Linux Manuals session 3

std::chrono::weekday::operator+=,std::chrono::weekday::operator-= – std::chrono::weekday::operator+=,std::chrono::weekday::operator-= Synopsis constexpr std::chrono::weekday &operator+=(const std::chrono::days &d) noexcept; (1)(since C++ 20) constexpr std::chrono::weekday & operator-=(const std::chrono::days &d) noexcept; (2) (since C++20) Adds or subtracts d.count() from the weekday value, reducing the result modulo 7 to an integer in the range [0, 6]. 1) Performs *this = *this + d; 2) Performs *this =…

std::chrono::weekday::operator++,std::chrono::weekday::operator– – std::chrono::weekday::operator++,std::chrono::weekday::operator– Synopsis constexpr std::chrono::weekday& operator++() noexcept; (1) (since C++20) constexpr std::chrono::weekday operator++(int) noexcept; (2) (since C++20) constexpr std::chrono::weekday& operator–() noexcept; (3) (since C++20) constexpr std::chrono::weekday operator–(int) noexcept; (4) (since C++20) Adds or subtracts 1 from the weekday value, reducing the result modulo 7 to an integer in the range [0, 6]. 1-2) Performs…

std::chrono::weekday::ok – std::chrono::weekday::ok Synopsis constexpr bool ok() const noexcept; (since C++20) Checks if the weekday value stored in *this is in the valid range, i.e., [0, 6]. Return value true if the weekday value stored in *this is in the range [0, 6]. Otherwise false.

std::chrono::weekday – std::chrono::weekday Synopsis Defined in header <chrono> class weekday; (since C++20) inline constexpr std::chrono::weekday Sunday{0}; (since C++20) inline constexpr std::chrono::weekday Monday{1}; (since C++20) inline constexpr std::chrono::weekday Tuesday{2}; (since C++20) inline constexpr std::chrono::weekday Wednesday{3}; (since C++20) inline constexpr std::chrono::weekday Thursday{4}; (since C++20) inline constexpr std::chrono::weekday Friday{5}; (since C++20) inline constexpr std::chrono::weekday Saturday{6}; (since C++20) The…

std::chrono::utc_clock::to_sys – std::chrono::utc_clock::to_sys Synopsis template <class Duration> static std::chrono::sys_time<std::common_type_t<Duration, std::chrono::seconds>>(since C++ 20) to_sys(const std::chrono::utc_time<Duration> &t); Converts a utc_time t to a sys_time representing the same point in time (if possible). If t represents a time point during a leap second insertion, the last representable value of sys_time prior to the insertion of the leap second…

std::chrono::utc_clock::now – std::chrono::utc_clock::now Synopsis static std::chrono::time_point<std::chrono::utc_clock> now(); (since C++20) Returns a time point representing the current point in time. The result is calculated as if by std::chrono::utc_clock::from_sys(std::chrono::system_clock::now()). Implementations may use a more accurate value of UTC time. Parameters (none) Return value A time point representing the current time. Example // Run this code #include <iostream>…

std::chrono::utc_clock::from_sys – std::chrono::utc_clock::from_sys Synopsis template <class Duration> static std::chrono::utc_time<std::common_type_t<Duration, std::chrono::seconds>>(since C++ 20) from_sys(const std::chrono::sys_time<Duration> &t); Converts a sys_time t to a utc_time u that represents the same point in time. u.time_since_epoch() – t.time_since_epoch() is equal to the number of leap seconds that was inserted between t and 1 January 1970. If t is the exact…

std::chrono::utc_clock – std::chrono::utc_clock Synopsis Defined in header <chrono> class utc_clock; (since C++20) The clock std::chrono::utc_clock is a Clock that represents Coordinated Universal Time (UTC). It measures time since 00:00:00 UTC, Thursday, 1 January 1970, including leap seconds. utc_clock meets the Clock requirements. It does not meet the TrivialClock requirements unless the implementation can guarantee that…

std::chrono::tzdb_list::front – std::chrono::tzdb_list::front Synopsis const std::chrono::tzdb &front() const noexcept; (since C++ 20) Obtains a reference to the first std::chrono::tzdb in the list. Simultaneous calls to this function and std::chrono::reload_tzdb() does not introduce a data race.

