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);
52 /// # Formatting `Duration` values
54 /// `Duration` intentionally does not have a `Display` impl, as there are a
55 /// variety of ways to format spans of time for human readability. `Duration`
56 /// provides a `Debug` impl that shows the full precision of the value.
58 /// The `Debug` output uses the non-ASCII "µs" suffix for microseconds. If your
59 /// program output may appear in contexts that cannot rely on full Unicode
60 /// compatibility, you may wish to format `Duration` objects yourself or use a
62 #[stable(feature = "duration", since = "1.3.0")]
63 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
66 nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC
70 /// The duration of one second.
75 /// #![feature(duration_constants)]
76 /// use std::time::Duration;
78 /// assert_eq!(Duration::SECOND, Duration::from_secs(1));
80 #[unstable(feature = "duration_constants", issue = "57391")]
81 pub const SECOND: Duration = Duration::from_secs(1);
83 /// The duration of one millisecond.
88 /// #![feature(duration_constants)]
89 /// use std::time::Duration;
91 /// assert_eq!(Duration::MILLISECOND, Duration::from_millis(1));
93 #[unstable(feature = "duration_constants", issue = "57391")]
94 pub const MILLISECOND: Duration = Duration::from_millis(1);
96 /// The duration of one microsecond.
101 /// #![feature(duration_constants)]
102 /// use std::time::Duration;
104 /// assert_eq!(Duration::MICROSECOND, Duration::from_micros(1));
106 #[unstable(feature = "duration_constants", issue = "57391")]
107 pub const MICROSECOND: Duration = Duration::from_micros(1);
109 /// The duration of one nanosecond.
114 /// #![feature(duration_constants)]
115 /// use std::time::Duration;
117 /// assert_eq!(Duration::NANOSECOND, Duration::from_nanos(1));
119 #[unstable(feature = "duration_constants", issue = "57391")]
120 pub const NANOSECOND: Duration = Duration::from_nanos(1);
122 /// A duration of zero time.
127 /// use std::time::Duration;
129 /// let duration = Duration::ZERO;
130 /// assert!(duration.is_zero());
131 /// assert_eq!(duration.as_nanos(), 0);
133 #[stable(feature = "duration_zero", since = "1.53.0")]
134 pub const ZERO: Duration = Duration::from_nanos(0);
136 /// The maximum duration.
138 /// It is roughly equal to a duration of 584,942,417,355 years.
143 /// #![feature(duration_constants)]
144 /// use std::time::Duration;
146 /// assert_eq!(Duration::MAX, Duration::new(u64::MAX, 1_000_000_000 - 1));
148 #[unstable(feature = "duration_constants", issue = "57391")]
149 pub const MAX: Duration = Duration::new(u64::MAX, NANOS_PER_SEC - 1);
151 /// Creates a new `Duration` from the specified number of whole seconds and
152 /// additional nanoseconds.
154 /// If the number of nanoseconds is greater than 1 billion (the number of
155 /// nanoseconds in a second), then it will carry over into the seconds provided.
159 /// This constructor will panic if the carry from the nanoseconds overflows
160 /// the seconds counter.
165 /// use std::time::Duration;
167 /// let five_seconds = Duration::new(5, 0);
169 #[stable(feature = "duration", since = "1.3.0")]
171 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
172 pub const fn new(secs: u64, nanos: u32) -> Duration {
173 let secs = match secs.checked_add((nanos / NANOS_PER_SEC) as u64) {
175 None => panic!("overflow in Duration::new"),
177 let nanos = nanos % NANOS_PER_SEC;
178 Duration { secs, nanos }
181 /// Creates a new `Duration` from the specified number of whole seconds.
186 /// use std::time::Duration;
188 /// let duration = Duration::from_secs(5);
190 /// assert_eq!(5, duration.as_secs());
191 /// assert_eq!(0, duration.subsec_nanos());
193 #[stable(feature = "duration", since = "1.3.0")]
195 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
196 pub const fn from_secs(secs: u64) -> Duration {
197 Duration { secs, nanos: 0 }
200 /// Creates a new `Duration` from the specified number of milliseconds.
