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 /// #![feature(duration_zero)]
128 /// use std::time::Duration;
130 /// let duration = Duration::ZERO;
131 /// assert!(duration.is_zero());
132 /// assert_eq!(duration.as_nanos(), 0);
134 #[unstable(feature = "duration_zero", issue = "73544")]
135 pub const ZERO: Duration = Duration::from_nanos(0);
137 /// The maximum duration.
139 /// It is roughly equal to a duration of 584,942,417,355 years.
144 /// #![feature(duration_constants)]
145 /// use std::time::Duration;
147 /// assert_eq!(Duration::MAX, Duration::new(u64::MAX, 1_000_000_000 - 1));
149 #[unstable(feature = "duration_constants", issue = "57391")]
150 pub const MAX: Duration = Duration::new(u64::MAX, NANOS_PER_SEC - 1);
152 /// Creates a new `Duration` from the specified number of whole seconds and
153 /// additional nanoseconds.
155 /// If the number of nanoseconds is greater than 1 billion (the number of
156 /// nanoseconds in a second), then it will carry over into the seconds provided.
160 /// This constructor will panic if the carry from the nanoseconds overflows
161 /// the seconds counter.
166 /// use std::time::Duration;
168 /// let five_seconds = Duration::new(5, 0);
170 #[stable(feature = "duration", since = "1.3.0")]
172 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
173 pub const fn new(secs: u64, nanos: u32) -> Duration {
174 let secs = match secs.checked_add((nanos / NANOS_PER_SEC) as u64) {
176 None => panic!("overflow in Duration::new"),
178 let nanos = nanos % NANOS_PER_SEC;
179 Duration { secs, nanos }
182 /// Creates a new `Duration` from the specified number of whole seconds.
187 /// use std::time::Duration;
189 /// let duration = Duration::from_secs(5);
191 /// assert_eq!(5, duration.as_secs());
192 /// assert_eq!(0, duration.subsec_nanos());
194 #[stable(feature = "duration", since = "1.3.0")]
196 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
197 pub const fn from_secs(secs: u64) -> Duration {
198 Duration { secs, nanos: 0 }
201 /// Creates a new `Duration` from the specified number of milliseconds.
206 /// use std::time::Duration;
208 /// let duration = Duration::from_millis(2569);
210 /// assert_eq!(2, duration.as_secs());
211 /// assert_eq!(569_000_000, duration.subsec_nanos());
213 #[stable(feature = "duration", since = "1.3.0")]
215 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
216 pub const fn from_millis(millis: u64) -> Duration {
218 secs: millis / MILLIS_PER_SEC,
219 nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI,
223 /// Creates a new `Duration` from the specified number of microseconds.
228 /// use std::time::Duration;
230 /// let duration = Duration::from_micros(1_000_002);
232 /// assert_eq!(1, duration.as_secs());
233 /// assert_eq!(2000, duration.subsec_nanos());
235 #[stable(feature = "duration_from_micros", since = "1.27.0")]
237 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
238 pub const fn from_micros(micros: u64) -> Duration {
240 secs: micros / MICROS_PER_SEC,
241 nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO,
245 /// Creates a new `Duration` from the specified number of nanoseconds.
250 /// use std::time::Duration;
252 /// let duration = Duration::from_nanos(1_000_000_123);
254 /// assert_eq!(1, duration.as_secs());
255 /// assert_eq!(123, duration.subsec_nanos());
257 #[stable(feature = "duration_extras", since = "1.27.0")]
259 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
260 pub const fn from_nanos(nanos: u64) -> Duration {
262 secs: nanos / (NANOS_PER_SEC as u64),
263 nanos: (nanos % (NANOS_PER_SEC as u64)) as u32,
267 /// Returns true if this `Duration` spans no time.
272 /// #![feature(duration_zero)]
273 /// use std::time::Duration;
275 /// assert!(Duration::ZERO.is_zero());
276 /// assert!(Duration::new(0, 0).is_zero());
277 /// assert!(Duration::from_nanos(0).is_zero());
278 /// assert!(Duration::from_secs(0).is_zero());
280 /// assert!(!Duration::new(1, 1).is_zero());
281 /// assert!(!Duration::from_nanos(1).is_zero());
282 /// assert!(!Duration::from_secs(1).is_zero());
284 #[unstable(feature = "duration_zero", issue = "73544")]
286 pub const fn is_zero(&self) -> bool {
287 self.secs == 0 && self.nanos == 0
290 /// Returns the number of _whole_ seconds contained by this `Duration`.
