fittingSizeCompression
When you send a Fittingsize message to a view, the smallest size that is large enough for the view’s contents is computed.
Declaration
static var fittingSizeCompression: NSLayoutConstraint.Priority { get }Discussion
This is the priority level with which the view wants to be as small as possible in that computation. It’s quite low. It is generally not appropriate to make a constraint at exactly this priority. You want to be higher or lower.