sans-io-time

Represent time as an abstract absolute value based on an arbitrary start point in a user-provided timeline.

Why?

1. no_std environments may require an implementation of Instant.
2. Network protocols may require that time continues during suspend of the OS which is not something that is guaranteed by std::time::Instant.
3. Other uses of std::time::Instant should not count time during suspend e.g. CPU process time.

The Instant type provided by this crate satisfies all of these constraints by only specifying the carriage of data. It does not specify how the current time is acquired or whether time continues during suspend. Both of these questions are required to be answered (or left unspecified) by the caller by either using std::time::Instant or std::time::SystemTime (with the "std" feature that is enabled by default), or converting from another source of time like boot-time.