From 69c28005720c3733413bfae3835c6e099015bb00 Mon Sep 17 00:00:00 2001
From: Muukii <muukii.app@gmail.com>
Date: Tue, 13 Aug 2024 22:24:20 +0200
Subject: [PATCH 1/2] Patch

---
 Sources/SwiftUISupport/ObjectEdge.swift | 117 ++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 Sources/SwiftUISupport/ObjectEdge.swift

diff --git a/Sources/SwiftUISupport/ObjectEdge.swift b/Sources/SwiftUISupport/ObjectEdge.swift
new file mode 100644
index 0000000000..3e28d891e4
--- /dev/null
+++ b/Sources/SwiftUISupport/ObjectEdge.swift
@@ -0,0 +1,117 @@
+import SwiftUI
+
+/**
+ https://forums.developer.apple.com/forums/thread/739163
+ */
+@propertyWrapper
+struct ObjectEdge<O>: DynamicProperty {
+
+  @State private var box: Box<O> = .init()
+
+  var wrappedValue: O {
+    if let value = box.value {
+      return value
+    } else {
+      box.value = factory()
+      return box.value!
+    }
+  }
+
+  private let factory: () -> O
+
+  init(wrappedValue factory: @escaping @autoclosure () -> O) {
+    self.factory = factory
+  }
+
+  private final class Box<Value> {
+    var value: Value?
+  }
+
+}
+
+#if DEBUG
+
+@available(iOS 17, *)
+@Observable
+private final class Model {
+
+  var count: Int = 0
+  
+  init(count: Int) {
+    print("Init model")
+    self.count = count    
+  }
+
+  func up() {
+    count += 1
+  }
+}
+
+@available(iOS 17, *)
+private struct Demo: View {
+
+  @ObjectEdge var model: Model = .init(count: 0)
+
+  var body: some View {
+
+    VStack {
+      Text("\(model.count)")
+      Button("Up") {
+        model.up()
+      }
+    }
+  }
+}
+
+@available(iOS 17, *)#Preview{
+  Demo()
+}
+
+struct Box<T> {
+
+  var value: T
+
+  init(_ value: T) {
+    print("Init box")
+    self.value = value
+  }
+}
+
+#Preview("State init value") {
+
+  struct StateInit<Nested: View>: View {
+
+    @State var value: Box<Int> = .init(0)
+
+    private let nested: () -> Nested
+
+    init(@ViewBuilder nested: @escaping () -> Nested) {
+      self.nested = nested
+    }
+
+    var body: some View {
+      VStack {
+        Text(value.value.description)
+        Button("Up") {
+          value.value += 1
+        }
+        nested()
+      }
+      .padding()
+      .background(
+        RoundedRectangle(cornerRadius: 8)
+          .fill(Color.yellow.opacity(0.2))
+      )
+    }
+  }
+
+  return StateInit {
+    StateInit {
+      StateInit {
+        EmptyView()
+      }
+    }
+  }
+}
+
+#endif

From fa898f038a262ecca379d08f726a1c63baeef685 Mon Sep 17 00:00:00 2001
From: Muukii <muukii.app@gmail.com>
Date: Tue, 13 Aug 2024 22:24:57 +0200
Subject: [PATCH 2/2] Update

---
 Sources/SwiftUISupport/ObjectEdge.swift | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Sources/SwiftUISupport/ObjectEdge.swift b/Sources/SwiftUISupport/ObjectEdge.swift
index 3e28d891e4..36914a0a2d 100644
--- a/Sources/SwiftUISupport/ObjectEdge.swift
+++ b/Sources/SwiftUISupport/ObjectEdge.swift
@@ -4,11 +4,11 @@ import SwiftUI
  https://forums.developer.apple.com/forums/thread/739163
  */
 @propertyWrapper
-struct ObjectEdge<O>: DynamicProperty {
+public struct ObjectEdge<O>: DynamicProperty {
 
   @State private var box: Box<O> = .init()
 
-  var wrappedValue: O {
+  public var wrappedValue: O {
     if let value = box.value {
       return value
     } else {
@@ -19,7 +19,7 @@ struct ObjectEdge<O>: DynamicProperty {
 
   private let factory: () -> O
 
-  init(wrappedValue factory: @escaping @autoclosure () -> O) {
+  public init(wrappedValue factory: @escaping @autoclosure () -> O) {
     self.factory = factory
   }