My Mistake On Converting Slice To Slice Of Ptr In Golang

I once made a function to convert a slice to slice of ptr and made a mistake.

My Function

func Slice2SliceOfPtr(slice []int) []*int { n := len(slice) r := make([]*int, n, n) for i, s := range slice { r[i] = &s } return r } 

It seems normal to me until I realize something was wrong.

My Main Func

func main() { x := []int{1, 2, 3} y := Slice2SliceOfPtr(x) fmt.Println(x) for _, yy := range y { fmt.Printf("%d ", *yy) } } 

Result

$ go run main.go [1 2 3] 3 3 3 

Why only the last element copied to the result?

Because the &s I used is mutated every iteration.

for i, s := range slice { r[i] = &s } 

s never created as a new variable on every iteration, but its value is mutated inside the for loop

So I changed the iteration like this:

Better One

for i := range slice { r[i] = &slice[i] }