Move time::Duration to libcore

2 files changed, 0 insertions, 1157 deletions

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);
-    }
-}
diff --git a/src/libstd/time/mod.rs b/src/libstd/time/mod.rs
deleted file mode 100644
index 6ce3b3e8a00..00000000000
--- a/src/libstd/time/mod.rs
+++ /dev/null
@@ -1,567 +0,0 @@
-// Copyright 2012-2014 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.
-
-//! Temporal quantification.
-//!
-//! Example:
-//!
-//! ```
-//! use std::time::Duration;
-//!
-//! let five_seconds = Duration::new(5, 0);
-//! // both declarations are equivalent
-//! assert_eq!(Duration::new(5, 0), Duration::from_secs(5));
-//! ```
-
-#![stable(feature = "time", since = "1.3.0")]
-
-use error::Error;
-use fmt;
-use ops::{Add, Sub, AddAssign, SubAssign};
-use sys::time;
-use sys_common::FromInner;
-
-#[stable(feature = "time", since = "1.3.0")]
-pub use self::duration::Duration;
-
-mod duration;
-
-/// A measurement of a monotonically nondecreasing clock.
-/// Opaque and useful only with `Duration`.
-///
-/// Instants are always guaranteed to be no less than any previously measured
-/// instant when created, and are often useful for tasks such as measuring
-/// benchmarks or timing how long an operation takes.
-///
-/// Note, however, that instants are not guaranteed to be **steady**.  In other
-/// words, each tick of the underlying clock may not be the same length (e.g.
-/// some seconds may be longer than others). An instant may jump forwards or
-/// experience time dilation (slow down or speed up), but it will never go
-/// backwards.
-///
-/// Instants are opaque types that can only be compared to one another. There is
-/// no method to get "the number of seconds" from an instant. Instead, it only
-/// allows measuring the duration between two instants (or comparing two
-/// instants).
-///
-/// Example:
-///
-/// ```no_run
-/// use std::time::{Duration, Instant};
-/// use std::thread::sleep;
-///
-/// fn main() {
-///    let now = Instant::now();
-///
-///    // we sleep for 2 seconds
-///    sleep(Duration::new(2, 0));
-///    // it prints '2'
-///    println!("{}", now.elapsed().as_secs());
-/// }
-/// ```
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[stable(feature = "time2", since = "1.8.0")]
-pub struct Instant(time::Instant);
-
-/// A measurement of the system clock, useful for talking to
-/// external entities like the file system or other processes.
-///
-/// Distinct from the [`Instant`] type, this time measurement **is not
-/// monotonic**. This means that you can save a file to the file system, then
-/// save another file to the file system, **and the second file has a
-/// `SystemTime` measurement earlier than the first**. In other words, an
-/// operation that happens after another operation in real time may have an
-/// earlier `SystemTime`!
-///
-/// Consequently, comparing two `SystemTime` instances to learn about the
-/// duration between them returns a [`Result`] instead of an infallible [`Duration`]
-/// to indicate that this sort of time drift may happen and needs to be handled.
-///
-/// Although a `SystemTime` cannot be directly inspected, the [`UNIX_EPOCH`]
-/// constant is provided in this module as an anchor in time to learn
-/// information about a `SystemTime`. By calculating the duration from this
-/// fixed point in time, a `SystemTime` can be converted to a human-readable time,
-/// or perhaps some other string representation.
-///
-/// [`Instant`]: ../../std/time/struct.Instant.html
-/// [`Result`]: ../../std/result/enum.Result.html
-/// [`Duration`]: ../../std/time/struct.Duration.html
-/// [`UNIX_EPOCH`]: ../../std/time/constant.UNIX_EPOCH.html
-///
-/// Example:
-///
-/// ```no_run
-/// use std::time::{Duration, SystemTime};
-/// use std::thread::sleep;
-///
-/// fn main() {
-///    let now = SystemTime::now();
-///
-///    // we sleep for 2 seconds
-///    sleep(Duration::new(2, 0));
-///    match now.elapsed() {
-///        Ok(elapsed) => {
-///            // it prints '2'
-///            println!("{}", elapsed.as_secs());
-///        }
-///        Err(e) => {
-///            // an error occurred!
