// 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.

// @dart = 2.9

/// @assertion From the Unified collection Spec:
/// A [spreadElement] starting with [...?] is a constant element if its
/// expression is constant and it evaluates to [null] or a constant [List], [Set]
/// or [Map] instance originally created by a list, set or map literal. It is a
/// potentially constant element if the expression is potentially constant
/// expression.
/// @description: Checks some disambiguilty cases for sets and maps.
/// @author iarkh@unipro.ru


const l = [];
const s = {11};
const m = {1: 1};

main() {
  const res1 = {...?l};
  const res2 = {1, ...?l, 2};
  const res3 = {...?s};
  const res4 = {1, ...?s, 2};
  const res5 = {...?m};
  const res6 = {2: 1, ...?m, 3: 14};

}