.cpp

@@ -3346,10 +3346,18 @@ get_tzdb()
 }
 
 const time_zone*
+#if HAS_STRING_VIEW
+TZ_DB::locate_zone(std::string_view tz_name) const
+#else
 TZ_DB::locate_zone(const std::string& tz_name) const
+#endif
 {
     auto zi = std::lower_bound(zones.begin(), zones.end(), tz_name,
+#if HAS_STRING_VIEW
+        [](const time_zone& z, const std::string_view& nm)
+#else
         [](const time_zone& z, const std::string& nm)
+#endif
         {
             return z.name() < nm;
         });
@@ -3357,7 +3365,11 @@ TZ_DB::locate_zone(const std::string& tz_name) const
     {
 #if !USE_OS_TZDB
         auto li = std::lower_bound(links.begin(), links.end(), tz_name,
+#if HAS_STRING_VIEW
+        [](const link& z, const std::string_view& nm)
+#else
         [](const link& z, const std::string& nm)
+#endif
         {
             return z.name() < nm;
         });
@@ -3372,13 +3384,17 @@ TZ_DB::locate_zone(const std::string& tz_name) const
                 return &*zi;
         }
 #endif  // !USE_OS_TZDB
-        throw std::runtime_error(tz_name + " not found in timezone database");
+        throw std::runtime_error(std::string(tz_name) + " not found in timezone database");
     }
     return &*zi;
 }
 
 const time_zone*
+#if HAS_STRING_VIEW
+locate_zone(std::string_view tz_name)
+#else
 locate_zone(const std::string& tz_name)
+#endif
 {
     return get_tzdb().locate_zone(tz_name);
 }

tz.h

@@ -95,6 +95,14 @@ static_assert(HAS_REMOTE_API == 0 ? AUTO_DOWNLOAD == 0 : true,
 #  endif
 #endif  // HAS_DEDUCTION_GUIDES
 
+#ifndef HAS_STRING_VIEW
+#  if __cplusplus >= 201703
+#    define HAS_STRING_VIEW 1
+#  else
+#    define HAS_STRING_VIEW 0
+#  endif
+#endif  // HAS_STRING_VIEW
+
 #include "date.h"
 
 #if defined(_MSC_VER) && (_MSC_VER < 1900)
@@ -280,24 +288,34 @@ operator<<(std::basic_ostream<CharT, Traits>& os, const local_info& r)
 }
 
 class time_zone;
+
+#if HAS_STRING_VIEW
+DATE_API const time_zone* locate_zone(std::string_view tz_name);
+#else
 DATE_API const time_zone* locate_zone(const std::string& tz_name);
+#endif
+
 DATE_API const time_zone* current_zone();
 
-template <class Duration>
+template <class Duration, class TimeZonePtr = const time_zone*>
 class zoned_time
 {
 public:
     using duration = typename std::common_type<Duration, std::chrono::seconds>::type;
 
 private:
-    const time_zone*   zone_;
+    TimeZonePtr        zone_;
     sys_time<duration> tp_;
 
 public:
              zoned_time();
              zoned_time(const sys_time<Duration>& st);
-    explicit zoned_time(const time_zone* z);
+    explicit zoned_time(TimeZonePtr z);
+#if HAS_STRING_VIEW
+    explicit zoned_time(const std::string_view& name);
+#else
     explicit zoned_time(const std::string& name);
+#endif
 
     template <class Duration2,
               class = typename std::enable_if
@@ -305,25 +323,32 @@ public:
                           std::is_convertible<sys_time<Duration2>,
                                               sys_time<Duration>>::value
                       >::type>
-        zoned_time(const zoned_time<Duration2>& zt) NOEXCEPT;
+        zoned_time(const zoned_time<Duration2, TimeZonePtr>& zt) NOEXCEPT;
 
