// 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.

/*@testedFeatures=inference*/
library test;

main() {
  var /*@ type=() ->* Iterable<Null>* */ f = /*@ returnType=Iterable<Null>* */ () sync* {
    yield null;
  };
  Iterable y = f();
  Iterable<String> z = f();
  String s = f(). /*@target=Iterable.first*/ first;
}