Struct core::time::Duration

1.3.0 · source · [−]
pub struct Duration { /* private fields */ }
Expand description

A Duration type to represent a span of time, typically used for system timeouts.

Each Duration is composed of a whole number of seconds and a fractional part represented in nanoseconds. If the underlying system does not support nanosecond-level precision, APIs binding a system timeout will typically round up the number of nanoseconds.

Durations implement many common traits, including Add, Sub, and other ops traits. It implements Default by returning a zero-length Duration.

Examples

use std::time::Duration;

let five_seconds = Duration::new(5, 0);
let five_seconds_and_five_nanos = five_seconds + Duration::new(0, 5);

assert_eq!(five_seconds_and_five_nanos.as_secs(), 5);
assert_eq!(five_seconds_and_five_nanos.subsec_nanos(), 5);

let ten_millis = Duration::from_millis(10);
Run

Formatting Duration values

Duration intentionally does not have a Display impl, as there are a variety of ways to format spans of time for human readability. Duration provides a Debug impl that shows the full precision of the value.

The Debug output uses the non-ASCII “µs” suffix for microseconds. If your program output may appear in contexts that cannot rely on full Unicode compatibility, you may wish to format Duration objects yourself or use a crate to do so.

Implementations

🔬This is a nightly-only experimental API. (duration_constants #57391)

The duration of one second.

Examples
#![feature(duration_constants)]
use std::time::Duration;

assert_eq!(Duration::SECOND, Duration::from_secs(1));
Run
🔬This is a nightly-only experimental API. (duration_constants #57391)

The duration of one millisecond.

Examples
#![feature(duration_constants)]
use std::time::Duration;

assert_eq!(Duration::MILLISECOND, Duration::from_millis(1));
Run
🔬This is a nightly-only experimental API. (duration_constants #57391)

The duration of one microsecond.

Examples
#![feature(duration_constants)]
use std::time::Duration;

assert_eq!(Duration::MICROSECOND, Duration::from_micros(1));
Run
🔬This is a nightly-only experimental API. (duration_constants #57391)

The duration of one nanosecond.

Examples
#![feature(duration_constants)]
use std::time::Duration;

assert_eq!(Duration::NANOSECOND, Duration::from_nanos(1));
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A duration of zero time.

Examples
use std::time::Duration;

let duration = Duration::ZERO;
assert!(duration.is_zero());
assert_eq!(duration.as_nanos(), 0);
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The maximum duration.

May vary by platform as necessary. Must be able to contain the difference between two instances of Instant or two instances of SystemTime. This constraint gives it a value of about 584,942,417,355 years in practice, which is currently used on all platforms.

Examples
use std::time::Duration;

assert_eq!(Duration::MAX, Duration::new(u64::MAX, 1_000_000_000 - 1));
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Creates a new Duration from the specified number of whole seconds and additional nanoseconds.

If the number of nanoseconds is greater than 1 billion (the number of nanoseconds in a second), then it will carry over into the seconds provided.

Panics

This constructor will panic if the carry from the nanoseconds overflows the seconds counter.

Examples
use std::time::Duration;

let five_seconds = Duration::new(5, 0);
Run

Creates a new Duration from the specified number of whole seconds.

Examples
use std::time::Duration;

let duration = Duration::from_secs(5);

assert_eq!(5, duration.as_secs());
assert_eq!(0, duration.subsec_nanos());
Run

Creates a new Duration from the specified number of milliseconds.

Examples
use std::time::Duration;

let duration = Duration::from_millis(2569);

assert_eq!(2, duration.as_secs());
assert_eq!(569_000_000, duration.subsec_nanos());
Run

Creates a new Duration from the specified number of microseconds.

Examples
use std::time::Duration;

let duration = Duration::from_micros(1_000_002);

assert_eq!(1, duration.as_secs());
assert_eq!(2000, duration.subsec_nanos());
Run

Creates a new Duration from the specified number of nanoseconds.

