// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// @dart = 2.9

/// @assertion To infer the type of element:
/// ...
/// If element is a spreadElement with expression e1:
/// ...
/// If P is Set<Ps> then let S be the inferred type of e1 in context Iterable<Ps>:
/// ...
/// Otherwise it is an error
///
/// @description Checks that otherwise it is an error
/// @author sgrekhov@unipro.ru


main() {
  var s = "Let it be";
  var x1 = <String>{...s};    //# 01: compile-time error
  var x2 = <String>{...?s};   //# 02: compile-time error
}