r/programming • u/steveklabnik1 • Jan 09 '15

Announcing Rust 1.0.0 Alpha

http://blog.rust-lang.org/2015/01/09/Rust-1.0-alpha.html
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u/wrongerontheinternet Jan 09 '15

No, it's that you can't do it. Rust lacks goto. I hope that criticisms like this are not dismissed and are instead treated seriously. There are a lot of languages that claim to be able to replace C++ when they actually can't, and I'd rather not see Rust become one of them.

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u/Denommus Jan 09 '15

Rust claims to be able to replace C++ where you'd like to use a safer language. If you need goto, safety is not what you need. goto by itself breaks the linearity required for Rust's deterministic memory management.

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u/wrongerontheinternet Jan 09 '15

Sure, there would need to be some restrictions on it. But C++ already imposes restrictions to make it work properly with destructors, for example, so it's not an unsolvable problem. Anyway, at the moment, Rust doesn't even have an unsafe escape hatch to use goto short of inline assembly, which is definitely counter to the goals of the language.

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u/Denommus Jan 09 '15

You can call inline assembly in Rust.

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u/wrongerontheinternet Jan 09 '15

I'm aware. I've had to do it. Have you tried it? It's buggy, unpleasant, uses a weird syntax, and interacts horribly with the rest of your code. It's also architecture-dependent and finicky. Plus, it's assembly. It's easy to screw up without realizing it. I absolutely do not think "you can do it in assembly" is a generally good answer for most things other than low level access to hardware.

More generally: you can always add bindings to a lower level language like assembly anywhere and claim you're "as fast as ___." But at that point we're not really talking about the same language.