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 /// [`Add`]: ../../std/ops/trait.Add.html
37 /// [`Sub`]: ../../std/ops/trait.Sub.html
38 /// [`ops`]: ../../std/ops/index.html
43 /// use std::time::Duration;
45 /// let five_seconds = Duration::new(5, 0);
46 /// let five_seconds_and_five_nanos = five_seconds + Duration::new(0, 5);
48 /// assert_eq!(five_seconds_and_five_nanos.as_secs(), 5);
49 /// assert_eq!(five_seconds_and_five_nanos.subsec_nanos(), 5);
51 /// let ten_millis = Duration::from_millis(10);
53 #[stable(feature = "duration", since = "1.3.0")]
54 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
57 nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC
61 /// The duration of one second.
66 /// #![feature(duration_constants)]
67 /// use std::time::Duration;
69 /// assert_eq!(Duration::SECOND, Duration::from_secs(1));
71 #[unstable(feature = "duration_constants", issue = "57391")]
72 pub const SECOND: Duration = Duration::from_secs(1);
74 /// The duration of one millisecond.
79 /// #![feature(duration_constants)]
80 /// use std::time::Duration;
82 /// assert_eq!(Duration::MILLISECOND, Duration::from_millis(1));
84 #[unstable(feature = "duration_constants", issue = "57391")]
85 pub const MILLISECOND: Duration = Duration::from_millis(1);
87 /// The duration of one microsecond.
92 /// #![feature(duration_constants)]
93 /// use std::time::Duration;
95 /// assert_eq!(Duration::MICROSECOND, Duration::from_micros(1));
97 #[unstable(feature = "duration_constants", issue = "57391")]
98 pub const MICROSECOND: Duration = Duration::from_micros(1);
100 /// The duration of one nanosecond.
105 /// #![feature(duration_constants)]
106 /// use std::time::Duration;
108 /// assert_eq!(Duration::NANOSECOND, Duration::from_nanos(1));
110 #[unstable(feature = "duration_constants", issue = "57391")]
111 pub const NANOSECOND: Duration = Duration::from_nanos(1);
113 /// Creates a new `Duration` from the specified number of whole seconds and
114 /// additional nanoseconds.
116 /// If the number of nanoseconds is greater than 1 billion (the number of
117 /// nanoseconds in a second), then it will carry over into the seconds provided.
121 /// This constructor will panic if the carry from the nanoseconds overflows
122 /// the seconds counter.
127 /// use std::time::Duration;
129 /// let five_seconds = Duration::new(5, 0);
131 #[stable(feature = "duration", since = "1.3.0")]
133 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
134 pub const fn new(secs: u64, nanos: u32) -> Duration {
135 let secs = match secs.checked_add((nanos / NANOS_PER_SEC) as u64) {
137 None => panic!("overflow in Duration::new"),
139 let nanos = nanos % NANOS_PER_SEC;
140 Duration { secs, nanos }
143 /// Creates a new `Duration` that spans no time.
148 /// #![feature(duration_zero)]
149 /// use std::time::Duration;
151 /// let duration = Duration::zero();
152 /// assert!(duration.is_zero());
153 /// assert_eq!(duration.as_nanos(), 0);
155 #[unstable(feature = "duration_zero", issue = "73544")]
157 pub const fn zero() -> Duration {
158 Duration { secs: 0, nanos: 0 }
161 /// Creates a new `Duration` from the specified number of whole seconds.
166 /// use std::time::Duration;
168 /// let duration = Duration::from_secs(5);
170 /// assert_eq!(5, duration.as_secs());
171 /// assert_eq!(0, duration.subsec_nanos());
173 #[stable(feature = "duration", since = "1.3.0")]
175 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
176 pub const fn from_secs(secs: u64) -> Duration {
177 Duration { secs, nanos: 0 }
180 /// Creates a new `Duration` from the specified number of milliseconds.
