pkg/front_end/testcases/general/issue45660.dart

// 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.

T Function<T extends num>(T) extendsNumReturnArg = <S extends num>(S s) => s;

functionInvocations() {
  extendsNumReturnArg/*<Null>*/(null);
  extendsNumReturnArg/*<String>*/("");
}

main() {}