tests/language_2/generic_function_type_as_type_argument_test.dart

// 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.
//
// VMOptions=--reify-generic-functions

import "package:expect/expect.dart";

T foo<T>(T i) => i;

void main() {
  Expect.equals(42, foo<int>(42));

  var bar = foo;
  Expect.equals(42, bar<int>(42));

  // Generic function types are not allowed as type arguments.
  List<T Function<T>(T)> typedList = <T Function<T>(T)>[foo];  //# 01: compile-time error

  // Type inference must also give an error.
  var inferredList = [foo];  //# 02: compile-time error

  // No error if illegal type cannot be inferred.
  var dynamicList = <dynamic>[foo];  //# 03: ok
  Expect.equals(42, (dynamicList[0] as T Function<T>(T))<int>(42));  //# 03: continued
}