185 /// use std::time::Duration;
187 /// let duration = Duration::from_millis(2569);
189 /// assert_eq!(2, duration.as_secs());
190 /// assert_eq!(569_000_000, duration.subsec_nanos());
192 #[stable(feature = "duration", since = "1.3.0")]
194 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
195 pub const fn from_millis(millis: u64) -> Duration {
197 secs: millis / MILLIS_PER_SEC,
198 nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI,
202 /// Creates a new `Duration` from the specified number of microseconds.
207 /// use std::time::Duration;
209 /// let duration = Duration::from_micros(1_000_002);
211 /// assert_eq!(1, duration.as_secs());
212 /// assert_eq!(2000, duration.subsec_nanos());
214 #[stable(feature = "duration_from_micros", since = "1.27.0")]
216 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
217 pub const fn from_micros(micros: u64) -> Duration {
219 secs: micros / MICROS_PER_SEC,
220 nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO,
224 /// Creates a new `Duration` from the specified number of nanoseconds.
229 /// use std::time::Duration;
231 /// let duration = Duration::from_nanos(1_000_000_123);
233 /// assert_eq!(1, duration.as_secs());
234 /// assert_eq!(123, duration.subsec_nanos());
236 #[stable(feature = "duration_extras", since = "1.27.0")]
238 #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
239 pub const fn from_nanos(nanos: u64) -> Duration {
241 secs: nanos / (NANOS_PER_SEC as u64),
242 nanos: (nanos % (NANOS_PER_SEC as u64)) as u32,
246 /// Returns true if this `Duration` spans no time.
251 /// #![feature(duration_zero)]
252 /// use std::time::Duration;
254 /// assert!(Duration::zero().is_zero());
255 /// assert!(Duration::new(0, 0).is_zero());
256 /// assert!(Duration::from_nanos(0).is_zero());
257 /// assert!(Duration::from_secs(0).is_zero());
259 /// assert!(!Duration::new(1, 1).is_zero());
260 /// assert!(!Duration::from_nanos(1).is_zero());
261 /// assert!(!Duration::from_secs(1).is_zero());
263 #[unstable(feature = "duration_zero", issue = "73544")]
265 pub const fn is_zero(&self) -> bool {
266 self.secs == 0 && self.nanos == 0
269 /// Returns the number of _whole_ seconds contained by this `Duration`.
271 /// The returned value does not include the fractional (nanosecond) part of the
272 /// duration, which can be obtained using [`subsec_nanos`].
277 /// use std::time::Duration;
279 /// let duration = Duration::new(5, 730023852);
280 /// assert_eq!(duration.as_secs(), 5);
283 /// To determine the total number of seconds represented by the `Duration`,
284 /// use `as_secs` in combination with [`subsec_nanos`]:
287 /// use std::time::Duration;
289 /// let duration = Duration::new(5, 730023852);
291 /// assert_eq!(5.730023852,
292 /// duration.as_secs() as f64
293 /// + duration.subsec_nanos() as f64 * 1e-9);
296 /// [`subsec_nanos`]: #method.subsec_nanos
297 #[stable(feature = "duration", since = "1.3.0")]
298 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
300 pub const fn as_secs(&self) -> u64 {
304 /// Returns the fractional part of this `Duration`, in whole milliseconds.
306 /// This method does **not** return the length of the duration when
307 /// represented by milliseconds. The returned number always represents a
308 /// fractional portion of a second (i.e., it is less than one thousand).
313 /// use std::time::Duration;
315 /// let duration = Duration::from_millis(5432);
316 /// assert_eq!(duration.as_secs(), 5);
317 /// assert_eq!(duration.subsec_millis(), 432);
319 #[stable(feature = "duration_extras", since = "1.27.0")]
320 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
322 pub const fn subsec_millis(&self) -> u32 {
323 self.nanos / NANOS_PER_MILLI
326 /// Returns the fractional part of this `Duration`, in whole microseconds.