205 /// use std::time::Duration;
207 /// let duration = Duration::from_millis(2569);
209 /// assert_eq!(2, duration.as_secs());
210 /// assert_eq!(569_000_000, duration.subsec_nanos());
212 #[stable(feature = "duration", since = "1.3.0")]
214 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
215 pub const fn from_millis(millis: u64) -> Duration {
217 secs: millis / MILLIS_PER_SEC,
218 nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI,
222 /// Creates a new `Duration` from the specified number of microseconds.
227 /// use std::time::Duration;
229 /// let duration = Duration::from_micros(1_000_002);
231 /// assert_eq!(1, duration.as_secs());
232 /// assert_eq!(2000, duration.subsec_nanos());
234 #[stable(feature = "duration_from_micros", since = "1.27.0")]
236 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
237 pub const fn from_micros(micros: u64) -> Duration {
239 secs: micros / MICROS_PER_SEC,
240 nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO,
244 /// Creates a new `Duration` from the specified number of nanoseconds.
249 /// use std::time::Duration;
251 /// let duration = Duration::from_nanos(1_000_000_123);
253 /// assert_eq!(1, duration.as_secs());
254 /// assert_eq!(123, duration.subsec_nanos());
256 #[stable(feature = "duration_extras", since = "1.27.0")]
258 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
259 pub const fn from_nanos(nanos: u64) -> Duration {
261 secs: nanos / (NANOS_PER_SEC as u64),
262 nanos: (nanos % (NANOS_PER_SEC as u64)) as u32,
266 /// Returns true if this `Duration` spans no time.
271 /// use std::time::Duration;
273 /// assert!(Duration::ZERO.is_zero());
274 /// assert!(Duration::new(0, 0).is_zero());
275 /// assert!(Duration::from_nanos(0).is_zero());
276 /// assert!(Duration::from_secs(0).is_zero());
278 /// assert!(!Duration::new(1, 1).is_zero());
279 /// assert!(!Duration::from_nanos(1).is_zero());
280 /// assert!(!Duration::from_secs(1).is_zero());
282 #[stable(feature = "duration_zero", since = "1.53.0")]
283 #[rustc_const_stable(feature = "duration_zero", since = "1.53.0")]
285 pub const fn is_zero(&self) -> bool {
286 self.secs == 0 && self.nanos == 0
289 /// Returns the number of _whole_ seconds contained by this `Duration`.
291 /// The returned value does not include the fractional (nanosecond) part of the
292 /// duration, which can be obtained using [`subsec_nanos`].
297 /// use std::time::Duration;
299 /// let duration = Duration::new(5, 730023852);
300 /// assert_eq!(duration.as_secs(), 5);
303 /// To determine the total number of seconds represented by the `Duration`,
304 /// use `as_secs` in combination with [`subsec_nanos`]:
307 /// use std::time::Duration;
309 /// let duration = Duration::new(5, 730023852);
311 /// assert_eq!(5.730023852,
312 /// duration.as_secs() as f64
313 /// + duration.subsec_nanos() as f64 * 1e-9);
316 /// [`subsec_nanos`]: Duration::subsec_nanos
317 #[stable(feature = "duration", since = "1.3.0")]
318 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
320 pub const fn as_secs(&self) -> u64 {
324 /// Returns the fractional part of this `Duration`, in whole milliseconds.
326 /// This method does **not** return the length of the duration when
327 /// represented by milliseconds. The returned number always represents a
328 /// fractional portion of a second (i.e., it is less than one thousand).
333 /// use std::time::Duration;
335 /// let duration = Duration::from_millis(5432);
336 /// assert_eq!(duration.as_secs(), 5);
337 /// assert_eq!(duration.subsec_millis(), 432);
339 #[stable(feature = "duration_extras", since = "1.27.0")]
340 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
342 pub const fn subsec_millis(&self) -> u32 {
343 self.nanos / NANOS_PER_MILLI
346 /// Returns the fractional part of this `Duration`, in whole microseconds.
348 /// This method does **not** return the length of the duration when
349 /// represented by microseconds. The returned number always represents a
350 /// fractional portion of a second (i.e., it is less than one million).
