Language/15_Types/4_Interface_Types_A08_t06.dart

/*
 * Copyright (c) 2011, 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 type T is more specific than a type S, written T << S, if S is a direct supertype of T.
 * << is a partial order on types. T is a subtype of S, written T <: S, iff [⊥/Dynamic]T << S.
 * A type T may be assigned to a type S, written T <=> S, if either T <: S or S <: T.
 * @description Checks that this statement is true for generic class types with a bunch of type parameters.
 * @author iefremov
 * @reviewer rodionov
 */
import "../../Utils/expect.dart";
import "dart:collection";

class G {}

class IManyArgs<A, B, C, D, E> {}
class CManyArgs<A, B, C> extends IManyArgs<int, A, B, C, double> {}

// these produce the required static type for static checker 
// but won't fail at run time because they return null after all
IManyArgs<int, G, G, G, double> make1() {}
IManyArgs<int, List, Map, Queue, double> make2() {}

main() {
  Expect.isTrue(new CManyArgs<G, G, G>() is IManyArgs<int, G, G, G, double>);
  CManyArgs<G, G, G> g6 = make1();
  IManyArgs<int, G, G, G, double> g6_ = new CManyArgs<G, G, G>();

  Expect.isTrue(new CManyArgs<List, Map, Queue>() is IManyArgs<int, List, Map, Queue, double>);
  CManyArgs<List, Map, Queue> g7 = make2();
  IManyArgs<int, List, Map, Queue, double> g7_ = new CManyArgs<List, Map, Queue>();
}