[time.zone] (original) (raw)
30.11.7.1 Overview [time.zone.zonedtime.overview]
namespace std::chrono { template<class Duration, class TimeZonePtr = const time_zone*> class zoned_time { public: using duration = common_type_t<Duration, seconds>;private: TimeZonePtr zone_; sys_time<duration> tp_; using traits = zoned_traits<TimeZonePtr>; public: zoned_time(); zoned_time(const zoned_time&) = default; zoned_time& operator=(const zoned_time&) = default; zoned_time(const sys_time<Duration>& st);explicit zoned_time(TimeZonePtr z);explicit zoned_time(string_view name);template<class Duration2> zoned_time(const zoned_time<Duration2, TimeZonePtr>& y); zoned_time(TimeZonePtr z, const sys_time<Duration>& st); zoned_time(string_view name, const sys_time<Duration>& st); zoned_time(TimeZonePtr z, const local_time<Duration>& tp); zoned_time(string_view name, const local_time<Duration>& tp); zoned_time(TimeZonePtr z, const local_time<Duration>& tp, choose c); zoned_time(string_view name, const local_time<Duration>& tp, choose c);template<class Duration2, class TimeZonePtr2> zoned_time(TimeZonePtr z, const zoned_time<Duration2, TimeZonePtr2>& y);template<class Duration2, class TimeZonePtr2> zoned_time(TimeZonePtr z, const zoned_time<Duration2, TimeZonePtr2>& y, choose);template<class Duration2, class TimeZonePtr2> zoned_time(string_view name, const zoned_time<Duration2, TimeZonePtr2>& y);template<class Duration2, class TimeZonePtr2> zoned_time(string_view name, const zoned_time<Duration2, TimeZonePtr2>& y, choose c); zoned_time& operator=(const sys_time<Duration>& st); zoned_time& operator=(const local_time<Duration>& lt);operator sys_time<duration>() const;explicit operator local_time<duration>() 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;}; zoned_time() -> zoned_time<seconds>;template<class Duration> zoned_time(sys_time<Duration>) -> zoned_time<common_type_t<Duration, seconds>>;template<class TimeZonePtrOrName> using time-zone-representation = conditional_t<is_convertible_v<TimeZonePtrOrName, string_view>,const time_zone*, remove_cvref_t<TimeZonePtrOrName>>;template<class TimeZonePtrOrName> zoned_time(TimeZonePtrOrName&&) -> zoned_time<seconds, _time-zone-representation_<TimeZonePtrOrName>>;template<class TimeZonePtrOrName, class Duration> zoned_time(TimeZonePtrOrName&&, sys_time<Duration>) -> zoned_time<common_type_t<Duration, seconds>,time-zone-representation<TimeZonePtrOrName>>;template<class TimeZonePtrOrName, class Duration> zoned_time(TimeZonePtrOrName&&, local_time<Duration>, choose = choose::earliest) -> zoned_time<common_type_t<Duration, seconds>,time-zone-representation<TimeZonePtrOrName>>;template<class Duration, class TimeZonePtrOrName, class TimeZonePtr2> zoned_time(TimeZonePtrOrName&&, zoned_time<Duration, TimeZonePtr2>, choose = choose::earliest) -> zoned_time<common_type_t<Duration, seconds>,time-zone-representation<TimeZonePtrOrName>>;}
zoned_time represents a logical pairing of a time_zone and a time_point with precision Duration.
zoned_time<Duration> maintains the invariant that it always refers to a valid time zone and represents a point in time that exists and is not ambiguous in that time zone.
If Duration is not a specialization of chrono::duration, the program is ill-formed.
Every constructor of zoned_time that accepts a string_view as its first parameter does not participate in class template argument deduction ([over.match.class.deduct]).
30.11.7.2 Constructors [time.zone.zonedtime.ctor]
Constraints: traits::default_zone() is a well-formed expression.
Effects: Initializes zone_ with traits::default_zone() and default constructs tp_.
zoned_time(const sys_time<Duration>& st);
Constraints: traits::default_zone() is a well-formed expression.
Effects: Initializes zone_ with traits::default_zone() and tp_ with st.
explicit zoned_time(TimeZonePtr z);
Preconditions: z refers to a time zone.
Effects: Initializes zone_ with std::move(z) and default constructs tp_.
explicit zoned_time(string_view name);
Constraints: traits::locate_zone(string_view{}) is a well-formed expression andzoned_time is constructible from the return type of traits::locate_zone(string_view{}).
Effects: Initializes zone_ with traits::locate_zone(name) and default constructs tp_.
template<class Duration2> zoned_time(const zoned_time<Duration2, TimeZonePtr>& y);
Constraints: is_convertible_v<sys_time<Duration2>, sys_time<Duration>> is true.
