Skip to content

Add str::Utf8Chunk::invalid range hint #156165

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

Draft
xtqqczze wants to merge 1 commit into
base: main
Choose a base branch
from
+7 −0
Draft

Add str::Utf8Chunk::invalid range hint #156165

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
7 changes: 7 additions & 0 deletions library/core/src/str/lossy.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -102,6 +102,10 @@ impl<'a> Utf8Chunk<'a> {
#[must_use]
#[stable(feature = "utf8_chunks", since = "1.79.0")]
pub fn invalid(&self) -> &'a [u8] {
// SAFETY: The invariant that `self.invalid.len() <= 3` is upheld by
// the implementation of `Utf8Chunks::next()`, which is the only way to
// construct a `Utf8Chunk`.
unsafe { crate::hint::assert_unchecked(self.invalid.len() <= 3) };
self.invalid
}
}
Expand Down Expand Up @@ -286,6 +290,9 @@ impl<'a> Iterator for Utf8Chunks<'a> {
// `valid_up_to = i` and `i` only increases.
let (valid, invalid) = unsafe { inspected.split_at_unchecked(valid_up_to) };

// In UTF-8, the longest possible invalid sequence is 3 bytes long.
debug_assert!(invalid.len() <= 3);

Some(Utf8Chunk {
// SAFETY: All bytes up to `valid_up_to` are valid UTF-8.
valid: unsafe { from_utf8_unchecked(valid) },
Expand Down
Loading