std::chrono::tzdb_list::erase_after – std::chrono::tzdb_list::erase_after Synopsis const_iterator erase_after(const_iterator p); (since C++20) Erases the std::chrono::tzdb referred to by the iterator following p. The behavior is undefined if that iterator is not dereferenceable. No pointers, references, or iterators are invalidated except for those referring to the erased element. Return value An iterator pointing to the element following the erased…

std::chrono::tzdb_list::end,std::chrono::tzdb_list::cend – std::chrono::tzdb_list::end,std::chrono::tzdb_list::cend Synopsis const_iterator end() const noexcept; (since C++20) const_iterator cend() const noexcept; (since C++20) Returns the past-the-end iterator of the tzdb_list. Attempting to dereference this iterator results in undefined behavior. Return value The past-the-end iterator.

std::chrono::tzdb_list::begin – std::chrono::tzdb_list::begin Synopsis const_iterator begin() const noexcept; (since C++20) const_iterator cbegin() const noexcept; (since C++20) Returns an iterator referring to the first std::chrono::tzdb in the container. Return value An iterator referring to the first std::chrono::tzdb in the container.

std::chrono::tzdb_list – std::chrono::tzdb_list Synopsis Defined in header <chrono> class tzdb_list; (since C++20) tzdb_list is a singleton list of std::chrono::tzdbs, each of which represents a copy of the IANA time zone database. Users cannot construct a tzdb_list and can only obtain access to one via the std::chrono::get_tzdb_list free function. Member types Member type Definition const_iterator constant…

std::chrono::tzdb::locate_zone – std::chrono::tzdb::locate_zone Synopsis const std::chrono::time_zone *locate_zone(std::string_view tz_name) const; (since C++ 20) Obtains a pointer to a std::chrono::time_zone in this database that represents the time zone designated by tz_name. If p is the returned pointer, then either p->name() == tz_name or that there is a std::chrono::link l in this database such that p->name() == l.target()…

std::chrono::tzdb::current_zone – std::chrono::tzdb::current_zone Synopsis const std::chrono::time_zone *current_zone() const; (since C++ 20) Obtains a pointer to a std::chrono::time_zone in this database that represents the local time zone of the computer. Return value A pointer to the std::chrono::time_zone in this database that represents the local time zone of the computer.

std::chrono::tzdb – std::chrono::tzdb Synopsis Defined in header <chrono> struct tzdb; (since C++20) The class tzdb represents a copy of the IANA_time_zone_database. Users cannot construct a tzdb and can only obtain read-only access to one via the free functions std::chrono::get_tzdb_list and std::chrono::get_tzdb. Member objects Member object Description version A std::string that contains the version of the…

std::chrono::treat_as_floating_point – std::chrono::treat_as_floating_point Synopsis Defined in header<chrono> template <class Rep> (since C++ 11) struct treat_as_floating_point : std::is_floating_point<Rep> { }; The std::chrono::treat_as_floating_point trait helps determine if a duration can be converted to another duration with a different tick period. Implicit conversions between two durations normally depends on the tick period of the durations. However, implicit conversions…

std::chrono::to_stream(std::chrono::zoned_time) – std::chrono::to_stream(std::chrono::zoned_time) Synopsis template <class CharT, class Traits, class Duration, class TimeZonePtr> std::basic_ostream<CharT, Traits> &(since C++ 20) to_stream(std::basic_ostream<CharT, Traits> &os, const CharT *fmt, const std::chrono::zoned_time<Duration, TimeZonePtr> &tp); Outputs tp to the stream os, formatted according to the null-terminated format string fmt. Equivalent to auto info = tp.get_info(); return std::chrono::to_stream(os, fmt, tp.get_local_time(), &info.abbrev, &info.offset); Format…

std::chrono::to_stream(std::chrono::year_month_day) – std::chrono::to_stream(std::chrono::year_month_day) Synopsis template <class CharT, class Traits> std::basic_ostream<CharT, Traits> &(since C++ 20) to_stream(std::basic_ostream<CharT, Traits> &os, const CharT *fmt, const std::chrono::year_month_day &ymd); Outputs ymd to the stream os, formatted according to the null-terminated format string fmt. Format string The format string consists of zero or more conversion specifiers and ordinary characters. All ordinary characters,…

std::chrono::to_stream(std::chrono::year_month) – std::chrono::to_stream(std::chrono::year_month) Synopsis template <class CharT, class Traits> std::basic_ostream<CharT, Traits> &(since C++ 20) to_stream(std::basic_ostream<CharT, Traits> &os, const CharT *fmt, const std::chrono::year_month &ym); Outputs ym to the stream os, formatted according to the null-terminated format string fmt. Format string The format string consists of zero or more conversion specifiers and ordinary characters. All ordinary characters,…