NAME¶

std::chrono::file_clock - std::chrono::file_clock

Synopsis¶

Defined in header <chrono>
using file_clock = /* see below */; (since C++20)

std::chrono::file_clock is an alias for the clock used for
std::filesystem::file_time_type. Its epoch is unspecified.

file_clock meets the TrivialClock requirements.

Time point family

Defined in namespace std::chrono
template<class Duration>
using file_time = std::chrono::time_point<std::chrono::file_clock, (since C++20)
Duration>;

operator<<(std::chrono::file_time) performs stream output on a file_time
(C++20) (function template)
from_stream(std::chrono::file_time) parses a file_time from a stream according to
(C++20) the provided format
(function template)
std::formatter<std::chrono::file_time> specialization of std::formatter that formats
(C++20) a file_time according to the provided format
(class template specialization)

Member types¶

Member type Definition
rep signed arithmetic type representing the number of ticks in the clock's
duration
period a std::ratio type representing the tick period of the clock, in seconds
duration std::chrono::duration<rep, period>, capable of representing negative
durations
time_point std::chrono::time_point<std::chrono::file_clock>

Member constants¶

true if the time between ticks is always constant, i.e.
constexpr bool is_steady calls to now() return values that increase monotonically
[static] even in case of some external clock adjustment, otherwise
false
(public static member constant)

Member functions¶

file_clock provides exactly one of the following two pairs of static member
functions:

* to_utc and from_utc; or
* to_sys and from_sys.

now returns a std::chrono::time_point representing the current point
[static] in time
(public static member function)
to_utc converts between file_time and utc_time
from_utc (public static member function)
[static] (optional)
to_sys converts between file_time and sys_time
from_sys (public static member function)
[static] (optional)