Codechange: make TownID an enum

src/cargomonitor.h

@@ -136,7 +136,7 @@ inline IndustryID DecodeMonitorIndustry(CargoMonitorID num)
 inline TownID DecodeMonitorTown(CargoMonitorID num)
 {
 	if (MonitorMonitorsIndustry(num)) return INVALID_TOWN;
-	return GB(num, CCB_TOWN_IND_NUMBER_START, CCB_TOWN_IND_NUMBER_LENGTH);
+	return static_cast<TownID>(GB(num, CCB_TOWN_IND_NUMBER_START, CCB_TOWN_IND_NUMBER_LENGTH));
 }
 
 void ClearCargoPickupMonitoring(CompanyID company = INVALID_OWNER);

src/saveload/afterload.cpp

@@ -1008,7 +1008,7 @@ bool AfterLoadGame()
 					if ((GB(t.m5(), 4, 2) == ROAD_TILE_CROSSING ? (Owner)t.m3() : GetTileOwner(t)) == OWNER_TOWN) {
 						SetTownIndex(t, CalcClosestTownFromTile(t)->index);
 					} else {
-						SetTownIndex(t, 0);
+						SetTownIndex(t, TOWN_BEGIN);
 					}
 					break;
 
@@ -1232,7 +1232,7 @@ bool AfterLoadGame()
 								GetRailType(t)
 							);
 						} else {
-							TownID town = IsTileOwner(t, OWNER_TOWN) ? ClosestTownFromTile(t, UINT_MAX)->index : 0;
+							TownID town = IsTileOwner(t, OWNER_TOWN) ? ClosestTownFromTile(t, UINT_MAX)->index : TOWN_BEGIN;
 
 							/* MakeRoadNormal */
 							SetTileType(t, MP_ROAD);

src/script/api/script_goal.cpp

@@ -36,7 +36,7 @@
 	return (type == GT_NONE && destination == 0) ||
 			(type == GT_TILE && ScriptMap::IsValidTile(::TileIndex(destination))) ||
 			(type == GT_INDUSTRY && ScriptIndustry::IsValidIndustry(destination)) ||
-			(type == GT_TOWN && ScriptTown::IsValidTown(destination)) ||
+			(type == GT_TOWN && ScriptTown::IsValidTown(static_cast<TownID>(destination))) ||
 			(type == GT_COMPANY && ScriptCompany::ResolveCompanyID(ScriptCompany::ToScriptCompanyID(static_cast<::CompanyID>(destination))) != ScriptCompany::COMPANY_INVALID) ||
 			(type == GT_STORY_PAGE && story_page != nullptr && (c == INVALID_COMPANY ? story_page->company == INVALID_COMPANY : story_page->company == INVALID_COMPANY || story_page->company == c));
 }

src/script/api/script_news.cpp

@@ -34,7 +34,7 @@
 	                           (ref_type == NR_TILE     && ScriptMap::IsValidTile(::TileIndex(reference))) ||
 	                           (ref_type == NR_STATION  && ScriptStation::IsValidStation(reference)) ||
 	                           (ref_type == NR_INDUSTRY && ScriptIndustry::IsValidIndustry(reference)) ||
-	                           (ref_type == NR_TOWN     && ScriptTown::IsValidTown(reference)));
+	                           (ref_type == NR_TOWN     && ScriptTown::IsValidTown(static_cast<TownID>(reference))));
 
 	::CompanyID c = ScriptCompany::FromScriptCompanyID(company);
 

src/script/api/script_subsidy.cpp

@@ -37,8 +37,8 @@
 	EnforcePrecondition(false, ScriptCargo::IsValidCargo(cargo_type));
 	EnforcePrecondition(false, from_type == SPT_INDUSTRY || from_type == SPT_TOWN);
 	EnforcePrecondition(false, to_type == SPT_INDUSTRY || to_type == SPT_TOWN);
-	EnforcePrecondition(false, (from_type == SPT_INDUSTRY && ScriptIndustry::IsValidIndustry(from_id)) || (from_type == SPT_TOWN && ScriptTown::IsValidTown(from_id)));
+	EnforcePrecondition(false, (from_type == SPT_INDUSTRY && ScriptIndustry::IsValidIndustry(from_id)) || (from_type == SPT_TOWN && ScriptTown::IsValidTown(static_cast<TownID>(from_id))));
-	EnforcePrecondition(false, (to_type == SPT_INDUSTRY && ScriptIndustry::IsValidIndustry(to_id)) || (to_type == SPT_TOWN && ScriptTown::IsValidTown(to_id)));
+	EnforcePrecondition(false, (to_type == SPT_INDUSTRY && ScriptIndustry::IsValidIndustry(to_id)) || (to_type == SPT_TOWN && ScriptTown::IsValidTown(static_cast<TownID>(to_id))));
 
