How do I use reference or pointer binding values?

[3038922]

json data{
    "chassis": {
        "motor": {
            "left": {
                "prot": 1,
                "isRevase": false,
                "gear": 1
            },
            "right": {
                "prot": 2,
                "isRevase": true,
                "gear": 1
            },
        },
}
static void action(void * ptr)
{
  // if jsonType is bool flaot? How to Realize Automatic Judgment?
   long *p=static_cast<long*>(ptr);
   *p=100;
   std::cout<< json data["chassis"]["motor"]["left"]["prot"]<<std::endl; //output 100

 //I want to be able to pass the value pointer directly, without restricting the type.
  json::autoType p=static_cast<json::autoType *>(ptr);
 *p=100;
   std::cout<< json data["chassis"]["motor"]["left"]["prot"]<<std::endl; //output 100
}
void test
{

  long*a =data["chassis"]["motor"]["left"]["prot"].get_ptr<long *>();
  action((void*)a);
 //I want to be able to pass the value pointer directly, without restricting the type.
  auto *a=&data["chassis"]["motor"]["left"]["prot"];  
  action((void*)a);
 // //I want to change JSON by a reference
}