355 /// use std::time::Duration;
357 /// let duration = Duration::from_micros(1_234_567);
358 /// assert_eq!(duration.as_secs(), 1);
359 /// assert_eq!(duration.subsec_micros(), 234_567);
361 #[stable(feature = "duration_extras", since = "1.27.0")]
362 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
364 pub const fn subsec_micros(&self) -> u32 {
365 self.nanos / NANOS_PER_MICRO
368 /// Returns the fractional part of this `Duration`, in nanoseconds.
370 /// This method does **not** return the length of the duration when
371 /// represented by nanoseconds. The returned number always represents a
372 /// fractional portion of a second (i.e., it is less than one billion).
377 /// use std::time::Duration;
379 /// let duration = Duration::from_millis(5010);
380 /// assert_eq!(duration.as_secs(), 5);
381 /// assert_eq!(duration.subsec_nanos(), 10_000_000);
383 #[stable(feature = "duration", since = "1.3.0")]
384 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
386 pub const fn subsec_nanos(&self) -> u32 {
390 /// Returns the total number of whole milliseconds contained by this `Duration`.
395 /// use std::time::Duration;
397 /// let duration = Duration::new(5, 730023852);
398 /// assert_eq!(duration.as_millis(), 5730);
400 #[stable(feature = "duration_as_u128", since = "1.33.0")]
401 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
403 pub const fn as_millis(&self) -> u128 {
404 self.secs as u128 * MILLIS_PER_SEC as u128 + (self.nanos / NANOS_PER_MILLI) as u128
407 /// Returns the total number of whole microseconds contained by this `Duration`.
412 /// use std::time::Duration;
414 /// let duration = Duration::new(5, 730023852);
415 /// assert_eq!(duration.as_micros(), 5730023);
417 #[stable(feature = "duration_as_u128", since = "1.33.0")]
418 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
420 pub const fn as_micros(&self) -> u128 {
421 self.secs as u128 * MICROS_PER_SEC as u128 + (self.nanos / NANOS_PER_MICRO) as u128
424 /// Returns the total number of nanoseconds contained by this `Duration`.
429 /// use std::time::Duration;
431 /// let duration = Duration::new(5, 730023852);
432 /// assert_eq!(duration.as_nanos(), 5730023852);
434 #[stable(feature = "duration_as_u128", since = "1.33.0")]
435 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
437 pub const fn as_nanos(&self) -> u128 {
438 self.secs as u128 * NANOS_PER_SEC as u128 + self.nanos as u128
441 /// Checked `Duration` addition. Computes `self + other`, returning [`None`]
442 /// if overflow occurred.
449 /// use std::time::Duration;
451 /// assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
452 /// assert_eq!(Duration::new(1, 0).checked_add(Duration::new(u64::MAX, 0)), None);
454 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
456 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
457 pub const fn checked_add(self, rhs: Duration) -> Option<Duration> {
458 if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
459 let mut nanos = self.nanos + rhs.nanos;
460 if nanos >= NANOS_PER_SEC {
461 nanos -= NANOS_PER_SEC;
462 if let Some(new_secs) = secs.checked_add(1) {
468 debug_assert!(nanos < NANOS_PER_SEC);
469 Some(Duration { secs, nanos })
475 /// Saturating `Duration` addition. Computes `self + other`, returning [`Duration::MAX`]
476 /// if overflow occurred.
481 /// #![feature(duration_constants)]
482 /// use std::time::Duration;
484 /// assert_eq!(Duration::new(0, 0).saturating_add(Duration::new(0, 1)), Duration::new(0, 1));
485 /// assert_eq!(Duration::new(1, 0).saturating_add(Duration::new(u64::MAX, 0)), Duration::MAX);
487 #[stable(feature = "duration_saturating_ops", since = "1.53.0")]
489 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
490 pub const fn saturating_add(self, rhs: Duration) -> Duration {
491 match self.checked_add(rhs) {
493 None => Duration::MAX,
497 /// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
498 /// if the result would be negative or if overflow occurred.
