1 files changed, 99 insertions, 0 deletions
diff --git a/third_party/rust/time/src/rand.rs b/third_party/rust/time/src/rand.rs
new file mode 100644
index 0000000000..8afefe5075
--- /dev/null
+++ b/third_party/rust/time/src/rand.rs
@@ -0,0 +1,99 @@
+//! Implementation of [`Distribution`] for various structs.
+
+use rand::distributions::{Distribution, Standard};
+use rand::Rng;
+
+use crate::{Date, Duration, Month, OffsetDateTime, PrimitiveDateTime, Time, UtcOffset, Weekday};
+
+impl Distribution<Time> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Time {
+        Time::__from_hms_nanos_unchecked(
+            rng.gen_range(0..24),
+            rng.gen_range(0..60),
+            rng.gen_range(0..60),
+            rng.gen_range(0..1_000_000_000),
+        )
+    }
+}
+
+impl Distribution<Date> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Date {
+        Date::from_julian_day_unchecked(
+            rng.gen_range(Date::MIN.to_julian_day()..=Date::MAX.to_julian_day()),
+        )
+    }
+}
+
+impl Distribution<UtcOffset> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> UtcOffset {
+        let seconds = rng.gen_range(-86399..=86399);
+        UtcOffset::__from_hms_unchecked(
+            (seconds / 3600) as _,
+            ((seconds % 3600) / 60) as _,
+            (seconds % 60) as _,
+        )
+    }
+}
+
+impl Distribution<PrimitiveDateTime> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> PrimitiveDateTime {
+        PrimitiveDateTime::new(Self.sample(rng), Self.sample(rng))
+    }
+}
+
+impl Distribution<OffsetDateTime> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> OffsetDateTime {
+        let date_time: PrimitiveDateTime = Self.sample(rng);
+        date_time.assume_offset(Self.sample(rng))
+    }
+}
+
+impl Distribution<Duration> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Duration {
+        Duration::nanoseconds_i128(
+            rng.gen_range(Duration::MIN.whole_nanoseconds()..=Duration::MAX.whole_nanoseconds()),
+        )
+    }
+}
+
+impl Distribution<Weekday> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Weekday {
+        use Weekday::*;
+
+        match rng.gen_range(0u8..7) {
+            0 => Monday,
+            1 => Tuesday,
+            2 => Wednesday,
+            3 => Thursday,
+            4 => Friday,
+            5 => Saturday,
+            val => {
+                debug_assert!(val == 6);
+                Sunday
+            }
+        }
+    }
+}
+
+impl Distribution<Month> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Month {
+        use Month::*;
+        match rng.gen_range(1u8..=12) {
+            1 => January,
+            2 => February,
+            3 => March,
+            4 => April,
+            5 => May,
+            6 => June,
+            7 => July,
+            8 => August,
+            9 => September,
+            10 => October,
+            11 => November,
+            val => {
+                debug_assert!(val == 12);
+                December
+            }
+        }
+    }
+}