Nov 27 2016

Basic (generic) swap function

(Swift 3)

var a: Int = 15
var b: Int = 12

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

print("a is \(a) ") //15

swap(a: &a, b: &b)

print("a is \(a) ") //12

So far, so good. I really like that this is doing away with the extra variable in many implementations: temp = a, a = b, b = temp. Making it generic wasn’t quite as intuitive for me: ‘T’ must be declared in the function name before it can be used.

func swap( a: inout T, b: inout T){
(a, b) = (b, a)
}

Of course, you can just use Swift’s inbuilt Swap function, but I felt that both the tuple trick and the generic usage were worth writing down.

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