BitArray - preview of what's to come?

[Suliman via Digitalmars-d-learn]

  bool[4] x = [1, 1, 0, 0];
  BitArray ba = BitArray(x);

When I try to compile this I am getting error:
source\app.d(13): Error: cannot implicitly convert expression (x) 
of type bool[4] to uint

What I am doing wrong?