blob: 79bc0aae6771e048272fc1bbe3f893cbb2ceb866 [file] [log] [blame]
// Copyright (c) 2021, 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
import "package:expect/expect.dart";
// Two function types that are identical except the argument type of the
// nested function is a type variable from the outer function.
typedef Fn = void Function<S>(S val) Function<T>(T val);
typedef Gn = void Function<S>(T val) Function<T>(T val);
void Function<S>(S) fn<T>(T val) => <R>(R val) {};
void Function<S>(T) gn<T>(T val) => <R>(T val) {};
// The same pattern here except with bounds on the type arguments.
typedef Xn = void Function<S extends num>(S val) Function<T extends num>(T val);
typedef Yn = void Function<S extends num>(T val) Function<T extends num>(T val);
void Function<S extends num>(S) xn<T extends num>(T val) =>
<R extends num>(R val) {};
void Function<S extends num>(T) yn<T extends num>(T val) =>
<R extends num>(T val) {};
// The nested function here uses concrete type in the argument position so it
// should satisfy either of the previous typedefs.
void Function<S extends num>(num) zn<T extends num>(T val) =>
<R extends num>(num val) {};
void main() {
Expect.isTrue(fn is Fn);
Expect.isFalse(fn is Gn);
Expect.isTrue(gn is Gn);
Expect.isFalse(gn is Fn);
Expect.isTrue(xn is Xn);
Expect.isFalse(xn is Yn);
Expect.isTrue(yn is Yn);
Expect.isFalse(yn is Xn);
Expect.isTrue(zn is Xn);
Expect.isTrue(zn is Yn);