main.dart

Future<int> foo() => Future.value(1);
Future<int> bar() async => Future.value(1);
Future<int> baz() async => await Future.value(1);
Future<int> qux() async => await Future.value(Future.value(1));
Future<int> quux() async => 1;
Future<int> quuz() async => await 1;

main() async {
  print(await foo());
  print(await bar());
  print(await baz());
  print(await qux());
  print(await quux());
  print(await quuz());
}