How do you return multiple values and assign them to mutable variables?

Question

This is what I have so far.

let Swap (left : int , right : int ) = (right, left)

let mutable x = 5
let mutable y = 10

let (newX, newY) = Swap(x, y) //<--thi         


        

Answer 1

F# has "by reference" parameters just like C#, so you can write a classic swap function similarly:

let swap (x: byref<'a>) (y: byref<'a>) =
    let temp = x
    x <- y
    y <- temp

let mutable x,y = 1,2
swap &x &y