292 /// The returned value does not include the fractional (nanosecond) part of the
293 /// duration, which can be obtained using [`subsec_nanos`].
298 /// use std::time::Duration;
300 /// let duration = Duration::new(5, 730023852);
301 /// assert_eq!(duration.as_secs(), 5);
304 /// To determine the total number of seconds represented by the `Duration`,
305 /// use `as_secs` in combination with [`subsec_nanos`]:
308 /// use std::time::Duration;
310 /// let duration = Duration::new(5, 730023852);
312 /// assert_eq!(5.730023852,
313 /// duration.as_secs() as f64
314 /// + duration.subsec_nanos() as f64 * 1e-9);
317 /// [`subsec_nanos`]: Duration::subsec_nanos
318 #[stable(feature = "duration", since = "1.3.0")]
319 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
321 pub const fn as_secs(&self) -> u64 {
325 /// Returns the fractional part of this `Duration`, in whole milliseconds.
327 /// This method does **not** return the length of the duration when
328 /// represented by milliseconds. The returned number always represents a
329 /// fractional portion of a second (i.e., it is less than one thousand).
334 /// use std::time::Duration;
336 /// let duration = Duration::from_millis(5432);
337 /// assert_eq!(duration.as_secs(), 5);
338 /// assert_eq!(duration.subsec_millis(), 432);
340 #[stable(feature = "duration_extras", since = "1.27.0")]
341 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
343 pub const fn subsec_millis(&self) -> u32 {
344 self.nanos / NANOS_PER_MILLI
347 /// Returns the fractional part of this `Duration`, in whole microseconds.
349 /// This method does **not** return the length of the duration when
350 /// represented by microseconds. The returned number always represents a
351 /// fractional portion of a second (i.e., it is less than one million).
356 /// use std::time::Duration;
358 /// let duration = Duration::from_micros(1_234_567);
359 /// assert_eq!(duration.as_secs(), 1);
360 /// assert_eq!(duration.subsec_micros(), 234_567);
362 #[stable(feature = "duration_extras", since = "1.27.0")]
363 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
365 pub const fn subsec_micros(&self) -> u32 {
366 self.nanos / NANOS_PER_MICRO
369 /// Returns the fractional part of this `Duration`, in nanoseconds.
371 /// This method does **not** return the length of the duration when
372 /// represented by nanoseconds. The returned number always represents a
373 /// fractional portion of a second (i.e., it is less than one billion).
378 /// use std::time::Duration;
380 /// let duration = Duration::from_millis(5010);
381 /// assert_eq!(duration.as_secs(), 5);
382 /// assert_eq!(duration.subsec_nanos(), 10_000_000);
384 #[stable(feature = "duration", since = "1.3.0")]
385 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
387 pub const fn subsec_nanos(&self) -> u32 {
391 /// Returns the total number of whole milliseconds contained by this `Duration`.
396 /// use std::time::Duration;
398 /// let duration = Duration::new(5, 730023852);
399 /// assert_eq!(duration.as_millis(), 5730);
401 #[stable(feature = "duration_as_u128", since = "1.33.0")]
402 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
404 pub const fn as_millis(&self) -> u128 {
405 self.secs as u128 * MILLIS_PER_SEC as u128 + (self.nanos / NANOS_PER_MILLI) as u128
408 /// Returns the total number of whole microseconds contained by this `Duration`.
413 /// use std::time::Duration;
415 /// let duration = Duration::new(5, 730023852);
416 /// assert_eq!(duration.as_micros(), 5730023);
418 #[stable(feature = "duration_as_u128", since = "1.33.0")]
419 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
421 pub const fn as_micros(&self) -> u128 {
422 self.secs as u128 * MICROS_PER_SEC as u128 + (self.nanos / NANOS_PER_MICRO) as u128
425 /// Returns the total number of nanoseconds contained by this `Duration`.
430 /// use std::time::Duration;
432 /// let duration = Duration::new(5, 730023852);
433 /// assert_eq!(duration.as_nanos(), 5730023852);
435 #[stable(feature = "duration_as_u128", since = "1.33.0")]
436 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
438 pub const fn as_nanos(&self) -> u128 {
439 self.secs as u128 * NANOS_PER_SEC as u128 + self.nanos as u128
442 /// Checked `Duration` addition. Computes `self + other`, returning [`None`]
443 /// if overflow occurred.
