import `reflect`
var typeRegistry = make(map[string]reflect.Type)
func RegisterType(elem interface{}) {
	t := reflect.TypeOf(elem).Elem()
	typeRegistry[t.Name()] = t
}
func NewStruct(name string) (interface{}, bool) {
	elem, ok := typeRegistry[name]
	if !ok {
		return nil, false
	}
	return reflect.New(elem).Elem().Interface(), true
}

// 定義結構體
type Student struct {
      Name string
      Age int
}
// 初始化時注冊類型
func init() {
	RegisterType((*Student)(nil))
}
// 獲取對象
func getObj(structName string) (*Student, error) {
	st, ok := NewStruct(structName)
	if !ok {
		return nil, errors.New("new struct not ok")
	}
	student, ok := st.(Student)
	if !ok {
		return nil, fmt.Errorf("assert st to Student error,st:%T", st)
	}
      // 給結構體字段賦值
      student.Name = "jones"
      student.Age = 18
	return &student, nil
}
func main(){
      // 獲取一個對象
      stu := getObj("Student")
      fmt.Printf("stu:%+v",stu)
}