Add wrapper class for diagonal or orthogonal tile iteration

src/landscape.cpp

@@ -786,8 +786,8 @@ CommandCost CmdClearArea(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 	const Company *c = (flags & (DC_AUTO | DC_BANKRUPT)) ? nullptr : Company::GetIfValid(_current_company);
 	int limit = (c == nullptr ? INT32_MAX : GB(c->clear_limit, 16, 16));
 
-	TileIterator *iter = HasBit(p2, 0) ? (TileIterator *)new DiagonalTileIterator(tile, p1) : new OrthogonalTileIterator(tile, p1);
+	OrthogonalOrDiagonalTileIterator iter(tile, p1, HasBit(p2, 0));
-	for (; *iter != INVALID_TILE; ++(*iter)) {
+	for (; *iter != INVALID_TILE; ++iter) {
 		TileIndex t = *iter;
 		CommandCost ret = DoCommand(t, 0, 0, flags & ~DC_EXEC, CMD_LANDSCAPE_CLEAR);
 		if (ret.Failed()) {
@@ -803,7 +803,6 @@ CommandCost CmdClearArea(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 			money -= ret.GetCost();
 			if (ret.GetCost() > 0 && money < 0) {
 				_additional_cash_required = ret.GetCost();
-				delete iter;
 				return cost;
 			}
 			DoCommand(t, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
@@ -823,7 +822,6 @@ CommandCost CmdClearArea(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 		cost.AddCost(ret);
 	}
 
-	delete iter;
 	return had_success ? cost : last_error;
 }
 

src/object_cmd.cpp

@@ -473,8 +473,8 @@ CommandCost CmdPurchaseLandArea(TileIndex tile, DoCommandFlag flags, uint32 p1,
 	const Company *c = Company::GetIfValid(_current_company);
 	int limit = (c == nullptr ? INT32_MAX : GB(c->purchase_land_limit, 16, 16));
 
-	TileIterator *iter = HasBit(p2, 0) ? (TileIterator *)new DiagonalTileIterator(tile, p1) : new OrthogonalTileIterator(tile, p1);
+	OrthogonalOrDiagonalTileIterator iter(tile, p1, HasBit(p2, 0));
-	for (; *iter != INVALID_TILE; ++(*iter)) {
+	for (; *iter != INVALID_TILE; ++iter) {
 		TileIndex t = *iter;
 		CommandCost ret = DoCommand(t, OBJECT_OWNED_LAND, 0, flags & ~DC_EXEC, CMD_BUILD_OBJECT);
 		if (ret.Failed()) {
@@ -490,7 +490,6 @@ CommandCost CmdPurchaseLandArea(TileIndex tile, DoCommandFlag flags, uint32 p1,
 			money -= ret.GetCost();
 			if (ret.GetCost() > 0 && money < 0) {
 				_additional_cash_required = ret.GetCost();
-				delete iter;
 				return cost;
 			}
 			DoCommand(t, OBJECT_OWNED_LAND, 0, flags, CMD_BUILD_OBJECT);
@@ -501,7 +500,6 @@ CommandCost CmdPurchaseLandArea(TileIndex tile, DoCommandFlag flags, uint32 p1,
 		cost.AddCost(ret);
 	}
 
-	delete iter;
 	return had_success ? cost : last_error;
 }
 
@@ -538,8 +536,8 @@ CommandCost CmdBuildObjectArea(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 	const Company *c = Company::GetIfValid(_current_company);
 	int limit = (c == nullptr ? INT32_MAX : GB(c->build_object_limit, 16, 16));
 
-	TileIterator *iter = HasBit(p2, 0) ? (TileIterator *)new DiagonalTileIterator(tile, p1) : new OrthogonalTileIterator(tile, p1);
+	OrthogonalOrDiagonalTileIterator iter(tile, p1, HasBit(p2, 0));
-	for (; *iter != INVALID_TILE; ++(*iter)) {
+	for (; *iter != INVALID_TILE; ++iter) {
 		TileIndex t = *iter;
 		CommandCost ret = DoCommand(t, type, view, flags & ~DC_EXEC, CMD_BUILD_OBJECT);
 		if (ret.Failed()) {
@@ -555,7 +553,6 @@ CommandCost CmdBuildObjectArea(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 			money -= ret.GetCost();
 			if (ret.GetCost() > 0 && money < 0) {
 				_additional_cash_required = ret.GetCost();
-				delete iter;
 				return cost;
 			}
 			DoCommand(t, type, view, flags, CMD_BUILD_OBJECT);
@@ -566,7 +563,6 @@ CommandCost CmdBuildObjectArea(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 		cost.AddCost(ret);
 	}
 
-	delete iter;
 	return had_success ? cost : last_error;
 }
 

src/rail_cmd.cpp

@@ -2411,8 +2411,8 @@ CommandCost CmdConvertRail(TileIndex tile, DoCommandFlag flags, uint32 p1, uint3
 	CommandCost error = CommandCost(STR_ERROR_NO_SUITABLE_RAILROAD_TRACK); // by default, there is no track to convert.
 	bool found_convertible_track = false; // whether we actually did convert some track (see bug #7633)
 