505 /// use std::time::Duration;
507 /// assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
508 /// assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
510 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
512 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
513 pub const fn checked_sub(self, rhs: Duration) -> Option<Duration> {
514 if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
515 let nanos = if self.nanos >= rhs.nanos {
516 self.nanos - rhs.nanos
518 if let Some(sub_secs) = secs.checked_sub(1) {
520 self.nanos + NANOS_PER_SEC - rhs.nanos
525 debug_assert!(nanos < NANOS_PER_SEC);
526 Some(Duration { secs, nanos })
532 /// Saturating `Duration` subtraction. Computes `self - other`, returning [`Duration::ZERO`]
533 /// if the result would be negative or if overflow occurred.
538 /// use std::time::Duration;
540 /// assert_eq!(Duration::new(0, 1).saturating_sub(Duration::new(0, 0)), Duration::new(0, 1));
541 /// assert_eq!(Duration::new(0, 0).saturating_sub(Duration::new(0, 1)), Duration::ZERO);
543 #[stable(feature = "duration_saturating_ops", since = "1.53.0")]
545 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
546 pub const fn saturating_sub(self, rhs: Duration) -> Duration {
547 match self.checked_sub(rhs) {
549 None => Duration::ZERO,
553 /// Checked `Duration` multiplication. Computes `self * other`, returning
554 /// [`None`] if overflow occurred.
561 /// use std::time::Duration;
563 /// assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
564 /// assert_eq!(Duration::new(u64::MAX - 1, 0).checked_mul(2), None);
566 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
568 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
569 pub const fn checked_mul(self, rhs: u32) -> Option<Duration> {
570 // Multiply nanoseconds as u64, because it cannot overflow that way.
571 let total_nanos = self.nanos as u64 * rhs as u64;
572 let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
573 let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
574 if let Some(s) = self.secs.checked_mul(rhs as u64) {
575 if let Some(secs) = s.checked_add(extra_secs) {
576 debug_assert!(nanos < NANOS_PER_SEC);
577 return Some(Duration { secs, nanos });
583 /// Saturating `Duration` multiplication. Computes `self * other`, returning
584 /// [`Duration::MAX`] if overflow occurred.
589 /// #![feature(duration_constants)]
590 /// use std::time::Duration;
592 /// assert_eq!(Duration::new(0, 500_000_001).saturating_mul(2), Duration::new(1, 2));
593 /// assert_eq!(Duration::new(u64::MAX - 1, 0).saturating_mul(2), Duration::MAX);
595 #[stable(feature = "duration_saturating_ops", since = "1.53.0")]
597 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
598 pub const fn saturating_mul(self, rhs: u32) -> Duration {
599 match self.checked_mul(rhs) {
601 None => Duration::MAX,
605 /// Checked `Duration` division. Computes `self / other`, returning [`None`]
613 /// use std::time::Duration;
615 /// assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
616 /// assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
617 /// assert_eq!(Duration::new(2, 0).checked_div(0), None);
619 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
621 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
622 pub const fn checked_div(self, rhs: u32) -> Option<Duration> {
624 let secs = self.secs / (rhs as u64);
625 let carry = self.secs - secs * (rhs as u64);
626 let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
627 let nanos = self.nanos / rhs + (extra_nanos as u32);
628 debug_assert!(nanos < NANOS_PER_SEC);
629 Some(Duration { secs, nanos })
635 /// Returns the number of seconds contained by this `Duration` as `f64`.
637 /// The returned value does include the fractional (nanosecond) part of the duration.
641 /// use std::time::Duration;
643 /// let dur = Duration::new(2, 700_000_000);
644 /// assert_eq!(dur.as_secs_f64(), 2.7);
646 #[stable(feature = "duration_float", since = "1.38.0")]
648 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
649 pub const fn as_secs_f64(&self) -> f64 {
650 (self.secs as f64) + (self.nanos as f64) / (NANOS_PER_SEC as f64)
653 /// Returns the number of seconds contained by this `Duration` as `f32`.
655 /// The returned value does include the fractional (nanosecond) part of the duration.
