Struct bitflags::__core::time::SystemTime [] [src]

pub struct SystemTime(_);
1.8.0
[]

A measurement of the system clock, useful for talking to external entities like the file system or other processes.

Distinct from the Instant type, this time measurement is not monotonic. This means that you can save a file to the file system, then save another file to the file system, and the second file has a SystemTime measurement earlier than the second. In other words, an operation that happens after another operation in real time may have an earlier SystemTime!

Consequently, comparing two SystemTime instances to learn about the duration between them returns a Result instead of an infallible Duration to indicate that this sort of time drift may happen and needs to be handled.

Although a SystemTime cannot be directly inspected, the UNIX_EPOCH constant is provided in this module as an anchor in time to learn information about a SystemTime. By calculating the duration from this fixed point in time, a SystemTime can be converted to a human-readable time, or perhaps some other string representation.

Example:

use std::time::{Duration, SystemTime};
use std::thread::sleep;

fn main() {
   let now = SystemTime::now();

   // we sleep for 2 seconds
   sleep(Duration::new(2, 0));
   match now.elapsed() {
       Ok(elapsed) => {
           // it prints '2'
           println!("{}", elapsed.as_secs());
       }
       Err(e) => {
           // an error occured!
           println!("Error: {:?}", e);
       }
   }
}