Struct timeout::Instant

pub struct Instant(_);

A measurement of a monotonically increasing clock. Opaque and useful only with Duration.

Instants are always guaranteed to be greater than any previously measured instant when created, and are often useful for tasks such as measuring benchmarks or timing how long an operation takes.

Note, however, that instants are not guaranteed to be steady. In other words, each tick of the underlying clock may not be the same length (e.g. some seconds may be longer than others). An instant may jump forwards or experience time dilation (slow down or speed up), but it will never go backwards.

Instants are opaque types that can only be compared to one another. There is no method to get "the number of seconds" from an instant. Instead, it only allows measuring the duration between two instants (or comparing two instants).

Example:

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

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

   // we sleep for 2 seconds
   sleep(Duration::new(2, 0));
   // it prints '2'
   println!("{}", now.elapsed().as_secs());
}

Methods

impl Instant

fn now() -> Instant

Returns an instant corresponding to "now".

Examples

use std::time::Instant;

let now = Instant::now();

fn duration_since(&self, earlier: Instant) -> Duration

Returns the amount of time elapsed from another instant to this one.

Panics

This function will panic if earlier is later than self, which should only be possible if earlier was created after self. Because Instant is monotonic, the only time that this should happen should be a bug.

Examples

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

let now = Instant::now();
sleep(Duration::new(1, 0));
let new_now = Instant::now();
println!("{:?}", new_now.duration_since(now));

fn elapsed(&self) -> Duration

Returns the amount of time elapsed since this instant was created.

Panics

This function may panic if the current time is earlier than this instant, which is something that can happen if an Instant is produced synthetically.

Examples

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

let instant = Instant::now();
let three_secs = Duration::from_secs(3);
sleep(three_secs);
assert!(instant.elapsed() >= three_secs);

Trait Implementations

impl Clone for Instant

fn clone(&self) -> Instant

impl SubAssign<Duration> for Instant

fn sub_assign(&mut self, other: Duration)

impl Add<Duration> for Instant

type Output = Instant

fn add(self, other: Duration) -> Instant

impl Debug for Instant

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

impl Eq for Instant

impl PartialOrd<Instant> for Instant

fn partial_cmp(&self, __arg_0: &Instant) -> Option<Ordering>

fn lt(&self, __arg_0: &Instant) -> bool

fn le(&self, __arg_0: &Instant) -> bool

fn gt(&self, __arg_0: &Instant) -> bool

fn ge(&self, __arg_0: &Instant) -> bool

impl PartialEq<Instant> for Instant

fn eq(&self, __arg_0: &Instant) -> bool

fn ne(&self, __arg_0: &Instant) -> bool

impl Sub<Instant> for Instant

type Output = Duration

fn sub(self, other: Instant) -> Duration

impl Sub<Duration> for Instant

type Output = Instant

fn sub(self, other: Duration) -> Instant

impl Ord for Instant

fn cmp(&self, __arg_0: &Instant) -> Ordering

impl AddAssign<Duration> for Instant

fn add_assign(&mut self, other: Duration)

impl Copy for Instant