450 /// use std::time::Duration;
452 /// assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
453 /// assert_eq!(Duration::new(1, 0).checked_add(Duration::new(u64::MAX, 0)), None);
455 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
457 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
458 pub const fn checked_add(self, rhs: Duration) -> Option<Duration> {
459 if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
460 let mut nanos = self.nanos + rhs.nanos;
461 if nanos >= NANOS_PER_SEC {
462 nanos -= NANOS_PER_SEC;
463 if let Some(new_secs) = secs.checked_add(1) {
469 debug_assert!(nanos < NANOS_PER_SEC);
470 Some(Duration { secs, nanos })
476 /// Saturating `Duration` addition. Computes `self + other`, returning [`Duration::MAX`]
477 /// if overflow occurred.
482 /// #![feature(duration_saturating_ops)]
483 /// #![feature(duration_constants)]
484 /// use std::time::Duration;
486 /// assert_eq!(Duration::new(0, 0).saturating_add(Duration::new(0, 1)), Duration::new(0, 1));
487 /// assert_eq!(Duration::new(1, 0).saturating_add(Duration::new(u64::MAX, 0)), Duration::MAX);
489 #[unstable(feature = "duration_saturating_ops", issue = "76416")]
491 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
492 pub const fn saturating_add(self, rhs: Duration) -> Duration {
493 match self.checked_add(rhs) {
495 None => Duration::MAX,
499 /// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
500 /// if the result would be negative or if overflow occurred.
507 /// use std::time::Duration;
509 /// assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
510 /// assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
512 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
514 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
515 pub const fn checked_sub(self, rhs: Duration) -> Option<Duration> {
516 if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
517 let nanos = if self.nanos >= rhs.nanos {
518 self.nanos - rhs.nanos
520 if let Some(sub_secs) = secs.checked_sub(1) {
522 self.nanos + NANOS_PER_SEC - rhs.nanos
527 debug_assert!(nanos < NANOS_PER_SEC);
528 Some(Duration { secs, nanos })
534 /// Saturating `Duration` subtraction. Computes `self - other`, returning [`Duration::ZERO`]
535 /// if the result would be negative or if overflow occurred.
540 /// #![feature(duration_saturating_ops)]
541 /// #![feature(duration_zero)]
542 /// use std::time::Duration;
544 /// assert_eq!(Duration::new(0, 1).saturating_sub(Duration::new(0, 0)), Duration::new(0, 1));
545 /// assert_eq!(Duration::new(0, 0).saturating_sub(Duration::new(0, 1)), Duration::ZERO);
547 #[unstable(feature = "duration_saturating_ops", issue = "76416")]
549 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
550 pub const fn saturating_sub(self, rhs: Duration) -> Duration {
551 match self.checked_sub(rhs) {
553 None => Duration::ZERO,
557 /// Checked `Duration` multiplication. Computes `self * other`, returning
558 /// [`None`] if overflow occurred.
565 /// use std::time::Duration;
567 /// assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
568 /// assert_eq!(Duration::new(u64::MAX - 1, 0).checked_mul(2), None);
570 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
572 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
573 pub const fn checked_mul(self, rhs: u32) -> Option<Duration> {
574 // Multiply nanoseconds as u64, because it cannot overflow that way.
575 let total_nanos = self.nanos as u64 * rhs as u64;
576 let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
577 let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
578 if let Some(s) = self.secs.checked_mul(rhs as u64) {
579 if let Some(secs) = s.checked_add(extra_secs) {
580 debug_assert!(nanos < NANOS_PER_SEC);
581 return Some(Duration { secs, nanos });
587 /// Saturating `Duration` multiplication. Computes `self * other`, returning
588 /// [`Duration::MAX`] if overflow occurred.
593 /// #![feature(duration_saturating_ops)]
594 /// #![feature(duration_constants)]
595 /// use std::time::Duration;
597 /// assert_eq!(Duration::new(0, 500_000_001).saturating_mul(2), Duration::new(1, 2));
598 /// assert_eq!(Duration::new(u64::MAX - 1, 0).saturating_mul(2), Duration::MAX);
600 #[unstable(feature = "duration_saturating_ops", issue = "76416")]
602 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
603 pub const fn saturating_mul(self, rhs: u32) -> Duration {
604 match self.checked_mul(rhs) {
606 None => Duration::MAX,
610 /// Checked `Duration` division. Computes `self / other`, returning [`None`]
618 /// use std::time::Duration;
620 /// assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
621 /// assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
622 /// assert_eq!(Duration::new(2, 0).checked_div(0), None);
624 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
626 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
627 pub const fn checked_div(self, rhs: u32) -> Option<Duration> {
629 let secs = self.secs / (rhs as u64);
630 let carry = self.secs - secs * (rhs as u64);
631 let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
632 let nanos = self.nanos / rhs + (extra_nanos as u32);
633 debug_assert!(nanos < NANOS_PER_SEC);
634 Some(Duration { secs, nanos })
640 /// Returns the number of seconds contained by this `Duration` as `f64`.
