[cortesoft]

Isn't that the point of unsafe blocks in rust? So you can write optimized code when you need to and the rust borrow checker won't let you?

[gmueckl]

Unsafe blocks are subject to the same borrow checking that the rest of the language is.

[tialaramex]

That is correct. However, raw pointers are not borrow checked, in safe Rust they're largely useless, but in unsafe Rust you can use raw pointers if that's what you need to do to get stuff done.

As an example inside a String is just a Vec<u8> and inside the Vec<u8> is a RawVec<u8> and that is just a pointer, either to nothing in particular or to the bytes inside the String if the String has allocated space for one or more bytes - plus a size and a capacity.