package main import ( "fmt" "reflect" ) func main() { var x float64 = 3.14 v := reflect.ValueOf(&x).Elem() v.SetFloat(6.28) fmt.Println(x) }In this example, we create a variable x with the initial value of 3.14. Then, we get a reflect.Value object for x using the `ValueOf` method of the reflect package. But since we need to set the value of x, we need to get a writable reference to it. This is why we call the `Elem` method on the reflect.Value. Finally, we call the `SetFloat` method on the writable reflect.Value with the value 6.28. This sets the value of x to 6.28. We then print x, which should now be 6.28. The package library used in this example is the `reflect` package.