Auto merge of #46666 - clarcharr:duration_core, r=alexcrichton

Move Duration to libcore

Fixes #46520; should be merged after #46508.

2 files changed, 1 insertions, 593 deletions

diff --git a/src/libstd/time/mod.rs b/src/libstd/time.rs
index 6ce3b3e8a00..12f2a9bb85f 100644
--- a/src/libstd/time/mod.rs
+++ b/src/libstd/time.rs
@@ -29,9 +29,7 @@ use sys::time;
 use sys_common::FromInner;
 
 #[stable(feature = "time", since = "1.3.0")]
-pub use self::duration::Duration;
-
-mod duration;
+pub use core::time::Duration;
 
 /// A measurement of a monotonically nondecreasing clock.
 /// Opaque and useful only with `Duration`.
diff --git a/src/libstd/time/duration.rs b/src/libstd/time/duration.rs
deleted file mode 100644
index ee444830be4..00000000000
--- a/src/libstd/time/duration.rs
+++ /dev/null
@@ -1,590 +0,0 @@
-// Copyright 2012-2017 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-use iter::Sum;
-use ops::{Add, Sub, Mul, Div, AddAssign, SubAssign, MulAssign, DivAssign};
-
-const NANOS_PER_SEC: u32 = 1_000_000_000;
-const NANOS_PER_MILLI: u32 = 1_000_000;
-const NANOS_PER_MICRO: u32 = 1_000;
-const MILLIS_PER_SEC: u64 = 1_000;
-const MICROS_PER_SEC: u64 = 1_000_000;
-
-/// A `Duration` type to represent a span of time, typically used for system
-/// timeouts.
-///
-/// Each `Duration` is composed of a whole number of seconds and a fractional part
-/// represented in nanoseconds.  If the underlying system does not support
-/// nanosecond-level precision, APIs binding a system timeout will typically round up
-/// the number of nanoseconds.
-///
-/// `Duration`s implement many common traits, including [`Add`], [`Sub`], and other
-/// [`ops`] traits.
-///
-/// [`Add`]: ../../std/ops/trait.Add.html
-/// [`Sub`]: ../../std/ops/trait.Sub.html
-/// [`ops`]: ../../std/ops/index.html
-///
-/// # Examples
-///
-/// ```
-/// use std::time::Duration;
-///
-/// let five_seconds = Duration::new(5, 0);
-/// let five_seconds_and_five_nanos = five_seconds + Duration::new(0, 5);
-///
-/// assert_eq!(five_seconds_and_five_nanos.as_secs(), 5);
-/// assert_eq!(five_seconds_and_five_nanos.subsec_nanos(), 5);
-///
-/// let ten_millis = Duration::from_millis(10);
-/// ```
-#[stable(feature = "duration", since = "1.3.0")]
-#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash, Default)]
-pub struct Duration {
-    secs: u64,
-    nanos: u32, // Always 0 <= nanos < NANOS_PER_SEC
-}
-
-impl Duration {
-    /// Creates a new `Duration` from the specified number of whole seconds and
-    /// additional nanoseconds.
-    ///
-    /// If the number of nanoseconds is greater than 1 billion (the number of
-    /// nanoseconds in a second), then it will carry over into the seconds provided.
