war.swift

//War tank objects
var t10 = WarTank()

var t11 = WarTank()
t11.topSpeed = 110.0


//Spy Jeep Objects
var sj10 = SpyJeep()

var sj11 = SpyJeep()
sj11.topSpeed = 190.0

// Extensions
extension WarCapable{
    func canTravelFaster(item : WarCapable)->Bool{
        return self.topSpeed > item.topSpeed
    }
}

t10.canTravelFaster(item: t11)
// returns false

sj11.canTravelFaster(item: t11)
// returns true