-    zoned_time(const time_zone* z,      const local_time<Duration>& tp);
+    zoned_time(TimeZonePtr z, const sys_time<Duration>& st);
-    zoned_time(const std::string& name, const local_time<Duration>& tp);
+    zoned_time(TimeZonePtr z, const local_time<Duration>& tp);
-    zoned_time(const char* name,        const local_time<Duration>& tp);
+    zoned_time(TimeZonePtr z, const local_time<Duration>& tp, choose c);
-    zoned_time(const time_zone* z,      const local_time<Duration>& tp, choose c);
+    zoned_time(TimeZonePtr z, const zoned_time<Duration, TimeZonePtr>& zt);
-    zoned_time(const std::string& name, const local_time<Duration>& tp, choose c);
+    zoned_time(TimeZonePtr z, const zoned_time<Duration, TimeZonePtr>& zt, choose);
-    zoned_time(const char* name,        const local_time<Duration>& tp, choose c);
 
-    zoned_time(const time_zone* z,      const zoned_time<Duration>& zt);
+#if HAS_STRING_VIEW
-    zoned_time(const std::string& name, const zoned_time<Duration>& zt);
+    zoned_time(std::string_view name,   const sys_time<Duration>& st);
-    zoned_time(const char* name,        const zoned_time<Duration>& zt);
+    zoned_time(std::string_view name,   const local_time<Duration>& tp);
-    zoned_time(const time_zone* z,      const zoned_time<Duration>& zt, choose);
+    zoned_time(std::string_view name,   const local_time<Duration>& tp, choose c);
-    zoned_time(const std::string& name, const zoned_time<Duration>& zt, choose);
+    zoned_time(std::string_view name,   const zoned_time<Duration, TimeZonePtr>& zt);
-    zoned_time(const char* name,        const zoned_time<Duration>& zt, choose);
+    zoned_time(std::string_view name,   const zoned_time<Duration, TimeZonePtr>& zt, choose);
-
+#else  // !HAS_STRING_VIEW
-    zoned_time(const time_zone* z,      const sys_time<Duration>& st);
     zoned_time(const std::string& name, const sys_time<Duration>& st);
     zoned_time(const char* name,        const sys_time<Duration>& st);
+    zoned_time(const std::string& name, const local_time<Duration>& tp);
+    zoned_time(const char* name,        const local_time<Duration>& tp);
+    zoned_time(const std::string& name, const local_time<Duration>& tp, choose c);
+    zoned_time(const char* name,        const local_time<Duration>& tp, choose c);
+    zoned_time(const std::string& name, const zoned_time<Duration, TimeZonePtr>& zt);
+    zoned_time(const char* name,        const zoned_time<Duration, TimeZonePtr>& zt);
+    zoned_time(const std::string& name, const zoned_time<Duration, TimeZonePtr>& zt, choose);
+    zoned_time(const char* name,        const zoned_time<Duration, TimeZonePtr>& zt, choose);
+#endif  // !HAS_STRING_VIEW
 
     zoned_time& operator=(const sys_time<Duration>& st);
     zoned_time& operator=(const local_time<Duration>& ut);
@@ -331,59 +356,102 @@ public:
     explicit operator sys_time<duration>() const;
     explicit operator local_time<duration>() const;
 
-    const time_zone*     get_time_zone() const;
+    TimeZonePtr          get_time_zone() const;
     local_time<duration> get_local_time() const;
     sys_time<duration>   get_sys_time() const;
     sys_info             get_info() const;
 
-    template <class Duration1, class Duration2>
+    template <class Duration1, class Duration2, class TimeZonePtr1>
     friend
     bool
-    operator==(const zoned_time<Duration1>& x, const zoned_time<Duration2>& y);
+    operator==(const zoned_time<Duration1, TimeZonePtr1>& x,
+               const zoned_time<Duration2, TimeZonePtr1>& y);
 
-    template <class CharT, class Traits, class Duration1>
+    template <class CharT, class Traits, class Duration1, class TimeZonePtr1>
     friend
     std::basic_ostream<CharT, Traits>&
-    operator<<(std::basic_ostream<CharT, Traits>& os, const zoned_time<Duration1>& t);
+    operator<<(std::basic_ostream<CharT, Traits>& os,
+               const zoned_time<Duration1, TimeZonePtr1>& t);
 
 private:
-    template <class D> friend class zoned_time;
+    template <class D, class T> friend class zoned_time;
 };
 
 using zoned_seconds = zoned_time<std::chrono::seconds>;
 
 #if HAS_DEDUCTION_GUIDES
 
+zoned_time()
+    -> zoned_time<std::chrono::seconds>;
+
 template <class Duration>
 zoned_time(sys_time<Duration>)
     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>>;
 
