Struct easytime::Instant

pub struct Instant(_);

This is supported on crate feature std only.

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

Instants are always guaranteed to be no less 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).

The size of an Instant struct may vary depending on the target operating system.

OS-specific behaviors

An Instant is a wrapper around system-specific types and it may behave differently depending on the underlying operating system. For example, the following snippet is fine on Linux but fails and returns None on macOS:

use easytime::{Duration, Instant};

let now = Instant::now();
let max_nanoseconds = u64::MAX / 1_000_000_000;
let duration = Duration::new(max_nanoseconds, 0);
// Unlike `std::time::Instant`, it won't panic!
let result = now + duration;

#[cfg(target_os = "linux")]
assert!(result.is_some());
#[cfg(target_os = "macos")]
assert!(result.is_none());

Underlying System calls

See the standard library documentation for the system calls used to get the current time using now().

Implementations

impl Instant

pub fn now() -> Self

Returns an instant corresponding to “now”.

Examples

use easytime::Instant;

let now = Instant::now();

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

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

Examples

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

use easytime::Instant;

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

pub fn elapsed(&self) -> Duration

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

Examples

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

use easytime::Instant;

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

pub const fn is_some(&self) -> bool

Returns true if into_inner returns Some.

pub const fn is_none(&self) -> bool

Returns true if into_inner returns None.

pub const fn into_inner(self) -> Option<Instant>

Returns the contained std::time::Instant or None.

pub const fn unwrap_or(self, default: Instant) -> Instant

Returns the contained std::time::Instant or a default.

instant.unwrap_or(default) is equivalent to instant.into_inner().unwrap_or(default).

pub fn unwrap_or_else<F>(self, default: F) -> Instant where
    F: FnOnce() -> Instant, 

Returns the contained std::time::Instant or computes it from a closure.

instant.unwrap_or_else(default) is equivalent to instant.into_inner().unwrap_or_else(default).

Trait Implementations

impl Add<Duration> for Instant

type Output = Self

The resulting type after applying the + operator.

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

Performs the + operation.

impl Add<Duration> for Instant

type Output = Self

The resulting type after applying the + operator.

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

Performs the + operation.

impl AddAssign<Duration> for Instant

fn add_assign(&mut self, other: Duration)

Performs the += operation.

impl AddAssign<Duration> for Instant

fn add_assign(&mut self, other: Duration)

Performs the += operation.

impl Clone for Instant

fn clone(&self) -> Instant

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Instant

impl Debug for Instant

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

Formats the value using the given formatter.

impl Eq for Instant

impl From<Instant> for Instant

fn from(instant: Instant) -> Self

Performs the conversion.

impl From<Option<Instant>> for Instant

fn from(dur: Option<Instant>) -> Self

Performs the conversion.

impl Hash for Instant

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

Feeds this value into the given Hasher.

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

Feeds a slice of this type into the given Hasher.

impl Ord for Instant

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

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub 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 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 ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> 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.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

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

#[must_use]pub fn le(&self, other: &Rhs) -> bool

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

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

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

#[must_use]pub 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 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.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

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

#[must_use]pub fn le(&self, other: &Rhs) -> bool

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

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

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

#[must_use]pub 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 StructuralEq for Instant

impl StructuralPartialEq for Instant

impl Sub<Duration> for Instant

type Output = Self

The resulting type after applying the - operator.

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

Performs the - operation.

impl Sub<Duration> for Instant

type Output = Self

The resulting type after applying the - operator.

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

Performs the - operation.

impl Sub<Instant> for Instant

type Output = Duration

The resulting type after applying the - operator.

fn sub(self, other: Self) -> Self::Output

Performs the - operation.

impl Sub<Instant> for Instant

type Output = Duration

The resulting type after applying the - operator.

fn sub(self, other: Instant) -> Self::Output

Performs the - operation.

impl SubAssign<Duration> for Instant

fn sub_assign(&mut self, other: Duration)

Performs the -= operation.

impl SubAssign<Duration> for Instant

fn sub_assign(&mut self, other: Duration)

Performs the -= operation.