A new proposal has been announced: #346. It will be announced at the next meeting to try and draw attention to it, but usually MCPs are not discussed during triage meetings. If you think this would benefit from discussion amongst the team, consider proposing a design meeting.
note that it has at least one known false positive: https://github.com/rust-lang/rust-clippy/issues/5838
I do wonder how hard it would be to treat the raw pointer returned from as_ptr as a reference for borrow checking, though perhaps just lifetime checking (not mutability tracking).
whoops I missed there was an MCP - I think this should be warn-by-default until the false positive is fixed.
@T-compiler: Proposal #346 has been seconded, and will be approved in 10 days if no objections are raised.
This proposal has been accepted: #346.