Language/Expressions/Function_Expressions/static_type_form_1_async_t02.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 The static type of a function literal of the form
/// (T1 a1,...,Tn an, [Tn+1 xn+1 = d1,...,Tn+k xn+k = dk]) async => e is
/// (T1,...,Tn, [Tn+1 xn+1,...,Tn+k xn+k]) -> Future <flatten(T0)>, where T0
/// is the static type of e and flatten(T0) is defined as follows:
/// If T = Future<S> then flatten(T) = flatten(S).
/// Otherwise if T <: Future then let S be a type such that T << Future<S> and
/// for all R, if T << Future<R> then S << R.
/// In any case where Ti, 1 <= i <= n + k, is not specified, it is considered
/// to have been specified as dynamic.
/// @description Checks that it is a compile error if a function literal of
/// the form (T1 a1,...,Tn an, [Tn+1 xn+1 = d1,...,Tn+k xn+k = dk]) async => e
/// with two parameters is assigned to a variable of a function type without
/// parameters.
/// @author ngl@unipro


import 'dart:async';

typedef Future<int> intFunc();

main() {
  intFunc intf = () async => 2;

  intf = (int p1, [int? p2]) async => 1;
//       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
// [analyzer] unspecified
// [cfe] unspecified

}