1 #![stable(feature = "duration_core", since = "1.25.0")]
3 //! Temporal quantification.
8 //! use std::time::Duration;
10 //! let five_seconds = Duration::new(5, 0);
11 //! // both declarations are equivalent
12 //! assert_eq!(Duration::new(5, 0), Duration::from_secs(5));
17 use crate::ops
::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign}
;
19 const NANOS_PER_SEC
: u32 = 1_000_000_000;
20 const NANOS_PER_MILLI
: u32 = 1_000_000;
21 const NANOS_PER_MICRO
: u32 = 1_000;
22 const MILLIS_PER_SEC
: u64 = 1_000;
23 const MICROS_PER_SEC
: u64 = 1_000_000;
25 /// A `Duration` type to represent a span of time, typically used for system
28 /// Each `Duration` is composed of a whole number of seconds and a fractional part
29 /// represented in nanoseconds. If the underlying system does not support
30 /// nanosecond-level precision, APIs binding a system timeout will typically round up
31 /// the number of nanoseconds.
33 /// [`Duration`]s implement many common traits, including [`Add`], [`Sub`], and other
34 /// [`ops`] traits. It implements [`Default`] by returning a zero-length `Duration`.
36 /// [`ops`]: crate::ops
41 /// use std::time::Duration;
43 /// let five_seconds = Duration::new(5, 0);
44 /// let five_seconds_and_five_nanos = five_seconds + Duration::new(0, 5);
46 /// assert_eq!(five_seconds_and_five_nanos.as_secs(), 5);
47 /// assert_eq!(five_seconds_and_five_nanos.subsec_nanos(), 5);
49 /// let ten_millis = Duration::from_millis(10);
51 #[stable(feature = "duration", since = "1.3.0")]
52 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
55 nanos
: u32, // Always 0 <= nanos < NANOS_PER_SEC
59 /// The duration of one second.
64 /// #![feature(duration_constants)]
65 /// use std::time::Duration;
67 /// assert_eq!(Duration::SECOND, Duration::from_secs(1));
69 #[unstable(feature = "duration_constants", issue = "57391")]
70 pub const SECOND
: Duration
= Duration
::from_secs(1);
72 /// The duration of one millisecond.
77 /// #![feature(duration_constants)]
78 /// use std::time::Duration;
80 /// assert_eq!(Duration::MILLISECOND, Duration::from_millis(1));
82 #[unstable(feature = "duration_constants", issue = "57391")]
83 pub const MILLISECOND
: Duration
= Duration
::from_millis(1);
85 /// The duration of one microsecond.
90 /// #![feature(duration_constants)]
91 /// use std::time::Duration;
93 /// assert_eq!(Duration::MICROSECOND, Duration::from_micros(1));
95 #[unstable(feature = "duration_constants", issue = "57391")]
96 pub const MICROSECOND
: Duration
= Duration
::from_micros(1);
98 /// The duration of one nanosecond.
103 /// #![feature(duration_constants)]
104 /// use std::time::Duration;
106 /// assert_eq!(Duration::NANOSECOND, Duration::from_nanos(1));
108 #[unstable(feature = "duration_constants", issue = "57391")]
109 pub const NANOSECOND
: Duration
= Duration
::from_nanos(1);
111 /// The minimum duration.
116 /// #![feature(duration_constants)]
117 /// use std::time::Duration;
119 /// assert_eq!(Duration::MIN, Duration::new(0, 0));
121 #[unstable(feature = "duration_constants", issue = "57391")]
122 pub const MIN
: Duration
= Duration
::from_nanos(0);
124 /// The maximum duration.
126 /// It is roughly equal to a duration of 584,942,417,355 years.
131 /// #![feature(duration_constants)]
132 /// use std::time::Duration;
134 /// assert_eq!(Duration::MAX, Duration::new(u64::MAX, 1_000_000_000 - 1));
136 #[unstable(feature = "duration_constants", issue = "57391")]
137 pub const MAX
: Duration
= Duration
::new(u64::MAX
, NANOS_PER_SEC
- 1);
139 /// Creates a new `Duration` from the specified number of whole seconds and
140 /// additional nanoseconds.
