LibTest/ffi/Pointer/elementAt_A04_t01.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 negative argument value
 * @author sgrekhov@unipro.ru
 */
import "dart:ffi";
import "package:ffi/ffi.dart";
import '../../../Utils/expect.dart';

void main() {
  Pointer<Int8> p1 = calloc<Int8>(3);
  try {
    p1.elementAt(0).value = 42;
    Pointer<Int8> p2 = new Pointer.fromAddress(p1.elementAt(1).address);
    Expect.equals(42, p2.elementAt(-1).value);
  } finally {
    calloc.free(p1);
  }
}