std: improve documentation for get_mut() methods regarding forgotten guards #139164
+13
−3
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Signed-off-by: xizheyin <[email protected]>
rustbot
added
S-waiting-on-review
joboet
approved these changes
Apr 3, 2025
Signed-off-by: xizheyin <[email protected]>
Signed-off-by: xizheyin <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Fixes #139034
This PR improves the documentation for
get_mut()methods inMutex,RefCell, andRwLockto clarify their behavior when lock guards are forgotten (e.g., via std::mem::forget).The current documentation for these methods states that a mutable borrow "statically guarantees no locks exist", which is not entirely accurate. While a mutable borrow prevents new locks from being created, it does not clear or detect previously abandoned locks through
forget(). This can lead to counterintuitive behavior:https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=e68cefec12dcd435daf2237c16824ed3
https://play.rust-lang.org/?version=nightly&mode=debug&edition=2024&gist=81263ad652c752afd63c903113d3082c
https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=311baa4edb3abf82a25c8d7bf21a4a52
r? libs