blob: c99cfb5d751907a0a691123e7416d9df587f5afc [file] [log] [blame]
// Copyright (c) 2017, 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";
typedef U F<T, U>(T x);
class C<T> {
T f(List<T> x) {}
F<List<num>, num> g(C<num> c) {
return c.f;
void main() {
var tearoff = g(new C<int>());
// Since C.f's x parameter is covariant, its type is changed to `Object?` when
// determining the type of the tearoff. So the type of the tearoff should be
// `(Object?) -> int`. (Not, for example, `(List<Object?>) -> int` or
// `(List<Object?>) -> Object?`)
Expect.isTrue(tearoff is F<Object, int>);
// Because the function accepts any object, we can pass strings to it. This
// will not work in Dart 1.
Expect.isTrue(tearoff is F<String, int>);