Update for Rust nightly 2018-04-19

1 files changed, 29 insertions, 0 deletions

diff --git a/ctr-std/src/time.rs b/ctr-std/src/time.rs
index 12f2a9b..1215302 100644
--- a/ctr-std/src/time.rs
+++ b/ctr-std/src/time.rs
@@ -49,6 +49,9 @@ pub use core::time::Duration;
 /// allows measuring the duration between two instants (or comparing two
 /// instants).
 ///
+/// The size of an `Instant` struct may vary depending on the target operating
+/// system.
+///
 /// Example:
 ///
 /// ```no_run
@@ -88,6 +91,9 @@ pub struct Instant(time::Instant);
 /// fixed point in time, a `SystemTime` can be converted to a human-readable time,
 /// or perhaps some other string representation.
 ///
+/// The size of a `SystemTime` struct may vary depending on the target operating
+/// system.
+///
 /// [`Instant`]: ../../std/time/struct.Instant.html
 /// [`Result`]: ../../std/result/enum.Result.html
 /// [`Duration`]: ../../std/time/struct.Duration.html
@@ -253,6 +259,29 @@ impl fmt::Debug for Instant {
 }
 
 impl SystemTime {
+    /// 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.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(assoc_unix_epoch)]
+    /// use std::time::SystemTime;
+    ///
+    /// match SystemTime::now().duration_since(SystemTime::UNIX_EPOCH) {
+    ///     Ok(n) => println!("1970-01-01 00:00:00 UTC was {} seconds ago!", n.as_secs()),
+    ///     Err(_) => panic!("SystemTime before UNIX EPOCH!"),
+    /// }
+    /// ```
+    #[unstable(feature = "assoc_unix_epoch", issue = "49502")]
+    pub const UNIX_EPOCH: SystemTime = UNIX_EPOCH;
+
     /// Returns the system time corresponding to "now".
     ///
     /// # Examples