Mimic File.Move if the destination already exists

Question

From the documentation of File.Move:

Note that if you attempt to replace a file by moving a file of the same name into that directory, you get an IOEx

Answer 1

It is difficult to simulate an atomic operation if the operating system doesn't give you good atomic operations. Move is atomic on some but not all filesystems, but not when you are moving disk to disk.

In case of the same disk, Delete + Move is somewhat elegant (fast and safe) as it does not really stuffle the data in any way. You could further extend it to

try
{
    Move(dest, tmp);
    Move(src, dest);
    Delete(tmp);
}
catch
{
    try
    {
        Move(tmp, dest);
    }
    catch
    {
    }
    throw;
}

(This makes it less likely that you will lose the destination file when you for example do not have the rights necessary to finish the move.)

In a scenario where you do not know that it is the same disk, your solution is safe enough and simple enough. However, it copies the data even within the same disk, bringing you a wider window of risk of a power failure.