659 /// use std::time::Duration;
661 /// let dur = Duration::new(2, 700_000_000);
662 /// assert_eq!(dur.as_secs_f32(), 2.7);
664 #[stable(feature = "duration_float", since = "1.38.0")]
666 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
667 pub const fn as_secs_f32(&self) -> f32 {
668 (self.secs as f32) + (self.nanos as f32) / (NANOS_PER_SEC as f32)
671 /// Creates a new `Duration` from the specified number of seconds represented
675 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
679 /// use std::time::Duration;
681 /// let dur = Duration::from_secs_f64(2.7);
682 /// assert_eq!(dur, Duration::new(2, 700_000_000));
684 #[stable(feature = "duration_float", since = "1.38.0")]
686 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
687 pub const fn from_secs_f64(secs: f64) -> Duration {
688 const MAX_NANOS_F64: f64 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f64;
689 let nanos = secs * (NANOS_PER_SEC as f64);
690 if !nanos.is_finite() {
691 panic!("got non-finite value when converting float to duration");
693 if nanos >= MAX_NANOS_F64 {
694 panic!("overflow when converting float to duration");
697 panic!("underflow when converting float to duration");
699 let nanos = nanos as u128;
701 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
702 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
706 /// Creates a new `Duration` from the specified number of seconds represented
710 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
714 /// use std::time::Duration;
716 /// let dur = Duration::from_secs_f32(2.7);
717 /// assert_eq!(dur, Duration::new(2, 700_000_000));
719 #[stable(feature = "duration_float", since = "1.38.0")]
721 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
722 pub const fn from_secs_f32(secs: f32) -> Duration {
723 const MAX_NANOS_F32: f32 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f32;
724 let nanos = secs * (NANOS_PER_SEC as f32);
725 if !nanos.is_finite() {
726 panic!("got non-finite value when converting float to duration");
728 if nanos >= MAX_NANOS_F32 {
729 panic!("overflow when converting float to duration");
732 panic!("underflow when converting float to duration");
734 let nanos = nanos as u128;
736 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
737 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
741 /// Multiplies `Duration` by `f64`.
744 /// This method will panic if result is not finite, negative or overflows `Duration`.
748 /// use std::time::Duration;
750 /// let dur = Duration::new(2, 700_000_000);
751 /// assert_eq!(dur.mul_f64(3.14), Duration::new(8, 478_000_000));
752 /// assert_eq!(dur.mul_f64(3.14e5), Duration::new(847_800, 0));
754 #[stable(feature = "duration_float", since = "1.38.0")]
756 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
757 pub const fn mul_f64(self, rhs: f64) -> Duration {
758 Duration::from_secs_f64(rhs * self.as_secs_f64())
761 /// Multiplies `Duration` by `f32`.
764 /// This method will panic if result is not finite, negative or overflows `Duration`.
768 /// use std::time::Duration;
770 /// let dur = Duration::new(2, 700_000_000);
771 /// // note that due to rounding errors result is slightly different
772 /// // from 8.478 and 847800.0
773 /// assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_640));
774 /// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847799, 969_120_256));
776 #[stable(feature = "duration_float", since = "1.38.0")]
778 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
779 pub const fn mul_f32(self, rhs: f32) -> Duration {
780 Duration::from_secs_f32(rhs * self.as_secs_f32())
783 /// Divide `Duration` by `f64`.
786 /// This method will panic if result is not finite, negative or overflows `Duration`.
790 /// use std::time::Duration;
792 /// let dur = Duration::new(2, 700_000_000);
793 /// assert_eq!(dur.div_f64(3.14), Duration::new(0, 859_872_611));
794 /// // note that truncation is used, not rounding
795 /// assert_eq!(dur.div_f64(3.14e5), Duration::new(0, 8_598));
797 #[stable(feature = "duration_float", since = "1.38.0")]
799 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
800 pub const fn div_f64(self, rhs: f64) -> Duration {
801 Duration::from_secs_f64(self.as_secs_f64() / rhs)
804 /// Divide `Duration` by `f32`.
807 /// This method will panic if result is not finite, negative or overflows `Duration`.
811 /// use std::time::Duration;
813 /// let dur = Duration::new(2, 700_000_000);
814 /// // note that due to rounding errors result is slightly
815 /// // different from 0.859_872_611
816 /// assert_eq!(dur.div_f32(3.14), Duration::new(0, 859_872_576));
817 /// // note that truncation is used, not rounding
818 /// assert_eq!(dur.div_f32(3.14e5), Duration::new(0, 8_598));
820 #[stable(feature = "duration_float", since = "1.38.0")]
822 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
823 pub const fn div_f32(self, rhs: f32) -> Duration {
824 Duration::from_secs_f32(self.as_secs_f32() / rhs)
827 /// Divide `Duration` by `Duration` and return `f64`.
