[asdkhadsj]

I don't understand, tbh. Eg does Rust not make great effort to prevent null pointer exceptions? OOB feels quite similar to null pointer.

It's strange to me because a lot of what I value in Rust is writing code that handles all outcomes safely and with confidence. Yet that all seems to be out the window if you access array values - as it may or may not work.

The safety of [] slice/array access is entirely up to how the dev wrote the code.. which largely feels the same as any other language.

Am I thinking about something incorrectly?

[Sharlin]

The usage pattern is somewhat different. The primary problem with null references in languages such as Java is that they are not opt-in, and they're not even opt-out! That is to say, you don't even have an option (heh!) to encode in the type system the fact that a reference is never null. What's worse, references tend to get passed around a lot, and stored inside objects, and programmers are lazy and don't assert or even think about preconditions, so the root cause of an unexpected NPE can be far removed from the code that finally triggers it.

With code that indexes slices, the index computation is usually much more proximate to the actual indexing operation. If ensuring the validity of the index is about upholding an invariant internal to the module, it makes no sense to return an "sorry, I have a bug" error to the caller if that invariant fails to hold. What would the caller do about that?

[sanderjd]

I think the slightly odd or inconsistent thing is that rust has [] at all. I think of it as a compromise for people's familiarity with the operator. And if that's all it is, it makes sense that it behaves the way it does; I think a panic is more similar to what other languages with that operator do with an out of bound index than returning Option would be.