Bundles should be unordered

[alice-i-cecile]

What problem does this solve or what need does it fill?

Semantically, the ordering of the components in a Bundle shouldn't matter. Components aren't inserted "in order" into our entities and Bundle(A, B) should be identical to Bundle(B, A).

Right now though, they're stored as ordered structs / tuples. This is less than ideal because:

1. It gives the wrong mental model.
2. It reduces the ability to batch bundles for command processing.
3. It makes implementing advanced bundle reliant features like archetype invariants (Archetype Invariants #1481) or kinded entities (Kinded entities #1634) much more cumbersome.

What solution would you like?

Bundles are altered to use an unordered collection representation, directly analogous to a HashSet.

What alternative(s) have you considered?

Implement bundle equality, subsetting etc and other needed features in a manual and indirect fashion, by e.g. comparing the HashSet of the TypeId of their components.

Additional context

Discussed on Discord.

Probably blocked on some Rust RFC that I don't know the name of :(

[alice-i-cecile]

From @cart on Discord, the conclusions are:

1. The misleading mental model isn't great but this can't be fixed without sacrifices.
2. The methods I really want for archetype invariants etc are actually needed at the archetype level.

Closing this, but feel free to resurrect it if you think of a really clever way to improve the ergonomics.