328 /// This method does **not** return the length of the duration when
329 /// represented by microseconds. The returned number always represents a
330 /// fractional portion of a second (i.e., it is less than one million).
335 /// use std::time::Duration;
337 /// let duration = Duration::from_micros(1_234_567);
338 /// assert_eq!(duration.as_secs(), 1);
339 /// assert_eq!(duration.subsec_micros(), 234_567);
341 #[stable(feature = "duration_extras", since = "1.27.0")]
342 #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
344 pub const fn subsec_micros(&self) -> u32 {
345 self.nanos / NANOS_PER_MICRO
348 /// Returns the fractional part of this `Duration`, in nanoseconds.
350 /// This method does **not** return the length of the duration when
351 /// represented by nanoseconds. The returned number always represents a
352 /// fractional portion of a second (i.e., it is less than one billion).
357 /// use std::time::Duration;
359 /// let duration = Duration::from_millis(5010);
360 /// assert_eq!(duration.as_secs(), 5);
361 /// assert_eq!(duration.subsec_nanos(), 10_000_000);
363 #[stable(feature = "duration", since = "1.3.0")]
364 #[rustc_const_stable(feature = "duration", since = "1.32.0")]
366 pub const fn subsec_nanos(&self) -> u32 {
370 /// Returns the total number of whole milliseconds contained by this `Duration`.
375 /// use std::time::Duration;
377 /// let duration = Duration::new(5, 730023852);
378 /// assert_eq!(duration.as_millis(), 5730);
380 #[stable(feature = "duration_as_u128", since = "1.33.0")]
381 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
383 pub const fn as_millis(&self) -> u128 {
384 self.secs as u128 * MILLIS_PER_SEC as u128 + (self.nanos / NANOS_PER_MILLI) as u128
387 /// Returns the total number of whole microseconds contained by this `Duration`.
392 /// use std::time::Duration;
394 /// let duration = Duration::new(5, 730023852);
395 /// assert_eq!(duration.as_micros(), 5730023);
397 #[stable(feature = "duration_as_u128", since = "1.33.0")]
398 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
400 pub const fn as_micros(&self) -> u128 {
401 self.secs as u128 * MICROS_PER_SEC as u128 + (self.nanos / NANOS_PER_MICRO) as u128
404 /// Returns the total number of nanoseconds contained by this `Duration`.
409 /// use std::time::Duration;
411 /// let duration = Duration::new(5, 730023852);
412 /// assert_eq!(duration.as_nanos(), 5730023852);
414 #[stable(feature = "duration_as_u128", since = "1.33.0")]
415 #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
417 pub const fn as_nanos(&self) -> u128 {
418 self.secs as u128 * NANOS_PER_SEC as u128 + self.nanos as u128
421 /// Checked `Duration` addition. Computes `self + other`, returning [`None`]
422 /// if overflow occurred.
424 /// [`None`]: ../../std/option/enum.Option.html#variant.None
431 /// use std::time::Duration;
433 /// assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
434 /// assert_eq!(Duration::new(1, 0).checked_add(Duration::new(u64::MAX, 0)), None);
436 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
438 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
439 pub const fn checked_add(self, rhs: Duration) -> Option<Duration> {
440 if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
441 let mut nanos = self.nanos + rhs.nanos;
442 if nanos >= NANOS_PER_SEC {
443 nanos -= NANOS_PER_SEC;
444 if let Some(new_secs) = secs.checked_add(1) {
450 debug_assert!(nanos < NANOS_PER_SEC);
451 Some(Duration { secs, nanos })
457 /// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
458 /// if the result would be negative or if overflow occurred.