-    ///
-    /// # Panics
-    ///
-    /// This constructor will panic if the carry from the nanoseconds overflows
-    /// the seconds counter.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// let five_seconds = Duration::new(5, 0);
-    /// ```
-    #[stable(feature = "duration", since = "1.3.0")]
-    #[inline]
-    pub fn new(secs: u64, nanos: u32) -> Duration {
-        let secs = secs.checked_add((nanos / NANOS_PER_SEC) as u64)
-            .expect("overflow in Duration::new");
-        let nanos = nanos % NANOS_PER_SEC;
-        Duration { secs: secs, nanos: nanos }
-    }
-
-    /// Creates a new `Duration` from the specified number of whole seconds.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// let duration = Duration::from_secs(5);
-    ///
-    /// assert_eq!(5, duration.as_secs());
-    /// assert_eq!(0, duration.subsec_nanos());
-    /// ```
-    #[stable(feature = "duration", since = "1.3.0")]
-    #[inline]
-    pub const fn from_secs(secs: u64) -> Duration {
-        Duration { secs: secs, nanos: 0 }
-    }
-
-    /// Creates a new `Duration` from the specified number of milliseconds.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// let duration = Duration::from_millis(2569);
-    ///
-    /// assert_eq!(2, duration.as_secs());
-    /// assert_eq!(569_000_000, duration.subsec_nanos());
-    /// ```
-    #[stable(feature = "duration", since = "1.3.0")]
-    #[inline]
-    pub const fn from_millis(millis: u64) -> Duration {
-        Duration {
-            secs: millis / MILLIS_PER_SEC,
-            nanos: ((millis % MILLIS_PER_SEC) as u32) * NANOS_PER_MILLI,
-        }
-    }
-
-    /// Creates a new `Duration` from the specified number of microseconds.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// #![feature(duration_from_micros)]
-    /// use std::time::Duration;
-    ///
-    /// let duration = Duration::from_micros(1_000_002);
-    ///
-    /// assert_eq!(1, duration.as_secs());
-    /// assert_eq!(2000, duration.subsec_nanos());
-    /// ```
-    #[unstable(feature = "duration_from_micros", issue = "44400")]
-    #[inline]
-    pub const fn from_micros(micros: u64) -> Duration {
-        Duration {
-            secs: micros / MICROS_PER_SEC,
-            nanos: ((micros % MICROS_PER_SEC) as u32) * NANOS_PER_MICRO,
-        }
-    }
-
-    /// Creates a new `Duration` from the specified number of nanoseconds.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// #![feature(duration_extras)]
-    /// use std::time::Duration;
-    ///
-    /// let duration = Duration::from_nanos(1_000_000_123);
-    ///
-    /// assert_eq!(1, duration.as_secs());
-    /// assert_eq!(123, duration.subsec_nanos());
-    /// ```
-    #[unstable(feature = "duration_extras", issue = "46507")]
-    #[inline]
-    pub const fn from_nanos(nanos: u64) -> Duration {
-        Duration {
-            secs: nanos / (NANOS_PER_SEC as u64),
-            nanos: (nanos % (NANOS_PER_SEC as u64)) as u32,
-        }
-    }
-
-    /// Returns the number of _whole_ seconds contained by this `Duration`.
-    ///
-    /// The returned value does not include the fractional (nanosecond) part of the
-    /// duration, which can be obtained using [`subsec_nanos`].
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// let duration = Duration::new(5, 730023852);
-    /// assert_eq!(duration.as_secs(), 5);
-    /// ```
-    ///
-    /// To determine the total number of seconds represented by the `Duration`,
-    /// use `as_secs` in combination with [`subsec_nanos`]:
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// let duration = Duration::new(5, 730023852);
-    ///
-    /// assert_eq!(5.730023852,
-    ///            duration.as_secs() as f64
-    ///            + duration.subsec_nanos() as f64 * 1e-9);
-    /// ```
-    ///
-    /// [`subsec_nanos`]: #method.subsec_nanos
-    #[stable(feature = "duration", since = "1.3.0")]
-    #[inline]
-    pub fn as_secs(&self) -> u64 { self.secs }
-
-    /// Returns the fractional part of this `Duration`, in milliseconds.
-    ///
-    /// This method does **not** return the length of the duration when
-    /// represented by milliseconds. The returned number always represents a
-    /// fractional portion of a second (i.e. it is less than one thousand).
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// #![feature(duration_extras)]
-    /// use std::time::Duration;
-    ///
-    /// let duration = Duration::from_millis(5432);
-    /// assert_eq!(duration.as_secs(), 5);
-    /// assert_eq!(duration.subsec_millis(), 432);
-    /// ```
-    #[unstable(feature = "duration_extras", issue = "46507")]
-    #[inline]
-    pub fn subsec_millis(&self) -> u32 { self.nanos / NANOS_PER_MILLI }
-
-    /// Returns the fractional part of this `Duration`, in microseconds.
-    ///
-    /// This method does **not** return the length of the duration when
-    /// represented by microseconds. The returned number always represents a
-    /// fractional portion of a second (i.e. it is less than one million).
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// #![feature(duration_extras, duration_from_micros)]
-    /// use std::time::Duration;
-    ///
-    /// let duration = Duration::from_micros(1_234_567);
-    /// assert_eq!(duration.as_secs(), 1);
-    /// assert_eq!(duration.subsec_micros(), 234_567);
-    /// ```
-    #[unstable(feature = "duration_extras", issue = "46507")]
-    #[inline]
-    pub fn subsec_micros(&self) -> u32 { self.nanos / NANOS_PER_MICRO }
-
-    /// Returns the fractional part of this `Duration`, in nanoseconds.