-template <class Zone, class Duration>
+template <class TimeZonePtr>
-zoned_time(Zone, sys_time<Duration>)
+zoned_time(TimeZonePtr)
+    -> zoned_time<std::chrono::seconds, TimeZonePtr>;
+
+template <class TimeZonePtr, class Duration>
+zoned_time(TimeZonePtr, sys_time<Duration>)
+    -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>, TimeZonePtr>;
+
+template <class TimeZonePtr, class Duration>
+zoned_time(TimeZonePtr, local_time<Duration>, choose = choose::earliest)
+    -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>, TimeZonePtr>;
+
+#if HAS_STRING_VIEW
+
+zoned_time(std::string_view)
+    -> zoned_time<std::chrono::seconds>;
+
+template <class Duration>
+zoned_time(std::string_view, sys_time<Duration>)
     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>>;
 
-template <class Zone, class Duration>
+template <class Duration>
-zoned_time(Zone, local_time<Duration>, choose = choose::earliest)
+zoned_time(std::string_view, local_time<Duration>, choose = choose::earliest)
     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>>;
 
-template <class Zone, class Duration>
+#else  // !HAS_STRING_VIEW
-zoned_time(Zone, zoned_time<Duration>, choose = choose::earliest)
+
+zoned_time(std::string)
+    -> zoned_time<std::chrono::seconds>;
+
+template <class Duration>
+zoned_time(std::string, sys_time<Duration>)
+    -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>>;
+
+template <class Duration>
+zoned_time(std::string, local_time<Duration>, choose = choose::earliest)
+    -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>>;
+
+#endif  // !HAS_STRING_VIEW
+
+template <class Duration>
+zoned_time(const char*, sys_time<Duration>)
+    -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>>;
+
+template <class Duration>
+zoned_time(const char*, local_time<Duration>, choose = choose::earliest)
     -> zoned_time<std::common_type_t<Duration, std::chrono::seconds>>;
 
 #endif  // HAS_DEDUCTION_GUIDES
 
-template <class Duration1, class Duration2>
+template <class Duration1, class Duration2, class TimeZonePtr>
 inline
 bool
-operator==(const zoned_time<Duration1>& x, const zoned_time<Duration2>& y)
+operator==(const zoned_time<Duration1, TimeZonePtr>& x,
+           const zoned_time<Duration2, TimeZonePtr>& y)
 {
     return x.zone_ == y.zone_ && x.tp_ == y.tp_;
 }
 
-template <class Duration1, class Duration2>
+template <class Duration1, class Duration2, class TimeZonePtr>
 inline
 bool
-operator!=(const zoned_time<Duration1>& x, const zoned_time<Duration2>& y)
+operator!=(const zoned_time<Duration1, TimeZonePtr>& x,
+           const zoned_time<Duration2, TimeZonePtr>& y)
 {
     return !(x == y);
 }
@@ -834,7 +902,11 @@ struct TZ_DB
     }
 #endif  // defined(_MSC_VER) && (_MSC_VER < 1900)
 
+#if HAS_STRING_VIEW
+    const time_zone* locate_zone(std::string_view tz_name) const;
+#else
     const time_zone* locate_zone(const std::string& tz_name) const;
+#endif
     const time_zone* current_zone() const;
 };
 
@@ -859,209 +931,291 @@ DATE_API bool        remote_install(const std::string& version);
 
 #endif
 
-DATE_API const time_zone* locate_zone(const std::string& tz_name);
-DATE_API const time_zone* current_zone();
-
 // zoned_time
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time()
+zoned_time<Duration, TimeZonePtr>::zoned_time()
     : zone_(locate_zone("UTC"))
     {}
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const sys_time<Duration>& st)
+zoned_time<Duration, TimeZonePtr>::zoned_time(const sys_time<Duration>& st)
     : zone_(locate_zone("UTC"))
     , tp_(st)
     {}
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const time_zone* z)
+zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z)
-    : zone_(z)
+    : zone_(std::move(z))
     {assert(zone_ != nullptr);}
 
-template <class Duration>
+#if HAS_DEDUCTION_GUIDES
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const std::string& name)
+zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string_view& name)
     : zoned_time(locate_zone(name))
     {}
 
