| // 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. |
| |
| // @dart = 2.9 |
| |
| /// @assertion |
| /// typeParameter ::= metadata identifier (extends typeNotVoid)? |
| /// typeParameters ::= ‘<’ typeParameter (‘,’ typeParameter)* ‘>’ |
| /// A type parameter [T] may be suffixed with an [extends] clause that specifies |
| /// the upper bound for [T]. |
| /// @description Statically checks that [extends] clause specifies upper bound |
| /// for the class type parameter |
| /// @author iarkh@unipro.ru |
| |
| |
| class A {} |
| class B extends A {} |
| class C extends B {} |
| |
| void func1<T extends A>() {} |
| void func2<T extends B>() {} |
| void func3<T extends C>() {} |
| |
| main() { |
| func1(); |
| func1<A>(); |
| func1<B>(); |
| func1<C>(); |
| |
| func2(); |
| func2<A>(); //# 01: compile-time error |
| func2<B>(); |
| func2<C>(); |
| |
| func3(); |
| func3<A>(); //# 02: compile-time error |
| func3<B>(); //# 03: compile-time error |
| func3<C>(); |
| } |