std::chrono::file_clock::to_utc, std::chrono::file_clock::from_utc

template <class Duration>
static std::chrono::utc_time</*see below*/>
    to_utc(const std::chrono::file_time<Duration>& t);
 (1) (since C++20)
(optional) 
template <class Duration>
static std::chrono::file_time</*see below*/>
    from_utc(const std::chrono::utc_time<Duration>& t);
 (2) (since C++20)
(optional)
1) Converts the file_time t to a utc_time representing the same point in time.
2) Converts the utc_time t to a file_time representing the same point in time.

The duration of the return type is computed from Duration in an unspecified manner.

These function templates are optional: an implementation may choose to instead provide to_sys and from_sys.

Return value

1) A utc_time representing the same point in time as the argument.
2) A file_time representing the same point in time as the argument.

Notes

User code should usually use std::chrono::clock_cast, which provides a generic interface to convert time points between clocks, rather than call these functions directly.

See also

[static] (optional)
 converts between file_time and sys_time
(public static member function)
(C++20)
 convert time points of one clock to another
(function template)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/cpp/chrono/file_clock/to_from_utc