From d720a19e2a0526794999997db399dd5d7521bd78 Mon Sep 17 00:00:00 2001 From: VillSnow Date: Sun, 28 Jun 2020 16:45:56 +0900 Subject: [PATCH] Update doc comment --- src/libcore/slice/mod.rs | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs index cd4967e10e44..11561c392864 100644 --- a/src/libcore/slice/mod.rs +++ b/src/libcore/slice/mod.rs @@ -2664,13 +2664,17 @@ impl [T] { self.iter().is_sorted_by_key(f) } - /// Returns index of partition point according to the given predicate, - /// such that all those that return true precede the index and - /// such that all those that return false succeed the index. + /// Returns the index of the partition point according to the given predicate + // (the index of the first element of the second partition). /// - /// The slice must be partitioned - /// so that all elements where the predicate returns true - /// precede the elements where the predicate returns false. + /// The slice is assumed to be partitioned according to the given predicate. + /// This means that all elements for which the predicate returns true are at the start of the slice + /// and all elements for which the predicate returns false are at the end. + /// For example, [7, 15, 3, 5, 4, 12, 6] is a partitioned under the predicate x % 2 != 0 + /// (all odd numbers are at the start, all even at the end). + /// + /// If this slice is not partitioned, the returned result is unspecified and meaningless, + /// as this method performs a kind of binary search. /// /// # Examples ///