Consider the following code:
The first line causes no warning. The second line causes a warning, "Expression of type 'UIViewController?' is unused."
Of course I understand why this is, in theory. The second call returns a value, and I am ignoring it. But from a practical point of view, to ignore this value is normal behavior, so the warning is just annoying (i.e. it isn't helpful). I can work around the problem by assigning the second line to an unnamed variable:
But this seems like a bit much. I'm ending up with my code peppered with that sort of expression; it's kind of ugly.