831 /// #![feature(div_duration)]
832 /// use std::time::Duration;
834 /// let dur1 = Duration::new(2, 700_000_000);
835 /// let dur2 = Duration::new(5, 400_000_000);
836 /// assert_eq!(dur1.div_duration_f64(dur2), 0.5);
838 #[unstable(feature = "div_duration", issue = "63139")]
840 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
841 pub const fn div_duration_f64(self, rhs: Duration) -> f64 {
842 self.as_secs_f64() / rhs.as_secs_f64()
845 /// Divide `Duration` by `Duration` and return `f32`.
849 /// #![feature(div_duration)]
850 /// use std::time::Duration;
852 /// let dur1 = Duration::new(2, 700_000_000);
853 /// let dur2 = Duration::new(5, 400_000_000);
854 /// assert_eq!(dur1.div_duration_f32(dur2), 0.5);
856 #[unstable(feature = "div_duration", issue = "63139")]
858 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
859 pub const fn div_duration_f32(self, rhs: Duration) -> f32 {
860 self.as_secs_f32() / rhs.as_secs_f32()
864 #[stable(feature = "duration", since = "1.3.0")]
865 impl Add for Duration {
866 type Output = Duration;
868 fn add(self, rhs: Duration) -> Duration {
869 self.checked_add(rhs).expect("overflow when adding durations")
873 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
874 impl AddAssign for Duration {
875 fn add_assign(&mut self, rhs: Duration) {
880 #[stable(feature = "duration", since = "1.3.0")]
881 impl Sub for Duration {
882 type Output = Duration;
884 fn sub(self, rhs: Duration) -> Duration {
885 self.checked_sub(rhs).expect("overflow when subtracting durations")
889 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
890 impl SubAssign for Duration {
891 fn sub_assign(&mut self, rhs: Duration) {
896 #[stable(feature = "duration", since = "1.3.0")]
897 impl Mul<u32> for Duration {
898 type Output = Duration;
900 fn mul(self, rhs: u32) -> Duration {
901 self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
905 #[stable(feature = "symmetric_u32_duration_mul", since = "1.31.0")]
906 impl Mul<Duration> for u32 {
907 type Output = Duration;
909 fn mul(self, rhs: Duration) -> Duration {
914 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
915 impl MulAssign<u32> for Duration {
916 fn mul_assign(&mut self, rhs: u32) {
921 #[stable(feature = "duration", since = "1.3.0")]
922 impl Div<u32> for Duration {
923 type Output = Duration;
925 fn div(self, rhs: u32) -> Duration {
926 self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
930 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
931 impl DivAssign<u32> for Duration {
932 fn div_assign(&mut self, rhs: u32) {
937 macro_rules! sum_durations {
939 let mut total_secs: u64 = 0;
940 let mut total_nanos: u64 = 0;
944 total_secs.checked_add(entry.secs).expect("overflow in iter::sum over durations");
945 total_nanos = match total_nanos.checked_add(entry.nanos as u64) {
948 total_secs = total_secs
949 .checked_add(total_nanos / NANOS_PER_SEC as u64)
950 .expect("overflow in iter::sum over durations");
951 (total_nanos % NANOS_PER_SEC as u64) + entry.nanos as u64
955 total_secs = total_secs
956 .checked_add(total_nanos / NANOS_PER_SEC as u64)
957 .expect("overflow in iter::sum over durations");
958 total_nanos = total_nanos % NANOS_PER_SEC as u64;
959 Duration { secs: total_secs, nanos: total_nanos as u32 }
963 #[stable(feature = "duration_sum", since = "1.16.0")]
964 impl Sum for Duration {
965 fn sum<I: Iterator<Item = Duration>>(iter: I) -> Duration {
970 #[stable(feature = "duration_sum", since = "1.16.0")]
971 impl<'a> Sum<&'a Duration> for Duration {
972 fn sum<I: Iterator<Item = &'a Duration>>(iter: I) -> Duration {
977 #[stable(feature = "duration_debug_impl", since = "1.27.0")]
978 impl fmt::Debug for Duration {
979 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
980 /// Formats a floating point number in decimal notation.
