// 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.

// Implements Function which is not allowed in Dart 3.
// @dart=2.19

// Dart test program to test arithmetic operations.

import "package:expect/expect.dart";

class C1 {
  int call(int i) => 2 * i;
}

class C2 implements Function {
  int call(int i) => 2 * i;
}

main() {
  C1 c1 = new C1();
  // Implicitly invokes c1.call(1)
  Expect.equals(c1(1), 2);
  dynamic d1 = c1;
  // Implicitly invokes d1.call(1)
  Expect.equals(d1(1), 2);
  C2 c2 = new C2();
  // Implicitly invokes c2.call(1)
  Expect.equals(c2(1), 2);
  dynamic d2 = c2;
  // Implicitly invokes d2.call(1)
  Expect.equals(d2(1), 2);
  // Cannot invoke with the wrong signature.
  c2();
  // ^
  // [analyzer] COMPILE_TIME_ERROR.NOT_ENOUGH_POSITIONAL_ARGUMENTS
  //^^
  // [cfe] Too few positional arguments: 1 required, 0 given.
  c2(3, 4);
  //    ^
  // [analyzer] COMPILE_TIME_ERROR.EXTRA_POSITIONAL_ARGUMENTS
  //^^^^^^
  // [cfe] Too many positional arguments: 1 allowed, but 2 found.
}