type Point = tuple[x: int, y: int]

proc add(a: Point, b: Point): Point =
  (x: a.x + b.x, y: a.y + b.y)

var a : Point
var b : ptr Point

a = (x: 1, y: 2)
b = cast[ptr Point](alloc(sizeof(Point)))
b.x = 4
b.y = 3
echo(add(a, b[]))
dealloc(b)