LanguageFeatures/Spread-collections/Ambiguity_A03_t03.dart

// 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 (Unified collections) Let [e] be a [setOrMapLiteral].
///
/// If [e] has a context [C], and the base type of [C] is [Cbase] (that is,
/// [Cbase] is [C] with all wrapping [FutureOrs] removed), and [Cbase] is not
/// [?], then let [S] be the greatest closure.
///
/// If [e] has [typeArguments] then:
///
/// If there is exactly one type argument [T], then [e] is a set literal with
/// static type [Set<T>].
///
/// @description Checks that [setOrMapLiteral] has one type argument, it's a set.
/// @author iarkh@unipro.ru

import "../../Utils/expect.dart";

main() {
  var aSet = {1, 2, 3} as Set?;
  var aList = [1, 2, 3] as List?;

  var res1 = <int>{...?aSet};
  Expect.isTrue(res1 is Set);
  Expect.runtimeIsType<Set>(res1);

  var res2 = <Object>{...?aList};
  Expect.isTrue(res2 is Set);
  Expect.runtimeIsType<Set>(res2);
}