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by tempodox 1130 days ago
If you use the Cocoa API with ObjC or Swift, you get Automatic Reference Counting (ARC), generated by the compiler. I guess with this you'd have to retain / release your objects manually again?
3 comments
xanathar 1130 days ago
No. Rust has RAII so you can have retain on 'clone' operations and release on drops, just like the native Rc/Arc types do.

This is, incidentally, how the servo bindings to core-foundation work (I prefer those bindings where there is overlap).

Servo bindings: https://github.com/servo/core-foundation-rs

Other crates of interest on this topic: - https://crates.io/crates/objc - https://crates.io/crates/block

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pjmlp 1130 days ago
Someone has to manually type .clone() calls.
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xanathar 1130 days ago
If you don't, the compiler tells you to, as per standard Rust semantics.
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pjmlp 1130 days ago
Automatic Reference Counting.

Writing by hand isn't the same.

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xanathar 1130 days ago
Except that even Apple's ARC is not automatic - try passing the pointer to a GArray, or putting it on a malloc'ed linked list or any other data structure not implemented in Swift or ObjectiveC (provided that you compile objectiveC with the correct build flags).

The point is: you can't leak, you can't end up keeping a reference without incrementing the refcount and you don't events have to worry about any of the refcounting as long as the code you write is sound according to Rust rules.

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pjmlp 1129 days ago
Moving goalposts.

We are speaking about the normal development experience, not corner cases or unsafe code.

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IshKebab 1130 days ago
Rust has ARC too so I very much doubt it.
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pjmlp 1130 days ago
Nope, someone has to manually type .clone() calls.
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IshKebab 1130 days ago
That's irrelevant (and barely different to having to type `=`). The salient point is that you don't need to manually call free/release.
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pjmlp 1130 days ago
That is more than relevant, otherwise we are comparing oranges to apples, pun intended.

Automatic Reference Counting.

Since = is the same as .clone() in character count?

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IshKebab 1129 days ago
Yes I'm aware that the A stands for Atomic in Rust, not Automatic. But it is still automatic because you do not need to increment and decrement the counter manually.

> Since = is the same as .clone() in character count?

Why does character count matter? I think you're getting a bit distracted from the point.

Will you need to manually free/release objects? No you will not.

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Klonoar 1130 days ago
Author here.

Nope, retain on create/etc and release on drop happens automatically.

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