Derive @Shared from a SwiftUI-Binding

[andtie]

I have sometimes found the need to derive Shared-State from an existing SwiftUI-Binding. For example, if I want to expose my feature to API-consumers that do not know about swift-sharing and just want to interact via a binding. I can bridge the two with onChange(of:), but this seems cumbersome and error-prone. It would be great if this hypothetical API would work:

@Shared var persons: IdentifiedArrayOf<Person>

init(persons: Binding<IdentifiedArrayOf<Person>>) {
   self._persons = Shared(.binding(persons))
}

I think this would be a useful addition to the library, especially for people who want to migrate an existing codebase stepwise to swift-sharing.

I took at stab at implementing it, but I'm not sure if this approach is sound and also I'm not sure if the id can somehow be derived automatically from the Binding. I know there were some past discussions about this topic, especially with bindings from computed properties in relation to those derived from keypaths. This is my current implementation:

public struct BindingSharedKey<Value>: SharedKey {

    public private(set) var id: AnyHashable

    var binding: Binding<Value>

    init(binding: Binding<Value>, id: AnyHashable) {
        self.binding = binding
        self.id = id
    }

    public func load(
        context: LoadContext<Value>,
        continuation: LoadContinuation<Value>
    ) {
        continuation.resume(returning: binding.wrappedValue)
    }

    public func subscribe(
        context: LoadContext<Value>,
        subscriber: SharedSubscriber<Value>
    ) -> SharedSubscription {
        SharedSubscription {}
    }

    public func save(
        _ value: Value,
        context: SaveContext,
        continuation: SaveContinuation
    ) {
        binding.wrappedValue = value
        continuation.resume()
    }
}

extension SharedKey {
    public static func binding<Value>(
        _ binding: Binding<Value>,
        id: AnyHashable
    ) -> Self where Self == BindingSharedKey<Value>.Default {
        Self[
            BindingSharedKey(binding: binding, id: id),
            default: binding.wrappedValue
        ]
    }
}

Any feedback would be welcome.