public static void CopyTo <T>(this T[] arr, ref T[] tar) where T : PacketObject <T>
{
if (tar == null)
{
tar = new T[arr.Length];
}
else
{
PacketObject.BackArray(tar);
Array.Resize(ref tar, arr.Length);
}
for (var i = 0; i < arr.Length; ++i)
{
tar[i] = arr[i].Clone();
}
}