type Metrics struct {
	Requests int64 `json:"requests"` // I want to replace this with an atomic.Int64
}

func main() {
	var metrics atomic.Pointer[Metrics]

	metrics.Store(&Metrics{})

	// Standin for somehthing like a HTTP handler or something else generating metrics...
	go func() {
		for {
			time.Sleep(time.Millisecond)

			m := metrics.Load()
			atomic.AddInt64(&m.Requests, 1) // Would become m.Add(1)
		}
	}()

	for {
		time.Sleep(time.Second)

		m := metrics.Swap(&Metrics{})

		// Give other goroutines another 100 milliseconds to do
		// their atomic operations on m.
		time.Sleep(time.Millisecond * 100)

		b, _ := json.Marshal(m) // This would become safe with atomic.Int64
		fmt.Println(string(b)) // Send to some other place etc...
	}
}

// MarshalText implements the encoding.TextMarshaler interface.
func (x *Int64) MarshalText() ([]byte, error) {
	if x == nil {
		return []byte("<nil>"), nil
	}
	return []byte(strconv.FormatInt(x.Load(), 10)), nil
}

// UnmarshalText implements the encoding.TextUnmarshaler interface.
func (x *Int64) UnmarshalText(text []byte) error {
	n, err := strconv.ParseInt(string(text), 10, 64)
	if err != nil {
		return err
	}
	x.Store(n)
	return nil
}

// MarshalJSON implements the json.Marshaler interface.
func (x *Int64) MarshalJSON() ([]byte, error) {
	if x == nil {
		return []byte("null"), nil
	}
	return x.MarshalText()
}

// UnmarshalJSON implements the json.Unmarshaler interface.
func (x *Int64) UnmarshalJSON(text []byte) error {
	// Ignore null, like in the main JSON package.
	if string(text) == "null" {
		return nil
	}
	return x.UnmarshalText(text)
}