460 /// [`None`]: ../../std/option/enum.Option.html#variant.None
467 /// use std::time::Duration;
469 /// assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
470 /// assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
472 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
474 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
475 pub const fn checked_sub(self, rhs: Duration) -> Option<Duration> {
476 if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
477 let nanos = if self.nanos >= rhs.nanos {
478 self.nanos - rhs.nanos
480 if let Some(sub_secs) = secs.checked_sub(1) {
482 self.nanos + NANOS_PER_SEC - rhs.nanos
487 debug_assert!(nanos < NANOS_PER_SEC);
488 Some(Duration { secs, nanos })
494 /// Checked `Duration` multiplication. Computes `self * other`, returning
495 /// [`None`] if overflow occurred.
497 /// [`None`]: ../../std/option/enum.Option.html#variant.None
504 /// use std::time::Duration;
506 /// assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
507 /// assert_eq!(Duration::new(u64::MAX - 1, 0).checked_mul(2), None);
509 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
511 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
512 pub const fn checked_mul(self, rhs: u32) -> Option<Duration> {
513 // Multiply nanoseconds as u64, because it cannot overflow that way.
514 let total_nanos = self.nanos as u64 * rhs as u64;
515 let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
516 let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
517 if let Some(s) = self.secs.checked_mul(rhs as u64) {
518 if let Some(secs) = s.checked_add(extra_secs) {
519 debug_assert!(nanos < NANOS_PER_SEC);
520 return Some(Duration { secs, nanos });
526 /// Checked `Duration` division. Computes `self / other`, returning [`None`]
529 /// [`None`]: ../../std/option/enum.Option.html#variant.None
536 /// use std::time::Duration;
538 /// assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
539 /// assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
540 /// assert_eq!(Duration::new(2, 0).checked_div(0), None);
542 #[stable(feature = "duration_checked_ops", since = "1.16.0")]
544 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
545 pub const fn checked_div(self, rhs: u32) -> Option<Duration> {
547 let secs = self.secs / (rhs as u64);
548 let carry = self.secs - secs * (rhs as u64);
549 let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
550 let nanos = self.nanos / rhs + (extra_nanos as u32);
551 debug_assert!(nanos < NANOS_PER_SEC);
552 Some(Duration { secs, nanos })
558 /// Returns the number of seconds contained by this `Duration` as `f64`.
560 /// The returned value does include the fractional (nanosecond) part of the duration.
564 /// use std::time::Duration;
566 /// let dur = Duration::new(2, 700_000_000);
567 /// assert_eq!(dur.as_secs_f64(), 2.7);
569 #[stable(feature = "duration_float", since = "1.38.0")]
571 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
572 pub const fn as_secs_f64(&self) -> f64 {
573 (self.secs as f64) + (self.nanos as f64) / (NANOS_PER_SEC as f64)
576 /// Returns the number of seconds contained by this `Duration` as `f32`.
578 /// The returned value does include the fractional (nanosecond) part of the duration.
582 /// use std::time::Duration;
584 /// let dur = Duration::new(2, 700_000_000);
585 /// assert_eq!(dur.as_secs_f32(), 2.7);
587 #[stable(feature = "duration_float", since = "1.38.0")]
589 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
590 pub const fn as_secs_f32(&self) -> f32 {
591 (self.secs as f32) + (self.nanos as f32) / (NANOS_PER_SEC as f32)
594 /// Creates a new `Duration` from the specified number of seconds represented
598 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
602 /// use std::time::Duration;
604 /// let dur = Duration::from_secs_f64(2.7);
605 /// assert_eq!(dur, Duration::new(2, 700_000_000));
607 #[stable(feature = "duration_float", since = "1.38.0")]
609 pub fn from_secs_f64(secs: f64) -> Duration {
610 const MAX_NANOS_F64: f64 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f64;
611 let nanos = secs * (NANOS_PER_SEC as f64);
612 if !nanos.is_finite() {
613 panic!("got non-finite value when converting float to duration");
615 if nanos >= MAX_NANOS_F64 {
616 panic!("overflow when converting float to duration");
619 panic!("underflow when converting float to duration");
621 let nanos = nanos as u128;
623 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
624 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
628 /// Creates a new `Duration` from the specified number of seconds represented
632 /// This constructor will panic if `secs` is not finite, negative or overflows `Duration`.
