alt Hacker News> In Rust you pay for it by arranging your program in a way the compiler can verify.
I disagree with this. The sentence implies that this work is done in order to make the compiler happy, where my experience is that it forces the programmer to actually get it right.
I had an "aha moment" when I was frustrated at failing to express my intent to the compiler, and suddenly realised that the reason I couldn't "just say the magic words" was that my object ownership design was inherently flawed. I had to make large changes not to make the compiler happy, but to actually have a coherent design.
So no, it's not about what "the compiler can verify". That's like saying "my lawyer won't let me do this". No, your lawyer is your employee, not your boss. They're just saying that if you do this, then you may go to prison. It's not the same thing.
("unsafe" is the Rust way to go "thank you, legal department, but I'm making a business decision to take this risk. Your concern has been noted")
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I've had that moment in Rust too, where there was no composition that effected what I wanted, because supporting that model would have meant a very different backing data structure. However in that case I actually didn't care about the kind of correctness problem it was saving me from.
I've also had the converse experience, where I know full well that the structure I'm trying to impose is correct and quite efficient, but its part of the space that rust doesn't cover.
Rust is great. It's a noble attempt to bring a degree of correctness to a problem space that suffers from a great deal of slop. But to pretend that the model is complete, or that the design decisions that were made are perfect in every way, is just wrong. That the rust compiler and runtime can't support my construct isn't really an absolute value judgement on that idea in the first place. The rust compiler isn't really an oracle that tells you whether something is right or not in an arbitrary value system.
I understand what you’re saying, but I read that phrase in a different way.
Let’s say you have two ways of doing the same thing: both work, both are legit and neither introduce GC bugs. The only difference between the two is that one can be verified by the compiler while the other can’t, so you are stuck with solution no. 1 although both would work.
To phrase it differently: the code that gets verified by the compiler is safe, but is all safe code verifiable by the compiler?
I’m not implying that’s the case, but that’s what I feel the author is saying.