Language/Generics/parameter_A01_t02.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.

// @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 Checks that [extends] clause specifies upper bound for the
/// [typedef] type parameter
/// @author iarkh@unipro.ru


class A {} 
class B extends A {}
class C extends B {}

class D<T> {}

typedef Alias1<T extends A> = void Function(T);
typedef Alias2<T extends B> = void Function(T);
typedef Alias3<T extends C> = void Function(T);

main() {
  Alias1 a1;
  Alias1<A> a2;
  Alias1<B> a3;
  Alias1<C> a4;

  Alias2 a5;
  Alias2<A> a6;  //# 01: compile-time error
  Alias2<B> a7;
  Alias2<C> a8;

  Alias3 a9;
  Alias3<A> a10; //# 02: compile-time error
  Alias3<B> a11; //# 03: compile-time error
  Alias3<C> a12;
}