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 pub fn from_secs_f64(secs: f64) -> Duration {
697 const MAX_NANOS_F64: f64 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f64;
698 let nanos = secs * (NANOS_PER_SEC as f64);
699 if !nanos.is_finite() {
700 panic!("got non-finite value when converting float to duration");
702 if nanos >= MAX_NANOS_F64 {
703 panic!("overflow when converting float to duration");
706 panic!("underflow when converting float to duration");
708 let nanos = nanos as u128;
710 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
711 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
715 /// Creates a new `Duration` from the specified number of seconds represented
719 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
723 /// use std::time::Duration;
725 /// let dur = Duration::from_secs_f32(2.7);
726 /// assert_eq!(dur, Duration::new(2, 700_000_000));
728 #[stable(feature = "duration_float", since = "1.38.0")]
730 pub fn from_secs_f32(secs: f32) -> Duration {
731 const MAX_NANOS_F32: f32 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f32;
732 let nanos = secs * (NANOS_PER_SEC as f32);
733 if !nanos.is_finite() {
734 panic!("got non-finite value when converting float to duration");
736 if nanos >= MAX_NANOS_F32 {
737 panic!("overflow when converting float to duration");
740 panic!("underflow when converting float to duration");
742 let nanos = nanos as u128;
744 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
745 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
749 /// Multiplies `Duration` by `f64`.
752 /// This method will panic if result is not finite, negative or overflows `Duration`.
756 /// use std::time::Duration;
758 /// let dur = Duration::new(2, 700_000_000);
759 /// assert_eq!(dur.mul_f64(3.14), Duration::new(8, 478_000_000));
760 /// assert_eq!(dur.mul_f64(3.14e5), Duration::new(847_800, 0));
762 #[stable(feature = "duration_float", since = "1.38.0")]
764 pub fn mul_f64(self, rhs: f64) -> Duration {
765 Duration::from_secs_f64(rhs * self.as_secs_f64())
768 /// Multiplies `Duration` by `f32`.
771 /// This method will panic if result is not finite, negative or overflows `Duration`.
775 /// use std::time::Duration;
777 /// let dur = Duration::new(2, 700_000_000);
778 /// // note that due to rounding errors result is slightly different
779 /// // from 8.478 and 847800.0
780 /// assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_640));
781 /// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847799, 969_120_256));
783 #[stable(feature = "duration_float", since = "1.38.0")]
785 pub fn mul_f32(self, rhs: f32) -> Duration {
786 Duration::from_secs_f32(rhs * self.as_secs_f32())
789 /// Divide `Duration` by `f64`.
792 /// This method will panic if result is not finite, negative or overflows `Duration`.
796 /// use std::time::Duration;
798 /// let dur = Duration::new(2, 700_000_000);
799 /// assert_eq!(dur.div_f64(3.14), Duration::new(0, 859_872_611));
800 /// // note that truncation is used, not rounding
801 /// assert_eq!(dur.div_f64(3.14e5), Duration::new(0, 8_598));
803 #[stable(feature = "duration_float", since = "1.38.0")]
805 pub fn div_f64(self, rhs: f64) -> Duration {
806 Duration::from_secs_f64(self.as_secs_f64() / rhs)
809 /// Divide `Duration` by `f32`.
812 /// This method will panic if result is not finite, negative or overflows `Duration`.
816 /// use std::time::Duration;
818 /// let dur = Duration::new(2, 700_000_000);
819 /// // note that due to rounding errors result is slightly
820 /// // different from 0.859_872_611
821 /// assert_eq!(dur.div_f32(3.14), Duration::new(0, 859_872_576));
822 /// // note that truncation is used, not rounding
823 /// assert_eq!(dur.div_f32(3.14e5), Duration::new(0, 8_598));
825 #[stable(feature = "duration_float", since = "1.38.0")]
827 pub fn div_f32(self, rhs: f32) -> Duration {
828 Duration::from_secs_f32(self.as_secs_f32() / rhs)
831 /// Divide `Duration` by `Duration` and return `f64`.
