[Manishearth]

You misunderstand me: I don't disagree that Rust is all about safe systems programming. I disagree that "data race freedom" is Rust's (only) core guarantee, and I disagree that the "seemingly arbitrary rules" are about "data race freedom". They're about so much more, since the same rules get us memory safety as well, among other things.

I don't think that Rust is trying to test out a programming paradigm or whatever, I'm saying that these "seemingly arbitrary rules" get us a lot of things, by proxy of a certain paradigm, and reducing it to "data race freedom" (when it's so much more) is something we should avoid.

(My comment seems to focus on the discipline, I was just using it as a proxy for all of the things it gets us)

[dbaupp]

As we discussed on IRC, "data race freedom" is equivalent to guaranteeing memory safety, and so, in a kind-of pedantic way, data race freedom is the core guarantee. That said, the original comment would've been better phrased as "one of Rust's core guarantees".

Furthermore, I still think the best phrasing of the rules is for that guarantee: if a rule is removed one can usually construct fairly simple programs that have data races/memory unsafety. Of course, it is definitely true that the arbitrary rules have other benefits, but if there was a simpler scheme that gave the core memory safety without the other things, I think Rust would've adopted it.