package main

import "fmt"

type NetMsg interface {
	Pack() []byte
}

type MsgToken struct {
	Token [4]byte
}

func (t MsgToken) Pack() []byte {
	return t.Token[:]
}

func main() {
	messages := []NetMsg{
		MsgToken {
			Token: [4]byte{0xff, 0xff, 0xff, 0xff},
		},
	}

	if token, ok := messages[0].(MsgToken); ok {
		token.Token = [4]byte{0x00, 0x00, 0x00, 0x00}
		fmt.Printf("setting token: %v\n", token.Token)
	}

	fmt.Printf("messages: %v\n", messages)
}