I have a database that stores IPv4 and IPv6 addresses as decimal(39,0). I need to convert a Golang Net.IP to this format. I have done it for IPv4 as follows:

```
func ipv4ToInt(IPv4Addr net.IP) int64 {
bits := strings.Split(IPv4Addr.String(), ".")
b0, _ := strconv.Atoi(bits[0])
b1, _ := strconv.Atoi(bits[1])
b2, _ := strconv.Atoi(bits[2])
b3, _ := strconv.Atoi(bits[3])
var sum int64
sum += int64(b0) << 24
sum += int64(b1) << 16
sum += int64(b2) << 8
sum += int64(b3)
return sum
}
```

I am trying the same with IPv6:

```
func ipv6ToInt(IPv6Addr net.IP) Int128 {
bits := strings.Split(IPv6Addr.String(), ":")
var arr [4]int64
var arr1 [4]uint64
for i := 0; i < 4; i++ {
arr[i], _ = strconv.ParseInt(bits[i], 16, 64)
}
for i := 0; i < 4; i++ {
arr1[i], _ = strconv.ParseUint(bits[i], 16, 64)
}
int1 := arr[0]
for i := 0; i < 4; i++ {
int1 = (int1 << 16) + arr[i]
}
int2 := arr1[0]
for i := 0; i < 4; i++ {
int2 = (int2 << 16) + arr1[i]
}
var IPv6Int Int128
IPv6Int.H = int1
IPv6Int.L = int2
return IPv6Int
}
```

Where int128 is

```
type Int128 struct {
H int64
L uint64
}
```

The result should look like:

```
42540578165168461141553663388954918914
```

from the IPv6 addr:

```
2001:470:0:76::2
```

Thanks!

EDIT, ANSWER: Thanks to the people in #go-nuts, the answer is as follows:

```
func ipv6ToInt(IPv6Addr net.IP) *big.Int {
IPv6Int := big.NewInt(0)
IPv6Int.SetBytes(IPv6Addr)
return IPv6Int
}
```

The same works for IPv6, just do IP.To4() first.