Function IntToReference

src/saveload/saveload.cpp:1258–1321

* Pointers cannot be loaded from a savegame, so this function * gets the index from the savegame and returns the appropriate * pointer from the already loaded base. * Remember that an index of 0 is a nullptr pointer so all indices * are +1 so vehicle 0 is saved as 1. * @param index The index that is being converted to a pointer * @param rt SLRefType type of the object the pointer is sought o

 * @return Return the index converted to a pointer of any type
 */
static void *IntToReference(size_t index, SLRefType rt)
{
	static_assert(sizeof(size_t) <= sizeof(void *));

	assert(_sl.action == SLA_PTRS);

	/* After version 4.3 REF_VEHICLE_OLD is saved as REF_VEHICLE,
	 * and should be loaded like that */
	if (rt == REF_VEHICLE_OLD && !IsSavegameVersionBefore(SLV_4, 4)) {
		rt = REF_VEHICLE;
	}

	/* No need to look up nullptr pointers, just return immediately */
	if (index == (rt == REF_VEHICLE_OLD ? 0xFFFF : 0)) return nullptr;

	/* Correct index. Old vehicles were saved differently:
	 * invalid vehicle was 0xFFFF, now we use 0x0000 for everything invalid. */
	if (rt != REF_VEHICLE_OLD) index--;

	switch (rt) {
		case REF_ORDERLIST:
			if (OrderList::IsValidID(index)) return OrderList::Get(index);
			SlErrorCorrupt("Referencing invalid OrderList");

		case REF_VEHICLE_OLD:
		case REF_VEHICLE:
			if (Vehicle::IsValidID(index)) return Vehicle::Get(index);
			SlErrorCorrupt("Referencing invalid Vehicle");

		case REF_STATION:
			if (Station::IsValidID(index)) return Station::Get(index);
			SlErrorCorrupt("Referencing invalid Station");

		case REF_TOWN:
			if (Town::IsValidID(index)) return Town::Get(index);
			SlErrorCorrupt("Referencing invalid Town");

		case REF_ROADSTOPS:
			if (RoadStop::IsValidID(index)) return RoadStop::Get(index);
			SlErrorCorrupt("Referencing invalid RoadStop");

		case REF_ENGINE_RENEWS:
			if (EngineRenew::IsValidID(index)) return EngineRenew::Get(index);
			SlErrorCorrupt("Referencing invalid EngineRenew");

		case REF_CARGO_PACKET:
			if (CargoPacket::IsValidID(index)) return CargoPacket::Get(index);
			SlErrorCorrupt("Referencing invalid CargoPacket");

		case REF_STORAGE:
			if (PersistentStorage::IsValidID(index)) return PersistentStorage::Get(index);
			SlErrorCorrupt("Referencing invalid PersistentStorage");

		case REF_LINK_GRAPH:
			if (LinkGraph::IsValidID(index)) return LinkGraph::Get(index);
			SlErrorCorrupt("Referencing invalid LinkGraph");

		case REF_LINK_GRAPH_JOB: