I've heard Rust classified as Safety, Performance, Usability in that order and Zig as Performance, Usability, Safety. From that perspective the build speed-ups make sense while an interpreter would only fit a triple where usability comes first.
This is why the value proposition of Zig is a question for people, because if you got measurably better performance out of Zig in exchange for worse safety that would be one thing. But Rust is just as performant, so with Zig you're exchanging safety for expressivity, which is a much less appealing tradeoff; the learning from C is that expressivity without safety encourages programmers to create a minefield of exploitable bugs.
Zig is a lot safer than C by nature. It does not aim to be as safe as Rust by default. But the language is a lot simpler. It also has excellent cross-compiling, much faster compilation (which will improve drastically as incremental compilation is finished), and a better experience interfacing with/using C code.
So there are situations where one may prefer Zig, but if memory-safe performance is the most important thing, Rust is the better tool since that is what it was designed for.
Zig feels like a small yet modern language that lacks many of C's footguns. It has far fewer implicit type conversions. There is no preprocessor. Importing native zig functionality is done via modules with no assumed stable ABI. Comptime allows for type and reflection chicanery that even C++ would be jealous of.
Yet I can just include a C header file and link a C library and 24 times out of 25, it just works. Same thing if you run translate-c on a C file, and as a bonus, it reveals the hoops that the tooling has to go through to preserve the fiddly edge cases while still remaining somewhat readable.
Zig isn't C-like in its syntax or its developer experience (e.g. whether it has a package manager), but in its execution model: unsafe, imperative, deemphasizes objects, metaprogramming by token manipulation.
I am only aware of the memory model, specifically pointer and consistency/synchronization which extends the C memory model by abstractions deemed "memory-safe" based on Separation Logic and Strict Aliasing. In my understanding you criticize Zig for not offering safety abstractions, because you can also write purely unsafe Rust also covered by the Rust "execution model".
Rust has no inheritance typical for OOP. Zig has no token manipulation, but uses "comptime".
> expressivity without safety encourages programmers to create a minefield of exploitable bugs.
Also, psychologically, the combination creates a powerful and dangerously false sensation of mastery in practitioners, especially less experienced ones. Part of Zig's allure, like C's bizarre continued relevance, is the extreme-sport nature of the user experience. It's exhilarating to do something dangerous and get away with it.
Zig is not an extreme sports experience. It has much better memory guarantees than C. It's clearly not as good as rust if that's your main concern but rust people need to also think long and hard about why rust has trouble competing with languages like Go, Zig and C++ nowadays.
What's the use case for Zig? You're in that 1% of projects in which you need something beyond what a garbage collector can deliver and, what, you're in the 1% of the 1% in which Rust's language design hurts the vibe or something?
You can also get that "safer, but not Safe" feeling from modern C++. So what? It doesn't really matter whether a language is "safer". Either a language lets you prove the absence of certain classes of bug or it doesn't. It's not like C, Zig, and Rust form a continuum of safety. Two of these are different from the third in a qualitative sense.
You want a modern language that has package management, bounds checks and pointer checks out of the box. Zig is a language you can pick up quickly whereas rust takes years to master. It's a good replacement to C++ if you're building a game engine for example.
> Either a language lets you prove the absence of certain classes of bug or it doesn't. It's not like C, Zig, and Rust form a continuum of safety. Two of these are different from the third in a qualitative sense.
Again repeating my critique from the previous comment – yes Zig brings in additional safety compared to C. Dismissing all of that out of hand does not convince anyone to use rust.
It's value proposition is aiming for the next generation of system programmers that aren't interested in Rust like languages but C like ones.
Current system devs working on C won't find Zig or Odin's value propositions to matter enough or indeed as you point out, to offer enough of a different solution like Rust does.
But I'm 100% positive that Zig will be a huge competitor for Rust in the next decade because it's very appealing to people willing to get into system programming, but not interested in Rust.