636 /// use std::time::Duration;
638 /// let dur = Duration::from_secs_f32(2.7);
639 /// assert_eq!(dur, Duration::new(2, 700_000_000));
641 #[stable(feature = "duration_float", since = "1.38.0")]
643 pub fn from_secs_f32(secs: f32) -> Duration {
644 const MAX_NANOS_F32: f32 = ((u64::MAX as u128 + 1) * (NANOS_PER_SEC as u128)) as f32;
645 let nanos = secs * (NANOS_PER_SEC as f32);
646 if !nanos.is_finite() {
647 panic!("got non-finite value when converting float to duration");
649 if nanos >= MAX_NANOS_F32 {
650 panic!("overflow when converting float to duration");
653 panic!("underflow when converting float to duration");
655 let nanos = nanos as u128;
657 secs: (nanos / (NANOS_PER_SEC as u128)) as u64,
658 nanos: (nanos % (NANOS_PER_SEC as u128)) as u32,
662 /// Multiplies `Duration` by `f64`.
665 /// This method will panic if result is not finite, negative or overflows `Duration`.
669 /// use std::time::Duration;
671 /// let dur = Duration::new(2, 700_000_000);
672 /// assert_eq!(dur.mul_f64(3.14), Duration::new(8, 478_000_000));
673 /// assert_eq!(dur.mul_f64(3.14e5), Duration::new(847_800, 0));
675 #[stable(feature = "duration_float", since = "1.38.0")]
677 pub fn mul_f64(self, rhs: f64) -> Duration {
678 Duration::from_secs_f64(rhs * self.as_secs_f64())
681 /// Multiplies `Duration` by `f32`.
684 /// This method will panic if result is not finite, negative or overflows `Duration`.
688 /// use std::time::Duration;
690 /// let dur = Duration::new(2, 700_000_000);
691 /// // note that due to rounding errors result is slightly different
692 /// // from 8.478 and 847800.0
693 /// assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_640));
694 /// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847799, 969_120_256));
696 #[stable(feature = "duration_float", since = "1.38.0")]
698 pub fn mul_f32(self, rhs: f32) -> Duration {
699 Duration::from_secs_f32(rhs * self.as_secs_f32())
702 /// Divide `Duration` by `f64`.
705 /// This method will panic if result is not finite, negative or overflows `Duration`.
709 /// use std::time::Duration;
711 /// let dur = Duration::new(2, 700_000_000);
712 /// assert_eq!(dur.div_f64(3.14), Duration::new(0, 859_872_611));
713 /// // note that truncation is used, not rounding
714 /// assert_eq!(dur.div_f64(3.14e5), Duration::new(0, 8_598));
716 #[stable(feature = "duration_float", since = "1.38.0")]
718 pub fn div_f64(self, rhs: f64) -> Duration {
719 Duration::from_secs_f64(self.as_secs_f64() / rhs)
722 /// Divide `Duration` by `f32`.
725 /// This method will panic if result is not finite, negative or overflows `Duration`.
729 /// use std::time::Duration;
731 /// let dur = Duration::new(2, 700_000_000);
732 /// // note that due to rounding errors result is slightly
733 /// // different from 0.859_872_611
734 /// assert_eq!(dur.div_f32(3.14), Duration::new(0, 859_872_576));
735 /// // note that truncation is used, not rounding
736 /// assert_eq!(dur.div_f32(3.14e5), Duration::new(0, 8_598));
738 #[stable(feature = "duration_float", since = "1.38.0")]
740 pub fn div_f32(self, rhs: f32) -> Duration {
741 Duration::from_secs_f32(self.as_secs_f32() / rhs)
744 /// Divide `Duration` by `Duration` and return `f64`.
