Provide a default implementation for a protocol method returning an associatedtype

Question

I have this basic protocol:

protocol MyProtocol {
    associatedtype Content: View
    @MainActor @ViewBuilder func content() -> Content
}

I want to provide a default implementation for content(), so I figured I'd do this:

extension MyProtocol {
    @MainActor @ViewBuilder func content() -> some View {
        EmptyView()
    }
}

That works. However, now autocompletion in conforming types does something strange. Instead of making the return type some View, it uses Content, which does not compile:

struct Implementation: MyProtocol {
    func content() -> Content { // Auto-completed, does not compile
        Text("ABC")
    }
}

I have to manually fix the return type:

struct Implementation: MyProtocol {
    func content() -> some View { // Now it compiles
        Text("ABC")
    }
}

Is there a way to fix this behavior?

Answer 1

As stated in the comment section, the issue is that the associatedtype Content is not yet defined when you are trying to use autocompletion. If you define Content with a typealias before implementing the content() func autocompletion will behave as expected. ie:

struct Implementation: MyProtocol {
    typealias Content = Text
    
    func content() -> Text {
        <#code#>
    }
}