gistfile1.dart

part of dartboard;

class FutureGroup<E> {
  Completer<E> _completer = new Completer<E>();
  Set<Future<E>> _futures = new Set<Future<E>>();
  
  bool add(Future<E> future) => _futures.add(future);
  
  Future<List<E>> wait() {
    Future.wait(_futures).then((result) => _completer.complete(result))
        ..catchError((err) => _completer.completeError(err));
    
    return _completer.future;
  }
}