748 /// #![feature(div_duration)]
749 /// use std::time::Duration;
751 /// let dur1 = Duration::new(2, 700_000_000);
752 /// let dur2 = Duration::new(5, 400_000_000);
753 /// assert_eq!(dur1.div_duration_f64(dur2), 0.5);
755 #[unstable(feature = "div_duration", issue = "63139")]
757 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
758 pub const fn div_duration_f64(self, rhs: Duration) -> f64 {
759 self.as_secs_f64() / rhs.as_secs_f64()
762 /// Divide `Duration` by `Duration` and return `f32`.
766 /// #![feature(div_duration)]
767 /// use std::time::Duration;
769 /// let dur1 = Duration::new(2, 700_000_000);
770 /// let dur2 = Duration::new(5, 400_000_000);
771 /// assert_eq!(dur1.div_duration_f32(dur2), 0.5);
773 #[unstable(feature = "div_duration", issue = "63139")]
775 #[rustc_const_unstable(feature = "duration_consts_2", issue = "72440")]
776 pub const fn div_duration_f32(self, rhs: Duration) -> f32 {
777 self.as_secs_f32() / rhs.as_secs_f32()
781 #[stable(feature = "duration", since = "1.3.0")]
782 impl Add for Duration {
783 type Output = Duration;
785 fn add(self, rhs: Duration) -> Duration {
786 self.checked_add(rhs).expect("overflow when adding durations")
790 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
791 impl AddAssign for Duration {
792 fn add_assign(&mut self, rhs: Duration) {
797 #[stable(feature = "duration", since = "1.3.0")]
798 impl Sub for Duration {
799 type Output = Duration;
801 fn sub(self, rhs: Duration) -> Duration {
802 self.checked_sub(rhs).expect("overflow when subtracting durations")
806 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
807 impl SubAssign for Duration {
808 fn sub_assign(&mut self, rhs: Duration) {
813 #[stable(feature = "duration", since = "1.3.0")]
814 impl Mul<u32> for Duration {
815 type Output = Duration;
817 fn mul(self, rhs: u32) -> Duration {
818 self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
822 #[stable(feature = "symmetric_u32_duration_mul", since = "1.31.0")]
823 impl Mul<Duration> for u32 {
824 type Output = Duration;
826 fn mul(self, rhs: Duration) -> Duration {
831 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
832 impl MulAssign<u32> for Duration {
833 fn mul_assign(&mut self, rhs: u32) {
838 #[stable(feature = "duration", since = "1.3.0")]
839 impl Div<u32> for Duration {
840 type Output = Duration;
842 fn div(self, rhs: u32) -> Duration {
843 self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
847 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
848 impl DivAssign<u32> for Duration {
849 fn div_assign(&mut self, rhs: u32) {
854 macro_rules! sum_durations {
856 let mut total_secs: u64 = 0;
857 let mut total_nanos: u64 = 0;
861 total_secs.checked_add(entry.secs).expect("overflow in iter::sum over durations");
862 total_nanos = match total_nanos.checked_add(entry.nanos as u64) {
865 total_secs = total_secs
866 .checked_add(total_nanos / NANOS_PER_SEC as u64)
867 .expect("overflow in iter::sum over durations");
868 (total_nanos % NANOS_PER_SEC as u64) + entry.nanos as u64
872 total_secs = total_secs
873 .checked_add(total_nanos / NANOS_PER_SEC as u64)
874 .expect("overflow in iter::sum over durations");
875 total_nanos = total_nanos % NANOS_PER_SEC as u64;
876 Duration { secs: total_secs, nanos: total_nanos as u32 }
880 #[stable(feature = "duration_sum", since = "1.16.0")]
881 impl Sum for Duration {
882 fn sum<I: Iterator<Item = Duration>>(iter: I) -> Duration {
887 #[stable(feature = "duration_sum", since = "1.16.0")]
888 impl<'a> Sum<&'a Duration> for Duration {
889 fn sum<I: Iterator<Item = &'a Duration>>(iter: I) -> Duration {
894 #[stable(feature = "duration_debug_impl", since = "1.27.0")]
895 impl fmt::Debug for Duration {
896 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
897 /// Formats a floating point number in decimal notation.
