Simple deep copy for Go(reflection/generics)

deepcopy.go

package main

import (
	"encoding/json"
	"fmt"
	"reflect"
)

// Example:
//
//	dest, err := genutil.DeepCopy(src)
func DeepCopy(src interface{}) (interface{}, error) {
	val := reflect.ValueOf(src).Elem()
	dest := reflect.New(val.Type()).Interface()

	dumped, err := json.Marshal(src)
	if err != nil {
		return nil, err
	}
	err = json.Unmarshal(dumped, dest)
	if err != nil {
		return nil, err
	}
	return dest, nil
}

// Example:
//
//	dest, err := genutil.DeepCopyGenerics(src)
func DeepCopyGenerics[T any](src *T) (*T, error) {
	dest := new(T)

	dumped, err := json.Marshal(src)
	if err != nil {
		return nil, err
	}
	err = json.Unmarshal(dumped, dest)
	if err != nil {
		return nil, err
	}
	return dest, nil
}

type Hoge struct {
	Value1 string
}

func main() {
	src := &Hoge{Value1: "value 1"}
	dest1, err := DeepCopy(src)
	if err != nil {
		panic(err)
	}
	dest2, err := DeepCopyGenerics(src)
	if err != nil {
		panic(err)
	}
	fmt.Printf("src: %#v\n", src)
	fmt.Printf("DeepCopy: %#v\n", dest1)
	fmt.Printf("DeepCopyGenerics: %#v\n", dest2)
}