CGRect has a very convenient built-in constant: CGRect.null

let aRect = ... //get rect from somewhere
CGRect.null.union(aRect) //is aRect
CGRect.null.intersection(aRect) //is CGRect.null

CGPath doesn’t have anything like this, meaning you can’t do something like:

let bunchOfPaths = [...] //array of CGPaths
let unionPath = bunchOfPaths.reduce(CGPath.null, { $0.union($1) }) //union of all the paths

Nor can you use CGRect.null to create the equivalent:

let nullRectPath = CGPath(rect: .null, transform: nil)
nullRectPath.isEmpty //false (?!)
let zeroRectPath = CGPath(rect: .zero, transform: nil)
nullRectPath.union(zeroRectPath) == zeroRectPath //false

Creating an empty path isn’t helpful either:

let emptyPath = zeroRectPath.subtracting(zeroRectPath)
emptyPath.isEmpty //true
emptyPath.union(zeroRectPath) == zeroRectPath //false (!!)

Does a CGPath with the properties described (its union with any CGPath is the other path, its intersection with any CGPath is itself) exist, and if so, how can it be created?