From ca15e9d8a11e7c25eb85930d1da3009647c1680e Mon Sep 17 00:00:00 2001
From: Giacomo Stevanato <giaco.stevanato@gmail.com>
Date: Sun, 20 Sep 2020 01:07:34 +0200
Subject: [PATCH] Fix time complexity in BinaryHeap::peek_mut docs

---
 library/alloc/src/collections/binary_heap.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/library/alloc/src/collections/binary_heap.rs b/library/alloc/src/collections/binary_heap.rs
index e3b738a70c888..06e5ac037ca79 100644
--- a/library/alloc/src/collections/binary_heap.rs
+++ b/library/alloc/src/collections/binary_heap.rs
@@ -399,7 +399,8 @@ impl<T: Ord> BinaryHeap<T> {
     ///
     /// # Time complexity
     ///
-    /// Cost is *O*(1) in the worst case.
+    /// If the item is modified then the worst case time complexity is *O*(log(*n*)),
+    /// otherwise it's *O*(1).
     #[stable(feature = "binary_heap_peek_mut", since = "1.12.0")]
     pub fn peek_mut(&mut self) -> Option<PeekMut<'_, T>> {
         if self.is_empty() { None } else { Some(PeekMut { heap: self, sift: false }) }