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A comment on The Billion Row Challenge (1BRC) – Step-by-Step from 71s to 1.7s. Parent comment

Re:The Billion Row Challenge (1BRC) – Step-by-Step from 71s ... by GrumpySloth on Friday February 23, 2024 @07:06AM (#39479571)
You can.

https://doc.rust-lang.org/std/collections/hash_map/enum.Entr...

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Re:The Billion Row Challenge (1BRC) – Step-by-Step from 71s ... by IshKebab on Friday February 23, 2024 @08:39AM (#39480427)
You can't. `entry()` takes they key by value, not by reference:

https://doc.rust-lang.org/std/collections/hash_map/struct.Ha...

You might be getting confused because in that example the `HashMap` keys are references.

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Re:The Billion Row Challenge (1BRC) – Step-by-Step from 71s ... by GrumpySloth on Friday February 23, 2024 @09:01AM (#39480645)
My bad. That’s not been an issue in my code, as I use arenas to manage memory and never put an owning container as key in a HashMap.
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