// Copyright (c) 2018, 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.

/*member: f:deps=[B],explicit=[f.T],needsArgs,needsInst=[<B.S>],test*/
bool f<T>(T a) => a is T;

typedef bool F<R>(R a);

/*spec.class: B:explicit=[bool Function(B.S)?],implicit=[B.S],needsArgs,test*/
/*prod.class: B:implicit=[B.S],needsArgs,test*/
class B<S> {
  F<S>? c;

  method() {
    return /*spec.needsSignature*/ () {
      c = f;
    };
  }
}

main() {
  B().method();
}