cppdraft_translate/cppdraft/time/zone/db/list.md

[time.zone.db.list]

30 Time library [time]

30.11 Time zones [time.zone]

30.11.2 Time zone database [time.zone.db]

30.11.2.2 Class tzdb_list [time.zone.db.list]

namespace std::chrono {class tzdb_list {public: tzdb_list(const tzdb_list&) = delete; tzdb_list& operator=(const tzdb_list&) = delete; // unspecified additional constructorsclass const_iterator; const tzdb& front() const noexcept;

const_iterator erase_after(const_iterator p);

const_iterator begin() const noexcept; const_iterator end() const noexcept;

const_iterator cbegin() const noexcept; const_iterator cend() const noexcept; };}

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The tzdb_list database is a singleton; the unique object of type tzdb_list can be accessed via the get_tzdb_list() function.

[Note 1:

This access is only needed for those applications that need to have long uptimes and have a need to update the time zone database while running.

Other applications can implicitly access the front() of this list via the read-only namespace scope functionsget_tzdb(),locate_zone(), andcurrent_zone().

— end note]

The tzdb_list object contains a list of tzdb objects.

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tzdb_list​::​const_iterator is a constant iterator which meets the Cpp17ForwardIterator requirements and has a value type of tzdb.

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const tzdb& front() const noexcept;

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Synchronization: This operation is thread-safe with respect to reload_tzdb().

[Note 2:

reload_tzdb() pushes a new tzdb onto the front of this container.

— end note]

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Returns: A reference to the first tzdb in the container.

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const_iterator erase_after(const_iterator p);

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Preconditions: The iterator following p is dereferenceable.

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Effects: Erases the tzdb referred to by the iterator following p.

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Postconditions: No pointers, references, or iterators are invalidated except those referring to the erased tzdb.

[Note 3:

It is not possible to erase the tzdb referred to by begin().

— end note]

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Returns: An iterator pointing to the element following the one that was erased, or end() if no such element exists.

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Throws: Nothing.

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const_iterator begin() const noexcept;

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Returns: An iterator referring to the first tzdb in the container.

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const_iterator end() const noexcept;

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Returns: An iterator referring to the position one past the last tzdb in the container.

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const_iterator cbegin() const noexcept;

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Returns: begin().

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const_iterator cend() const noexcept;

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Returns: end().