899 /// The number is given as the `integer_part` and a fractional part.
900 /// The value of the fractional part is `fractional_part / divisor`. So
901 /// `integer_part` = 3, `fractional_part` = 12 and `divisor` = 100
902 /// represents the number `3.012`. Trailing zeros are omitted.
904 /// `divisor` must not be above 100_000_000. It also should be a power
905 /// of 10, everything else doesn't make sense. `fractional_part` has
906 /// to be less than `10 * divisor`!
908 f: &mut fmt::Formatter<'_>,
909 mut integer_part: u64,
910 mut fractional_part: u32,
913 // Encode the fractional part into a temporary buffer. The buffer
914 // only need to hold 9 elements, because `fractional_part` has to
915 // be smaller than 10^9. The buffer is prefilled with '0' digits
916 // to simplify the code below.
917 let mut buf = [b'0'; 9];
919 // The next digit is written at this position
922 // We keep writing digits into the buffer while there are non-zero
923 // digits left and we haven't written enough digits yet.
924 while fractional_part > 0 && pos < f.precision().unwrap_or(9) {
925 // Write new digit into the buffer
926 buf[pos] = b'0' + (fractional_part / divisor) as u8;
928 fractional_part %= divisor;
933 // If a precision < 9 was specified, there may be some non-zero
934 // digits left that weren't written into the buffer. In that case we
935 // need to perform rounding to match the semantics of printing
936 // normal floating point numbers. However, we only need to do work
937 // when rounding up. This happens if the first digit of the
938 // remaining ones is >= 5.
939 if fractional_part > 0 && fractional_part >= divisor * 5 {
940 // Round up the number contained in the buffer. We go through
941 // the buffer backwards and keep track of the carry.
942 let mut rev_pos = pos;
943 let mut carry = true;
944 while carry && rev_pos > 0 {
947 // If the digit in the buffer is not '9', we just need to
948 // increment it and can stop then (since we don't have a
949 // carry anymore). Otherwise, we set it to '0' (overflow)
951 if buf[rev_pos] < b'9' {
959 // If we still have the carry bit set, that means that we set
960 // the whole buffer to '0's and need to increment the integer
967 // Determine the end of the buffer: if precision is set, we just
968 // use as many digits from the buffer (capped to 9). If it isn't
969 // set, we only use all digits up to the last non-zero one.
970 let end = f.precision().map(|p| crate::cmp::min(p, 9)).unwrap_or(pos);
972 // If we haven't emitted a single fractional digit and the precision
973 // wasn't set to a non-zero value, we don't print the decimal point.
975 write!(f, "{}", integer_part)
977 // SAFETY: We are only writing ASCII digits into the buffer and it was
978 // initialized with '0's, so it contains valid UTF8.
979 let s = unsafe { crate::str::from_utf8_unchecked(&buf[..end]) };
981 // If the user request a precision > 9, we pad '0's at the end.
982 let w = f.precision().unwrap_or(pos);
983 write!(f, "{}.{:0<width$}", integer_part, s, width = w)
987 // Print leading '+' sign if requested
993 fmt_decimal(f, self.secs, self.nanos, 100_000_000)?;
995 } else if self.nanos >= 1_000_000 {
996 fmt_decimal(f, self.nanos as u64 / 1_000_000, self.nanos % 1_000_000, 100_000)?;
998 } else if self.nanos >= 1_000 {
999 fmt_decimal(f, self.nanos as u64 / 1_000, self.nanos % 1_000, 100)?;
1002 fmt_decimal(f, self.nanos as u64, 0, 1)?;