Dismiss a SwiftUI View that is contained in a UIHostingController

I have rewritten my sign in view controller as a SwiftUI View. The SignInView is wrapped in a UIHostingController subclass (final class SignInViewController: UIHostingController<SignInView> {}), and is presented modally, full screen, when sign in is necessary.

Everything is working fine, except I can't figure out how to dismiss the SignInViewController from the SignInView. I have tried adding:

@Environment(\.isPresented) var isPresented

in SignInView and assigning it to false when sign in is successful, but this doesn't appear to interop with UIKit. How can I dismiss the view?

UPDATE: From the release notes of iOS 15 beta 1:

isPresented, PresentationMode, and the new DismissAction action dismiss a hosting controller presented from UIKit. (52556186)

I ended up finding a much simpler solution than what was offered:

final class SettingsViewController: UIHostingController<SettingsView> {
    required init?(coder: NSCoder) {
        super.init(coder: coder, rootView: SettingsView())
        rootView.dismiss = dismiss
    }

    func dismiss() {
        dismiss(animated: true, completion: nil)
    }
}

struct SettingsView: View {
    var dismiss: (() -> Void)?
    
    var body: some View {
        NavigationView {
            Form {
                Section {
                    Button("Dimiss", action: dismiss!)
                }
            }
            .navigationBarTitle("Settings")
        }
    }
}