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Section: 29.11.7.2 [time.zone.zonedtime.ctor] Status: C++20 Submitter: Tomasz Kamiński Opened: 2019-06-20 Last modified: 2021-02-25
Priority: 0
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Discussion:
The zoned_time constructor from zoned_time<Duration2,
TimeZonePtr> (preserving same time zone, different precision of
representation) is currently marked noexcept. Given that the exposition-only
member tp_ of type sys_time<duration> has essentially type
time_point<system_clock, Duration>, this is incompatible with the
invoked time_point constructor, which is not marked as noexcept.
[2019-07 Issue Prioritization]
Status to Tentatively Ready after five positive votes on the reflector.
Proposed resolution:
This wording is relative to N4820.
Modify 29.11.7.1 [time.zone.zonedtime.overview], class template zoned_time synopsis, as indicated:
template<class Duration2> zoned_time(const zoned_time<Duration2, TimeZonePtr>& zt)noexcept;
Modify 29.11.7.2 [time.zone.zonedtime.ctor] as indicated:
template<class Duration2> zoned_time(const zoned_time<Duration2, TimeZonePtr>& y)noexcept;-9- Requires: Does not participate in overload resolution unless sys_time<Duration2> is implicitly convertible to sys_time<Duration>.
-10- Effects: Constructs a zoned_time by initializing zone_ with y.zone_ and tp_ with y.tp_.