Copying data hidden by interface

I have got some TCP connection which returns some data for me. Also I have got a structure that represents this data.

type Item struct {
  A int32
  B int32
}

Item supports Unpacker interface

func (item *Item) Unpack(data []int32) {
	item.A = data[0]
	item.B = data[1]
	return
}

type Unpacker interface {
	Unpack([]int32)
}

So I receive some data from Network which represents a bunch of items. Now I want to pass my structure to function and I want to get back a slice of structures filled with data:

func find(packet [][]int32, responseItem Unpacker) (items []Unpacker) {
	items = make([]Unpacker, len(packet))
	for i, data := range(packet) {
		responseItem.Unpack(data)
		items[i] = responseItem
	}
	return
}

Of course in this case I have got a slice with a number of identical items (pointers to same item). But I want to get different items and

items[i] = *responseItem

doesn't work in my case.

Here is link to playground: http://play.golang.org/p/RP4ryxoG2I

I believe I didn't understand how Go works (it is my first time with Go). And also good to be noticed: I don't want to use reflection here if it is possible.

You've got unpacker backwards. You want to create new Item in your loop, Unpack into the item and then assign into your slice. You can do this by making find accept a function returning an Unpacker.

See the following: http://play.golang.org/p/rFoa1eoh4A

Your find function:

type UnpackerMaker func() (Unpacker)

func find(packet [][]int32, makeUnpacker UnpackerMaker) (items []Unpacker) {
    items = make([]Unpacker, len(packet))
    for i, data := range(packet) {
        unpacker := makeUnpacker()
        unpacker.Unpack(data)
        items[i] = unpacker
    }
    return
}