Examples
use std::time::Duration;

let duration = Duration::from_nanos(1_000_000_123);

assert_eq!(1, duration.as_secs());
assert_eq!(123, duration.subsec_nanos());
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Returns true if this Duration spans no time.

Examples
use std::time::Duration;

assert!(Duration::ZERO.is_zero());
assert!(Duration::new(0, 0).is_zero());
assert!(Duration::from_nanos(0).is_zero());
assert!(Duration::from_secs(0).is_zero());

assert!(!Duration::new(1, 1).is_zero());
assert!(!Duration::from_nanos(1).is_zero());
assert!(!Duration::from_secs(1).is_zero());
Run

Returns the number of whole seconds contained by this Duration.

The returned value does not include the fractional (nanosecond) part of the duration, which can be obtained using subsec_nanos.

Examples
use std::time::Duration;

let duration = Duration::new(5, 730023852);
assert_eq!(duration.as_secs(), 5);
Run

To determine the total number of seconds represented by the Duration including the fractional part, use as_secs_f64 or as_secs_f32

Returns the fractional part of this Duration, in whole milliseconds.

This method does not return the length of the duration when represented by milliseconds. The returned number always represents a fractional portion of a second (i.e., it is less than one thousand).

Examples
use std::time::Duration;

let duration = Duration::from_millis(5432);
assert_eq!(duration.as_secs(), 5);
assert_eq!(duration.subsec_millis(), 432);
Run

Returns the fractional part of this Duration, in whole microseconds.

This method does not return the length of the duration when represented by microseconds. The returned number always represents a fractional portion of a second (i.e., it is less than one million).

Examples
use std::time::Duration;

let duration = Duration::from_micros(1_234_567);
assert_eq!(duration.as_secs(), 1);
assert_eq!(duration.subsec_micros(), 234_567);
Run

Returns the fractional part of this Duration, in nanoseconds.

This method does not return the length of the duration when represented by nanoseconds. The returned number always represents a fractional portion of a second (i.e., it is less than one billion).

Examples
use std::time::Duration;

let duration = Duration::from_millis(5010);
assert_eq!(duration.as_secs(), 5);
assert_eq!(duration.subsec_nanos(), 10_000_000);
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Returns the total number of whole milliseconds contained by this Duration.

Examples
use std::time::Duration;

let duration = Duration::new(5, 730023852);
assert_eq!(duration.as_millis(), 5730);
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Returns the total number of whole microseconds contained by this Duration.

Examples
use std::time::Duration;

let duration = Duration::new(5, 730023852);
assert_eq!(duration.as_micros(), 5730023);
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Returns the total number of nanoseconds contained by this Duration.

Examples
use std::time::Duration;

let duration = Duration::new(5, 730023852);
assert_eq!(duration.as_nanos(), 5730023852);
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Checked Duration addition. Computes self + other, returning None if overflow occurred.

Examples

Basic usage:

use std::time::Duration;

assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
assert_eq!(Duration::new(1, 0).checked_add(Duration::new(u64::MAX, 0)), None);
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Saturating Duration addition. Computes self + other, returning Duration::MAX if overflow occurred.

Examples
#![feature(duration_constants)]
use std::time::Duration;

assert_eq!(Duration::new(0, 0).saturating_add(Duration::new(0, 1)), Duration::new(0, 1));
assert_eq!(Duration::new(1, 0).saturating_add(Duration::new(u64::MAX, 0)), Duration::MAX);
Run

Checked Duration subtraction. Computes self - other, returning None if the result would be negative or if overflow occurred.

Examples

Basic usage:

use std::time::Duration;

assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
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Saturating Duration subtraction. Computes self - other, returning Duration::ZERO if the result would be negative or if overflow occurred.

Examples
use std::time::Duration;

assert_eq!(Duration::new(0, 1).saturating_sub(Duration::new(0, 0)), Duration::new(0, 1));
assert_eq!(Duration::new(0, 0).saturating_sub(Duration::new(0, 1)), Duration::ZERO);
Run

Checked Duration multiplication. Computes self * other, returning None if overflow occurred.

