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by saghm 34 days ago
Exactly; I feel like a lot of people seem to misunderstand what Rust is trying to solve. It's fundamentally not trying to make unsafe code impossible; it's making the number of places you need to audit it a tiny fraction of your codebase compared to needing to audit the entirety of a C or C++ codebase. When I'm doing code reviews, you'd better believe I'm going to spend some extra time on any unsafe block I see to figure out if it's necessary and if so, if it's actually safe safe (with the default assumption for both of those being that they're not until I can convince myself otherwise).
1 comments
skydhash 34 days ago
The thing is you can actually write quite good C code (see OpenBSD project). The power of C is that it's pragmatic. It lets you write code with you taking the full responsibility of being a responsible person. To err is human, but we developed a set of practices to handle this (by making sure the gun is unloaded and the safety is on before storing it to avoid putting holes in feet).

I like type checking and other compile time checks, but sometimes they feel very ceremonial. And all of them are inference based, so they still relies on the axiom being right and that the chain of rules is not broken somewhere. And in the end they are annotations, not the runtime algorithm.

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kibwen 34 days ago
> To err is human

Yes, which is precisely why I write in Rust, because the compiler errs less than I do.

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skydhash 33 days ago
It may, but it still requires careful annotations. So you should hope that you have not made an error there and described the wrong structure for the code.
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saghm 33 days ago
It seems like you have this backwards. Messing up lifetimes in safe Rust can't cause unsafety; the compiler checks if the lifetimes are valid, and if they're not, you get a compiler error. You don't need to "hope" you did it right because the entire point is that you can't compile if you didn't.

On the other hand, when you're relying on your ability to "actually write quite good C code"...you'd better hope that you have not made an error there. In practice, some of the most widely used C libraries in the world still seem to have bugs like this, so I don't really understand why you'd think that's a winning strategy.

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