-///            println!("Error: {:?}", e);
-///        }
-///    }
-/// }
-/// ```
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-#[stable(feature = "time2", since = "1.8.0")]
-pub struct SystemTime(time::SystemTime);
-
-/// An error returned from the `duration_since` and `elapsed` methods on
-/// `SystemTime`, used to learn how far in the opposite direction a system time
-/// lies.
-///
-/// # Examples
-///
-/// ```no_run
-/// use std::thread::sleep;
-/// use std::time::{Duration, SystemTime};
-///
-/// let sys_time = SystemTime::now();
-/// sleep(Duration::from_secs(1));
-/// let new_sys_time = SystemTime::now();
-/// match sys_time.duration_since(new_sys_time) {
-///     Ok(_) => {}
-///     Err(e) => println!("SystemTimeError difference: {:?}", e.duration()),
-/// }
-/// ```
-#[derive(Clone, Debug)]
-#[stable(feature = "time2", since = "1.8.0")]
-pub struct SystemTimeError(Duration);
-
-impl Instant {
-    /// Returns an instant corresponding to "now".
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::time::Instant;
-    ///
-    /// let now = Instant::now();
-    /// ```
-    #[stable(feature = "time2", since = "1.8.0")]
-    pub fn now() -> Instant {
-        Instant(time::Instant::now())
-    }
-
-    /// Returns the amount of time elapsed from another instant to this one.
-    ///
-    /// # Panics
-    ///
-    /// This function will panic if `earlier` is later than `self`.
-    ///
-    /// # Examples
-    ///
-    /// ```no_run
-    /// use std::time::{Duration, Instant};
-    /// use std::thread::sleep;
-    ///
-    /// let now = Instant::now();
-    /// sleep(Duration::new(1, 0));
-    /// let new_now = Instant::now();
-    /// println!("{:?}", new_now.duration_since(now));
-    /// ```
-    #[stable(feature = "time2", since = "1.8.0")]
-    pub fn duration_since(&self, earlier: Instant) -> Duration {
-        self.0.sub_instant(&earlier.0)
-    }
-
-    /// Returns the amount of time elapsed since this instant was created.
-    ///
-    /// # Panics
-    ///
-    /// This function may panic if the current time is earlier than this
-    /// instant, which is something that can happen if an `Instant` is
-    /// produced synthetically.
-    ///
-    /// # Examples
-    ///
-    /// ```no_run
-    /// use std::thread::sleep;
-    /// use std::time::{Duration, Instant};
-    ///
-    /// let instant = Instant::now();
-    /// let three_secs = Duration::from_secs(3);
-    /// sleep(three_secs);
-    /// assert!(instant.elapsed() >= three_secs);
-    /// ```
-    #[stable(feature = "time2", since = "1.8.0")]
-    pub fn elapsed(&self) -> Duration {
-        Instant::now() - *self
-    }
-}
-
-#[stable(feature = "time2", since = "1.8.0")]
-impl Add<Duration> for Instant {
-    type Output = Instant;
-
-    fn add(self, other: Duration) -> Instant {
-        Instant(self.0.add_duration(&other))
-    }
-}
-
-#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl AddAssign<Duration> for Instant {
-    fn add_assign(&mut self, other: Duration) {
-        *self = *self + other;
-    }
-}
-
-#[stable(feature = "time2", since = "1.8.0")]
-impl Sub<Duration> for Instant {
-    type Output = Instant;
-
-    fn sub(self, other: Duration) -> Instant {
-        Instant(self.0.sub_duration(&other))
-    }
-}
-
-#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl SubAssign<Duration> for Instant {
-    fn sub_assign(&mut self, other: Duration) {
-        *self = *self - other;
-    }
-}
-
-#[stable(feature = "time2", since = "1.8.0")]
-impl Sub<Instant> for Instant {
-    type Output = Duration;
-
-    fn sub(self, other: Instant) -> Duration {
-        self.duration_since(other)
-    }
-}
-
-#[stable(feature = "time2", since = "1.8.0")]
-impl fmt::Debug for Instant {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.0.fmt(f)
-    }
-}
-
-impl SystemTime {
-    /// Returns the system time corresponding to "now".
