We can add adaptivity to any subclass of
UIView which we add on view controller in nib file.
Lets take an example of adding adaptivity using size classes to a view.
These constraints defines that the added view will be placed in it's superview as
CGRect(20, 0, superview.width - 20, superview.height - 20)
We can also see the preview with landscape mode by moving mouse on the name of device and clicking the rotation button as: