generic_swap.swift

func swapTwo(_ a: inout Int, _ b: inout Int) {
    (a, b) = (b, a)
}

var x = 4
var y = 7

swapTwo(&x, &y)

// What about two string, double, etc. ???

print("x: \(x)")
print("y: \(y)")
/*
 x: 7
 y: 4
 */

// Generic solution
func swapTwoGenerics<T>(_ a: inout T, _ b: inout T) {
    (a, b) = (b, a)
}

swapTwoGenerics(&x, &y)

print("x: \(x)")
print("y: \(y)")
/*
 x: 4
 y: 7
 */

var first = "1"
var second = "2"

swapTwoGenerics(&first, &second)

print("first: \(first)")
print("second: \(second)")
/*
 first: 2
 second: 1
 */