1 files changed, 34 insertions, 2 deletions
diff --git a/library/std/src/f64.rs b/library/std/src/f64.rs
index 16359766b..6782b861f 100644
--- a/library/std/src/f64.rs
+++ b/library/std/src/f64.rs
@@ -78,10 +78,14 @@ impl f64 {
     /// let f = 3.3_f64;
     /// let g = -3.3_f64;
     /// let h = -3.7_f64;
+    /// let i = 3.5_f64;
+    /// let j = 4.5_f64;
     ///
     /// assert_eq!(f.round(), 3.0);
     /// assert_eq!(g.round(), -3.0);
     /// assert_eq!(h.round(), -4.0);
+    /// assert_eq!(i.round(), 4.0);
+    /// assert_eq!(j.round(), 5.0);
     /// ```
     #[rustc_allow_incoherent_impl]
     #[must_use = "method returns a new number and does not mutate the original value"]
@@ -91,6 +95,32 @@ impl f64 {
         unsafe { intrinsics::roundf64(self) }
     }
 
+    /// Returns the nearest integer to a number. Rounds half-way cases to the number
+    /// with an even least significant digit.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(round_ties_even)]
+    ///
+    /// let f = 3.3_f64;
+    /// let g = -3.3_f64;
+    /// let h = 3.5_f64;
+    /// let i = 4.5_f64;
+    ///
+    /// assert_eq!(f.round_ties_even(), 3.0);
+    /// assert_eq!(g.round_ties_even(), -3.0);
+    /// assert_eq!(h.round_ties_even(), 4.0);
+    /// assert_eq!(i.round_ties_even(), 4.0);
+    /// ```
+    #[rustc_allow_incoherent_impl]
+    #[must_use = "method returns a new number and does not mutate the original value"]
+    #[unstable(feature = "round_ties_even", issue = "96710")]
+    #[inline]
+    pub fn round_ties_even(self) -> f64 {
+        unsafe { intrinsics::rintf64(self) }
+    }
+
     /// Returns the integer part of `self`.
     /// This means that non-integer numbers are always truncated towards zero.
     ///
@@ -553,8 +583,10 @@ impl f64 {
         unsafe { cmath::cbrt(self) }
     }
 
-    /// Calculates the length of the hypotenuse of a right-angle triangle given
-    /// legs of length `x` and `y`.
+    /// Compute the distance between the origin and a point (`x`, `y`) on the
+    /// Euclidean plane. Equivalently, compute the length of the hypotenuse of a
+    /// right-angle triangle with other sides having length `x.abs()` and
+    /// `y.abs()`.
     ///
     /// # Examples
     ///