LibTest/ffi/Pointer/elementAt_A01_t03.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 Pointer<T> elementAt(int index)
 *  Pointer arithmetic (takes element size into account).
 *  This method must be invoked with a compile-time constant T.
 *  Does not accept dynamic invocations -- where the type of the receiver is
 *  dynamic.
 *
 * @description Checks that this method implements pointer arithmetic
 * @author sgrekhov@unipro.ru
 */
import "dart:ffi";
import "package:ffi/ffi.dart";
import '../../../Utils/expect.dart';

void main() {
  Pointer<Pointer<Int8>> p1 = calloc<Pointer<Int8>>(3);
  try {
    Expect.isTrue(p1.elementAt(1).address - p1.address == 4 ||
        p1.elementAt(2).address - p1.elementAt(1).address == 8);
  } finally {
    calloc.free(p1);
  }
}