/*
 * 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.
 */
/**
 * @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
 */
// SharedOptions=--enable-experiment=constant-update-2018

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