Language/Types/Interface_Types/subtype_t37.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 one
 * of the following conditions is met:
 *  • T is S.
 *  • T is ⊥
 *  • S is dynamic.
 *  • S is a direct supertype of T.
 *  • T is a type parameter and S is the upper bound of T.
 *  • T is a type parameter and S is Object.
 *  • T is of the form I<T1, ..., Tn > and S is of the form I <S1, ..., Sn>
 *    and Ti << Si 1 <= i <= n.
 *  • T and S are both function types, and T << S under the rules of section
 *    (Types/Function Types).
 *  • T is a function type and S is Function.
 *  • T << U and U << S.
 * << is a partial order on types. T is a subtype of S, written T <: S, iff
 * [⊥/Dynamic]T << S.
 * . . .
 * An interface type T may be assigned to a type S, written T <=> S, if either
 * T <: S or S <: T.
 * @description Checks that two generic types are not assignable even if just
 * one type argument is not assignable. Using complex generic types.
 * @compile-error
 * @author iefremov
 * @reviewer rodionov
 */

class I<A, B, C> {}
class J<A, B, C> extends I<A, B, C> {}
class K extends J {}
class C extends K {}

typedef J   f(I<J, List<Map>,           num> i, [List j]);
typedef K f_1(I<K, List<Map<int, num>>, int> i, [List<Map> j]);

I<f, num, List<Map<num, Map<int, double>>>> checker() {}

main() {
//  I<f_1, int, List<Map<int, Map<int, int>>>> i = new I<f, num, List<Map<num, Map<int, double>>>>();
//                                     ^^^     <=/=>                                    ^^^
  I<f_1, int, List<Map<int, Map<int, int>>>> i = checker();
}