LanguageFeatures/Set-literals/type_inference_A20_t01.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 Finally, we define inference on a setOrMapLiteral collection as
 * follows:
 *
 * If collection is unambiguously a set literal:
 *
 * If P is ? then the static type of collection is Set<T> where T is the least
 * upper bound of the inferred set element types of the elements.
 *
 * @description Checks that if collection is unambiguously a set literal and P
 * is ? then the static type of collection is Set<T> where T is the least upper
 * bound of the inferred set element types of the elements
 * @author sgrekhov@unipro.ru
 * @issue 43280
 */
import "../../Utils/expect.dart";

class C<X> {
  test(X x) {
    var v = {x, 1, 2};
    Expect.isTrue(v is Set<Object?>);
    Expect.isFalse(v is Set<int?>);
  }
}

main() {
  C<int?>().test(42);
  C<int?>().test(null);
}