142 /// If the number of nanoseconds is greater than 1 billion (the number of
143 /// nanoseconds in a second), then it will carry over into the seconds provided.
147 /// This constructor will panic if the carry from the nanoseconds overflows
148 /// the seconds counter.
153 /// use std::time::Duration;
155 /// let five_seconds = Duration::new(5, 0);
157 #[stable(feature = "duration", since = "1.3.0")]
159 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
160 pub const fn new(secs
: u64, nanos
: u32) -> Duration
{
161 let secs
= match secs
.checked_add((nanos
/ NANOS_PER_SEC
) as u64) {
163 None
=> panic
!("overflow in Duration::new"),
165 let nanos
= nanos
% NANOS_PER_SEC
;
166 Duration { secs, nanos }
169 /// Creates a new `Duration` that spans no time.
174 /// #![feature(duration_zero)]
175 /// use std::time::Duration;
177 /// let duration = Duration::zero();
178 /// assert!(duration.is_zero());
179 /// assert_eq!(duration.as_nanos(), 0);
181 #[unstable(feature = "duration_zero", issue = "73544")]
183 pub const fn zero() -> Duration
{
184 Duration { secs: 0, nanos: 0 }
187 /// Creates a new `Duration` from the specified number of whole seconds.
192 /// use std::time::Duration;
194 /// let duration = Duration::from_secs(5);
196 /// assert_eq!(5, duration.as_secs());
197 /// assert_eq!(0, duration.subsec_nanos());
199 #[stable(feature = "duration", since = "1.3.0")]
201 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
202 pub const fn from_secs(secs
: u64) -> Duration
{
203 Duration { secs, nanos: 0 }
206 /// Creates a new `Duration` from the specified number of milliseconds.
211 /// use std::time::Duration;
213 /// let duration = Duration::from_millis(2569);
215 /// assert_eq!(2, duration.as_secs());
216 /// assert_eq!(569_000_000, duration.subsec_nanos());
218 #[stable(feature = "duration", since = "1.3.0")]
220 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
221 pub const fn from_millis(millis
: u64) -> Duration
{
223 secs
: millis
/ MILLIS_PER_SEC
,
224 nanos
: ((millis
% MILLIS_PER_SEC
) as u32) * NANOS_PER_MILLI
,
228 /// Creates a new `Duration` from the specified number of microseconds.
233 /// use std::time::Duration;
235 /// let duration = Duration::from_micros(1_000_002);
237 /// assert_eq!(1, duration.as_secs());
238 /// assert_eq!(2000, duration.subsec_nanos());
240 #[stable(feature = "duration_from_micros", since = "1.27.0")]
242 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
243 pub const fn from_micros(micros
: u64) -> Duration
{
245 secs
: micros
/ MICROS_PER_SEC
,
246 nanos
: ((micros
% MICROS_PER_SEC
) as u32) * NANOS_PER_MICRO
,
250 /// Creates a new `Duration` from the specified number of nanoseconds.
255 /// use std::time::Duration;
257 /// let duration = Duration::from_nanos(1_000_000_123);
259 /// assert_eq!(1, duration.as_secs());
260 /// assert_eq!(123, duration.subsec_nanos());
262 #[stable(feature = "duration_extras", since = "1.27.0")]
264 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
265 pub const fn from_nanos(nanos
: u64) -> Duration
{
267 secs
: nanos
/ (NANOS_PER_SEC
as u64),
268 nanos
: (nanos
% (NANOS_PER_SEC
as u64)) as u32,
272 /// Returns true if this `Duration` spans no time.
277 /// #![feature(duration_zero)]
278 /// use std::time::Duration;
280 /// assert!(Duration::zero().is_zero());
281 /// assert!(Duration::new(0, 0).is_zero());
282 /// assert!(Duration::from_nanos(0).is_zero());
283 /// assert!(Duration::from_secs(0).is_zero());
285 /// assert!(!Duration::new(1, 1).is_zero());
286 /// assert!(!Duration::from_nanos(1).is_zero());
287 /// assert!(!Duration::from_secs(1).is_zero());
289 #[unstable(feature = "duration_zero", issue = "73544")]
291 pub const fn is_zero(&self) -> bool
{
292 self.secs
== 0 && self.nanos
== 0
295 /// Returns the number of _whole_ seconds contained by this `Duration`.
