std::chrono::get_tzdb_list, std::chrono::get_tzdb, std::chrono::remote_version, std::chrono::reload_tzdb - cppreference.com (original) (raw)

std::chrono::tzdb_list& get_tzdb_list(); (1) (since C++20)
const std::chrono::tzdb& get_tzdb(); (2) (since C++20)
std::string remote_version(); (3) (since C++20)
const std::chrono::tzdb& reload_tzdb(); (4) (since C++20)

These functions provide access to the program-wide time zone database.

  1. Returns a reference to the global std::chrono::tzdb_list singleton. If this is the first access to the database, initialize the database. After the initialization, the database will hold a single initialized std::chrono::tzdb object. This function is thread-safe: concurrent calls to this function from multiple threads do not introduce a data race.

  2. Returns a reference to the first std::chrono::tzdb object held by the tzdb_list singleton. Equivalent to std::chrono::get_tzdb_list().front().

  3. Returns a string containing the latest remote database version.

  4. If remote_version() != get_tzdb().version, pushes a new tzdb object representing the remote database to the front of the tzdb_list singleton referenced by get_tzdb_list(). Otherwise there are no effects. No references, pointers or iterators are invalidated. Calling this function concurrently with get_tzdb_list().front() or get_tzdb_list().erase_after() does not introduce a data race.

[edit] Exceptions

  1. std::runtime_error if for any reason a reference to a tzdb_list containing one or more valid tzdb cannot be returned.

[edit] Return value

  1. A reference to the global std::chrono::tzdb_list singleton.

  2. std::chrono::get_tzdb_list().front().

  3. A string containing the latest remote database version.

  4. std::chrono::get_tzdb_list().front() (after any update made by this function).