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

Optimize empty case in Vec::retain #128234

Merged
merged 1 commit into from
Jul 30, 2024
Merged

Optimize empty case in Vec::retain #128234

Changes from all commits
Commits
Show all changes
1 commit
Select commit
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
6 changes: 6 additions & 0 deletions library/alloc/src/vec/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1711,6 +1711,12 @@ impl<T, A: Allocator> Vec<T, A> {
F: FnMut(&mut T) -> bool,
{
let original_len = self.len();

if original_len == 0 {
// Empty case: explicit return allows better optimization, vs letting compiler infer it
return;
}

// Avoid double drop if the drop guard is not executed,
// since we may make some holes during the process.
unsafe { self.set_len(0) };
Expand Down
Loading