Examples

Basic usage:

use std::time::Duration;

assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
assert_eq!(Duration::new(u64::MAX - 1, 0).checked_mul(2), None);
Run

Saturating Duration multiplication. Computes self * other, returning Duration::MAX if overflow occurred.

Examples
#![feature(duration_constants)]
use std::time::Duration;

assert_eq!(Duration::new(0, 500_000_001).saturating_mul(2), Duration::new(1, 2));
assert_eq!(Duration::new(u64::MAX - 1, 0).saturating_mul(2), Duration::MAX);
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Checked Duration division. Computes self / other, returning None if other == 0.

Examples

Basic usage:

use std::time::Duration;

assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
assert_eq!(Duration::new(2, 0).checked_div(0), None);
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Returns the number of seconds contained by this Duration as f64.

The returned value does include the fractional (nanosecond) part of the duration.

Examples
use std::time::Duration;

let dur = Duration::new(2, 700_000_000);
assert_eq!(dur.as_secs_f64(), 2.7);
Run

Returns the number of seconds contained by this Duration as f32.

The returned value does include the fractional (nanosecond) part of the duration.

Examples
use std::time::Duration;

let dur = Duration::new(2, 700_000_000);
assert_eq!(dur.as_secs_f32(), 2.7);
Run

Creates a new Duration from the specified number of seconds represented as f64.

Panics

This constructor will panic if secs is negative, overflows Duration or not finite.

Examples
use std::time::Duration;

let res = Duration::from_secs_f64(0.0);
assert_eq!(res, Duration::new(0, 0));
let res = Duration::from_secs_f64(1e-20);
assert_eq!(res, Duration::new(0, 0));
let res = Duration::from_secs_f64(4.2e-7);
assert_eq!(res, Duration::new(0, 420));
let res = Duration::from_secs_f64(2.7);
assert_eq!(res, Duration::new(2, 700_000_000));
let res = Duration::from_secs_f64(3e10);
assert_eq!(res, Duration::new(30_000_000_000, 0));
// subnormal float
let res = Duration::from_secs_f64(f64::from_bits(1));
assert_eq!(res, Duration::new(0, 0));
// conversion uses rounding
let res = Duration::from_secs_f64(0.999e-9);
assert_eq!(res, Duration::new(0, 1));
Run

Creates a new Duration from the specified number of seconds represented as f32.

Panics

This constructor will panic if secs is negative, overflows Duration or not finite.

Examples
use std::time::Duration;

let res = Duration::from_secs_f32(0.0);
assert_eq!(res, Duration::new(0, 0));
let res = Duration::from_secs_f32(1e-20);
assert_eq!(res, Duration::new(0, 0));
let res = Duration::from_secs_f32(4.2e-7);
assert_eq!(res, Duration::new(0, 420));
let res = Duration::from_secs_f32(2.7);
assert_eq!(res, Duration::new(2, 700_000_048));
let res = Duration::from_secs_f32(3e10);
assert_eq!(res, Duration::new(30_000_001_024, 0));
// subnormal float
let res = Duration::from_secs_f32(f32::from_bits(1));
assert_eq!(res, Duration::new(0, 0));
// conversion uses rounding
let res = Duration::from_secs_f32(0.999e-9);
assert_eq!(res, Duration::new(0, 1));
Run

Multiplies Duration by f64.

Panics

This method will panic if result is negative, overflows Duration or not finite.

Examples
use std::time::Duration;

let dur = Duration::new(2, 700_000_000);
assert_eq!(dur.mul_f64(3.14), Duration::new(8, 478_000_000));
assert_eq!(dur.mul_f64(3.14e5), Duration::new(847_800, 0));
Run

Multiplies Duration by f32.

Panics

This method will panic if result is negative, overflows Duration or not finite.

