Language/15_Types/5_Function_Types_A01_t11.dart

/*
 * Copyright (c) 2011, 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.
 */
/**
 * @assertion A function type (T1,...Tk,[Tk+1,...,Tn+m]) -> T is a subtype of the function
 * type (S1,...,Sk+j,[Sk+j+1,...,Sn]) -> S, if all of the following conditions are met:
 * 1. Either S is void, or T <=> S.
 * 2. For all i 1 <= i <= n, Ti <=> Si.
 * @description Checks that function type t1 is not a subtype of function type t2 
 * even if just one of its formal parameters has a type that is not mutually assignable
 * with the type of the corresponding formal parameter of t2.
 * @author iefremov
 * @reviewer rodionov
 */
import "../../Utils/expect.dart";

abstract class B {}

typedef B func(Object o);
typedef B t1(int i, B b, Map<int, num> m, var x);

B f1(double i, B b, Map<int, num> m, var x) {}
//    ^^^ double <=/=> int
B f2(int i, func b, Map<int, num> m, var x) {}
//           ^^^ func <=/=> B
B f3(int i, B b, Map<int, func> m, var x) {}
//                         ^^^ func <=/=> num

main() {
  Expect.isFalse(f1 is t1);
  Expect.isFalse(f2 is t1);
  Expect.isFalse(f3 is t1);
}