Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Avoid useless sift_down when std::collections::binary_heap::PeekMut is never mutably dereferenced #75974

Merged
merged 3 commits into from
Sep 21, 2020
Merged

Avoid useless sift_down when std::collections::binary_heap::PeekMut is never mutably dereferenced #75974

Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
924cd13
Added benchmarks for BinaryHeap
SkiFire13 Sep 5, 2020
af1e363
Set sift=true only when PeekMut yields a mutable reference
SkiFire13 Aug 26, 2020
ca15e9d
Fix time complexity in BinaryHeap::peek_mut docs
SkiFire13 Sep 19, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Fix time complexity in BinaryHeap::peek_mut docs
  • Loading branch information
@SkiFire13
SkiFire13 committed Sep 19, 2020
commit ca15e9d8a11e7c25eb85930d1da3009647c1680e
3 changes: 2 additions & 1 deletion library/alloc/src/collections/binary_heap.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -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 }) }
Expand Down