Struct futures_time::time::Instant

pub struct Instant(_);

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

This type wraps std::time::Duration so we can implement traits on it without coherence issues, just like if we were implementing this in the stdlib.

Implementations

impl Instant

pub fn now() -> Self

Returns an instant corresponding to “now”.

Examples

use futures_time::time::Instant;

let now = Instant::now();

Methods from Deref<Target = Instant>

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

Returns the amount of time elapsed from another instant to this one, or zero duration if that instant is later than this one.

Panics

Previous rust versions panicked when earlier was later than self. Currently this method saturates. Future versions may reintroduce the panic in some circumstances. See Monotonicity.

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));
println!("{:?}", now.duration_since(new_now)); // 0ns

pub fn checked_duration_since(&self, earlier: Instant) -> Option<Duration>

Returns the amount of time elapsed from another instant to this one, or None if that instant is later than this one.

Due to monotonicity bugs, even under correct logical ordering of the passed Instants, this method can return None.

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.checked_duration_since(now));
println!("{:?}", now.checked_duration_since(new_now)); // None

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

Returns the amount of time elapsed from another instant to this one, or zero duration if that instant is later than this one.

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.saturating_duration_since(now));
println!("{:?}", now.saturating_duration_since(new_now)); // 0ns

pub fn elapsed(&self) -> Duration

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

Panics

Previous rust versions panicked when self was earlier than the current time. Currently this method returns a Duration of zero in that case. Future versions may reintroduce the panic. See Monotonicity.

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);

pub fn checked_add(&self, duration: Duration) -> Option<Instant>

Returns Some(t) where t is the time self + duration if t can be represented as Instant (which means it’s inside the bounds of the underlying data structure), None otherwise.

pub fn checked_sub(&self, duration: Duration) -> Option<Instant>

Returns Some(t) where t is the time self - duration if t can be represented as Instant (which means it’s inside the bounds of the underlying data structure), None otherwise.

Trait Implementations

impl Add<Duration> for Instant

type Output = Instant

The resulting type after applying the + operator.

fn add(self, rhs: Duration) -> Self::Output

Performs the + operation.

impl AddAssign<Duration> for Instant

fn add_assign(&mut self, rhs: Duration)

Performs the += operation.

impl Clone for Instant

fn clone(&self) -> Instant

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Instant

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

Formats the value using the given formatter.

impl Deref for Instant

type Target = Instant

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for Instant

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl From<Instant> for Instant

fn from(inner: Instant) -> Self

Converts to this type from the input type.

impl Hash for Instant

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl Into<Instant> for Instant

fn into(self) -> Instant

Converts this type into the (usually inferred) input type.

impl IntoFuture for Instant

type Output = Instant

The output that the future will produce on completion.

type IntoFuture = SleepUntil

Which kind of future are we turning this into?

fn into_future(self) -> Self::IntoFuture

Creates a future from a value.

impl Ord for Instant

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

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Instant> for Instant

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialOrd<Instant> for Instant

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

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Sub<Duration> for Instant

type Output = Instant

The resulting type after applying the - operator.

fn sub(self, rhs: Duration) -> Self::Output

Performs the - operation.

impl SubAssign<Duration> for Instant

fn sub_assign(&mut self, rhs: Duration)

Performs the -= operation.

impl Copy for Instant

impl Eq for Instant

impl StructuralEq for Instant

impl StructuralPartialEq for Instant