implements three-valued logic. For a long time,
I couldnt imagine a practical use of this, but now I know one: user
authentication. Currently, the authenticate method of
returns true if the user
authentication worked and false if not.
But there's a third possibility. He existed but did not
authenticate. And presumably you would want different feedback to the
user in that case. So 3-valued logic would be nice. But I think it's a
bit fixed. Better just to return 0 for success and a status code for
each form of failure?