297 /// The returned value does not include the fractional (nanosecond) part of the
298 /// duration, which can be obtained using [`subsec_nanos`].
303 /// use std::time::Duration;
305 /// let duration = Duration::new(5, 730023852);
306 /// assert_eq!(duration.as_secs(), 5);
309 /// To determine the total number of seconds represented by the `Duration`,
310 /// use `as_secs` in combination with [`subsec_nanos`]:
313 /// use std::time::Duration;
315 /// let duration = Duration::new(5, 730023852);
317 /// assert_eq!(5.730023852,
318 /// duration.as_secs() as f64
319 /// + duration.subsec_nanos() as f64 * 1e-9);
322 /// [`subsec_nanos`]: Duration::subsec_nanos
323 #[stable(feature = "duration", since = "1.3.0")]
324 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
326 pub const fn as_secs(&self) -> u64 {
330 /// Returns the fractional part of this `Duration`, in whole milliseconds.
332 /// This method does **not** return the length of the duration when
333 /// represented by milliseconds. The returned number always represents a
334 /// fractional portion of a second (i.e., it is less than one thousand).
339 /// use std::time::Duration;
341 /// let duration = Duration::from_millis(5432);
342 /// assert_eq!(duration.as_secs(), 5);
343 /// assert_eq!(duration.subsec_millis(), 432);
345 #[stable(feature = "duration_extras", since = "1.27.0")]
346 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
348 pub const fn subsec_millis(&self) -> u32 {
349 self.nanos
/ NANOS_PER_MILLI
352 /// Returns the fractional part of this `Duration`, in whole microseconds.
354 /// This method does **not** return the length of the duration when
355 /// represented by microseconds. The returned number always represents a
356 /// fractional portion of a second (i.e., it is less than one million).
361 /// use std::time::Duration;
363 /// let duration = Duration::from_micros(1_234_567);
364 /// assert_eq!(duration.as_secs(), 1);
365 /// assert_eq!(duration.subsec_micros(), 234_567);
367 #[stable(feature = "duration_extras", since = "1.27.0")]
368 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
370 pub const fn subsec_micros(&self) -> u32 {
371 self.nanos
/ NANOS_PER_MICRO
374 /// Returns the fractional part of this `Duration`, in nanoseconds.
376 /// This method does **not** return the length of the duration when
377 /// represented by nanoseconds. The returned number always represents a
378 /// fractional portion of a second (i.e., it is less than one billion).
383 /// use std::time::Duration;
385 /// let duration = Duration::from_millis(5010);
386 /// assert_eq!(duration.as_secs(), 5);
387 /// assert_eq!(duration.subsec_nanos(), 10_000_000);
389 #[stable(feature = "duration", since = "1.3.0")]
390 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
392 pub const fn subsec_nanos(&self) -> u32 {
396 /// Returns the total number of whole milliseconds contained by this `Duration`.
401 /// use std::time::Duration;
403 /// let duration = Duration::new(5, 730023852);
404 /// assert_eq!(duration.as_millis(), 5730);
406 #[stable(feature = "duration_as_u128", since = "1.33.0")]
407 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
409 pub const fn as_millis(&self) -> u128
{
410 self.secs
as u128
* MILLIS_PER_SEC
as u128
+ (self.nanos
/ NANOS_PER_MILLI
) as u128
413 /// Returns the total number of whole microseconds contained by this `Duration`.
418 /// use std::time::Duration;
420 /// let duration = Duration::new(5, 730023852);
421 /// assert_eq!(duration.as_micros(), 5730023);
423 #[stable(feature = "duration_as_u128", since = "1.33.0")]
424 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
426 pub const fn as_micros(&self) -> u128
{
427 self.secs
as u128
* MICROS_PER_SEC
as u128
+ (self.nanos
/ NANOS_PER_MICRO
) as u128
430 /// Returns the total number of nanoseconds contained by this `Duration`.
