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

Move Duration to libcore

Fixes #46520; should be merged after #46508.

src/libcore/lib.rs

@@ -168,6 +168,7 @@ pub mod slice;
 pub mod str;
 pub mod hash;
 pub mod fmt;
+pub mod time;
 
 // note: does not need to be public
 mod char_private;

src/libcore/time.rs

@@ -7,6 +7,19 @@
 // <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.
+#![stable(feature = "duration_core", since = "1.24.0")]
+
+//! 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));
+//! ```
 
 use iter::Sum;
 use ops::{Add, Sub, Mul, Div, AddAssign, SubAssign, MulAssign, DivAssign};
@@ -45,7 +58,7 @@ const MICROS_PER_SEC: u64 = 1_000_000;
 ///
 /// let ten_millis = Duration::from_millis(10);
 /// ```
-#[stable(feature = "duration", since = "1.3.0")]
+#[stable(feature = "duration_core", since = "1.24.0")]
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash, Default)]
 pub struct Duration {
     secs: u64,

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`.