From 7f7a2e939682ba0fabea62a528cec4fec7148c42 Mon Sep 17 00:00:00 2001
From: Stjepan Glavina <stjepang@gmail.com>
Date: Sun, 6 Jan 2019 13:44:55 +0100
Subject: [PATCH 1/3] Add duration constants

---
 src/libcore/time.rs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/libcore/time.rs b/src/libcore/time.rs
index b12ee0497d2c2..30e0873a4a2ea 100644
--- a/src/libcore/time.rs
+++ b/src/libcore/time.rs
@@ -23,6 +23,22 @@ const MILLIS_PER_SEC: u64 = 1_000;
 const MICROS_PER_SEC: u64 = 1_000_000;
 const MAX_NANOS_F64: f64 = ((u64::MAX as u128 + 1)*(NANOS_PER_SEC as u128)) as f64;
 
+/// The duration of one second.
+#[unstable(feature = "duration_constants", issue = "0")]
+pub const SECOND: Duration = Duration::from_secs(1);
+
+/// The duration of one millisecond.
+#[unstable(feature = "duration_constants", issue = "0")]
+pub const MILLISECOND: Duration = Duration::from_millis(1);
+
+/// The duration of one microsecond.
+#[unstable(feature = "duration_constants", issue = "0")]
+pub const MICROSECOND: Duration = Duration::from_micros(1);
+
+/// The duration of one nanosecond.
+#[unstable(feature = "duration_constants", issue = "0")]
+pub const NANOSECOND: Duration = Duration::from_nanos(1);
+
 /// A `Duration` type to represent a span of time, typically used for system
 /// timeouts.
 ///

From 72ec5aa08055fade5122cc306cd9a08c64d4b635 Mon Sep 17 00:00:00 2001
From: Stjepan Glavina <stjepang@gmail.com>
Date: Sun, 6 Jan 2019 14:02:42 +0100
Subject: [PATCH 2/3] Re-export constants from core into std

---
 src/libstd/lib.rs  | 1 +
 src/libstd/time.rs | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 6ded43dfed1f4..13669c1c0e1f5 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -248,6 +248,7 @@
 #![feature(const_cstr_unchecked)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
+#![feature(duration_constants)]
 #![feature(exact_size_is_empty)]
 #![feature(external_doc)]
 #![feature(fixed_size_array)]
diff --git a/src/libstd/time.rs b/src/libstd/time.rs
index ffe604cd33bd8..d8cdef8b2ab30 100644
--- a/src/libstd/time.rs
+++ b/src/libstd/time.rs
@@ -21,6 +21,9 @@ use sys_common::FromInner;
 #[stable(feature = "time", since = "1.3.0")]
 pub use core::time::Duration;
 
+#[unstable(feature = "duration_constants", issue = "0")]
+pub use core::time::{SECOND, MILLISECOND, MICROSECOND, NANOSECOND};
+
 /// A measurement of a monotonically nondecreasing clock.
 /// Opaque and useful only with `Duration`.
 ///

From 8c902b66339f54b40d3033c864675929b2c8a65b Mon Sep 17 00:00:00 2001
From: Stjepan Glavina <stjepang@gmail.com>
Date: Mon, 7 Jan 2019 11:39:22 +0100
Subject: [PATCH 3/3] Specify the tracking issue

---
 src/libcore/time.rs | 8 ++++----
 src/libstd/time.rs  | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/libcore/time.rs b/src/libcore/time.rs
index 30e0873a4a2ea..a751965dffab3 100644
--- a/src/libcore/time.rs
+++ b/src/libcore/time.rs
@@ -24,19 +24,19 @@ const MICROS_PER_SEC: u64 = 1_000_000;
 const MAX_NANOS_F64: f64 = ((u64::MAX as u128 + 1)*(NANOS_PER_SEC as u128)) as f64;
 
 /// The duration of one second.
-#[unstable(feature = "duration_constants", issue = "0")]
+#[unstable(feature = "duration_constants", issue = "57391")]
 pub const SECOND: Duration = Duration::from_secs(1);
 
 /// The duration of one millisecond.
-#[unstable(feature = "duration_constants", issue = "0")]
+#[unstable(feature = "duration_constants", issue = "57391")]
 pub const MILLISECOND: Duration = Duration::from_millis(1);
 
 /// The duration of one microsecond.
-#[unstable(feature = "duration_constants", issue = "0")]
+#[unstable(feature = "duration_constants", issue = "57391")]
 pub const MICROSECOND: Duration = Duration::from_micros(1);
 
 /// The duration of one nanosecond.
-#[unstable(feature = "duration_constants", issue = "0")]
+#[unstable(feature = "duration_constants", issue = "57391")]
 pub const NANOSECOND: Duration = Duration::from_nanos(1);
 
 /// A `Duration` type to represent a span of time, typically used for system
diff --git a/src/libstd/time.rs b/src/libstd/time.rs
index d8cdef8b2ab30..5d9c726995a34 100644
--- a/src/libstd/time.rs
+++ b/src/libstd/time.rs
@@ -21,7 +21,7 @@ use sys_common::FromInner;
 #[stable(feature = "time", since = "1.3.0")]
 pub use core::time::Duration;
 
-#[unstable(feature = "duration_constants", issue = "0")]
+#[unstable(feature = "duration_constants", issue = "57391")]
 pub use core::time::{SECOND, MILLISECOND, MICROSECOND, NANOSECOND};
 
 /// A measurement of a monotonically nondecreasing clock.