Language/Generics/typedef_A01_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 A generic type alias is a declaration [D] of one of the following
/// forms:
///    m typedef id<X1extendsB1, ..., Xs extendsBs> = T;
/// ...
/// where [m] is derived from metadata, [T] is a type, and [S?] is a type or the
/// empty string. Let [S0] be [S?] if it is a type, otherwise let [S0] be
/// [dynamic]. The associated type of [D], call it [F], is, respectively:
///   T
/// ...
/// @description Checks that non-function generic type alias declaration can
/// contain metadata.
/// @Issue 42432
/// @author iarkh@unipro.ru

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

const i = 1;
class A { const A(); }

class C<T> {}
class D<T1 extends num, T2 extends String> {}

@i  typedef CAlias<T extends num> = C<T>;
@A() typedef DAlias<T1 extends num, T2 extends String> = D<T1, T2>;

main() {
  CAlias ca1 = new CAlias();
  Expect.isTrue(ca1 is C<num>);
  Expect.runtimeIsType<C<num>>(ca1);

  CAlias<int> ca2 = new CAlias<int>();
  Expect.isTrue(ca2 is C<int>);
  Expect.runtimeIsType<C<int>>(ca2);

  DAlias da = new DAlias();
  Expect.isTrue(da is D<num, String>);
  Expect.runtimeIsType<D<num, String>>(da);
}