> Then why do my data structures detect if I go out of bounds?
I didn't mean you can't write C++ code that enforces that, I said C++ itself doesn't enforce it.
> Yes. You can clean up memory allocations automatically with destructors and have value semantics for memory that is on the heap.
Surely there are other ways to do that. E.g. Zig has defer. You can say that you may forget to write defer, which is true, but the implicitness of RAII has cause (me, at least) many problems over the years. It's a pros-and-cons thing, and Zig chooses the side of explicitness.
> Why are you talking about rust here? Focus on what I'm saying.
You're right, sorry :)
> Says who?
Says most people in the field of software correctness (and me https://pron.github.io). In the seventies, the prevalent opinion was that proofs of correctness would be the only viable approach to correctness. Since then, we've learnt two things, both of which were surprising.
The first was new results in the computational complexity of model checking (not to be confused with the computational complexity of model checkers; we're talking about the intrinsic computation complexity of the model checking problem, i.e. the problem of knowing whether a program satisfies some correctness property, regardless of how we learn that). This included results (e.g. by Philippe Schnoebelen) showing that even though there would be the reasonable expectation that language abstractions could make the problem easier, even in the worst case - it doesn't.
The second was that unsound techniques, including engineering best practices, have proven far more effective than was thought possible in the seventies. This came as quite a shock to formal methods people (most famously, Tony Hoare, who wrote a famous paper about it).
As a result, the field of software correctness has shifted its main focus from proving program correct to finding interesting confidence/cost tradeoffs to reduce the number of bugs, realising that there's no single best path to more correctness (as far as we know today).
> I'm saying that these are solved problems in C++ and I don't have to deal with them. Zig does not have destructors and move semantics.
That's true, but these are not memory safety guarantees. These are mechanisms that could mitigate bugs (though perhaps cause others), and Zig has other, different mechanisms to mitigate bugs (though perhaps cause others). E.g. see how easy it is to write a type-safe printf in Zig compared to C++, or how Zig handles various numeric overflow issues compared to C++. So it's true that C++ has some features we may find helpful that Zig doesn't and vice-versa, we can't judge which of them leads to more correct programs. All I said was that Zig offers more safety guarantees than C++, which it does.