Effects: Initializes zone_ with y.zone_ and tp_ with y.tp_.
zoned_time(TimeZonePtr z, const sys_time<Duration>& st);
Preconditions: z refers to a time zone.
Effects: Initializes zone_ with std::move(z) and tp_ with st.
zoned_time(string_view name, const sys_time<Duration>& st);
Constraints: zoned_time is constructible from the return type of traits::locate_zone(name) and st.
Effects: Equivalent to construction with {traits::locate_zone(name), st}.
zoned_time(TimeZonePtr z, const local_time<Duration>& tp);
Constraints: is_convertible_v< decltype(declval<TimeZonePtr&>()->to_sys(local_time<Duration>{})), sys_time<duration>> is true.
Preconditions: z refers to a time zone.
Effects: Initializes zone_ with std::move(z) and tp_ with zone_->to_sys(tp).
zoned_time(string_view name, const local_time<Duration>& tp);
Constraints: zoned_time is constructible from the return type of traits::locate_zone(name) and tp.
Effects: Equivalent to construction with {traits::locate_zone(name), tp}.
zoned_time(TimeZonePtr z, const local_time<Duration>& tp, choose c);
Constraints: is_convertible_v< decltype(declval<TimeZonePtr&>()->to_sys(local_time<Duration>{}, choose::earliest)), sys_time<duration>> is true.
Preconditions: z refers to a time zone.
Effects: Initializes zone_ with std::move(z) and tp_ with zone_->to_sys(tp, c).
zoned_time(string_view name, const local_time<Duration>& tp, choose c);
Constraints: zoned_time is constructible from the return type of traits::locate_zone(name), local_time<Duration>, and choose.
Effects: Equivalent to construction with {traits::locate_zone(name), tp, c}.
template<class Duration2, class TimeZonePtr2> zoned_time(TimeZonePtr z, const zoned_time<Duration2, TimeZonePtr2>& y);
Constraints: is_convertible_v<sys_time<Duration2>, sys_time<Duration>> is true.
Preconditions: z refers to a valid time zone.
Effects: Initializes zone_ with std::move(z) and tp_ with y.tp_.
template<class Duration2, class TimeZonePtr2> zoned_time(TimeZonePtr z, const zoned_time<Duration2, TimeZonePtr2>& y, choose);
Constraints: is_convertible_v<sys_time<Duration2>, sys_time<Duration>> is true.
Preconditions: z refers to a valid time zone.
Effects: Equivalent to construction with {z, y}.
[Note 1:
The choose parameter has no effect.
— _end note_]
template<class Duration2, class TimeZonePtr2> zoned_time(string_view name, const zoned_time<Duration2, TimeZonePtr2>& y);
Constraints: zoned_time is constructible from the return type of traits::locate_zone(name) and the type zoned_time<Duration2, TimeZonePtr2>.
Effects: Equivalent to construction with {traits::locate_zone(name), y}.
template<class Duration2, class TimeZonePtr2> zoned_time(string_view name, const zoned_time<Duration2, TimeZonePtr2>& y, choose c);
Constraints: zoned_time is constructible from the return type of traits::locate_zone(name), the type zoned_time<Duration2, TimeZonePtr2>, and the type choose.
Effects: Equivalent to construction with {traits::locate_zone(name), y, c}.
[Note 2:
The choose parameter has no effect.
— _end note_]
30.11.7.3 Member functions [time.zone.zonedtime.members]
zoned_time& operator=(const sys_time<Duration>& st);
Effects: After assignment, get_sys_time() == st.
This assignment has no effect on the return value of get_time_zone().
zoned_time& operator=(const local_time<Duration>& lt);
Effects: After assignment, get_local_time() == lt.
This assignment has no effect on the return value of get_time_zone().
operator sys_time<duration>() const;
explicit operator local_time<duration>() const;
Returns: get_local_time().
TimeZonePtr get_time_zone() const;
local_time<duration> get_local_time() const;
Returns: zone_->to_local(tp_).
sys_time<duration> get_sys_time() const;
sys_info get_info() const;
Returns: zone_->get_info(tp_).
30.11.7.4 Non-member functions [time.zone.zonedtime.nonmembers]
template<class Duration1, class Duration2, class TimeZonePtr> bool operator==(const zoned_time<Duration1, TimeZonePtr>& x,const zoned_time<Duration2, TimeZonePtr>& y);
Returns: x.zone_ == y.zone_ && x.tp_ == y.tp_.
template<class charT, class traits, class Duration, class TimeZonePtr> basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os,const zoned_time<Duration, TimeZonePtr>& t);
Effects: Equivalent to:return os << format(os.getloc(), _STATICALLY-WIDEN_<charT>("{:L%F %T %Z}"), t);