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::time::SystemTime;
-    ///
-    /// let sys_time = SystemTime::now();
-    /// ```
-    #[stable(feature = "time2", since = "1.8.0")]
-    pub fn now() -> SystemTime {
-        SystemTime(time::SystemTime::now())
-    }
-
-    /// Returns the amount of time elapsed from an earlier point in time.
-    ///
-    /// This function may fail because measurements taken earlier are not
-    /// guaranteed to always be before later measurements (due to anomalies such
-    /// as the system clock being adjusted either forwards or backwards).
-    ///
-    /// If successful, [`Ok`]`(`[`Duration`]`)` is returned where the duration represents
-    /// the amount of time elapsed from the specified measurement to this one.
-    ///
-    /// Returns an [`Err`] if `earlier` is later than `self`, and the error
-    /// contains how far from `self` the time is.
-    ///
-    /// [`Ok`]: ../../std/result/enum.Result.html#variant.Ok
-    /// [`Duration`]: ../../std/time/struct.Duration.html
-    /// [`Err`]: ../../std/result/enum.Result.html#variant.Err
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use std::time::SystemTime;
-    ///
-    /// let sys_time = SystemTime::now();
-    /// let difference = sys_time.duration_since(sys_time)
-    ///                          .expect("SystemTime::duration_since failed");
-    /// println!("{:?}", difference);
-    /// ```
-    #[stable(feature = "time2", since = "1.8.0")]
-    pub fn duration_since(&self, earlier: SystemTime)
-                          -> Result<Duration, SystemTimeError> {
-        self.0.sub_time(&earlier.0).map_err(SystemTimeError)
-    }
-
-    /// Returns the amount of time elapsed since this system time was created.
-    ///
-    /// This function may fail as the underlying system clock is susceptible to
-    /// drift and updates (e.g. the system clock could go backwards), so this
-    /// function may not always succeed. If successful, [`Ok`]`(`[`Duration`]`)` is
-    /// returned where the duration represents the amount of time elapsed from
-    /// this time measurement to the current time.
-    ///
-    /// Returns an [`Err`] if `self` is later than the current system time, and
-    /// the error contains how far from the current system time `self` is.
-    ///
-    /// [`Ok`]: ../../std/result/enum.Result.html#variant.Ok
-    /// [`Duration`]: ../../std/time/struct.Duration.html
-    /// [`Err`]: ../../std/result/enum.Result.html#variant.Err
-    ///
-    /// # Examples
-    ///
-    /// ```no_run
-    /// use std::thread::sleep;
-    /// use std::time::{Duration, SystemTime};
-    ///
-    /// let sys_time = SystemTime::now();
-    /// let one_sec = Duration::from_secs(1);
-    /// sleep(one_sec);
-    /// assert!(sys_time.elapsed().unwrap() >= one_sec);
-    /// ```
-    #[stable(feature = "time2", since = "1.8.0")]
-    pub fn elapsed(&self) -> Result<Duration, SystemTimeError> {
-        SystemTime::now().duration_since(*self)
-    }
-}
-
-#[stable(feature = "time2", since = "1.8.0")]
-impl Add<Duration> for SystemTime {
-    type Output = SystemTime;
-
-    fn add(self, dur: Duration) -> SystemTime {
-        SystemTime(self.0.add_duration(&dur))
-    }
-}
-
-#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl AddAssign<Duration> for SystemTime {
-    fn add_assign(&mut self, other: Duration) {
-        *self = *self + other;
-    }
-}
-
-#[stable(feature = "time2", since = "1.8.0")]
-impl Sub<Duration> for SystemTime {
-    type Output = SystemTime;
-
-    fn sub(self, dur: Duration) -> SystemTime {
-        SystemTime(self.0.sub_duration(&dur))
-    }
-}
-
-#[stable(feature = "time_augmented_assignment", since = "1.9.0")]
-impl SubAssign<Duration> for SystemTime {
-    fn sub_assign(&mut self, other: Duration) {
-        *self = *self - other;
-    }
-}
-
-#[stable(feature = "time2", since = "1.8.0")]
-impl fmt::Debug for SystemTime {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.0.fmt(f)
-    }
-}
-
-/// An anchor in time which can be used to create new `SystemTime` instances or
-/// learn about where in time a `SystemTime` lies.