642 /// The returned value does include the fractional (nanosecond) part of the duration.
646 /// use std::time::Duration;
648 /// let dur = Duration::new(2, 700_000_000);
649 /// assert_eq!(dur.as_secs_f64(), 2.7);
651 #[stable(feature = "duration_float", since = "1.38.0")]
653 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
654 pub const fn as_secs_f64(&self) -> f64 {
655 (self.secs as f64) + (self.nanos as f64) / (NANOS_PER_SEC as f64)
658 /// Returns the number of seconds contained by this `Duration` as `f32`.
660 /// The returned value does include the fractional (nanosecond) part of the duration.
664 /// use std::time::Duration;
666 /// let dur = Duration::new(2, 700_000_000);
667 /// assert_eq!(dur.as_secs_f32(), 2.7);
669 #[stable(feature = "duration_float", since = "1.38.0")]
671 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
672 pub const fn as_secs_f32(&self) -> f32 {
673 (self.secs as f32) + (self.nanos as f32) / (NANOS_PER_SEC as f32)
676 /// Creates a new `Duration` from the specified number of seconds represented
680 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
684 /// use std::time::Duration;
686 /// let dur = Duration::from_secs_f64(2.7);
687 /// assert_eq!(dur, Duration::new(2, 700_000_000));
689 #[stable(feature = "duration_float", since = "1.38.0")]
691 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
692 pub const fn from_secs_f64(secs: f64) -> Duration {
693 const MAX_NANOS_F64: f64 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f64;
694 let nanos = secs * (NANOS_PER_SEC as f64);
695 if !nanos.is_finite() {
696 panic!("got non-finite value when converting float to duration");
698 if nanos >= MAX_NANOS_F64 {
699 panic!("overflow when converting float to duration");
702 panic!("underflow when converting float to duration");
704 let nanos = nanos as u128;
706 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
707 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
711 /// Creates a new `Duration` from the specified number of seconds represented
715 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
719 /// use std::time::Duration;
721 /// let dur = Duration::from_secs_f32(2.7);
722 /// assert_eq!(dur, Duration::new(2, 700_000_000));
724 #[stable(feature = "duration_float", since = "1.38.0")]
726 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
727 pub const fn from_secs_f32(secs: f32) -> Duration {
728 const MAX_NANOS_F32: f32 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f32;
729 let nanos = secs * (NANOS_PER_SEC as f32);
730 if !nanos.is_finite() {
731 panic!("got non-finite value when converting float to duration");
733 if nanos >= MAX_NANOS_F32 {
734 panic!("overflow when converting float to duration");
737 panic!("underflow when converting float to duration");
739 let nanos = nanos as u128;
741 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
742 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
746 /// Multiplies `Duration` by `f64`.
749 /// This method will panic if result is not finite, negative or overflows `Duration`.
753 /// use std::time::Duration;
755 /// let dur = Duration::new(2, 700_000_000);
756 /// assert_eq!(dur.mul_f64(3.14), Duration::new(8, 478_000_000));
757 /// assert_eq!(dur.mul_f64(3.14e5), Duration::new(847_800, 0));
759 #[stable(feature = "duration_float", since = "1.38.0")]
761 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
762 pub const fn mul_f64(self, rhs: f64) -> Duration {
763 Duration::from_secs_f64(rhs * self.as_secs_f64())
766 /// Multiplies `Duration` by `f32`.
769 /// This method will panic if result is not finite, negative or overflows `Duration`.
773 /// use std::time::Duration;
775 /// let dur = Duration::new(2, 700_000_000);
776 /// // note that due to rounding errors result is slightly different
777 /// // from 8.478 and 847800.0
778 /// assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_640));
779 /// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847799, 969_120_256));
781 #[stable(feature = "duration_float", since = "1.38.0")]
783 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
784 pub const fn mul_f32(self, rhs: f32) -> Duration {
785 Duration::from_secs_f32(rhs * self.as_secs_f32())
788 /// Divide `Duration` by `f64`.