Examples
use std::time::Duration;

let dur = Duration::new(2, 700_000_000);
assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_641));
assert_eq!(dur.mul_f32(3.14e5), Duration::new(847800, 0));
Run

Divide Duration by f64.

Panics

This method will panic if result is negative, overflows Duration or not finite.

Examples
use std::time::Duration;

let dur = Duration::new(2, 700_000_000);
assert_eq!(dur.div_f64(3.14), Duration::new(0, 859_872_611));
assert_eq!(dur.div_f64(3.14e5), Duration::new(0, 8_599));
Run

Divide Duration by f32.

Panics

This method will panic if result is negative, overflows Duration or not finite.

Examples
use std::time::Duration;

let dur = Duration::new(2, 700_000_000);
// note that due to rounding errors result is slightly
// different from 0.859_872_611
assert_eq!(dur.div_f32(3.14), Duration::new(0, 859_872_580));
assert_eq!(dur.div_f32(3.14e5), Duration::new(0, 8_599));
Run
🔬This is a nightly-only experimental API. (div_duration #63139)

Divide Duration by Duration and return f64.

Examples
#![feature(div_duration)]
use std::time::Duration;

let dur1 = Duration::new(2, 700_000_000);
let dur2 = Duration::new(5, 400_000_000);
assert_eq!(dur1.div_duration_f64(dur2), 0.5);
Run
🔬This is a nightly-only experimental API. (div_duration #63139)

Divide Duration by Duration and return f32.

Examples
#![feature(div_duration)]
use std::time::Duration;

let dur1 = Duration::new(2, 700_000_000);
let dur2 = Duration::new(5, 400_000_000);
assert_eq!(dur1.div_duration_f32(dur2), 0.5);
Run

The checked version of from_secs_f32.

This constructor will return an Err if secs is negative, overflows Duration or not finite.

Examples
use std::time::Duration;

let res = Duration::try_from_secs_f32(0.0);
assert_eq!(res, Ok(Duration::new(0, 0)));
let res = Duration::try_from_secs_f32(1e-20);
assert_eq!(res, Ok(Duration::new(0, 0)));
let res = Duration::try_from_secs_f32(4.2e-7);
assert_eq!(res, Ok(Duration::new(0, 420)));
let res = Duration::try_from_secs_f32(2.7);
assert_eq!(res, Ok(Duration::new(2, 700_000_048)));
let res = Duration::try_from_secs_f32(3e10);
assert_eq!(res, Ok(Duration::new(30_000_001_024, 0)));
// subnormal float:
let res = Duration::try_from_secs_f32(f32::from_bits(1));
assert_eq!(res, Ok(Duration::new(0, 0)));

let res = Duration::try_from_secs_f32(-5.0);
assert!(res.is_err());
let res = Duration::try_from_secs_f32(f32::NAN);
assert!(res.is_err());
let res = Duration::try_from_secs_f32(2e19);
assert!(res.is_err());

// the conversion uses rounding with tie resolution to even
let res = Duration::try_from_secs_f32(0.999e-9);
assert_eq!(res, Ok(Duration::new(0, 1)));

// this float represents exactly 976562.5e-9
let val = f32::from_bits(0x3A80_0000);
let res = Duration::try_from_secs_f32(val);
assert_eq!(res, Ok(Duration::new(0, 976_562)));

// this float represents exactly 2929687.5e-9
let val = f32::from_bits(0x3B40_0000);
let res = Duration::try_from_secs_f32(val);
assert_eq!(res, Ok(Duration::new(0, 2_929_688)));

// this float represents exactly 1.000_976_562_5
let val = f32::from_bits(0x3F802000);
let res = Duration::try_from_secs_f32(val);
assert_eq!(res, Ok(Duration::new(1, 976_562)));

// this float represents exactly 1.002_929_687_5
let val = f32::from_bits(0x3F806000);
let res = Duration::try_from_secs_f32(val);
assert_eq!(res, Ok(Duration::new(1, 2_929_688)));
Run

The checked version of from_secs_f64.