982 /// The number is given as the `integer_part` and a fractional part.
983 /// The value of the fractional part is `fractional_part / divisor`. So
984 /// `integer_part` = 3, `fractional_part` = 12 and `divisor` = 100
985 /// represents the number `3.012`. Trailing zeros are omitted.
987 /// `divisor` must not be above 100_000_000. It also should be a power
988 /// of 10, everything else doesn't make sense. `fractional_part` has
989 /// to be less than `10 * divisor`!
991 f: &mut fmt::Formatter<'_>,
992 mut integer_part: u64,
993 mut fractional_part: u32,
996 // Encode the fractional part into a temporary buffer. The buffer
997 // only need to hold 9 elements, because `fractional_part` has to
998 // be smaller than 10^9. The buffer is prefilled with '0' digits
999 // to simplify the code below.
1000 let mut buf = [b'0'; 9];
1002 // The next digit is written at this position
1005 // We keep writing digits into the buffer while there are non-zero
1006 // digits left and we haven't written enough digits yet.
1007 while fractional_part > 0 && pos < f.precision().unwrap_or(9) {
1008 // Write new digit into the buffer
1009 buf[pos] = b'0' + (fractional_part / divisor) as u8;
1011 fractional_part %= divisor;
1016 // If a precision < 9 was specified, there may be some non-zero
1017 // digits left that weren't written into the buffer. In that case we
1018 // need to perform rounding to match the semantics of printing
1019 // normal floating point numbers. However, we only need to do work
1020 // when rounding up. This happens if the first digit of the
1021 // remaining ones is >= 5.
1022 if fractional_part > 0 && fractional_part >= divisor * 5 {
1023 // Round up the number contained in the buffer. We go through
1024 // the buffer backwards and keep track of the carry.
1025 let mut rev_pos = pos;
1026 let mut carry = true;
1027 while carry && rev_pos > 0 {
1030 // If the digit in the buffer is not '9', we just need to
1031 // increment it and can stop then (since we don't have a
1032 // carry anymore). Otherwise, we set it to '0' (overflow)
1034 if buf[rev_pos] < b'9' {
1038 buf[rev_pos] = b'0';
1042 // If we still have the carry bit set, that means that we set
1043 // the whole buffer to '0's and need to increment the integer
1050 // Determine the end of the buffer: if precision is set, we just
1051 // use as many digits from the buffer (capped to 9). If it isn't
1052 // set, we only use all digits up to the last non-zero one.
1053 let end = f.precision().map(|p| crate::cmp::min(p, 9)).unwrap_or(pos);
1055 // If we haven't emitted a single fractional digit and the precision
1056 // wasn't set to a non-zero value, we don't print the decimal point.
1058 write!(f, "{}", integer_part)
1060 // SAFETY: We are only writing ASCII digits into the buffer and it was
1061 // initialized with '0's, so it contains valid UTF8.
1062 let s = unsafe { crate::str::from_utf8_unchecked(&buf[..end]) };
1064 // If the user request a precision > 9, we pad '0's at the end.
1065 let w = f.precision().unwrap_or(pos);
1066 write!(f, "{}.{:0<width$}", integer_part, s, width = w)
1070 // Print leading '+' sign if requested
1076 fmt_decimal(f, self.secs, self.nanos, NANOS_PER_SEC / 10)?;
1078 } else if self.nanos >= NANOS_PER_MILLI {
1081 (self.nanos / NANOS_PER_MILLI) as u64,
1082 self.nanos % NANOS_PER_MILLI,
1083 NANOS_PER_MILLI / 10,
1086 } else if self.nanos >= NANOS_PER_MICRO {
1089 (self.nanos / NANOS_PER_MICRO) as u64,
1090 self.nanos % NANOS_PER_MICRO,
1091 NANOS_PER_MICRO / 10,
1095 fmt_decimal(f, self.nanos as u64, 0, 1)?;