791 /// This method will panic if result is not finite, negative or overflows `Duration`.
795 /// use std::time::Duration;
797 /// let dur = Duration::new(2, 700_000_000);
798 /// assert_eq!(dur.div_f64(3.14), Duration::new(0, 859_872_611));
799 /// // note that truncation is used, not rounding
800 /// assert_eq!(dur.div_f64(3.14e5), Duration::new(0, 8_598));
802 #[stable(feature = "duration_float", since = "1.38.0")]
804 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
805 pub const 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 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
828 pub const fn div_f32(self, rhs: f32) -> Duration {
829 Duration::from_secs_f32(self.as_secs_f32() / rhs)
832 /// Divide `Duration` by `Duration` and return `f64`.
836 /// #![feature(div_duration)]
837 /// use std::time::Duration;
839 /// let dur1 = Duration::new(2, 700_000_000);
840 /// let dur2 = Duration::new(5, 400_000_000);
841 /// assert_eq!(dur1.div_duration_f64(dur2), 0.5);
843 #[unstable(feature = "div_duration", issue = "63139")]
845 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
846 pub const fn div_duration_f64(self, rhs: Duration) -> f64 {
847 self.as_secs_f64() / rhs.as_secs_f64()
850 /// Divide `Duration` by `Duration` and return `f32`.
854 /// #![feature(div_duration)]
855 /// use std::time::Duration;
857 /// let dur1 = Duration::new(2, 700_000_000);
858 /// let dur2 = Duration::new(5, 400_000_000);
859 /// assert_eq!(dur1.div_duration_f32(dur2), 0.5);
861 #[unstable(feature = "div_duration", issue = "63139")]
863 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
864 pub const fn div_duration_f32(self, rhs: Duration) -> f32 {
865 self.as_secs_f32() / rhs.as_secs_f32()
869 #[stable(feature = "duration", since = "1.3.0")]
870 impl Add for Duration {
871 type Output = Duration;
873 fn add(self, rhs: Duration) -> Duration {
874 self.checked_add(rhs).expect("overflow when adding durations")
878 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
879 impl AddAssign for Duration {
880 fn add_assign(&mut self, rhs: Duration) {
885 #[stable(feature = "duration", since = "1.3.0")]
886 impl Sub for Duration {
887 type Output = Duration;
889 fn sub(self, rhs: Duration) -> Duration {
890 self.checked_sub(rhs).expect("overflow when subtracting durations")
894 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
895 impl SubAssign for Duration {
896 fn sub_assign(&mut self, rhs: Duration) {
901 #[stable(feature = "duration", since = "1.3.0")]
902 impl Mul<u32> for Duration {
903 type Output = Duration;
905 fn mul(self, rhs: u32) -> Duration {
906 self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
910 #[stable(feature = "symmetric_u32_duration_mul", since = "1.31.0")]
911 impl Mul<Duration> for u32 {
912 type Output = Duration;
914 fn mul(self, rhs: Duration) -> Duration {
919 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
920 impl MulAssign<u32> for Duration {
921 fn mul_assign(&mut self, rhs: u32) {
926 #[stable(feature = "duration", since = "1.3.0")]
927 impl Div<u32> for Duration {
928 type Output = Duration;
930 fn div(self, rhs: u32) -> Duration {
931 self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
935 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
936 impl DivAssign<u32> for Duration {
937 fn div_assign(&mut self, rhs: u32) {
942 macro_rules! sum_durations {
944 let mut total_secs: u64 = 0;
945 let mut total_nanos: u64 = 0;
949 total_secs.checked_add(entry.secs).expect("overflow in iter::sum over durations");
950 total_nanos = match total_nanos.checked_add(entry.nanos as u64) {
953 total_secs = total_secs
954 .checked_add(total_nanos / NANOS_PER_SEC as u64)
955 .expect("overflow in iter::sum over durations");
956 (total_nanos % NANOS_PER_SEC as u64) + entry.nanos as u64
960 total_secs = total_secs
961 .checked_add(total_nanos / NANOS_PER_SEC as u64)
962 .expect("overflow in iter::sum over durations");
963 total_nanos = total_nanos % NANOS_PER_SEC as u64;
964 Duration { secs: total_secs, nanos: total_nanos as u32 }
968 #[stable(feature = "duration_sum", since = "1.16.0")]
969 impl Sum for Duration {
970 fn sum<I: Iterator<Item = Duration>>(iter: I) -> Duration {
975 #[stable(feature = "duration_sum", since = "1.16.0")]
976 impl<'a> Sum<&'a Duration> for Duration {
977 fn sum<I: Iterator<Item = &'a Duration>>(iter: I) -> Duration {
982 #[stable(feature = "duration_debug_impl", since = "1.27.0")]
983 impl fmt::Debug for Duration {
984 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
985 /// Formats a floating point number in decimal notation.
