func swap<T>(_: inout T, _: inout T) Exchanges the values of the two arguments. The two arguments must not alias each other. To swap two elements of a mutable collection, use the swapAt(_:_:) method of that collection instead of this function. Parameters: a: The first value to swap. b: The second value to swap. Declaration func swap<T>(_ a: inout T, _ b: inout T)