Time units

src/libcore/lib.rs

@@ -122,6 +122,7 @@
 #![feature(const_slice_len)]
 #![feature(const_str_as_bytes)]
 #![feature(const_str_len)]
+#![feature(time_units)]
 
 #[prelude_import]
 #[allow(unused)]

src/libcore/time.rs

@@ -31,6 +31,35 @@ const NANOS_PER_MICRO: u32 = 1_000;
 const MILLIS_PER_SEC: u64 = 1_000;
 const MICROS_PER_SEC: u64 = 1_000_000;
 
+/// 1 nanosecond `Duration`.
+#[unstable(feature = "time_units", issue = "0")]
+pub const NANOSECOND: Duration = Duration { secs: 0, nanos: 1 };
+/// 1 microsecond `Duration`.
+#[unstable(feature = "time_units", issue = "0")]
+pub const MICROSECOND: Duration = Duration { secs: 0, nanos: NANOS_PER_MICRO };
+/// 1 millisecond `Duration`.
+#[unstable(feature = "time_units", issue = "0")]
+pub const MILLISECOND: Duration = Duration { secs: 0, nanos: NANOS_PER_MILLI };
+/// 1 second `Duration`.
+#[unstable(feature = "time_units", issue = "0")]
+pub const SECOND: Duration = Duration { secs: 1, nanos: 0 };
+/// 1 minute `Duration` (60 seconds).
+///
+/// Note that it's different from UTC minute, which can be 59-61 seconds long.
+#[unstable(feature = "time_units", issue = "0")]
+pub const MINUTE: Duration = Duration { secs: 60, nanos: 0 };
+/// 1 hour `Duration` (60*60 = 3 600 seconds).
+///
+/// Note that it's different from UTC hour, which can be 3559-3661 seconds long.
+#[unstable(feature = "time_units", issue = "0")]
+pub const HOUR: Duration = Duration { secs: 3_600, nanos: 0 };
+/// 1 day `Duration` (24*60*60 = 86 400 seconds).
+///
+/// Note that it's different from UTC day, length of which can vary from plus
+/// minus second (leap seconds) and up to plus minus an hour (Daylight Save Time).
+#[unstable(feature = "time_units", issue = "0")]
+pub const DAY: Duration = Duration { secs: 86_400, nanos: 0 };
+
 /// A `Duration` type to represent a span of time, typically used for system
 /// timeouts.
 ///
@@ -501,6 +530,15 @@ impl Mul<u32> for Duration {
     }
 }
 
+#[stable(feature = "u32_duration_mul", since = "1.29.0")]
+impl Mul<Duration> for u32 {
+    type Output = Duration;
+
+    fn mul(self, rhs: Duration) -> Duration {
+        rhs.checked_mul(self).expect("overflow when multiplying scalar by duration")
+    }
+}
+
 #[stable(feature = "time_augmented_assignment", since = "1.9.0")]
 impl MulAssign<u32> for Duration {
     fn mul_assign(&mut self, rhs: u32) {

src/libstd/lib.rs

@@ -324,6 +324,7 @@
 #![feature(float_internals)]
 #![feature(panic_info_message)]
 #![feature(panic_implementation)]
+#![feature(time_units)]
 
 #![default_lib_allocator]
 

src/libstd/time.rs

@@ -30,6 +30,10 @@ use sys_common::FromInner;
 
 #[stable(feature = "time", since = "1.3.0")]
 pub use core::time::Duration;
+#[unstable(feature = "time_units", issue = "0")]
+pub use core::time::{
+    NANOSECOND, MICROSECOND, MILLISECOND, SECOND, MINUTE, HOUR, DAY,
+};
 
 /// A measurement of a monotonically nondecreasing clock.
 /// Opaque and useful only with `Duration`.