I tried to use noinit with a []byte slice, but the parser complained that field must be a pointer to have noinit. It seems a bit unnecessary to insist on having a pointer to a slice, since a slice in itself can be nil. Consider the following code:

package main

import "fmt"

type Lala struct {
	Blah []byte
}

func main() {
	lala := Lala{}
	if lala.Blah == nil {
		fmt.Println("Blah is nil")
	}
	lala.Blah = []byte{}
	if lala.Blah != nil {
		fmt.Println("Blah is not nil")
	}
}

The result is:

Blah is nil
Blah is not nil