DevAndArtist

import SwiftUI

extension EnvironmentValues {
  struct UnconstrainedObjectKey<Object>:
    EnvironmentKey
    where
    Object: AnyObject
  {
    static var defaultValue: Object? {
      nil

DevAndArtist

import SwiftUI
import UniformTypeIdentifiers

// DOCUMENT EXAMPLE

extension UTType {
  static var exampleText: UTType {
    UTType(importedAs: "com.example.plain-text")
  }
}

DevAndArtist

import SwiftUI
import Combine

/// The idea is to use State to create a storage object which will be
/// cached and restored by the framework. Then during the update phase we
/// re-inject the object into a nested ObservableObject and subscribe to the
/// ObjectType’s objectWillChange to forward to the _MessageForwarder’s
/// objectWillChange which is already subscribed by the framework as it’s an
/// inner dynamic property of our custom PW which is also a dynamic property.
@propertyWrapper

DevAndArtist

import SwiftUI

struct HeroAnimationTest: View {
  let indices = 0 ..< 3

  @State
  var showsOtherView = false

  @Namespace
  var namespaceID: Namespace.ID

DevAndArtist

import Combine
import SwiftUI

// To re-align the cells to the center we use a workaround through debouncing
// the nearest cell ID which is computed every time the scroll view moves.
//
// HOWEVER there is a bug that still needs to be solved:
// If you drag the scroll view and hold, the debounce event will still happen
// and reposition the cell.
//

DevAndArtist

import PlaygroundSupport
import Dispatch

let page = PlaygroundPage.current
page.needsIndefiniteExecution = true

struct Weak<T> {
  struct _ObjectBox {
    weak var object: AnyObject?
  }

DevAndArtist

public protocol MapKey {
  associatedtype Value
  static var defaultValue: Value { get }
}

public struct Map<Base> {
  typealias _Key = ObjectIdentifier

  var _values: [_Key: Any]

DevAndArtist

import SwiftUI

// T.Type -> AlignmentID.Type -> Any.Type -> UInt

extension HorizontalAlignment {
  enum TestH: AlignmentID {
    static func defaultValue(in context: ViewDimensions) -> CGFloat {
      0
    }
  }

DevAndArtist

// BUG: FB7635852

import SwiftUI

struct ContentView: View {
  let count: Int

  var body: some View {
    HStack
      .init(alignment: .top, spacing: 0) {

DevAndArtist

// SOME OBSERVATIONS:
// * In Xcode 11.3.1 `V_Struct_Representable_ObservedObject` won't update
//   which is clearly a bug. This bug is fixed in Xcode 11.4 beta 1.
//
// * `V_Struct` and `V_Struct_Representable` both never update because
//   they shouldn't as the framework internal raw-diffing likely won't
//   identify any change. (EXPECTED BEHAVIOR)
//
// * `V_Class` and `V_Class_ObservedObject` both produce a runtime crash,
//   which might be a bug as well. `View` conforming types shouldn't be