-    ///
-    /// This method does **not** return the length of the duration when
-    /// represented by nanoseconds. The returned number always represents a
-    /// fractional portion of a second (i.e. it is less than one billion).
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// let duration = Duration::from_millis(5010);
-    /// assert_eq!(duration.as_secs(), 5);
-    /// assert_eq!(duration.subsec_nanos(), 10_000_000);
-    /// ```
-    #[stable(feature = "duration", since = "1.3.0")]
-    #[inline]
-    pub fn subsec_nanos(&self) -> u32 { self.nanos }
-
-    /// Checked `Duration` addition. Computes `self + other`, returning [`None`]
-    /// if overflow occurred.
-    ///
-    /// [`None`]: ../../std/option/enum.Option.html#variant.None
-    ///
-    /// # Examples
-    ///
-    /// Basic usage:
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)), Some(Duration::new(0, 1)));
-    /// assert_eq!(Duration::new(1, 0).checked_add(Duration::new(std::u64::MAX, 0)), None);
-    /// ```
-    #[stable(feature = "duration_checked_ops", since = "1.16.0")]
-    #[inline]
-    pub fn checked_add(self, rhs: Duration) -> Option<Duration> {
-        if let Some(mut secs) = self.secs.checked_add(rhs.secs) {
-            let mut nanos = self.nanos + rhs.nanos;
-            if nanos >= NANOS_PER_SEC {
-                nanos -= NANOS_PER_SEC;
-                if let Some(new_secs) = secs.checked_add(1) {
-                    secs = new_secs;
-                } else {
-                    return None;
-                }
-            }
-            debug_assert!(nanos < NANOS_PER_SEC);
-            Some(Duration {
-                secs,
-                nanos,
-            })
-        } else {
-            None
-        }
-    }
-
-    /// Checked `Duration` subtraction. Computes `self - other`, returning [`None`]
-    /// if the result would be negative or if overflow occurred.
-    ///
-    /// [`None`]: ../../std/option/enum.Option.html#variant.None
-    ///
-    /// # Examples
-    ///
-    /// Basic usage:
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// assert_eq!(Duration::new(0, 1).checked_sub(Duration::new(0, 0)), Some(Duration::new(0, 1)));
-    /// assert_eq!(Duration::new(0, 0).checked_sub(Duration::new(0, 1)), None);
-    /// ```
-    #[stable(feature = "duration_checked_ops", since = "1.16.0")]
-    #[inline]
-    pub fn checked_sub(self, rhs: Duration) -> Option<Duration> {
-        if let Some(mut secs) = self.secs.checked_sub(rhs.secs) {
-            let nanos = if self.nanos >= rhs.nanos {
-                self.nanos - rhs.nanos
-            } else {
-                if let Some(sub_secs) = secs.checked_sub(1) {
-                    secs = sub_secs;
-                    self.nanos + NANOS_PER_SEC - rhs.nanos
-                } else {
-                    return None;
-                }
-            };
-            debug_assert!(nanos < NANOS_PER_SEC);
-            Some(Duration { secs: secs, nanos: nanos })
-        } else {
-            None
-        }
-    }
-
-    /// Checked `Duration` multiplication. Computes `self * other`, returning
-    /// [`None`] if overflow occurred.
-    ///
-    /// [`None`]: ../../std/option/enum.Option.html#variant.None
-    ///
-    /// # Examples
-    ///
-    /// Basic usage:
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// assert_eq!(Duration::new(0, 500_000_001).checked_mul(2), Some(Duration::new(1, 2)));
-    /// assert_eq!(Duration::new(std::u64::MAX - 1, 0).checked_mul(2), None);
-    /// ```
-    #[stable(feature = "duration_checked_ops", since = "1.16.0")]
-    #[inline]
-    pub fn checked_mul(self, rhs: u32) -> Option<Duration> {
-        // Multiply nanoseconds as u64, because it cannot overflow that way.
-        let total_nanos = self.nanos as u64 * rhs as u64;
-        let extra_secs = total_nanos / (NANOS_PER_SEC as u64);
-        let nanos = (total_nanos % (NANOS_PER_SEC as u64)) as u32;
-        if let Some(secs) = self.secs
-            .checked_mul(rhs as u64)
-            .and_then(|s| s.checked_add(extra_secs)) {
-            debug_assert!(nanos < NANOS_PER_SEC);
-            Some(Duration {
-                secs,
-                nanos,
-            })
-        } else {
-            None
-        }
-    }
-
-    /// Checked `Duration` division. Computes `self / other`, returning [`None`]
-    /// if `other == 0`.
