Yes. When people describe Rust as "a memory-safe programming language" they are describing an aspirational vision, and not a programming language that has actually been designed with sufficient rigor to guarantee memory safety. Any failure of rustc to actually guarantee this is just a bug in rustc itself, a failure to properly implement the Rust spec, because the closest thing Rust has to a spec is literally just the vague ideal that the compiler should guarantee safety somehow.

Rust cannot fail, it can only be failed.

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DriverDaily 2 hours ago | parent | next [-]

> Rust cannot fail, it can only be failed.

“Please build the perfect system. Because I specified ‘perfect’ any flaws are due to your incomplete implementation, not my awful brief.”

If the person writing the rust spec was a client I would have to drop them because they would be setting themselves up for dissatisfaction.

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insanitybit 2 hours ago | parent | prev | next [-]

I don't think the definition of "memory safe" has ever required full end to end stack conformance with a proof. Very few languages have achieved that, though some have. Most people call Java memory safe, C#, Python, Typescript, etc - all of those fall short of a formally verified, sound type system with a verified toolchain.

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afdbcreid 2 hours ago | parent [-]

Not to talk about Go, which has intentional unchecked-at-runtime UB (data races) yet many argue to consider it memory safe (and I have a feeling that the same people arguing Rust isn't memory safe are also there. Just a feeling though).

	▲	2 hours ago \| parent [-]
		[deleted]

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UncleMeat 2 hours ago | parent | prev | next [-]

Would you say the same thing about Java? It’s type system is also unsound.

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csande17 2 hours ago | parent | next [-]

I'm not an expert on the Java specification, but my understanding is that Java as a language is well-defined enough that we can say things like "Java's type system is unsound", independently from any specific implementation of Java.

You can't do that with Rust because "Rust's type system" is literally just the vague concept of "a type system that is safe". The implementation of this ideal in rustc can have flaws, but Rust itself cannot, because Rust itself has no flaws by definition.

	▲	mcherm 38 minutes ago \| parent [-]
		It is true that Rust does not have a complete formal specification for its type system which has been analyzed and proven to be sound. You seem to be implying that because of this, Rust has no definition of its type system (other than whatever happens to be implemented in the current compiler). I would disagree. As evidence, I would like to point out that not a single person argued that this flaw was not a bug, but was in fact the officially defined behavior. Clearly, the community has a shared understanding of what Rust's type system "ought" to do.

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vrighter 2 hours ago | parent | prev [-]

but it isn't claiming to be saving you from things it can't prove it can either.

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lolakutty 3 hours ago | parent | prev [-]

>Rust cannot fail, it can only be failed...

Sweet. But why should anyone care..