835 /// #![feature(div_duration)]
836 /// use std::time::Duration;
838 /// let dur1 = Duration::new(2, 700_000_000);
839 /// let dur2 = Duration::new(5, 400_000_000);
840 /// assert_eq!(dur1.div_duration_f64(dur2), 0.5);
842 #[unstable(feature = "div_duration", issue = "63139")]
844 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
845 pub const fn div_duration_f64(self, rhs: Duration) -> f64 {
846 self.as_secs_f64() / rhs.as_secs_f64()
849 /// Divide `Duration` by `Duration` and return `f32`.
853 /// #![feature(div_duration)]
854 /// use std::time::Duration;
856 /// let dur1 = Duration::new(2, 700_000_000);
857 /// let dur2 = Duration::new(5, 400_000_000);
858 /// assert_eq!(dur1.div_duration_f32(dur2), 0.5);
860 #[unstable(feature = "div_duration", issue = "63139")]
862 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
863 pub const fn div_duration_f32(self, rhs: Duration) -> f32 {
864 self.as_secs_f32() / rhs.as_secs_f32()
868 #[stable(feature = "duration", since = "1.3.0")]
869 impl Add for Duration {
870 type Output = Duration;
872 fn add(self, rhs: Duration) -> Duration {
873 self.checked_add(rhs).expect("overflow when adding durations")
877 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
878 impl AddAssign for Duration {
879 fn add_assign(&mut self, rhs: Duration) {
884 #[stable(feature = "duration", since = "1.3.0")]
885 impl Sub for Duration {
886 type Output = Duration;
888 fn sub(self, rhs: Duration) -> Duration {
889 self.checked_sub(rhs).expect("overflow when subtracting durations")
893 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
894 impl SubAssign for Duration {
895 fn sub_assign(&mut self, rhs: Duration) {
900 #[stable(feature = "duration", since = "1.3.0")]
901 impl Mul<u32> for Duration {
902 type Output = Duration;
904 fn mul(self, rhs: u32) -> Duration {
905 self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
909 #[stable(feature = "symmetric_u32_duration_mul", since = "1.31.0")]
910 impl Mul<Duration> for u32 {
911 type Output = Duration;
913 fn mul(self, rhs: Duration) -> Duration {
918 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
919 impl MulAssign<u32> for Duration {
920 fn mul_assign(&mut self, rhs: u32) {
925 #[stable(feature = "duration", since = "1.3.0")]
926 impl Div<u32> for Duration {
927 type Output = Duration;
929 fn div(self, rhs: u32) -> Duration {
930 self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
934 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
935 impl DivAssign<u32> for Duration {
936 fn div_assign(&mut self, rhs: u32) {
941 macro_rules! sum_durations {
943 let mut total_secs: u64 = 0;
944 let mut total_nanos: u64 = 0;
948 total_secs.checked_add(entry.secs).expect("overflow in iter::sum over durations");
949 total_nanos = match total_nanos.checked_add(entry.nanos as u64) {
952 total_secs = total_secs
953 .checked_add(total_nanos / NANOS_PER_SEC as u64)
954 .expect("overflow in iter::sum over durations");
955 (total_nanos % NANOS_PER_SEC as u64) + entry.nanos as u64
959 total_secs = total_secs
960 .checked_add(total_nanos / NANOS_PER_SEC as u64)
961 .expect("overflow in iter::sum over durations");
962 total_nanos = total_nanos % NANOS_PER_SEC as u64;
963 Duration { secs: total_secs, nanos: total_nanos as u32 }
967 #[stable(feature = "duration_sum", since = "1.16.0")]
968 impl Sum for Duration {
969 fn sum<I: Iterator<Item = Duration>>(iter: I) -> Duration {
974 #[stable(feature = "duration_sum", since = "1.16.0")]
975 impl<'a> Sum<&'a Duration> for Duration {
976 fn sum<I: Iterator<Item = &'a Duration>>(iter: I) -> Duration {
981 #[stable(feature = "duration_debug_impl", since = "1.27.0")]
982 impl fmt::Debug for Duration {
983 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
984 /// Formats a floating point number in decimal notation.
