Skip to content

Add an explanation shared to exclusive transmute #344

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

Merged
merged 1 commit into from
Mar 17, 2022
Merged

Add an explanation shared to exclusive transmute #344

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
5 changes: 4 additions & 1 deletion src/transmutes.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,10 @@ boggling.
* Transmute has an overloaded return type. If you do not specify the return type
it may produce a surprising type to satisfy inference.

* Transmuting an `&` to `&mut` is UB.
* Transmuting an `&` to `&mut` is UB. While certain usages may *appear* safe,
note that the Rust optimizer is free to assume that a shared reference won't
change through its lifetime and thus such transmutation will run afoul of those
assumptions. So:
* Transmuting an `&` to `&mut` is *always* UB.
* No you can't do it.
* No you're not special.
Expand Down