435 /// use std::time::Duration;
437 /// let duration = Duration::new(5, 730023852);
438 /// assert_eq!(duration.as_nanos(), 5730023852);
440 #[stable(feature = "duration_as_u128", since = "1.33.0")]
441 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
443 pub const fn as_nanos(&self) -> u128
{
444 self.secs
as u128
* NANOS_PER_SEC
as u128
+ self.nanos
as u128
447 /// Checked `Duration` addition. Computes `self + other`, returning [`None`]
448 /// if overflow occurred.
455 /// use std::time::Duration;
457 /// assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
458 /// assert_eq!(Duration::new(1, 0).checked_add(Duration::new(u64::MAX, 0)), None);
460 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
462 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
463 pub const fn checked_add(self, rhs
: Duration
) -> Option
<Duration
> {
464 if let Some(mut secs
) = self.secs
.checked_add(rhs
.secs
) {
465 let mut nanos
= self.nanos
+ rhs
.nanos
;
466 if nanos
>= NANOS_PER_SEC
{
467 nanos
-= NANOS_PER_SEC
;
468 if let Some(new_secs
) = secs
.checked_add(1) {
474 debug_assert
!(nanos
< NANOS_PER_SEC
);
475 Some(Duration { secs, nanos }
)
481 /// Saturating `Duration` addition. Computes `self + other`, returning [`Duration::MAX`]
482 /// if overflow occurred.
487 /// #![feature(duration_saturating_ops)]
488 /// #![feature(duration_constants)]
489 /// use std::time::Duration;
491 /// assert_eq!(Duration::new(0, 0).saturating_add(Duration::new(0, 1)), Duration::new(0, 1));
492 /// assert_eq!(Duration::new(1, 0).saturating_add(Duration::new(u64::MAX, 0)), Duration::MAX);
494 #[unstable(feature = "duration_saturating_ops", issue = "76416")]
496 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
497 pub const fn saturating_add(self, rhs
: Duration
) -> Duration
{
498 match self.checked_add(rhs
) {
500 None
=> Duration
::MAX
,
504 /// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
505 /// if the result would be negative or if overflow occurred.
512 /// use std::time::Duration;
514 /// assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
515 /// assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
517 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
519 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
520 pub const fn checked_sub(self, rhs
: Duration
) -> Option
<Duration
> {
521 if let Some(mut secs
) = self.secs
.checked_sub(rhs
.secs
) {
522 let nanos
= if self.nanos
>= rhs
.nanos
{
523 self.nanos
- rhs
.nanos
525 if let Some(sub_secs
) = secs
.checked_sub(1) {
527 self.nanos
+ NANOS_PER_SEC
- rhs
.nanos
532 debug_assert
!(nanos
< NANOS_PER_SEC
);
533 Some(Duration { secs, nanos }
)
539 /// Saturating `Duration` subtraction. Computes `self - other`, returning [`Duration::MIN`]
540 /// if the result would be negative or if overflow occurred.
545 /// #![feature(duration_saturating_ops)]
546 /// #![feature(duration_constants)]
547 /// use std::time::Duration;
549 /// assert_eq!(Duration::new(0, 1).saturating_sub(Duration::new(0, 0)), Duration::new(0, 1));
550 /// assert_eq!(Duration::new(0, 0).saturating_sub(Duration::new(0, 1)), Duration::MIN);
552 #[unstable(feature = "duration_saturating_ops", issue = "76416")]
554 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
555 pub const fn saturating_sub(self, rhs
: Duration
) -> Duration
{
556 match self.checked_sub(rhs
) {
558 None
=> Duration
::MIN
,
562 /// Checked `Duration` multiplication. Computes `self * other`, returning
563 /// [`None`] if overflow occurred.
570 /// use std::time::Duration;
572 /// assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
573 /// assert_eq!(Duration::new(u64::MAX - 1, 0).checked_mul(2), None);
575 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
577 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
578 pub const fn checked_mul(self, rhs
: u32) -> Option
<Duration
> {
579 // Multiply nanoseconds as u64, because it cannot overflow that way.
