SwiftUI: sheetとNavigationStackで同じビューを使いたいときに「閉じる」を付けたいという話

struct ContentView: View {
    @State var sheetPresented: Bool = false
    @State var closableSheetPresented: Bool = false
    var body: some View {
        NavigationStack {
            NavigationLink("navigationDestinationを表示", destination: {
                SecondView()
            })
            Button("sheetを表示") {
                sheetPresented.toggle()
            }
            Button("closableSheetを表示") {
                closableSheetPresented.toggle()
            }
        }
        .sheet(isPresented: $sheetPresented) {
            SecondView()
        }
        .sheet(isPresented: $closableSheetPresented) {
            ClosableSheet {
                SecondView()
            }
        }
        .padding()
    }
}

struct SecondView: View {
    var body: some View {
        Form {
            Text("これがSecondViewなんです！")
        }
    }
}

struct ClosableSheet<ViewT>: View where ViewT : View {
    var content: () -> ViewT
    @Environment(\.dismiss) var dismiss
    
    init(@ViewBuilder content: @escaping () -> ViewT) {
        self.content = content
    }
    
    var body: some View {
        VStack {
            HStack {
                Spacer()
                Button("閉じる") {
                    dismiss()
                }
                .buttonStyle(.bordered)
                .font(.caption)
            }
            .padding(8)
            .background(Color(white: 0.9))
            content()
                .padding(.top, -8)
        }
    }
}