Rust tip: if you implement `Borrow<B>` and `Hash` for a type `Ty`, then for all `x: Ty`, `hash(x) == hash(x.borrow())` must be true. If this property does not hold, then objects of type `Ty` won't work properly with hashmaps.
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I may have spent several hours debugging this yesterday :-(
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sounds like a job for a borrow test macro or some such to assert the invariant
If clippy could work out that Hash<Ty> and Hash<Borrow<Ty>> were different implementations it could at least warn. I don't know if it'd be able to dive into whether they did the same thing as different implementations though.

May 30, 2019 ยท 6:49 AM UTC