580 let total_nanos
= self.nanos
as u64 * rhs
as u64;
581 let extra_secs
= total_nanos
/ (NANOS_PER_SEC
as u64);
582 let nanos
= (total_nanos
% (NANOS_PER_SEC
as u64)) as u32;
583 if let Some(s
) = self.secs
.checked_mul(rhs
as u64) {
584 if let Some(secs
) = s
.checked_add(extra_secs
) {
585 debug_assert
!(nanos
< NANOS_PER_SEC
);
586 return Some(Duration { secs, nanos }
);
592 /// Saturating `Duration` multiplication. Computes `self * other`, returning
593 /// [`Duration::MAX`] if overflow occurred.
598 /// #![feature(duration_saturating_ops)]
599 /// #![feature(duration_constants)]
600 /// use std::time::Duration;
602 /// assert_eq!(Duration::new(0, 500_000_001).saturating_mul(2), Duration::new(1, 2));
603 /// assert_eq!(Duration::new(u64::MAX - 1, 0).saturating_mul(2), Duration::MAX);
605 #[unstable(feature = "duration_saturating_ops", issue = "76416")]
607 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
608 pub const fn saturating_mul(self, rhs
: u32) -> Duration
{
609 match self.checked_mul(rhs
) {
611 None
=> Duration
::MAX
,
615 /// Checked `Duration` division. Computes `self / other`, returning [`None`]
623 /// use std::time::Duration;
625 /// assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
626 /// assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
627 /// assert_eq!(Duration::new(2, 0).checked_div(0), None);
629 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
631 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
632 pub const fn checked_div(self, rhs
: u32) -> Option
<Duration
> {
634 let secs
= self.secs
/ (rhs
as u64);
635 let carry
= self.secs
- secs
* (rhs
as u64);
636 let extra_nanos
= carry
* (NANOS_PER_SEC
as u64) / (rhs
as u64);
637 let nanos
= self.nanos
/ rhs
+ (extra_nanos
as u32);
638 debug_assert
!(nanos
< NANOS_PER_SEC
);
639 Some(Duration { secs, nanos }
)
645 /// Returns the number of seconds contained by this `Duration` as `f64`.
647 /// The returned value does include the fractional (nanosecond) part of the duration.
651 /// use std::time::Duration;
653 /// let dur = Duration::new(2, 700_000_000);
654 /// assert_eq!(dur.as_secs_f64(), 2.7);
656 #[stable(feature = "duration_float", since = "1.38.0")]
658 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
659 pub const fn as_secs_f64(&self) -> f64 {
660 (self.secs
as f64) + (self.nanos
as f64) / (NANOS_PER_SEC
as f64)
663 /// Returns the number of seconds contained by this `Duration` as `f32`.
665 /// The returned value does include the fractional (nanosecond) part of the duration.
669 /// use std::time::Duration;
671 /// let dur = Duration::new(2, 700_000_000);
672 /// assert_eq!(dur.as_secs_f32(), 2.7);
674 #[stable(feature = "duration_float", since = "1.38.0")]
676 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
677 pub const fn as_secs_f32(&self) -> f32 {
678 (self.secs
as f32) + (self.nanos
as f32) / (NANOS_PER_SEC
as f32)
681 /// Creates a new `Duration` from the specified number of seconds represented
685 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
689 /// use std::time::Duration;
691 /// let dur = Duration::from_secs_f64(2.7);
692 /// assert_eq!(dur, Duration::new(2, 700_000_000));
694 #[stable(feature = "duration_float", since = "1.38.0")]
696 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
697 pub const fn from_secs_f64(secs
: f64) -> Duration
{
698 const MAX_NANOS_F64
: f64 = ((u64::MAX
as u128
+ 1) * (NANOS_PER_SEC
as u128
)) as f64;
699 let nanos
= secs
* (NANOS_PER_SEC
as f64);
700 if !nanos
.is_finite() {
701 panic
!("got non-finite value when converting float to duration");
703 if nanos
>= MAX_NANOS_F64
{
704 panic
!("overflow when converting float to duration");
707 panic
!("underflow when converting float to duration");
709 let nanos
= nanos
as u128
;
711 secs
: (nanos
/ (NANOS_PER_SEC
as u128
)) as u64,
712 nanos
: (nanos
% (NANOS_PER_SEC
as u128
)) as u32,
716 /// Creates a new `Duration` from the specified number of seconds represented
720 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
724 /// use std::time::Duration;
726 /// let dur = Duration::from_secs_f32(2.7);
727 /// assert_eq!(dur, Duration::new(2, 700_000_000));
729 #[stable(feature = "duration_float", since = "1.38.0")]
731 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
732 pub const fn from_secs_f32(secs
: f32) -> Duration
{
733 const MAX_NANOS_F32
: f32 = ((u64::MAX
as u128
+ 1) * (NANOS_PER_SEC
as u128
)) as f32;
734 let nanos
= secs
* (NANOS_PER_SEC
as f32);
735 if !nanos
.is_finite() {
736 panic
!("got non-finite value when converting float to duration");
738 if nanos
>= MAX_NANOS_F32
{
739 panic
!("overflow when converting float to duration");
742 panic
!("underflow when converting float to duration");
744 let nanos
= nanos
as u128
;
746 secs
: (nanos
/ (NANOS_PER_SEC
as u128
)) as u64,
747 nanos
: (nanos
% (NANOS_PER_SEC
as u128
)) as u32,
751 /// Multiplies `Duration` by `f64`.