 	Source from{static_cast<SourceID>(from_id), static_cast<SourceType>(from_type)};
 	Source to{static_cast<SourceID>(to_id), static_cast<SourceType>(to_type)};

src/town.h

@@ -33,7 +33,7 @@ static const uint TOWN_GROWTH_DESERT = 0xFFFFFFFF; ///< The town needs the cargo
 static const uint16_t TOWN_GROWTH_RATE_NONE = 0xFFFF; ///< Special value for Town::growth_rate to disable town growth.
 static const uint16_t MAX_TOWN_GROWTH_TICKS = 930; ///< Max amount of original town ticks that still fit into uint16_t, about equal to UINT16_MAX / TOWN_GROWTH_TICKS but slightly less to simplify calculations
 
-typedef Pool<Town, TownID, 64, 64000> TownPool;
+typedef Pool<Town, TownID, 64, TOWN_END> TownPool;
 extern TownPool _town_pool;
 
 /** Data structure with cached data of towns. */

src/town_gui.cpp

@@ -326,7 +326,7 @@ public:
 			}
 
 			case WID_TA_EXECUTE:
-				Command<CMD_DO_TOWN_ACTION>::Post(STR_ERROR_CAN_T_DO_THIS, this->town->xy, this->window_number, this->sel_index);
+				Command<CMD_DO_TOWN_ACTION>::Post(STR_ERROR_CAN_T_DO_THIS, this->town->xy, static_cast<TownID>(this->window_number), this->sel_index);
 				break;
 		}
 	}
@@ -521,12 +521,12 @@ public:
 				break;
 
 			case WID_TV_EXPAND: { // expand town - only available on Scenario editor
-				Command<CMD_EXPAND_TOWN>::Post(STR_ERROR_CAN_T_EXPAND_TOWN, this->window_number, 0);
+				Command<CMD_EXPAND_TOWN>::Post(STR_ERROR_CAN_T_EXPAND_TOWN, static_cast<TownID>(this->window_number), 0);
 				break;
 			}
 
 			case WID_TV_DELETE: // delete town - only available on Scenario editor
-				Command<CMD_DELETE_TOWN>::Post(STR_ERROR_TOWN_CAN_T_DELETE, this->window_number);
+				Command<CMD_DELETE_TOWN>::Post(STR_ERROR_TOWN_CAN_T_DELETE, static_cast<TownID>(this->window_number));
 				break;
 		}
 	}
@@ -615,7 +615,7 @@ public:
 	{
 		if (!str.has_value()) return;
 
-		Command<CMD_RENAME_TOWN>::Post(STR_ERROR_CAN_T_RENAME_TOWN, this->window_number, *str);
+		Command<CMD_RENAME_TOWN>::Post(STR_ERROR_CAN_T_RENAME_TOWN, static_cast<TownID>(this->window_number), *str);
 	}
 
 	IntervalTimer<TimerGameCalendar> daily_interval = {{TimerGameCalendar::DAY, TimerGameCalendar::Priority::NONE}, [this](auto) {

src/town_map.h

@@ -23,7 +23,7 @@
 inline TownID GetTownIndex(Tile t)
 {
 	assert(IsTileType(t, MP_HOUSE) || (IsTileType(t, MP_ROAD) && !IsRoadDepot(t)));
-	return t.m2();
+	return static_cast<TownID>(t.m2());
 }
 
 /**

src/town_type.h

@@ -12,8 +12,11 @@
 
 #include "core/enum_type.hpp"
 
-typedef uint16_t TownID;
+enum TownID : uint16_t {
-static const TownID INVALID_TOWN = 0xFFFF;
+	TOWN_BEGIN = 0,
+	TOWN_END = 64000,
+	INVALID_TOWN = 0xFFFF
+};
 
 struct Town;