tab Function - leider fehlerhaft

BikeView.swift

@@ -4,6 +4,10 @@ import SwiftUI
 
 
 struct BikeView: View {
+    static var title = "Bike"
+    static var image = "bicycle"
+    
+    
     var bike = Bike(name: "Fahrrad", price: 11.31, color: Color.cyan)
     var body: some View {
         VStack{

ContentView.swift

@@ -7,19 +7,35 @@ enum TabLabel: String {
     case trains
     case cars
     var title: String { rawValue.capitalized }
+    var image: String { switch self {
+    case .bikes:
+        "bicycle"
+    case .trains:
+        "train.side.front.car"
+    case .cars:
+        "hand.draw.fill"
+    } }
 }
+//
+//func tab<C: TabContent>(_ contentType: C.Type)
+//-> Tab<Never, C, DefaultTabLabel> {
+//    Tab(C.title, systemImage: C.image) {
+//        C()
+//    }
+//}
+
 
 
 struct ContentView: View {
     var body: some View {
         TabView {
-            Tab(TabLabel.bikes.title, systemImage: "bicycle")   {
+            Tab(TabLabel.bikes.title, systemImage: TabLabel.bikes.image)   {
                 BikeView()
             }
-            Tab(TabLabel.bikes.title, systemImage: "train.side.front.car")   {
+            Tab(TabLabel.bikes.title, systemImage: TabLabel.trains.image)   {
                 TrainView()
             }
-            Tab("drücken", systemImage: "car") {
+            Tab("drücken", systemImage: TabLabel.cars.image) {
                 SwapperView()
             }
         }

Models.swift

@@ -6,6 +6,18 @@ protocol Vehicle {
     var name: String { get }
     var color: Color { get set }
 }
+
+protocol TabContent {
+ init() //title: String, image: String)
+    
+//        <#statements#>
+//    }
+
+
+    static var title: String { get }
+    static var image: String { get }
+}
+
 struct Train: Vehicle, CustomStringConvertible , CustomLocalizedStringResourceConvertible {
     var name: String
     var color: Color

SwapperView.swift

@@ -1,7 +1,10 @@
 import SwiftUI
 
 struct SwapperView: View{
-
+    static var title = "Swap"
+    static var image = "rectangle.2.swap"
+    
+    
     @State var sw = Swapper(a: "Apfel", b: "Banana")
     @State var a = "Apfel"
     @State var b = "Banane"

TrainView.swift

@@ -3,7 +3,10 @@
 import SwiftUI
 
 
-struct TrainView: View {
+struct TrainView: View , TabContent {
+    static var title = "Train"
+    static var image = "train.side.front.car"
+    
     var train = Train(name: "RE3412", color: Color.yellow, delay: 2 ){ Bike.trek}
     var train2 = Train(name: "RE1423", delay: 1){ Bike(name: "Bulls", price: 1.90, color: Color.red)}