LanguageFeatures/Spread-collections/StaticSemantic_A05_t01.dart

// Copyright (c) 2019, 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 It is a static error if:
///    If a list or set spread element's static type implements [Iterable<T>] for
///    some [T] and [T] is not assignable to the element type of the list.
/// @description Checks that compile error is not thrown if spread element type
/// in the list literal is assignable to the type of the list.
/// @author iarkh@unipro.ru

import "dart:collection";

class MyIterable<T> extends IterableBase<T> {
  late MyIterator<T> iterator;
  MyIterable() { iterator = new MyIterator(); }
  Iterator getIterator<T>() { return iterator; }
}

class MyIterator<T> extends Iterator<T> {
   @override
  bool moveNext() { return false; }

  @override
  T get current => throw "Should not reach here!";
}

main() {
  test1();
  test2();
}

void test1() {
  List l1  = <Object> [];
  List<bool> l2  = <bool>[true, false, true, true];
  List<String> l3  = <String>[];
  List<String> l4  = <String>["1", "2"];
  List l5 = <Object>["1", "2"];

  Iterable<String> i1 = new MyIterable<String>();
  Iterable i2 = new MyIterable<Object>();

  List list1 = <String>[...l1];
  List list2 = <Object>[...l2];
  List list3 = <String>[...l3];
  List list4 = <String>[...l4];
  List list5 = <String>[...l5];

  List list16 = <String>[...i1];
  List list17 = <String>[...i2];
}

void test2() {
  var l1  = <Object> [] as List?;
  var l2  = <bool>[true, false, true, true] as List<bool>?;
  var l3  = <String>[] as List<String>?;
  var l4  = <String>["1", "2"] as List<String>?;
  var l5 = <Object>["1", "2"] as List?;

  var i1 = new MyIterable<String>() as Iterable<String>?;
  var i2 = new MyIterable<Object>() as Iterable?;

  List list8 = <String>[...?l1];
  List list9 = <Object>[...?l2];
  List list10 = <String>[...?l3];
  List list11 = <String>[...?l4];
  List list12 = <String>[...?l5];

  List list13 = <String>[...?i1];
  List list14 = <String>[...?i2];
}