(I'm separately skeptical that it's the most important memory safety property; I suspect that a review of Chrome and Firefox 0days would show that UAFs and type confusion are, at least to attackers, equally if not more important.)
Where? The GP's comment says "prefers," which I didn't read to mean a blanket statement. I don't think anybody with more than passing experience in Rust (or C) would make such a claim.
> Some dependently types languages can prove this statically, also model checking can do this, etc. So it can be done statically as well, but not in Rust.
You're couching the part where it can't be done with full generality or can be done with full generality, but with punishing semantics. The appropriate comparison here is with other normal general purpose compiled languages.
Dependently types languages and model checking do exist. They come with tradeoffs, but this is also true for Rust.
(You mentioned WUFFS below, which is why I qualified with general-purpose! One thing that WUFFS does that I think Rust could add pretty easily is provable indexing, e.g. allow me to use a `u8` to index a `[u8; 256]` without having to widen to a `usize` first and hope that LLVM optimizes it back out.)
My thought here is to proactively verify that LLVM elided the automatic bounds checks in places where you believe that your explicit checks should be sufficient.
That was a key part of my article on "No-Panic Rust": https://blog.reverberate.org/2025/02/03/no-panic-rust.html ("A Dance With The Optimizer")
for i in some_arr {
println!("{i}");
}