How to convert an ip's network segment in Golang?

In golang, how can I convert 10.222.1.2/16 to 10.223.1.2/16?
Masks can be considered the same.

For example:

func Netmap(ip string, dest string) string{}
Netmap("10.222.1.2/16", "10.223.0.0/16") // => "10.223.1.2/16"
Netmap("10.222.1.5/16", "10.224.0.0/16") // => "10.224.1.5/16"

==== Update 2023/05/09 ====

** @Volker: What have you tried so far? Where did you get stuck? **

I am very sorry that the previous description is not detailed enough. If the conversion is completed on paper, my thinking is as follows:

I tried how to implement this process through code, and I found a series of conversion methods that can convert ip to: []byte, uint32, etc.

ip, ipNet, _ := net.ParseCIDR("10.222.1.2/16")
bytes := []byte(ip)
maskBits := binary.BigEndian.Uint32(ipNet.Mask)
ipBits := binary.BigEndian.Uint32(ip.To4())

prefix, _ := netip.ParsePrefix("10.222.1.2/16")
binary, _ := prefix.Addr().MarshalBinary()

But I'm not quite sure what these things mean, and how to manipulate the data.

Thank you very much @Zeke Lu, I'm learning to understand this line of code, I use too few bit operators, and I'm not familiar with them:

v := ((v2 >> (32 - bits)) << (32 - bits)) | ((v1 << bits) >> bits)

Maybe this is what you want:

package main

import (
	"encoding/binary"
	"errors"
	"fmt"
	"net/netip"
)

func Netmap(ip string, dest string) (string, error) {
	v1, bits, err := parse(ip)
	if err != nil {
		return "", err
	}

	v2, bits2, err := parse(dest)
	if err != nil {
		return "", err
	}

	if bits2 != bits {
		return "", errors.New("bits not matched")
	}

	// Construct from the high bits from v2 and the low bits from v1.
	v := ((v2 >> (32 - bits)) << (32 - bits)) | ((v1 << bits) >> bits)

	a4 := [4]byte{}
	binary.BigEndian.PutUint32(a4[:], v)
	addr := netip.AddrFrom4(a4)

	p := netip.PrefixFrom(addr, bits)

	return p.String(), nil
}

// parse parses the prefix and returns the IPv4 address as uint32.
func parse(prefix string) (uint32, int, error) {
	p, err := netip.ParsePrefix(prefix)
	if err != nil {
		return 0, 0, err
	}

	// Let's focus on IPv4.
	if !p.Addr().Is4() {
		return 0, 0, errors.New("unsupported IP version")
	}

	a4 := p.Addr().As4()
	v := binary.BigEndian.Uint32(a4[:])

	return v, p.Bits(), nil
}

func main() {
	fmt.Println(Netmap("10.222.1.2/16", "10.223.0.0/16"))
	fmt.Println(Netmap("10.222.1.5/16", "10.224.0.0/16"))
}

Note: this is not fully tested. Use with caution.