Codechange: Use single vector for next station order.

Pass vector to insert into to avoid handling multiple vectors.

This may change the order of returned stations.

src/aircraft_cmd.cpp

@@ -135,7 +135,8 @@ static StationID FindNearestHangar(const Aircraft *v)
 			next_dest = Station::GetIfValid(v->current_order.GetDestination().ToStationID());
 		} else {
 			last_dest = GetTargetAirportIfValid(v);
-			std::vector<StationID> next_station = v->GetNextStoppingStation();
+			std::vector<StationID> next_station;
+			v->GetNextStoppingStation(next_station);
 			if (!next_station.empty()) next_dest = Station::GetIfValid(next_station.back());
 		}
 	}

src/economy.cpp

@@ -1270,7 +1270,8 @@ void PrepareUnload(Vehicle *front_v)
 	assert(CargoPayment::CanAllocateItem());
 	front_v->cargo_payment = new CargoPayment(front_v);
 
-	std::vector<StationID> next_station = front_v->GetNextStoppingStation();
+	std::vector<StationID> next_station;
+	front_v->GetNextStoppingStation(next_station);
 	if (front_v->orders == nullptr || (front_v->current_order.GetUnloadType() & OUFB_NO_UNLOAD) == 0) {
 		Station *st = Station::Get(front_v->last_station_visited);
 		for (Vehicle *v = front_v; v != nullptr; v = v->Next()) {
@@ -1618,7 +1619,8 @@ static void LoadUnloadVehicle(Vehicle *front)
 	StationID last_visited = front->last_station_visited;
 	Station *st = Station::Get(last_visited);
 
-	std::vector<StationID> next_station = front->GetNextStoppingStation();
+	std::vector<StationID> next_station;
+	front->GetNextStoppingStation(next_station);
 	bool use_autorefit = front->current_order.IsRefit() && front->current_order.GetRefitCargo() == CARGO_AUTO_REFIT;
 	CargoArray consist_capleft{};
 	if (_settings_game.order.improved_load && use_autorefit ?

src/order_base.h

@@ -367,7 +367,7 @@ public:
 	 */
 	inline VehicleOrderID GetNumManualOrders() const { return this->num_manual_orders; }
 
-	std::vector<StationID> GetNextStoppingStation(const Vehicle *v, VehicleOrderID first = INVALID_VEH_ORDER_ID, uint hops = 0) const;
+	void GetNextStoppingStation(std::vector<StationID> &next_station, const Vehicle *v, VehicleOrderID first = INVALID_VEH_ORDER_ID, uint hops = 0) const;
 	VehicleOrderID GetNextDecisionNode(VehicleOrderID next, uint hops) const;
 
 	void InsertOrderAt(Order &&order, VehicleOrderID index);

src/order_cmd.cpp

@@ -361,14 +361,14 @@ VehicleOrderID OrderList::GetNextDecisionNode(VehicleOrderID next, uint hops) co
  * @pre The vehicle is currently loading and v->last_station_visited is meaningful.
  * @note This function may draw a random number. Don't use it from the GUI.
  */
-std::vector<StationID> OrderList::GetNextStoppingStation(const Vehicle *v, VehicleOrderID first, uint hops) const
+void OrderList::GetNextStoppingStation(std::vector<StationID> &next_station, const Vehicle *v, VehicleOrderID first, uint hops) const
 {
 	VehicleOrderID next = first;
 	if (first == INVALID_VEH_ORDER_ID) {
 		next = v->cur_implicit_order_index;
 		if (next >= this->GetNumOrders()) {
 			next = this->GetFirstOrder();
-			if (next == INVALID_VEH_ORDER_ID) return {};
+			if (next == INVALID_VEH_ORDER_ID) return;
 		} else {
 			/* GetNext never returns INVALID_VEH_ORDER_ID if there is a valid station in the list.
 			 * As the given "next" is already valid and a station in the list, we
@@ -392,10 +392,9 @@ std::vector<StationID> OrderList::GetNextStoppingStation(const Vehicle *v, Vehic
 			} else if (skip_to == INVALID_VEH_ORDER_ID || skip_to == first) {
 				next = (advance == first) ? INVALID_VEH_ORDER_ID : advance;
 			} else {
-				std::vector<StationID> st1 = this->GetNextStoppingStation(v, skip_to, hops);
+				this->GetNextStoppingStation(next_station, v, skip_to, hops);
-				std::vector<StationID> st2 = this->GetNextStoppingStation(v, advance, hops);
+				this->GetNextStoppingStation(next_station, v, advance, hops);
-				std::copy(st2.rbegin(), st2.rend(), std::back_inserter(st1));
+				return;
-				return st1;
 			}
 			++hops;
 		}
@@ -404,11 +403,11 @@ std::vector<StationID> OrderList::GetNextStoppingStation(const Vehicle *v, Vehic
 		if (next == INVALID_VEH_ORDER_ID || ((orders[next].IsType(OT_GOTO_STATION) || orders[next].IsType(OT_IMPLICIT)) &&
 				orders[next].GetDestination() == v->last_station_visited &&
 				(orders[next].GetUnloadType() & (OUFB_TRANSFER | OUFB_UNLOAD)) != 0)) {
-			return {};
+			return;
 		}
 	} while (orders[next].IsType(OT_GOTO_DEPOT) || orders[next].GetDestination() == v->last_station_visited);
 
-	return {orders[next].GetDestination().ToStationID()};
+	next_station.push_back(orders[next].GetDestination().ToStationID());
 }
 
 /**

src/vehicle_base.h

@@ -714,9 +714,10 @@ public:
 	 * Get the next station the vehicle will stop at.
 	 * @return ID of the next station the vehicle will stop at or StationID::Invalid().
 	 */
-	inline std::vector<StationID> GetNextStoppingStation() const
+	inline void GetNextStoppingStation(std::vector<StationID> &next_station) const
 	{
-		return (this->orders == nullptr) ? std::vector<StationID>{} : this->orders->GetNextStoppingStation(this);
+		if (this->orders == nullptr) return;
+		this->orders->GetNextStoppingStation(next_station, this);
 	}
 
 	void ResetRefitCaps();