> I'm not interested in the definition so much as I am in calling it "table stakes", and so the fact that these languages satisfy their promises is uninteresting in isolation. What matters is the value of their promises. The majority of Rust programs I see, I wouldn't have written in a low-level language, so the fact that it offers memory safety for the things I don't need it to do does nothing for me.

I mean, if you're already going to say "I don't want a low level language for anything other than what I can use unsafe for", then of course Rust will seem like overkill. I'd argue that the value of Rust is that it makes low-level viable for a lot of stuff that would otherwise require a lack of memory safety; a lot of it is stuff that might be written in a higher level language, but that's just because relatively few programs are impossible to write in higher level languages. That doesn't mean that the ones that need to be lower level can't be written in Rust though.

> Now, clearly, Rust's originators didn't consider what Java offers (or at least what it offered 20 years ago when Rust was first conceived) to be table stakes or they wouldn't have wanted Rust. Java exacted some price in exchange for its memory safety that was unacceptable to Rust's originators and trumped its memory safety. But the same thing happens with Rust vs Zig. Rust exacts a heavy price for its memory safety, that - just as in Rust's case vs Java - is sometimes unacceptable. So I can't see how any of these could be "table stakes".

Yes, "table stakes" is a value judgment, and one some people will disagree with. The cost for memory safety in Java is performance overhead though, and the cost for memory safety in Rust is not being able to express certain valid things that can't be validated; those are both objectively different from not offering memory safety at all, and my point is that the cases where what you want to express is literally impossible in Rust to do safely while actually being memory safe are pretty rare. There are some cases where what you're trying to do are fundamentally unsafe, in which case you need to use an unsafe block, but that's not anywhere close to the same as removing validation from the entire program. I'm fairly skeptical that you're basing your view that there are so many cases where you want to do something that's guaranteed to be safe but impossible to write in safe Rust on objective criteria, and extremely skeptical that the programs you write are anywhere close to entirely comprised of logic that can't be expressed safely.

> What Rust can validate and what can fundamentally be validated are two very, very different things. Compared to what ATS can validate, what Rust can validate is almost indistinguishable from C. In Rust you have to do lots and lots of things that require you to be "smart enough not to screw up" that you could prove in ATS, and still no one (including Rust programmers) would say that what ATS offers is "table stakes" because, obviously, it comes at a high price that the people who choose Rust don't want to pay.

> So clearly different languages offer different capabilities and charge a price for them. Sometimes the price is worth it and sometimes it isn't.

Sure, no one is disputing that. But that doesn't change the fact that some languages objectively require you to opt into which parts are memory unsafe, and others don't. It's obvious we won't see eye to eye on whether that's table stakes or not, but that's a difference of opinion, and having a different opinion than you isn't literally illogical; I find your take on it to be as hard to understand as mine is to you.

> But Java or Rust programs still suffer from a lot of bugs that ATS could eliminate, if you're willing to pay the price, and you're clearly unwilling. ATS programmers could say about Rust programmers what you say about C++ programmers. Clearly there's no universal table stakes here.

You're again taking an empirical argument as an abstract one and ignoring the real world outcomes that languages produce. You mentioned finding the fact that they actually produce real world software that in practice do not suffer from the class of bugs that C/C++ suffers from uninteresting, and that's fine, but it's meaningful for people who care about software actually getting used in the real world for real things. You seem to be arguing that unless you can eliminate literally the most bugs of any language in existence, then eliminating any bugs by picking a language that eliminates some of them is a useless endeavor. To me, the reasonable thing would be to choose a place to draw the line and say "anything beyond this is too risky, but I'll tolerate anything that's at least this safe", and memory safety is in practice the place I think it makes sense to do. I don't agree at all that not drawing any line at all is the only logical choice in a scenario when there are multiple places to draw it.

> I'd argue that the value of Rust is that it makes low-level viable for a lot of stuff that would otherwise require a lack of memory safety; a lot of it is stuff that might be written in a higher level language, but that's just because relatively few programs are impossible to write in higher level languages.

Maybe, but I don't see making a low language viable for something it's not needed as offering much value. Low-level languages are primarily designed to give you direct, low-level control over interaction with the hardware, they sacrifice other things for that goal (including performance [1]), and so if I don't need that control I don't use a low-level language. When I do need that control, I find that Rust requires reaching for unsafe too frequently while still paying the full price for the safety of things I don't use (even Rust's memory management of strings doesn't give me the control I want; I have to work pretty hard for it).

> The cost for memory safety in Java is performance overhead though,

It's not performance (you often gain performance, especially in large programs). It's warmup and footprint.

> But that doesn't change the fact that some languages objectively require you to opt into which parts are memory unsafe, and others don't.

Like I said, C also fits in the category, so it's not a meaningful distinction. The difference is in what you can do in the safe subset. Zig lets you do more things in a safe way than C (where the safe subset is effectively empty), Rust lets you do more safe things than Zig, and Java lets you do more safe things than Rust.

> You mentioned finding the fact that they actually produce real world software that in practice do not suffer from the class of bugs that C/C++ suffers from uninteresting

I didn't say that that's uninteresting; in fact Zig also eliminates spatial unsafety as well as Rust, and I think that's good. I said that merely looking at broad statistics is uninteresting if you don't consider the kinds of programs being written. I.e. Rust gives me safety mostly when I write code with the same level of low-level control as I have in Java, then that's the part I find interesting.

> You seem to be arguing that unless you can eliminate literally the most bugs of any language in existence, then eliminating any bugs by picking a language that eliminates some of them is a useless endeavor.

That's the very thing I'm arguing against. I'm saying that different languages eliminate different bugs at a cost (again, Zig eliminates many memory safety bugs you'd find in C or even C++, arguably the most dangerous ones). What I'm saying is that what you get and whether the price is worth it depends both on the program you're writing and on your personal preferences. Just to be clear, "preferences" doesn't mean I care more or less about correctness, but which approaches to correctness I find more or less effective, something on which there is no consensus.

> To me, the reasonable thing would be to choose a place to draw the line and say "anything beyond this is too risky, but I'll tolerate anything that's at least this safe", and memory safety is in practice the place I think it makes sense to do.

I think it also depends on the kinds of programs you write, because for many programs I write (and for which I pick Java) Rust's level of memory safety is too low, and for the programs I pick a low-level language I wish I could have some cheap memory safety, but it's not offered to me. So in those cases I would prefer Zig's spatial memory safety, as it's no worse than Rust, and not pay the high price for Rust's while getting little in return. Anyway, I'm saying that it's both a matter of which approach you believe leads to better correctness and the kinds of programs you write in the language.

[1]: For example, the fact that in Java, references are not required to be stable machine pointers opens the door to some powerful optimisations that are not available to languages where pointers are required to be machine pointers (or something close enough to them). Or the fact that low-level languages require that the machine instructions executed are those present in the compiled image (or close enough), or, if you want, caring about worst-case performance at the expense of average case performance (although both C++ and Rust specifically don't always make that easy) precludes some other very powerful optimisations. People like me who've spent years on huge C++ programs know that the low-level control offered by low-level languages (regardless of the question of safety) sometimes helps performance and sometimes harms it.