Language/Generics/typedef_A08_t03.dart - co19 - Git at Google Sign in dart / co19 / refs/heads/1004 / . / Language / Generics / typedef_A08_t03.dart blob: 243c9a5f486b923e8df454e4df10e4f27d503f16 [file] [log] [blame] /* * 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<X1 extends B1, . . . , Xs extends Bs> = T; * m typedef S? id<X1 extends B1, . . . , Xs extends Bs>( * T1 p1, . . . , Tn pn, [Tn+1 pn+1, . . . , Tn+k pn+k]); * m typedef S? id<X1 extends B1, . . . , Xs extends Bs>( * T1 p1, . . . , Tn pn, {Tn+1 pn+1, . . . , Tn+k pn+k}); * 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 * S0 Function(T1, . . . , Tn, [Tn+1, . . . , Tn+k]) * S0 Function(T1, . . . , Tn, {Tn+1 xn+1, . . . , Tn+k xn+k}) * ... * Moreover, let [T1], . . . , [Tl] be types and let [U] be the parameterized * type id<T1, . . . , Tl> in a location where [id] denotes [D]. ... It is a * compile-time error if [U] is not well-bounded * @description Checks that compile error is thrown if [U] is not well-bounded. * @Issue 36959, 37050 * @author iarkh@unipro.ru */ // SharedOptions=--enable-experiment=nonfunction-type-aliases class A<X extends A<X>> {} typedef AAlias<T extends A<T>> = T Function<T1 extends T>(); main() { AAlias a1; AAlias<A> a2; AAlias<A<Never>> a3; AAlias<A<dynamic>> a4; AAlias<A<Object?>> a5; AAlias<A<int>> a6; // [error line 40, column 0] // [analyzer] unspecified // [cfe] unspecified AAlias<int> a7; // ^^^ // [analyzer] COMPILE_TIME_ERROR.TYPE_ARGUMENT_NOT_MATCHING_BOUNDS // ^ // [cfe] Type argument 'int' doesn't conform to the bound 'A<T>' of the type variable 'T' on 'AAlias'. AAlias<Null> a8; // ^^^^ // [analyzer] COMPILE_TIME_ERROR.TYPE_ARGUMENT_NOT_MATCHING_BOUNDS // ^ // [cfe] Type argument 'Null' doesn't conform to the bound 'A<T>' of the type variable 'T' on 'AAlias'. AAlias<dynamic> a9; } Powered by Gitiles| Privacytxt json