Language/Generics/syntax_t25.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 A class declaration, type alias, or function [G] may be generic,
/// that is, [G] may have formal type parameters declared.
/// @description @description Checks various correct type alias declarations.
/// @author iarkh@unipro.ru

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

class B<T1, T2> {
  B(this.x, this.y) {}
  T1 x;
  T2 y;
}

typedef BAlias<T1, T2 extends T1> = B<T1, T2>;

main() {
  BAlias b1 = new B(1, 2);
  Expect.isTrue(b1 is B<dynamic, dynamic>);
  Expect.isTrue(b1 is BAlias);
  Expect.isTrue(b1 is BAlias<dynamic, dynamic>);
  Expect.runtimeIsType<B<dynamic, dynamic>>(b1);
  Expect.runtimeIsType<BAlias>(b1);
  Expect.runtimeIsType<BAlias<dynamic, dynamic>>(b1);

  BAlias<num, int> b2 = new B<num, int>(0, 149);
  Expect.isTrue(b2 is B<num, int>);
  Expect.isTrue(b2 is BAlias<num, int>);
  Expect.runtimeIsType<B<num, int>>(b2);
  Expect.runtimeIsType<BAlias<num, int>>(b2);
  Expect.equals(0, b2.x);
  Expect.equals(149, b2.y);

  BAlias<num, int> b3 = new B<int, int>(0, 149);
  Expect.isTrue(b3 is B<int, int>);
  Expect.isTrue(b3 is BAlias<int, int>);
  Expect.equals(0, b3.x);
  Expect.equals(149, b3.y);
}