pkg/front_end/lib/src/fasta/blacklisted_classes.dart

// 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.

// List of special classes in dart:core that can't be subclassed.
const List<String> blacklistedCoreClasses = [
  "bool",
  "int",
  "num",
  "double",
  "String",
  "Null"
];