On MacOS, if you do:
import Foundation
let x = Int32(1) as? NSNumber
x is non-nil.
On Ubuntu Linux, if you do the same (even with Swift 3.1.1), x is nil.
Am I doing something wrong, or is this just a fact of a lack of bridging of numeric types to NSNumber with the Foundation with Swift on Ubuntu/Linux?
See also Is it possible to replicate Swifts automatic numeric value bridging to Foundation (NSNumber) for (U)Int8/16/32/64 types? and https://github.com/SwiftyJSON/SwiftyJSON/issues/745