27 Time library [time]

27.11 Time zones [time.zone]

27.11.2 Time zone database [time.zone.db]

27.11.2.1 Class tzdb [time.zone.db.tzdb]

namespace std::chrono {
  struct tzdb {
    string                 version;
    vector<time_zone>      zones;
    vector<time_zone_link> links;
    vector<leap_second>    leap_seconds;

    const time_zone* locate_zone(string_view tz_name) const;
    const time_zone* current_zone() const;
  };
}
1
#
Each vector in a tzdb object is sorted to enable fast lookup.
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const time_zone* locate_zone(string_view tz_name) const;
2
#
Returns:
  • (2.1)
    If zones contains an element tz for which tz.name() == tz_­name, a pointer to tz;
  • (2.2)
    otherwise, if links contains an element tz_­l for which tz_­l.name() == tz_­name, then a pointer to the element tz of zones for which tz.name() == tz_­l.target().
[ Note
:
A time_­zone_­link specifies an alternative name for a time_­zone.
— end note
 ]
3
#
Throws: If a const time_­zone* cannot be found as described in the Returns: clause, throws a runtime_­error.
[ Note
:
On non-exceptional return, the return value is always a pointer to a valid time_­zone.
— end note
 ]
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const time_zone* current_zone() const;
4
#
Returns: A pointer to the time zone which the computer has set as its local time zone.