import SwiftUI @MainActor struct ContentView: View { let bar = Bar() var body: some View { Text("Hello, world!") .onAppear { Foo().start(bar: bar) } } } @MainActor final class Bar { func bar() -> Int { print("bar", Thread.isMainThread) return 42 } } final class Foo { func start(bar: Bar) { Task { print("1", Thread.isMainThread, ObjectIdentifier(Thread.current)) let x = await bar.bar() print("2", Thread.isMainThread, ObjectIdentifier(Thread.current), x) Task { print("3", Thread.isMainThread, ObjectIdentifier(Thread.current)) let x = await bar.bar() print("4", Thread.isMainThread, ObjectIdentifier(Thread.current), x) Task.detached { print("5", Thread.isMainThread, ObjectIdentifier(Thread.current)) let x = await bar.bar() print("6", Thread.isMainThread, ObjectIdentifier(Thread.current), x) } } } } }
1 false ObjectIdentifier(0x0000600001348780) bar true 2 false ObjectIdentifier(0x0000600001319580) 42 3 false ObjectIdentifier(0x0000600001319580) bar true 4 false ObjectIdentifier(0x0000600001348780) 42 5 false ObjectIdentifier(0x0000600001319580) bar true 6 false ObjectIdentifier(0x0000600001348780) 42