-template <class Duration>
+#else
+
+template <class Duration, class TimeZonePtr>
+inline
+zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name)
+    : zoned_time(locate_zone(name))
+    {}
+
+#endif
+
+template <class Duration, class TimeZonePtr>
 template <class Duration2, class>
 inline
-zoned_time<Duration>::zoned_time(const zoned_time<Duration2>& zt) NOEXCEPT
+zoned_time<Duration, TimeZonePtr>::zoned_time(const zoned_time<Duration2, TimeZonePtr>& zt) NOEXCEPT
     : zone_(zt.zone_)
     , tp_(zt.tp_)
     {}
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const time_zone* z, const local_time<Duration>& t)
+zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z, const local_time<Duration>& t)
-    : zone_(z)
+    : zone_(std::move(z))
     , tp_(z->to_sys(t))
     {}
 
-template <class Duration>
+#if HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const std::string& name, const local_time<Duration>& t)
+zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name, const local_time<Duration>& t)
     : zoned_time(locate_zone(name), t)
     {}
 
-template <class Duration>
+#else  // !HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const char* name, const local_time<Duration>& t)
+zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name, const local_time<Duration>& t)
     : zoned_time(locate_zone(name), t)
     {}
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const time_zone* z, const local_time<Duration>& t,
+zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name, const local_time<Duration>& t)
+    : zoned_time(locate_zone(name), t)
+    {}
+
+#endif  // HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
+inline
+zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z, const local_time<Duration>& t,
                                  choose c)
-    : zone_(z)
+    : zone_(std::move(z))
     , tp_(z->to_sys(t, c))
     {}
 
-template <class Duration>
+#if HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const std::string& name, const local_time<Duration>& t,
+zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name, const local_time<Duration>& t,
                                  choose c)
     : zoned_time(locate_zone(name), t, c)
     {}
 
-template <class Duration>
+#else  // !HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const char* name, const local_time<Duration>& t,
+zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name, const local_time<Duration>& t,
                                  choose c)
     : zoned_time(locate_zone(name), t, c)
     {}
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const time_zone* z, const zoned_time<Duration>& zt)
+zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name, const local_time<Duration>& t,
-    : zone_(z)
+                                 choose c)
+    : zoned_time(locate_zone(name), t, c)
+    {}
+
+#endif  // !HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
+inline
+zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z, const zoned_time<Duration, TimeZonePtr>& zt)
+    : zone_(std::move(z))
     , tp_(zt.tp_)
     {}
 
-template <class Duration>
+#if HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const std::string& name, const zoned_time<Duration>& zt)
+zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name,
+                                              const zoned_time<Duration, TimeZonePtr>& zt)
     : zoned_time(locate_zone(name), zt)
     {}
 
-template <class Duration>
+#else  // !HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const char* name, const zoned_time<Duration>& zt)
+zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name,
+                                              const zoned_time<Duration, TimeZonePtr>& zt)
     : zoned_time(locate_zone(name), zt)
     {}
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const time_zone* z, const zoned_time<Duration>& zt, choose)
+zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name,
-    : zoned_time(z, zt)
+                                              const zoned_time<Duration, TimeZonePtr>& zt)
+    : zoned_time(locate_zone(name), zt)
     {}
 
-template <class Duration>
+#endif  // !HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const std::string& name,
+zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z,
-                                 const zoned_time<Duration>& zt, choose c)
+                                      const zoned_time<Duration, TimeZonePtr>& zt, choose)
+    : zoned_time(std::move(z), zt)
+    {}
+
+#if HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
+inline
+zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name,
+                                 const zoned_time<Duration, TimeZonePtr>& zt, choose c)
     : zoned_time(locate_zone(name), zt, c)
     {}
 
-template <class Duration>
+#else  // !HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const char* name,
+zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name,
-                                 const zoned_time<Duration>& zt, choose c)
+                                 const zoned_time<Duration, TimeZonePtr>& zt, choose c)
     : zoned_time(locate_zone(name), zt, c)
     {}
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const time_zone* z, const sys_time<Duration>& st)
+zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name,
-    : zone_(z)
+                                 const zoned_time<Duration, TimeZonePtr>& zt, choose c)
+    : zoned_time(locate_zone(name), zt, c)
+    {}
+
+#endif  // !HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
+inline
+zoned_time<Duration, TimeZonePtr>::zoned_time(TimeZonePtr z, const sys_time<Duration>& st)
+    : zone_(std::move(z))
     , tp_(st)
     {}
 
