std::chrono::get_tzdb_list,std::chrono::get_tzdb,std::chrono::remote_version, (3) - Linux Manuals

std::chrono::get_tzdb_list,std::chrono::get_tzdb,std::chrono::remote_version,: std::chrono::get_tzdb_list,std::chrono::get_tzdb,std::chrono::remote_version,

NAME

std::chrono::get_tzdb_list,std::chrono::get_tzdb,std::chrono::remote_version, - std::chrono::get_tzdb_list,std::chrono::get_tzdb,std::chrono::remote_version,

Synopsis

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.

Exceptions

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

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).