986 /// The number is given as the `integer_part` and a fractional part.
987 /// The value of the fractional part is `fractional_part / divisor`. So
988 /// `integer_part` = 3, `fractional_part` = 12 and `divisor` = 100
989 /// represents the number `3.012`. Trailing zeros are omitted.
991 /// `divisor` must not be above 100_000_000. It also should be a power
992 /// of 10, everything else doesn't make sense. `fractional_part` has
993 /// to be less than `10 * divisor`!
995 f: &mut fmt::Formatter<'_>,
996 mut integer_part: u64,
997 mut fractional_part: u32,
1000 // Encode the fractional part into a temporary buffer. The buffer
1001 // only need to hold 9 elements, because `fractional_part` has to
1002 // be smaller than 10^9. The buffer is prefilled with '0' digits
1003 // to simplify the code below.
1004 let mut buf = [b'0'; 9];
1006 // The next digit is written at this position
1009 // We keep writing digits into the buffer while there are non-zero
1010 // digits left and we haven't written enough digits yet.
1011 while fractional_part > 0 && pos < f.precision().unwrap_or(9) {
1012 // Write new digit into the buffer
1013 buf[pos] = b'0' + (fractional_part / divisor) as u8;
1015 fractional_part %= divisor;
1020 // If a precision < 9 was specified, there may be some non-zero
1021 // digits left that weren't written into the buffer. In that case we
1022 // need to perform rounding to match the semantics of printing
1023 // normal floating point numbers. However, we only need to do work
1024 // when rounding up. This happens if the first digit of the
1025 // remaining ones is >= 5.
1026 if fractional_part > 0 && fractional_part >= divisor * 5 {
1027 // Round up the number contained in the buffer. We go through
1028 // the buffer backwards and keep track of the carry.
1029 let mut rev_pos = pos;
1030 let mut carry = true;
1031 while carry && rev_pos > 0 {
1034 // If the digit in the buffer is not '9', we just need to
1035 // increment it and can stop then (since we don't have a
1036 // carry anymore). Otherwise, we set it to '0' (overflow)
1038 if buf[rev_pos] < b'9' {
1042 buf[rev_pos] = b'0';
1046 // If we still have the carry bit set, that means that we set
1047 // the whole buffer to '0's and need to increment the integer
1054 // Determine the end of the buffer: if precision is set, we just
1055 // use as many digits from the buffer (capped to 9). If it isn't
1056 // set, we only use all digits up to the last non-zero one.
1057 let end = f.precision().map(|p| crate::cmp::min(p, 9)).unwrap_or(pos);
1059 // If we haven't emitted a single fractional digit and the precision
1060 // wasn't set to a non-zero value, we don't print the decimal point.
1062 write!(f, "{}", integer_part)
1064 // SAFETY: We are only writing ASCII digits into the buffer and it was
1065 // initialized with '0's, so it contains valid UTF8.
1066 let s = unsafe { crate::str::from_utf8_unchecked(&buf[..end]) };
1068 // If the user request a precision > 9, we pad '0's at the end.
1069 let w = f.precision().unwrap_or(pos);
1070 write!(f, "{}.{:0<width$}", integer_part, s, width = w)
1074 // Print leading '+' sign if requested
1080 fmt_decimal(f, self.secs, self.nanos, 100_000_000)?;
1082 } else if self.nanos >= 1_000_000 {
1083 fmt_decimal(f, self.nanos as u64 / 1_000_000, self.nanos % 1_000_000, 100_000)?;
1085 } else if self.nanos >= 1_000 {
1086 fmt_decimal(f, self.nanos as u64 / 1_000, self.nanos % 1_000, 100)?;
1089 fmt_decimal(f, self.nanos as u64, 0, 1)?;