-template <class Duration>
+#if HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const std::string& name, const sys_time<Duration>& st)
+zoned_time<Duration, TimeZonePtr>::zoned_time(std::string_view name, const sys_time<Duration>& st)
     : zoned_time(locate_zone(name), st)
     {}
 
-template <class Duration>
+#else  // !HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::zoned_time(const char* name, const sys_time<Duration>& st)
+zoned_time<Duration, TimeZonePtr>::zoned_time(const std::string& name, const sys_time<Duration>& st)
     : zoned_time(locate_zone(name), st)
     {}
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>&
+zoned_time<Duration, TimeZonePtr>::zoned_time(const char* name, const sys_time<Duration>& st)
-zoned_time<Duration>::operator=(const sys_time<Duration>& st)
+    : zoned_time(locate_zone(name), st)
+    {}
+
+#endif  // !HAS_STRING_VIEW
+
+template <class Duration, class TimeZonePtr>
+inline
+zoned_time<Duration, TimeZonePtr>&
+zoned_time<Duration, TimeZonePtr>::operator=(const sys_time<Duration>& st)
 {
     tp_ = st;
     return *this;
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>&
+zoned_time<Duration, TimeZonePtr>&
-zoned_time<Duration>::operator=(const local_time<Duration>& ut)
+zoned_time<Duration, TimeZonePtr>::operator=(const local_time<Duration>& ut)
 {
     tp_ = zone_->to_sys(ut);
     return *this;
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::operator local_time<zoned_time::duration>() const
+zoned_time<Duration, TimeZonePtr>::operator local_time<zoned_time::duration>() const
 {
     return get_local_time();
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<Duration>::operator sys_time<zoned_time::duration>() const
+zoned_time<Duration, TimeZonePtr>::operator sys_time<zoned_time::duration>() const
 {
     return get_sys_time();
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-const time_zone*
+TimeZonePtr
-zoned_time<Duration>::get_time_zone() const
+zoned_time<Duration, TimeZonePtr>::get_time_zone() const
 {
     return zone_;
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-local_time<typename zoned_time<Duration>::duration>
+local_time<typename zoned_time<Duration, TimeZonePtr>::duration>
-zoned_time<Duration>::get_local_time() const
+zoned_time<Duration, TimeZonePtr>::get_local_time() const
 {
     return zone_->to_local(tp_);
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-sys_time<typename zoned_time<Duration>::duration>
+sys_time<typename zoned_time<Duration, TimeZonePtr>::duration>
-zoned_time<Duration>::get_sys_time() const
+zoned_time<Duration, TimeZonePtr>::get_sys_time() const
 {
     return tp_;
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
 sys_info
-zoned_time<Duration>::get_info() const
+zoned_time<Duration, TimeZonePtr>::get_info() const
 {
     return zone_->get_info(tp_);
 }
 
 // make_zoned_time
 
+inline
+zoned_time<std::chrono::seconds>
+make_zoned()
+{
+    return {};
+}
+
 template <class Duration>
 inline
 zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
@@ -1070,12 +1224,50 @@ make_zoned(const sys_time<Duration>& tp)
     return {tp};
 }
 
-template <class Duration>
+template <class TimeZonePtr,
+          class = typename std::enable_if
+          <
+            std::is_class<typename std::decay<decltype(*std::declval<TimeZonePtr&>())>::type>{}
+          >::type
+         >
 inline
-zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
+zoned_time<std::chrono::seconds, TimeZonePtr>
-make_zoned(const time_zone* zone, const local_time<Duration>& tp)
+make_zoned(TimeZonePtr z)
 {
-    return {zone, tp};
+    return zoned_time<std::chrono::seconds, TimeZonePtr>{std::move(z)};
+}
+
+inline
+zoned_seconds
+make_zoned(const std::string& name)
+{
+    return zoned_seconds{name};
+}
+
+template <class Duration, class TimeZonePtr,
+          class = typename std::enable_if
+          <
+            std::is_class<typename std::decay<decltype(*std::declval<TimeZonePtr&>())>::type>{}
+          >::type
+         >
+inline
+zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type, TimeZonePtr>
+make_zoned(TimeZonePtr zone, const local_time<Duration>& tp)
+{
+    return {std::move(zone), tp};
+}
+
+template <class Duration, class TimeZonePtr,
+          class = typename std::enable_if
+          <
+            std::is_class<typename std::decay<decltype(*std::declval<TimeZonePtr&>())>::type>{}
+          >::type
+         >
+inline
+zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type, TimeZonePtr>
+make_zoned(TimeZonePtr zone, const local_time<Duration>& tp, choose c)
+{
+    return {std::move(zone), tp, c};
 }
 
