Immutable Struct in Golang

It is possible to make a struct read-only outside of its package by making its members non-exported and providing readers. For example:

package mypackage

type myReadOnly struct {
  value int
}

func (s myReadOnly) Value() int {
  return s.value
}

func NewMyReadonly(value int) myReadOnly{
  return myReadOnly{value: value}
}

And usage:

myReadonly := mypackage.NewMyReadonly(3)
fmt.Println(myReadonly.Value())  // Prints 3