Yes, unsafe blocks one way in which the Rust doesn't privilege built-ins and the standard library (much) over external code: people can write high performance a abstractions without them needing to be baked into the language. This is exactly what has occurred with multidimensional arrays with external libraries like ndarray.

Unsafe allows you to dereference raw pointers and foreign-function calls, but you cannot go around the borrow checker, which is what's causing annoyance.

That said, you can create raw and dereference raw pointers, which lets you to do the above.

If you take a ref into a pointer that lets you work around the borrow checker(and I've bitten myself just about every time I've done it now that I'm used to the borrow checker).

Using unsafe blocks and pointers can silence the borrow checker, but that doesn't mean that code is well defined. For example, using swap (mentioned in the article) with overlapping references would be undefined behaviour.