 template <class Duration>
@@ -1086,14 +1278,6 @@ make_zoned(const std::string& name, const local_time<Duration>& tp)
     return {name, tp};
 }
 
-template <class Duration>
-inline
-zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
-make_zoned(const time_zone* zone, const local_time<Duration>& tp, choose c)
-{
-    return {zone, tp, c};
-}
-
 template <class Duration>
 inline
 zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
@@ -1102,44 +1286,49 @@ make_zoned(const std::string& name, const local_time<Duration>& tp, choose c)
     return {name, tp, c};
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
+zoned_time<Duration, TimeZonePtr>
-make_zoned(const time_zone* zone, const zoned_time<Duration>& zt)
+make_zoned(TimeZonePtr zone, const zoned_time<Duration, TimeZonePtr>& zt)
 {
-    return {zone, zt};
+    return {std::move(zone), zt};
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
+zoned_time<Duration, TimeZonePtr>
-make_zoned(const std::string& name, const zoned_time<Duration>& zt)
+make_zoned(const std::string& name, const zoned_time<Duration, TimeZonePtr>& zt)
 {
     return {name, zt};
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
+zoned_time<Duration, TimeZonePtr>
-make_zoned(const time_zone* zone, const zoned_time<Duration>& zt, choose c)
+make_zoned(TimeZonePtr zone, const zoned_time<Duration, TimeZonePtr>& zt, choose c)
 {
-    return {zone, zt, c};
+    return {std::move(zone), zt, c};
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr>
 inline
-zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
+zoned_time<Duration, TimeZonePtr>
-make_zoned(const std::string& name, const zoned_time<Duration>& zt, choose c)
+make_zoned(const std::string& name, const zoned_time<Duration, TimeZonePtr>& zt, choose c)
 {
     return {name, zt, c};
 }
 
-template <class Duration>
+template <class Duration, class TimeZonePtr,
+          class = typename std::enable_if
+          <
+            std::is_class<typename std::decay<decltype(*std::declval<TimeZonePtr&>())>::type>{}
+          >::type
+         >
 inline
-zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type>
+zoned_time<typename std::common_type<Duration, std::chrono::seconds>::type, TimeZonePtr>
-make_zoned(const time_zone* zone, const sys_time<Duration>& st)
+make_zoned(TimeZonePtr zone, const sys_time<Duration>& st)
 {
-    return {zone, st};
+    return {std::move(zone), st};
 }
 
 template <class Duration>
@@ -1150,19 +1339,19 @@ make_zoned(const std::string& name, const sys_time<Duration>& st)
     return {name, st};
 }
 
-template <class CharT, class Traits, class Duration>
+template <class CharT, class Traits, class Duration, class TimeZonePtr>
 std::basic_ostream<CharT, Traits>&
 to_stream(std::basic_ostream<CharT, Traits>& os, const CharT* fmt,
-          const zoned_time<Duration>& tp)
+          const zoned_time<Duration, TimeZonePtr>& tp)
 {
     auto const info = tp.get_info();
     return to_stream(os, fmt, tp.get_local_time(), &info.abbrev, &info.offset);
 }
 
-template <class CharT, class Traits, class Duration>
+template <class CharT, class Traits, class Duration, class TimeZonePtr>
 inline
 std::basic_ostream<CharT, Traits>&
-operator<<(std::basic_ostream<CharT, Traits>& os, const zoned_time<Duration>& t)
+operator<<(std::basic_ostream<CharT, Traits>& os, const zoned_time<Duration, TimeZonePtr>& t)
 {
     const CharT fmt[] = {'%', 'F', ' ', '%', 'T', ' ', '%', 'Z', CharT{}};
     return to_stream(os, fmt, t);