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The Handle trait (smallcultfollowing.com)
submitted 10 months ago by to c/rust@programming.dev
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[–] 1 point 10 months ago (1 child)

What's the use-case for &Arc? Modifying an Arc object in outer scope?

To me, this handle trait sounds a lot like "reference-counted reference". When there already exists a pure "reference" in the language

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  • [–] [S] 1 point 10 months ago (1 child)

    I don't know but it could be anything else than an Arc. Obviously you should still be able to take a usual reference to such a thing.

    References are just pointers, they don't have any counting. This proposal as I understand it is an attempt at making reference-counting more ergonomic.

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  • [–] 2 points 10 months ago

    I don’t know but it could be anything else than an Arc. Obviously you should still be able to take a usual reference to such a thing.

    Maybe. My point is that unless you want to, for example, have a reference that you switch between which object it references, I think you would be fine with using the ref-counted reference. With eventual optimization done via compiler when it's sure the code won't be trying to access the object after it got deleted. But even if I'm wrong, there could be another way to get a pure reference

    This proposal as I understand it is an attempt at making reference-counting more ergonomic.

    Yes, and IMO by using Handle for that it breaks a pattern. Rust keeps * and & for speaking about values and memory management (I want data vs I want reference). Using a trait for ref-counted referencing adds another layer. So suddenly we have *, & and ::Handle(). You see what I'm getting at?

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