import Foundation

func f(_ n: NSNumber) {}

let int: Int = 0

f(int)
/*
⛔️ error: cannot convert value of type 'Int' to expected argument type 'NSNumber'
f(int)
 ^
 NSNumber( )
 */

// Fix it as advised...
f(NSNumber(int))
/*
⛔️ error: no exact matches in call to initializer
f(NSNumber(int))
 ^
Foundation.NSNumber:41:12: note: incorrect labels for candidate (have: '(_:)', expected: '(value:)')
   public init(value: Int)
          ^
Foundation.NSNumber:2:42: note: incorrect labels for candidate (have: '(_:)', expected: '(integerLiteral:)')
   @nonobjc required public convenience init(integerLiteral value: Int)
                                        ^
 */

f(NSNumber(value: int)) // ✅ OK