SubviewReader.swift

// TODO docs
public typealias SubviewProxy = _VariadicView.Children

// TODO docs
public struct SubviewReader<Children, Content>: View where Children: View, Content: View {
    var children: Children
    var content: (SubviewProxy) -> Content

    // TODO docs
    public init(_ children: Children, @ViewBuilder content: @escaping (SubviewProxy) -> Content) {
        self.children = children
        self.content = content
    }

    public var body: some View {
        _VariadicView.Tree(Layout(content: content)) {
            children
        }
    }

    struct Layout: _VariadicView.MultiViewRoot {
        var content: (SubviewProxy) -> Content

        func body(children: SubviewProxy) -> Content {
            content(children)
        }
    }
}

public struct Divided<Content>: View where Content: View {
    var content: Content

    public init(@ViewBuilder content: () -> Content) {
        self.content = content()
    }

    public var body: some View {
        SubviewReader(content) { children in
            ForEach(children) { view in
                view

                if view.id != children.last?.id {
                    Divider()
                }
            }
        }
    }
}

struct Divided_Previews: PreviewProvider {
    static var previews: some View {
        VStack(alignment: .leading) {
            Divided {
                Text("Milk")
                Text("Eggs")
                Text("Cheese")
            }
        }
        .padding()
    }
}