blob: 5fd1ec598a45c2cdb698e50ce7335460b5ccedf0 [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
/// typeParameter ::= metadata identifier (extends typeNotVoid)?
/// typeParameters ::= ‘<’ typeParameter (‘,’ typeParameter)* ‘>’
/// ...
/// It is a compile-time error if a type parameter is a supertype of its upper
/// bound when that upper bound is itself a type variable.
/// This prevents circular declarations like [X extends X] and [X extends Y, Y
/// extends X].
/// @description Checks that it is a compile error if typedef type variable is a
/// supertype of its upper bound.
/// @author
typedef Alias1<X extends X> = void Function(X);
// ^^^^^^^^^^^
// [cfe] Type 'X' can't use itself as a bound.
typedef Alias2<X extends Y, Y extends X> = void Function(X, Y);
// ^^^^^^^^^^^
// [analyzer] unspecified
// [cfe] unspecified
typedef Alias3<X extends Y, Y extends Z, Z extends X> = void Function(X, Y, Z);
// ^^^^^^^^^^^
// [analyzer] unspecified
// [cfe] unspecified
main() {}