You have to use a temporary to swap the values: tmp := a.Interface() a.Set(b) b.Set(reflect.ValueOf(tmp))
---- *Josh Humphries* jh...@bluegosling.com On Mon, Jul 31, 2017 at 10:18 AM, eZio Pan <eziopa...@gmail.com> wrote: > Hello, > I want to build a "universal slice reverser" with reflect.MakeFunc. But I > don't know how to get a copy of reflect.Value's underlying value, which > make result not correct. > > Here is the code: > > package main > > import ( > "fmt" > "reflect" > ) > > func reverse(in []reflect.Value) (out []reflect.Value) { > inls := in[0] > inlslen := inls.Len() > > for i, j := 0, inlslen-1; i < j; i, j = i+1, j-1 { > a := inls.Index(i) > b := inls.Index(j) > // how to get underlying value of a and b ? > a.Set(b) > b.Set(a) > } > return in > } > > var intFlipper func([]int) []int > > func main() { > emptyFunc := reflect.ValueOf(&intFlipper).Elem() > pseudoFunc := reflect.MakeFunc(emptyFunc.Type(), reverse) > emptyFunc.Set(pseudoFunc) > fmt.Printf("%v\n", intFlipper([]int{2, 3, 4, 5, 6, 7})) > } > > My code return [7 6 5 5 6 7], but excepting result is [7 6 5 4 3 2] > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.