-///
-/// This constant is defined to be "1970-01-01 00:00:00 UTC" on all systems with
-/// respect to the system clock. Using `duration_since` on an existing
-/// [`SystemTime`] instance can tell how far away from this point in time a
-/// measurement lies, and using `UNIX_EPOCH + duration` can be used to create a
-/// [`SystemTime`] instance to represent another fixed point in time.
-///
-/// [`SystemTime`]: ../../std/time/struct.SystemTime.html
-///
-/// # Examples
-///
-/// ```no_run
-/// use std::time::{SystemTime, UNIX_EPOCH};
-///
-/// match SystemTime::now().duration_since(UNIX_EPOCH) {
-///     Ok(n) => println!("1970-01-01 00:00:00 UTC was {} seconds ago!", n.as_secs()),
-///     Err(_) => panic!("SystemTime before UNIX EPOCH!"),
-/// }
-/// ```
-#[stable(feature = "time2", since = "1.8.0")]
-pub const UNIX_EPOCH: SystemTime = SystemTime(time::UNIX_EPOCH);
-
-impl SystemTimeError {
-    /// Returns the positive duration which represents how far forward the
-    /// second system time was from the first.
-    ///
-    /// A `SystemTimeError` is returned from the [`duration_since`] and [`elapsed`]
-    /// methods of [`SystemTime`] whenever the second system time represents a point later
-    /// in time than the `self` of the method call.
-    ///
-    /// [`duration_since`]: ../../std/time/struct.SystemTime.html#method.duration_since
-    /// [`elapsed`]: ../../std/time/struct.SystemTime.html#method.elapsed
-    /// [`SystemTime`]: ../../std/time/struct.SystemTime.html
-    ///
-    /// # Examples
-    ///
-    /// ```no_run
-    /// use std::thread::sleep;
-    /// use std::time::{Duration, SystemTime};
-    ///
-    /// let sys_time = SystemTime::now();
-    /// sleep(Duration::from_secs(1));
-    /// let new_sys_time = SystemTime::now();
-    /// match sys_time.duration_since(new_sys_time) {
-    ///     Ok(_) => {}
-    ///     Err(e) => println!("SystemTimeError difference: {:?}", e.duration()),
-    /// }
-    /// ```
-    #[stable(feature = "time2", since = "1.8.0")]
-    pub fn duration(&self) -> Duration {
-        self.0
-    }
-}
-
-#[stable(feature = "time2", since = "1.8.0")]
-impl Error for SystemTimeError {
-    fn description(&self) -> &str { "other time was not earlier than self" }
-}
-
-#[stable(feature = "time2", since = "1.8.0")]
-impl fmt::Display for SystemTimeError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "second time provided was later than self")
-    }
-}
-
-impl FromInner<time::SystemTime> for SystemTime {
-    fn from_inner(time: time::SystemTime) -> SystemTime {
-        SystemTime(time)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::{Instant, SystemTime, Duration, UNIX_EPOCH};
-
-    macro_rules! assert_almost_eq {
-        ($a:expr, $b:expr) => ({
-            let (a, b) = ($a, $b);
-            if a != b {
-                let (a, b) = if a > b {(a, b)} else {(b, a)};
-                assert!(a - Duration::new(0, 100) <= b);
-            }
-        })
-    }
-
-    #[test]
-    fn instant_monotonic() {
-        let a = Instant::now();
-        let b = Instant::now();
-        assert!(b >= a);
-    }
-
-    #[test]
-    fn instant_elapsed() {
-        let a = Instant::now();
-        a.elapsed();