987 /// The number is given as the `integer_part` and a fractional part.
988 /// The value of the fractional part is `fractional_part / divisor`. So
989 /// `integer_part` = 3, `fractional_part` = 12 and `divisor` = 100
990 /// represents the number `3.012`. Trailing zeros are omitted.
992 /// `divisor` must not be above 100_000_000. It also should be a power
993 /// of 10, everything else doesn't make sense. `fractional_part` has
994 /// to be less than `10 * divisor`!
996 f: &mut fmt::Formatter<'_>,
997 mut integer_part: u64,
998 mut fractional_part: u32,
1001 // Encode the fractional part into a temporary buffer. The buffer
1002 // only need to hold 9 elements, because `fractional_part` has to
1003 // be smaller than 10^9. The buffer is prefilled with '0' digits
1004 // to simplify the code below.
1005 let mut buf = [b'0'; 9];
1007 // The next digit is written at this position
1010 // We keep writing digits into the buffer while there are non-zero
1011 // digits left and we haven't written enough digits yet.
1012 while fractional_part > 0 && pos < f.precision().unwrap_or(9) {
1013 // Write new digit into the buffer
1014 buf[pos] = b'0' + (fractional_part / divisor) as u8;
1016 fractional_part %= divisor;
1021 // If a precision < 9 was specified, there may be some non-zero
1022 // digits left that weren't written into the buffer. In that case we
1023 // need to perform rounding to match the semantics of printing
1024 // normal floating point numbers. However, we only need to do work
1025 // when rounding up. This happens if the first digit of the
1026 // remaining ones is >= 5.
1027 if fractional_part > 0 && fractional_part >= divisor * 5 {
1028 // Round up the number contained in the buffer. We go through
1029 // the buffer backwards and keep track of the carry.
1030 let mut rev_pos = pos;
1031 let mut carry = true;
1032 while carry && rev_pos > 0 {
1035 // If the digit in the buffer is not '9', we just need to
1036 // increment it and can stop then (since we don't have a
1037 // carry anymore). Otherwise, we set it to '0' (overflow)
1039 if buf[rev_pos] < b'9' {
1043 buf[rev_pos] = b'0';
1047 // If we still have the carry bit set, that means that we set
1048 // the whole buffer to '0's and need to increment the integer
1055 // Determine the end of the buffer: if precision is set, we just
1056 // use as many digits from the buffer (capped to 9). If it isn't
1057 // set, we only use all digits up to the last non-zero one.
1058 let end = f.precision().map(|p| crate::cmp::min(p, 9)).unwrap_or(pos);
1060 // If we haven't emitted a single fractional digit and the precision
1061 // wasn't set to a non-zero value, we don't print the decimal point.
1063 write!(f, "{}", integer_part)
1065 // SAFETY: We are only writing ASCII digits into the buffer and it was
1066 // initialized with '0's, so it contains valid UTF8.
1067 let s = unsafe { crate::str::from_utf8_unchecked(&buf[..end]) };
1069 // If the user request a precision > 9, we pad '0's at the end.
1070 let w = f.precision().unwrap_or(pos);
1071 write!(f, "{}.{:0<width$}", integer_part, s, width = w)
1075 // Print leading '+' sign if requested
1081 fmt_decimal(f, self.secs, self.nanos, NANOS_PER_SEC / 10)?;
1083 } else if self.nanos >= NANOS_PER_MILLI {
1086 (self.nanos / NANOS_PER_MILLI) as u64,
1087 self.nanos % NANOS_PER_MILLI,
1088 NANOS_PER_MILLI / 10,
1091 } else if self.nanos >= NANOS_PER_MICRO {
1094 (self.nanos / NANOS_PER_MICRO) as u64,
1095 self.nanos % NANOS_PER_MICRO,
1096 NANOS_PER_MICRO / 10,
1100 fmt_decimal(f, self.nanos as u64, 0, 1)?;