Add way of getting multiple mutable references from storages

[WaDelma]

Add API that allows getting multiple mutable references from a storage in a way that preserves correctness. If we had integer generics we could provide generic API:

fn get_muts<const N: usize>(&mut self, [Entity; N]) -> Option<[&mut T; N]>;

Right now we could provide more specific instances of it.

The API should be restricted to DistinctStorages and should check that parameter indices are different.

[WaDelma]

Should we also add API for getting multiple entries?

[torkleyy]

Actually, DistinctStorage is one part of the API that I'm not so sure about. We don't know if in the future Rust still permits this hack.

[WaDelma]

That would be shame.. It would basically destroy any chance of reusing any storages for parallel iteration.

[torkleyy]

Well, I think we could still make it work with VecStorage and DenseVecStorage.

[torkleyy]

@mjadczak May I add your source code (the roboter following the other one) here so that we have a real-world example?

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[mjadczak]

Hey @torkleyy , I hadn't noticed your comment until now. I don't know if this is still relevant / helpful, but the relevant code is here - I have to collect up all the changes I want to apply and only then apply them.

[torkleyy]

Thanks @mjadczak! I'm still looking for a good solution here.

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This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 7 days if no further activity occurs. Feel free to comment if this is still relevant.

[mjadczak]

Commenting to keep open (presumably hasn't been solved yet)

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[OvermindDL1]

Ditto?

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This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 7 days if no further activity occurs. Feel free to comment if this is still relevant.