title: Type infer error on seemingly simple class method
body: <p>During running (numba compilation) of the following class method:</p>
  
  <pre><code>@jit(nopython=True)
  def isInPosition(self):
      """Returns whether the axis is in the desired position."""
      return True if self.state &amp; 0x04 else False
  </code></pre>
  
  <p>I receive a type infer error message:</p>
  
  <p>cannot determine Numba type of class X.X</p>
  
  <p>How can I make it work?</p>