So how do you solve SIMD with C, without language extensions?
C is not a special snowflake.
Writing generic SIMD code is more portable. C has libraries, and Zig also has vector primitives available through built-in functions.
In fact, a few GC enabled languages have explicit SIMD support.
For certain problems you would want a TLA+ specification for safety and especially liveness either way. It's not like Rust absolutely guarantees correctness in all cases.
Rust sits in a sweet spot between C/Zig and languages like Java, but it's not an appropriate replacement for either of them.
I believe that Rust can be as low level as you want. If you have to fight the language to accomplish something, it's because you're probably trying to do something unsafe, and Rust will let you do that if you pay the price.
I was looking for examples of real cases where Zig is a better option than Rust. And while Zig is a lovely language, its main points against Rust are that it lets you do unsafe things more easily, and it's easier to learn.
There is a scalable solution for UAF that doesn't involve introducing a lifetime/region system: garbage collection. Of course, that comes with its own set of tradeoffs.
There are many cool possibilities that C++ has never explored and frankly I find your argument unimaginative.
From the man page (which I believe quotes ISO C): "The free() function shall cause the space pointed to by ptr to be deallocated; that is, made available for further allocation." If free doesn't do that because another allocation is pointing into that page, that's a violation of the contract. Standard quarantine doesn't violate the spec because the space will eventually become available no matter what, but perpetual quarantine does.
One way to fix the problem would be to round up all allocations to 4kB, but that's very wasteful and slow due to cache and page table traffic; you'd be better off from a performance point of view with a garbage collector. More promising is ARM MTE, though the tag is currently too small to really be called a solution to UAF as opposed to a mitigation. A 64-bit tag would be enough, but I'm not sure what the performance costs of that would be--I wouldn't be surprised if the increased memory traffic makes it slower than a GC.
Quoting and bolding. I think this is the thing that I need to change most about my own style of programming.