754 /// This method will panic if result is not finite, negative or overflows `Duration`.
758 /// use std::time::Duration;
760 /// let dur = Duration::new(2, 700_000_000);
761 /// assert_eq!(dur.mul_f64(3.14), Duration::new(8, 478_000_000));
762 /// assert_eq!(dur.mul_f64(3.14e5), Duration::new(847_800, 0));
764 #[stable(feature = "duration_float", since = "1.38.0")]
766 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
767 pub const fn mul_f64(self, rhs
: f64) -> Duration
{
768 Duration
::from_secs_f64(rhs
* self.as_secs_f64())
771 /// Multiplies `Duration` by `f32`.
774 /// This method will panic if result is not finite, negative or overflows `Duration`.
778 /// use std::time::Duration;
780 /// let dur = Duration::new(2, 700_000_000);
781 /// // note that due to rounding errors result is slightly different
782 /// // from 8.478 and 847800.0
783 /// assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_640));
784 /// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847799, 969_120_256));
786 #[stable(feature = "duration_float", since = "1.38.0")]
788 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
789 pub const fn mul_f32(self, rhs
: f32) -> Duration
{
790 Duration
::from_secs_f32(rhs
* self.as_secs_f32())
793 /// Divide `Duration` by `f64`.
796 /// This method will panic if result is not finite, negative or overflows `Duration`.
800 /// use std::time::Duration;
802 /// let dur = Duration::new(2, 700_000_000);
803 /// assert_eq!(dur.div_f64(3.14), Duration::new(0, 859_872_611));
804 /// // note that truncation is used, not rounding
805 /// assert_eq!(dur.div_f64(3.14e5), Duration::new(0, 8_598));
807 #[stable(feature = "duration_float", since = "1.38.0")]
809 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
810 pub const fn div_f64(self, rhs
: f64) -> Duration
{
811 Duration
::from_secs_f64(self.as_secs_f64() / rhs
)
814 /// Divide `Duration` by `f32`.
817 /// This method will panic if result is not finite, negative or overflows `Duration`.
821 /// use std::time::Duration;
823 /// let dur = Duration::new(2, 700_000_000);
824 /// // note that due to rounding errors result is slightly
825 /// // different from 0.859_872_611
826 /// assert_eq!(dur.div_f32(3.14), Duration::new(0, 859_872_576));
827 /// // note that truncation is used, not rounding
828 /// assert_eq!(dur.div_f32(3.14e5), Duration::new(0, 8_598));
830 #[stable(feature = "duration_float", since = "1.38.0")]
832 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
833 pub const fn div_f32(self, rhs
: f32) -> Duration
{
834 Duration
::from_secs_f32(self.as_secs_f32() / rhs
)
837 /// Divide `Duration` by `Duration` and return `f64`.