This constructor will return an Err if secs is negative, overflows Duration or not finite.

Examples
use std::time::Duration;

let res = Duration::try_from_secs_f64(0.0);
assert_eq!(res, Ok(Duration::new(0, 0)));
let res = Duration::try_from_secs_f64(1e-20);
assert_eq!(res, Ok(Duration::new(0, 0)));
let res = Duration::try_from_secs_f64(4.2e-7);
assert_eq!(res, Ok(Duration::new(0, 420)));
let res = Duration::try_from_secs_f64(2.7);
assert_eq!(res, Ok(Duration::new(2, 700_000_000)));
let res = Duration::try_from_secs_f64(3e10);
assert_eq!(res, Ok(Duration::new(30_000_000_000, 0)));
// subnormal float
let res = Duration::try_from_secs_f64(f64::from_bits(1));
assert_eq!(res, Ok(Duration::new(0, 0)));

let res = Duration::try_from_secs_f64(-5.0);
assert!(res.is_err());
let res = Duration::try_from_secs_f64(f64::NAN);
assert!(res.is_err());
let res = Duration::try_from_secs_f64(2e19);
assert!(res.is_err());

// the conversion uses rounding with tie resolution to even
let res = Duration::try_from_secs_f64(0.999e-9);
assert_eq!(res, Ok(Duration::new(0, 1)));
let res = Duration::try_from_secs_f64(0.999_999_999_499);
assert_eq!(res, Ok(Duration::new(0, 999_999_999)));
let res = Duration::try_from_secs_f64(0.999_999_999_501);
assert_eq!(res, Ok(Duration::new(1, 0)));
let res = Duration::try_from_secs_f64(42.999_999_999_499);
assert_eq!(res, Ok(Duration::new(42, 999_999_999)));
let res = Duration::try_from_secs_f64(42.999_999_999_501);
assert_eq!(res, Ok(Duration::new(43, 0)));

// this float represents exactly 976562.5e-9
let val = f64::from_bits(0x3F50_0000_0000_0000);
let res = Duration::try_from_secs_f64(val);
assert_eq!(res, Ok(Duration::new(0, 976_562)));

// this float represents exactly 2929687.5e-9
let val = f64::from_bits(0x3F68_0000_0000_0000);
let res = Duration::try_from_secs_f64(val);
assert_eq!(res, Ok(Duration::new(0, 2_929_688)));

// this float represents exactly 1.000_976_562_5
let val = f64::from_bits(0x3FF0_0400_0000_0000);
let res = Duration::try_from_secs_f64(val);
assert_eq!(res, Ok(Duration::new(1, 976_562)));

// this float represents exactly 1.002_929_687_5
let val = f64::from_bits(0x3_FF00_C000_0000_000);
let res = Duration::try_from_secs_f64(val);
assert_eq!(res, Ok(Duration::new(1, 2_929_688)));
Run

Trait Implementations

The resulting type after applying the + operator.
Performs the + operation. Read more
Performs the += operation. Read more
Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Returns the “default value” for a type. Read more
The resulting type after applying the / operator.
Performs the / operation. Read more
Performs the /= operation. Read more
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
The resulting type after applying the * operator.
Performs the * operation. Read more
The resulting type after applying the * operator.
Performs the * operation. Read more
Performs the *= operation. Read more
This method returns an Ordering between self and other. Read more
Compares and returns the maximum of two values. Read more
Compares and returns the minimum of two values. Read more
Restrict a value to a certain interval. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
The resulting type after applying the - operator.
Performs the - operation. Read more
Performs the -= operation. Read more
Method which takes an iterator and generates Self from the elements by “summing up” the items. Read more
Method which takes an iterator and generates Self from the elements by “summing up” the items. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.
This documentation is an old archive. Please see https://rust.docs.kernel.org instead.