std::chrono::file_clock::to_sys, std::chrono::file_clock::from_sys

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

Return value

1) A sys_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 utc_time
(public static member function)
(C++20)
 convert time points of one clock to another
(function template)

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