Comment by pron

5 years ago

You've misunderstood. There is no doubt that Rust eliminates more undefined behaviour than Zig (though not completely), but it does it at the cost of harming other aspects of correctness. Zig does not try to eliminate UB as much as Rust, but it focuses more on reducing other types of bugs. At the end of the day, you don't care if your program fails due to UB or another bug, and it is unclear which approach results in more correct programs overall.

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pron

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roca  5 years ago

> you don't care if your program fails due to UB or another bug,

Actually you do, because memory safety bugs are more likely to be exploitable than some arbitrary correctness bug, because they can be weaponized to take full control of the program.

The reality is that UAF/dangling pointers are a major source of CVEs in mature software. Rust prevents those in practice, Zig doesn't. You think Zig is going to be much better than Rust at preventing other kinds of bugs. I see zero evidence of that.

  • pron  5 years ago

    I don't think Zig is going to be better than Rust at preventing other bugs. I don't know. No one knows. Software correctness is a very tricky thing about which we don't know much more than we know. UB are a cause of many bugs, and Zig eliminates many kinds of UB; Rust eliminates more. But Zig is also better at things we also know reduce bugs: simple semantics with simpler analysability, and shorter turnaround, which means more tests. In formal methods research we also have an analogous choice of approaches: more soundness at the cost of higher complexity and effort or vice-versa. There is no point hypothesising about which works better because even the experts have no idea, and it's certainly possible they are about even. The only thing that can settle this is empirical research.