LanguageFeatures/Constructor-tear-offs/expression_A01_t02.dart

// Copyright (c) 2021, 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 For an expression of the form e<typeArgs>, which is not followed
/// by an argument list (that would turn it into a generic function invocation),
/// the meaning of e<typeArgs> depends on the expression e:
///
/// - If e denotes a generic class, mixin or type alias declaration (which means
/// that e is an identifier, possibly a qualified identifier, which resolves to
/// the class, mixin or type alias declaration), then e<typeArgs> is a type
/// literal. If followed by .id then that id must denote a constructor, which
/// can then be either torn off or invoked. If followed by == or != or any
/// "stop-token", the expression evaluates to a Type object.
///
/// @description Checks that if in the expression of the form e<typeArgs> e
/// denotes a class and followed by .id then it denotes a constructor
/// @author sgrekhov@unipro.ru

// SharedOptions=--enable-experiment=constructor-tearoffs

import "../../Utils/expect.dart";

class C<T> {
  C.id();
}

typedef CAlias<T> = C<T>;

main() {
  var c1 = C<int>.id;
  Expect.isFalse(c1 is Type);
  Expect.isTrue(c1 is C<int> Function());
  Expect.runtimeIsType<C<int> Function()>(c1);

  var c2 = CAlias<int>.id;
  Expect.isFalse(c2 is Type);
  Expect.isTrue(c2 is C<int> Function());
  Expect.runtimeIsType<C<int> Function()>(c2);
}