-    }
-
-    #[test]
-    fn instant_math() {
-        let a = Instant::now();
-        let b = Instant::now();
-        let dur = b.duration_since(a);
-        assert_almost_eq!(b - dur, a);
-        assert_almost_eq!(a + dur, b);
-
-        let second = Duration::new(1, 0);
-        assert_almost_eq!(a - second + second, a);
-    }
-
-    #[test]
-    #[should_panic]
-    fn instant_duration_panic() {
-        let a = Instant::now();
-        (a - Duration::new(1, 0)).duration_since(a);
-    }
-
-    #[test]
-    fn system_time_math() {
-        let a = SystemTime::now();
-        let b = SystemTime::now();
-        match b.duration_since(a) {
-            Ok(dur) if dur == Duration::new(0, 0) => {
-                assert_almost_eq!(a, b);
-            }
-            Ok(dur) => {
-                assert!(b > a);
-                assert_almost_eq!(b - dur, a);
-                assert_almost_eq!(a + dur, b);
-            }
-            Err(dur) => {
-                let dur = dur.duration();
-                assert!(a > b);
-                assert_almost_eq!(b + dur, a);
-                assert_almost_eq!(a - dur, b);
-            }
-        }
-
-        let second = Duration::new(1, 0);
-        assert_almost_eq!(a.duration_since(a - second).unwrap(), second);
-        assert_almost_eq!(a.duration_since(a + second).unwrap_err()
-                           .duration(), second);
-
-        assert_almost_eq!(a - second + second, a);
-
-        // A difference of 80 and 800 years cannot fit inside a 32-bit time_t
-        if !(cfg!(unix) && ::mem::size_of::<::libc::time_t>() <= 4) {
-            let eighty_years = second * 60 * 60 * 24 * 365 * 80;
-            assert_almost_eq!(a - eighty_years + eighty_years, a);
-            assert_almost_eq!(a - (eighty_years * 10) + (eighty_years * 10), a);
-        }
-
-        let one_second_from_epoch = UNIX_EPOCH + Duration::new(1, 0);
-        let one_second_from_epoch2 = UNIX_EPOCH + Duration::new(0, 500_000_000)
-            + Duration::new(0, 500_000_000);
-        assert_eq!(one_second_from_epoch, one_second_from_epoch2);
-    }
-
-    #[test]
-    fn system_time_elapsed() {
-        let a = SystemTime::now();
-        drop(a.elapsed());
-    }
-
-    #[test]
-    fn since_epoch() {
-        let ts = SystemTime::now();
-        let a = ts.duration_since(UNIX_EPOCH).unwrap();
-        let b = ts.duration_since(UNIX_EPOCH - Duration::new(1, 0)).unwrap();
-        assert!(b > a);
-        assert_eq!(b - a, Duration::new(1, 0));
-
-        let thirty_years = Duration::new(1, 0) * 60 * 60 * 24 * 365 * 30;
-
-        // Right now for CI this test is run in an emulator, and apparently the
-        // aarch64 emulator's sense of time is that we're still living in the
-        // 70s.
-        //
-        // Otherwise let's assume that we're all running computers later than
-        // 2000.
-        if !cfg!(target_arch = "aarch64") {
-            assert!(a > thirty_years);
-        }
-
-        // let's assume that we're all running computers earlier than 2090.
-        // Should give us ~70 years to fix this!
-        let hundred_twenty_years = thirty_years * 4;
-        assert!(a < hundred_twenty_years);
-    }
-}