-    ///
-    /// [`None`]: ../../std/option/enum.Option.html#variant.None
-    ///
-    /// # Examples
-    ///
-    /// Basic usage:
-    ///
-    /// ```
-    /// use std::time::Duration;
-    ///
-    /// assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
-    /// assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
-    /// assert_eq!(Duration::new(2, 0).checked_div(0), None);
-    /// ```
-    #[stable(feature = "duration_checked_ops", since = "1.16.0")]
-    #[inline]
-    pub fn checked_div(self, rhs: u32) -> Option<Duration> {
-        if rhs != 0 {
-            let secs = self.secs / (rhs as u64);
-            let carry = self.secs - secs * (rhs as u64);
-            let extra_nanos = carry * (NANOS_PER_SEC as u64) / (rhs as u64);
-            let nanos = self.nanos / rhs + (extra_nanos as u32);
-            debug_assert!(nanos < NANOS_PER_SEC);
-            Some(Duration { secs: secs, nanos: nanos })
-        } else {
-            None
-        }
-    }
-}
-
-#[stable(feature = "duration", since = "1.3.0")]
-impl Add for Duration {
-    type Output = Duration;
-
-    fn add(self, rhs: Duration) -> Duration {
-        self.checked_add(rhs).expect("overflow when adding durations")
-    }
-}
-
-#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl AddAssign for Duration {
-    fn add_assign(&mut self, rhs: Duration) {
-        *self = *self + rhs;
-    }
-}
-
-#[stable(feature = "duration", since = "1.3.0")]
-impl Sub for Duration {
-    type Output = Duration;
-
-    fn sub(self, rhs: Duration) -> Duration {
-        self.checked_sub(rhs).expect("overflow when subtracting durations")
-    }
-}
-
-#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl SubAssign for Duration {
-    fn sub_assign(&mut self, rhs: Duration) {
-        *self = *self - rhs;
-    }
-}
-
-#[stable(feature = "duration", since = "1.3.0")]
-impl Mul<u32> for Duration {
-    type Output = Duration;
-
-    fn mul(self, rhs: u32) -> Duration {
-        self.checked_mul(rhs).expect("overflow when multiplying duration by scalar")
-    }
-}
-
-#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl MulAssign<u32> for Duration {
-    fn mul_assign(&mut self, rhs: u32) {
-        *self = *self * rhs;
-    }
-}
-
-#[stable(feature = "duration", since = "1.3.0")]
-impl Div<u32> for Duration {
-    type Output = Duration;
-
-    fn div(self, rhs: u32) -> Duration {
-        self.checked_div(rhs).expect("divide by zero error when dividing duration by scalar")
-    }
-}
-
-#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl DivAssign<u32> for Duration {
-    fn div_assign(&mut self, rhs: u32) {
-        *self = *self / rhs;
-    }
-}
-
-#[stable(feature = "duration_sum", since = "1.16.0")]
-impl Sum for Duration {
-    fn sum<I: Iterator<Item=Duration>>(iter: I) -> Duration {
-        iter.fold(Duration::new(0, 0), |a, b| a + b)
-    }
-}
-
-#[stable(feature = "duration_sum", since = "1.16.0")]
-impl<'a> Sum<&'a Duration> for Duration {
-    fn sum<I: Iterator<Item=&'a Duration>>(iter: I) -> Duration {
-        iter.fold(Duration::new(0, 0), |a, b| a + *b)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::Duration;
-
-    #[test]
-    fn creation() {
-        assert!(Duration::from_secs(1) != Duration::from_secs(0));
-        assert_eq!(Duration::from_secs(1) + Duration::from_secs(2),
-                   Duration::from_secs(3));
-        assert_eq!(Duration::from_millis(10) + Duration::from_secs(4),
-                   Duration::new(4, 10 * 1_000_000));
-        assert_eq!(Duration::from_millis(4000), Duration::new(4, 0));
-    }
-
-    #[test]
-    fn secs() {
-        assert_eq!(Duration::new(0, 0).as_secs(), 0);
-        assert_eq!(Duration::from_secs(1).as_secs(), 1);