-	std::unique_ptr<TileIterator> iter(diagonal ? (TileIterator *)new DiagonalTileIterator(area_start, area_end) : new OrthogonalTileIterator(area_start, area_end));
+	OrthogonalOrDiagonalTileIterator iter(area_start, area_end, diagonal);
-	for (; (tile = *iter) != INVALID_TILE; ++(*iter)) {
+	for (; (tile = *iter) != INVALID_TILE; ++iter) {
 		TileType tt = GetTileType(tile);
 
 		/* Check if there is any track on tile */

src/terraform_cmd.cpp

@@ -371,8 +371,8 @@ CommandCost CmdLevelLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 	int limit = (c == nullptr ? INT32_MAX : GB(c->terraform_limit, 16, 16));
 	if (limit == 0) return_cmd_error(STR_ERROR_TERRAFORM_LIMIT_REACHED);
 
-	TileIterator *iter = HasBit(p2, 0) ? (TileIterator *)new DiagonalTileIterator(tile, p1) : new OrthogonalTileIterator(tile, p1);
+	OrthogonalOrDiagonalTileIterator iter(tile, p1, HasBit(p2, 0));
-	for (; *iter != INVALID_TILE; ++(*iter)) {
+	for (; *iter != INVALID_TILE; ++iter) {
 		TileIndex t = *iter;
 		uint curh = TileHeight(t);
 		while (curh != h) {
@@ -389,7 +389,6 @@ CommandCost CmdLevelLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 				money -= ret.GetCost();
 				if (money < 0) {
 					_additional_cash_required = ret.GetCost();
-					delete iter;
 					return cost;
 				}
 				DoCommand(t, SLOPE_N, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
@@ -413,6 +412,5 @@ CommandCost CmdLevelLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 		if (limit <= 0) break;
 	}
 
-	delete iter;
 	return had_success ? cost : last_error;
 }

src/terraform_gui.cpp

@@ -110,17 +110,11 @@ static bool IsQueryConfirmIndustryOrRailStationInArea(TileIndex start_tile, Tile
 {
 	if (_settings_client.gui.demolish_confirm_mode == DCM_OFF) return false;
 
-	std::unique_ptr<TileIterator> tile_iterator;
+	OrthogonalOrDiagonalTileIterator tile_iterator(end_tile, start_tile, diagonal);
-
-	if (diagonal) {
-		tile_iterator = std::make_unique<DiagonalTileIterator>(end_tile, start_tile);
-	} else {
-		tile_iterator = std::make_unique<OrthogonalTileIterator>(end_tile, start_tile);
-	}
 
 	bool destroying_industry_or_station = false;
 
-	for (; *tile_iterator != INVALID_TILE; ++(*tile_iterator)) {
+	for (; *tile_iterator != INVALID_TILE; ++tile_iterator) {
 		if ((_cheats.magic_bulldozer.value && IsTileType(*tile_iterator, MP_INDUSTRY)) ||
 				(_settings_client.gui.demolish_confirm_mode == DCM_INDUSTRY_RAIL_STATION && IsRailStationTile(*tile_iterator))) {
 			destroying_industry_or_station = true;

src/tilearea_type.h

@@ -305,4 +305,56 @@ public:
 	}
 };
 
+class OrthogonalOrDiagonalTileIterator {
+	union {
+		OrthogonalTileIterator ortho;
+		DiagonalTileIterator diag;
+	};
+	bool diagonal;
+
+public:
+
+	OrthogonalOrDiagonalTileIterator(TileIndex corner1, TileIndex corner2, bool diagonal) : diagonal(diagonal)
+	{
+		if (diagonal) {
+			new (&this->diag) DiagonalTileIterator(corner1, corner2);
+		} else {
+			new (&this->ortho) OrthogonalTileIterator(corner1, corner2);
+		}
+	}
+
+	~OrthogonalOrDiagonalTileIterator()
+	{
+		if (diagonal) {
+			this->diag.~DiagonalTileIterator();
+		} else {
+			this->ortho.~OrthogonalTileIterator();
+		}
+	}
+
+	inline operator TileIndex () const
+	{
+		if (diagonal) {
+			return *(this->diag);
+		} else {
+			return *(this->ortho);
+		}
+	}
+
+	inline TileIndex operator *() const
+	{
+		return (TileIndex) (*this);
+	}
+
+	OrthogonalOrDiagonalTileIterator& operator ++()
+	{
+		if (diagonal) {
+			++this->diag;
+		} else {
+			++this->ortho;
+		}
+		return *this;
+	}
+};
+
 #endif /* TILEAREA_TYPE_H */

src/water_cmd.cpp

@@ -476,8 +476,8 @@ CommandCost CmdBuildCanal(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32
 
 	CommandCost cost(EXPENSES_CONSTRUCTION);
 
-	std::unique_ptr<TileIterator> iter(HasBit(p2, 2) ? (TileIterator *)new DiagonalTileIterator(tile, p1) : new OrthogonalTileIterator(tile, p1));
+	OrthogonalOrDiagonalTileIterator iter(tile, p1, HasBit(p2, 2));
-	for (; *iter != INVALID_TILE; ++(*iter)) {
+	for (; *iter != INVALID_TILE; ++iter) {
 		TileIndex current_tile = *iter;
 		CommandCost ret;