841 /// #![feature(div_duration)]
842 /// use std::time::Duration;
844 /// let dur1 = Duration::new(2, 700_000_000);
845 /// let dur2 = Duration::new(5, 400_000_000);
846 /// assert_eq!(dur1.div_duration_f64(dur2), 0.5);
848 #[unstable(feature = "div_duration", issue = "63139")]
850 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
851 pub const fn div_duration_f64(self, rhs
: Duration
) -> f64 {
852 self.as_secs_f64() / rhs
.as_secs_f64()
855 /// Divide `Duration` by `Duration` and return `f32`.
859 /// #![feature(div_duration)]
860 /// use std::time::Duration;
862 /// let dur1 = Duration::new(2, 700_000_000);
863 /// let dur2 = Duration::new(5, 400_000_000);
864 /// assert_eq!(dur1.div_duration_f32(dur2), 0.5);
866 #[unstable(feature = "div_duration", issue = "63139")]
868 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
869 pub const fn div_duration_f32(self, rhs
: Duration
) -> f32 {
870 self.as_secs_f32() / rhs
.as_secs_f32()
874 #[stable(feature = "duration", since = "1.3.0")]
875 impl Add
for Duration
{
876 type Output
= Duration
;
878 fn add(self, rhs
: Duration
) -> Duration
{
879 self.checked_add(rhs
).expect("overflow when adding durations")
883 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
884 impl AddAssign
for Duration
{
885 fn add_assign(&mut self, rhs
: Duration
) {
890 #[stable(feature = "duration", since = "1.3.0")]
891 impl Sub
for Duration
{
892 type Output
= Duration
;
894 fn sub(self, rhs
: Duration
) -> Duration
{
895 self.checked_sub(rhs
).expect("overflow when subtracting durations")
899 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
900 impl SubAssign
for Duration
{
901 fn sub_assign(&mut self, rhs
: Duration
) {
906 #[stable(feature = "duration", since = "1.3.0")]
907 impl Mul
<u32> for Duration
{
908 type Output
= Duration
;
910 fn mul(self, rhs
: u32) -> Duration
{
911 self.checked_mul(rhs
).expect("overflow when multiplying duration by scalar")
915 #[stable(feature = "symmetric_u32_duration_mul", since = "1.31.0")]
916 impl Mul
<Duration
> for u32 {
917 type Output
= Duration
;
919 fn mul(self, rhs
: Duration
) -> Duration
{
924 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
925 impl MulAssign
<u32> for Duration
{
926 fn mul_assign(&mut self, rhs
: u32) {
931 #[stable(feature = "duration", since = "1.3.0")]
932 impl Div
<u32> for Duration
{
933 type Output
= Duration
;
935 fn div(self, rhs
: u32) -> Duration
{
936 self.checked_div(rhs
).expect("divide by zero error when dividing duration by scalar")
940 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
941 impl DivAssign
<u32> for Duration
{
942 fn div_assign(&mut self, rhs
: u32) {
947 macro_rules
! sum_durations
{
949 let mut total_secs
: u64 = 0;
950 let mut total_nanos
: u64 = 0;
954 total_secs
.checked_add(entry
.secs
).expect("overflow in iter::sum over durations");
955 total_nanos
= match total_nanos
.checked_add(entry
.nanos
as u64) {
958 total_secs
= total_secs
959 .checked_add(total_nanos
/ NANOS_PER_SEC
as u64)
960 .expect("overflow in iter::sum over durations");
961 (total_nanos
% NANOS_PER_SEC
as u64) + entry
.nanos
as u64
965 total_secs
= total_secs
966 .checked_add(total_nanos
/ NANOS_PER_SEC
as u64)
967 .expect("overflow in iter::sum over durations");
968 total_nanos
= total_nanos
% NANOS_PER_SEC
as u64;
969 Duration { secs: total_secs, nanos: total_nanos as u32 }
973 #[stable(feature = "duration_sum", since = "1.16.0")]
974 impl Sum
for Duration
{
975 fn sum
<I
: Iterator
<Item
= Duration
>>(iter
: I
) -> Duration
{
980 #[stable(feature = "duration_sum", since = "1.16.0")]
981 impl<'a
> Sum
<&'a Duration
> for Duration
{
982 fn sum
<I
: Iterator
<Item
= &'a Duration
>>(iter
: I
) -> Duration
{
987 #[stable(feature = "duration_debug_impl", since = "1.27.0")]
988 impl fmt
::Debug
for Duration
{
989 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
990 /// Formats a floating point number in decimal notation.
