Struct time::Instant

pub struct Instant { /* private fields */ }

A measurement of a monotonically non-decreasing 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).

This implementation allows for operations with signed Durations, but is otherwise identical to std::time::Instant.

Implementations

impl Instant

pub fn now() -> Self

Returns an Instant corresponding to “now”.

println!("{:?}", Instant::now());

pub fn elapsed(self) -> Duration

Returns the amount of time elapsed since this instant was created. The duration will always be nonnegative if the instant is not synthetically created.

let instant = Instant::now();
thread::sleep(1.std_milliseconds());
assert!(instant.elapsed() >= 1.milliseconds());

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

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.

let now = Instant::now();
assert_eq!(
    now.checked_add(5.seconds()),
    Some(now + 5.seconds())
);
assert_eq!(
    now.checked_add((-5).seconds()),
    Some(now + (-5).seconds())
);

This function is only present when using rustc >= 1.34.0.

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

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.

let now = Instant::now();
assert_eq!(
    now.checked_sub(5.seconds()),
    Some(now - 5.seconds())
);
assert_eq!(
    now.checked_sub((-5).seconds()),
    Some(now - (-5).seconds())
);

This function is only present when using rustc >= 1.34.0.

Trait Implementations

impl Add<Duration> for Instant

type Output = Self

The resulting type after applying the + operator.

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

Performs the + operation.

impl Add<Duration> for Instant

type Output = Self

The resulting type after applying the + operator.

fn add(self, duration: StdDuration) -> Self::Output

Performs the + operation.

impl AddAssign<Duration> for Instant

fn add_assign(&mut self, duration: Duration)

Performs the += operation.

impl AddAssign<Duration> for Instant

fn add_assign(&mut self, duration: StdDuration)

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 From<Instant> for Instant

fn from(instant: StdInstant) -> Self

Performs the conversion.

impl From<Instant> for StdInstant

fn from(instant: Instant) -> Self

Performs the conversion.

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 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 PartialEq<Instant> for Instant

fn eq(&self, rhs: &StdInstant) -> bool

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

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

This method tests for !=.

impl PartialEq<Instant> for StdInstant

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

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

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.

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 PartialOrd<Instant> for Instant

fn partial_cmp(&self, rhs: &StdInstant) -> 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 PartialOrd<Instant> for StdInstant

fn partial_cmp(&self, rhs: &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 = Self

The resulting type after applying the - operator.

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

Performs the - operation.

impl Sub<Duration> for Instant

type Output = Self

The resulting type after applying the - operator.

fn sub(self, duration: StdDuration) -> 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: StdInstant) -> Self::Output

Performs the - operation.

impl Sub<Instant> for StdInstant

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, duration: Duration)

Performs the -= operation.

impl SubAssign<Duration> for Instant

fn sub_assign(&mut self, duration: StdDuration)

Performs the -= operation.

impl Copy for Instant

impl Eq for Instant

impl StructuralEq for Instant

impl StructuralPartialEq for Instant