-        assert_eq!(Duration::from_millis(999).as_secs(), 0);
-        assert_eq!(Duration::from_millis(1001).as_secs(), 1);
-    }
-
-    #[test]
-    fn nanos() {
-        assert_eq!(Duration::new(0, 0).subsec_nanos(), 0);
-        assert_eq!(Duration::new(0, 5).subsec_nanos(), 5);
-        assert_eq!(Duration::new(0, 1_000_000_001).subsec_nanos(), 1);
-        assert_eq!(Duration::from_secs(1).subsec_nanos(), 0);
-        assert_eq!(Duration::from_millis(999).subsec_nanos(), 999 * 1_000_000);
-        assert_eq!(Duration::from_millis(1001).subsec_nanos(), 1 * 1_000_000);
-    }
-
-    #[test]
-    fn add() {
-        assert_eq!(Duration::new(0, 0) + Duration::new(0, 1),
-                   Duration::new(0, 1));
-        assert_eq!(Duration::new(0, 500_000_000) + Duration::new(0, 500_000_001),
-                   Duration::new(1, 1));
-    }
-
-    #[test]
-    fn checked_add() {
-        assert_eq!(Duration::new(0, 0).checked_add(Duration::new(0, 1)),
-                   Some(Duration::new(0, 1)));
-        assert_eq!(Duration::new(0, 500_000_000).checked_add(Duration::new(0, 500_000_001)),
-                   Some(Duration::new(1, 1)));
-        assert_eq!(Duration::new(1, 0).checked_add(Duration::new(::u64::MAX, 0)), None);
-    }
-
-    #[test]
-    fn sub() {
-        assert_eq!(Duration::new(0, 1) - Duration::new(0, 0),
-                   Duration::new(0, 1));
-        assert_eq!(Duration::new(0, 500_000_001) - Duration::new(0, 500_000_000),
-                   Duration::new(0, 1));
-        assert_eq!(Duration::new(1, 0) - Duration::new(0, 1),
-                   Duration::new(0, 999_999_999));
-    }
-
-    #[test]
-    fn checked_sub() {
-        let zero = Duration::new(0, 0);
-        let one_nano = Duration::new(0, 1);
-        let one_sec = Duration::new(1, 0);
-        assert_eq!(one_nano.checked_sub(zero), Some(Duration::new(0, 1)));
-        assert_eq!(one_sec.checked_sub(one_nano),
-                   Some(Duration::new(0, 999_999_999)));
-        assert_eq!(zero.checked_sub(one_nano), None);
-        assert_eq!(zero.checked_sub(one_sec), None);
-    }
-
-    #[test] #[should_panic]
-    fn sub_bad1() {
-        Duration::new(0, 0) - Duration::new(0, 1);
-    }
-
-    #[test] #[should_panic]
-    fn sub_bad2() {
-        Duration::new(0, 0) - Duration::new(1, 0);
-    }
-
-    #[test]
-    fn mul() {
-        assert_eq!(Duration::new(0, 1) * 2, Duration::new(0, 2));
-        assert_eq!(Duration::new(1, 1) * 3, Duration::new(3, 3));
-        assert_eq!(Duration::new(0, 500_000_001) * 4, Duration::new(2, 4));
-        assert_eq!(Duration::new(0, 500_000_001) * 4000,
-                   Duration::new(2000, 4000));
-    }
-
-    #[test]
-    fn checked_mul() {
-        assert_eq!(Duration::new(0, 1).checked_mul(2), Some(Duration::new(0, 2)));
-        assert_eq!(Duration::new(1, 1).checked_mul(3), Some(Duration::new(3, 3)));
-        assert_eq!(Duration::new(0, 500_000_001).checked_mul(4), Some(Duration::new(2, 4)));
-        assert_eq!(Duration::new(0, 500_000_001).checked_mul(4000),
-                   Some(Duration::new(2000, 4000)));
-        assert_eq!(Duration::new(::u64::MAX - 1, 0).checked_mul(2), None);
-    }
-
-    #[test]
-    fn div() {
-        assert_eq!(Duration::new(0, 1) / 2, Duration::new(0, 0));
-        assert_eq!(Duration::new(1, 1) / 3, Duration::new(0, 333_333_333));
-        assert_eq!(Duration::new(99, 999_999_000) / 100,
-                   Duration::new(0, 999_999_990));
-    }
-
-    #[test]
-    fn checked_div() {
-        assert_eq!(Duration::new(2, 0).checked_div(2), Some(Duration::new(1, 0)));
-        assert_eq!(Duration::new(1, 0).checked_div(2), Some(Duration::new(0, 500_000_000)));
-        assert_eq!(Duration::new(2, 0).checked_div(0), None);
-    }
-}