title: getline in if statement
body: <p>From what I've read, <code>getline()</code> used in a Boolean context returns an implicitly conversion to <code>void*</code>. I haven't found anywhere on the web any real reference to this statement. Everywhere it says that implicit conversion doesn't exist and that in a Boolean context pointers should be of the same kind (and if <code>ptr == 0</code> than <code>0</code> is converted to type of the pointer <code>ptr</code>).</p>
  
  <p>Also in the standard says in a Boolean context it is converted to an unspecified-Boolean-type. What does that even mean?</p>