It is safe btw. The difference is that it returns two mutable references vs. one...

loeg · 2026-01-01T08:47:34 1767257254

The implementation is unsafe, as I said:

> split_at_mut is just unsafe code (and sibling comment mentioned it hours before you did). The borrow checker doesn't natively understand that.

https://doc.rust-lang.org/src/core/slice/mod.rs.html#2086

Cyph0n · 2026-01-01T19:00:31 1767294031

No, that’s the unchecked version. Two people are telling you that this method exists and is safe, so I am not sure why you’re still doubting this lol.

bmandale · 2026-01-01T19:13:42 1767294822

The checked variant just calls the unchecked, and the panicking variant calls the checked variant. They all need to call unsafe code. See here for details: https://doc.rust-lang.org/nomicon/borrow-splitting.html

Cyph0n · 2026-01-01T20:22:22 1767298942

Then you misunderstand what unsafe means in Rust. Every single Rust binary needs to eventually call unsafe code at some layer of the callstack.

Is creating a TCP socket using stdlib functions unsafe? How about writing to a file? Or acquiring a mutex?

I would suggest doing some more reading before chiming in here :)

bmandale · 2026-01-03T03:48:29 1767412109

You have totally misunderstood what the person you are talking with means by unsafe. Perhaps you should resolve that prior to such condescensions.

Cyph0n · 2026-01-04T21:04:48 1767560688

Indeed I have haha - my bad :)

Easier to lose context with longer comment chains...