Go like error handling in Dart

main.dart

typedef AsyncErrorRecord = ({Object error, StackTrace? stackTrace});

abstract class Async<T> {
  const Async();

  static Future<(AsyncErrorRecord? error, T? result)> guard<T>(
    Future<T> Function() future,
  ) async {
    try {
      final result = await future();
      return (null, result);
    } catch (e, s) {
      return ((error: e, stackTrace: s), null);
    }
  }
}

Future<void> main() async {
  var (err, result) = await Async.guard(() async {
    return Future.delayed(Duration(milliseconds: 150), () => 'Hello, world!');
  });
  
  if (err != null) {
    print(err.error);
    return;
  }
  
  print(result);
  
  (err, result) = await Async.guard(() async {
     return Future.delayed(Duration(milliseconds: 150), () => throw Exception('Just an exception'));
  });
  
  if (err != null) {
    print(err.error);
    return;
  }
  
  print(result);
}