992 /// The number is given as the `integer_part` and a fractional part.
993 /// The value of the fractional part is `fractional_part / divisor`. So
994 /// `integer_part` = 3, `fractional_part` = 12 and `divisor` = 100
995 /// represents the number `3.012`. Trailing zeros are omitted.
997 /// `divisor` must not be above 100_000_000. It also should be a power
998 /// of 10, everything else doesn't make sense. `fractional_part` has
999 /// to be less than `10 * divisor`!
1001 f
: &mut fmt
::Formatter
<'_
>,
1002 mut integer_part
: u64,
1003 mut fractional_part
: u32,
1006 // Encode the fractional part into a temporary buffer. The buffer
1007 // only need to hold 9 elements, because `fractional_part` has to
1008 // be smaller than 10^9. The buffer is prefilled with '0' digits
1009 // to simplify the code below.
1010 let mut buf
= [b'
0'
; 9];
1012 // The next digit is written at this position
1015 // We keep writing digits into the buffer while there are non-zero
1016 // digits left and we haven't written enough digits yet.
1017 while fractional_part
> 0 && pos
< f
.precision().unwrap_or(9) {
1018 // Write new digit into the buffer
1019 buf
[pos
] = b'
0'
+ (fractional_part
/ divisor
) as u8;
1021 fractional_part
%= divisor
;
1026 // If a precision < 9 was specified, there may be some non-zero
1027 // digits left that weren't written into the buffer. In that case we
1028 // need to perform rounding to match the semantics of printing
1029 // normal floating point numbers. However, we only need to do work
1030 // when rounding up. This happens if the first digit of the
1031 // remaining ones is >= 5.
1032 if fractional_part
> 0 && fractional_part
>= divisor
* 5 {
1033 // Round up the number contained in the buffer. We go through
1034 // the buffer backwards and keep track of the carry.
1035 let mut rev_pos
= pos
;
1036 let mut carry
= true;
1037 while carry
&& rev_pos
> 0 {
1040 // If the digit in the buffer is not '9', we just need to
1041 // increment it and can stop then (since we don't have a
1042 // carry anymore). Otherwise, we set it to '0' (overflow)
1044 if buf
[rev_pos
] < b'
9'
{
1048 buf
[rev_pos
] = b'
0'
;
1052 // If we still have the carry bit set, that means that we set
1053 // the whole buffer to '0's and need to increment the integer
1060 // Determine the end of the buffer: if precision is set, we just
1061 // use as many digits from the buffer (capped to 9). If it isn't
1062 // set, we only use all digits up to the last non-zero one.
1063 let end
= f
.precision().map(|p
| crate::cmp
::min(p
, 9)).unwrap_or(pos
);
1065 // If we haven't emitted a single fractional digit and the precision
1066 // wasn't set to a non-zero value, we don't print the decimal point.
1068 write
!(f
, "{}", integer_part
)
1070 // SAFETY: We are only writing ASCII digits into the buffer and it was
1071 // initialized with '0's, so it contains valid UTF8.
1072 let s
= unsafe { crate::str::from_utf8_unchecked(&buf[..end]) }
;
1074 // If the user request a precision > 9, we pad '0's at the end.
1075 let w
= f
.precision().unwrap_or(pos
);
1076 write
!(f
, "{}.{:0<width$}", integer_part
, s
, width
= w
)
1080 // Print leading '+' sign if requested
1086 fmt_decimal(f
, self.secs
, self.nanos
, 100_000_000)?
;
1088 } else if self.nanos
>= 1_000_000 {
1089 fmt_decimal(f
, self.nanos
as u64 / 1_000_000, self.nanos
% 1_000_000, 100_000)?
;
1091 } else if self.nanos
>= 1_000 {
1092 fmt_decimal(f
, self.nanos
as u64 / 1_000, self.nanos
% 1_000, 100)?
;
1095 fmt_decimal(f
, self.nanos
as u64, 0, 1)?
;