How do you perform a deep copy of a ternary tree in Go?

I'm attempting to perform a deep copy of the following struct:

// Ternary Tree
type Tree struct {
    Left  *Tree
    Mid *Tree
    Right *Tree
    Value interface{}
    Parent *Tree
    Orientation string
    IsTerminal bool
    Type string
}

The following is my sorry attempt. It looks like I'm creating a new tree at the root but it's children are still pointing to the same address in memory.

func (tree *Tree) CopyTree() *Tree {
    if (tree == nil) {
        return nil
    } else {
        copiedTree := &Tree {
            tree.Left.CopyTree(),
            tree.Mid.CopyTree(),
            tree.Right.CopyTree(),
            tree.Value,
            tree.Parent.CopyTree(),
            tree.Orientation,
            tree.IsTerminal,
            tree.Type}
        return copiedTree
    }
}

Are there any useful constructs in go that assist with deep copying a struct? If not, how would I perform this deep copy myself? Note, the "deepcopy" package no longer works as it uses a few functions that were deprecated with the release of Go 1

I was close. I should have assigned the copiedTree to the parent property.

func (tree *Tree) CopyTree() *Tree {
    if (tree == nil) {
        return nil
    } else {
        copiedTree := &Tree {
            tree.Left.CopyTree(),
            tree.Mid.CopyTree(),
            tree.Right.CopyTree(),
            tree.Value,
            nil,
            tree.Orientation,
            tree.IsTerminal,
            tree.Type,
        }
    
        if copiedTree.Left != nil {
            copiedTree.Left.Parent = copiedTree
        }
        if copiedTree.Right != nil {
            copiedTree.Right.Parent = copiedTree
        }
        if copiedTree.Mid != nil {
            copiedTree.Mid.Parent = copiedTree
        }
        return copiedTree
    }
}

You can roundtrip it through encoding/gob:

package main

import (
   "bytes"
   "encoding/gob"
)

func copyStruct(in, out interface{}) {
   buf := new(bytes.Buffer)
   gob.NewEncoder(buf).Encode(in)
   gob.NewDecoder(buf).Decode(out)
}

func main() {
   type date struct { Month, Day int }
   a := date{12, 31}
   var b date
   copyStruct(a, &b)
}

https://golang.org/pkg/encoding/gob

How about json.Marshal and json.Unmarshal. If performance is critical, I perfer to use protobuf.