Rust's lifetimes need full subtyping, with covariant and contravariant type cons... | Hacker News

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		remexre on Nov 23, 2021 \| parent \| context \| favorite \| on: Go does not need a Java-style GC Rust's lifetimes need full subtyping, with covariant and contravariant type constructors (though I don't think it supports annotations for them, and always infers them instead), which I think would make the generics implementation quite a bit more complicated than it currently is...

Yoric on Nov 23, 2021 [–]

Yeah, the fact that co/contravariant type constructors aren't (or aren't always?) annotated has always felt a bit awkward to me. Ah, well, it works :)

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