Codechange: use Label for NewGRF class global ids

src/core/CMakeLists.txt

@@ -13,6 +13,8 @@ add_files(
     geometry_func.hpp
     geometry_type.hpp
     kdtree.hpp
+    label.cpp
+    label_type.hpp
     math_func.cpp
     math_func.hpp
     multimap.hpp

src/core/label.cpp

@@ -0,0 +1,29 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
+ */
+
+/** @file label.cpp Implementation of label functions. */
+
+#include "../stdafx.h"
+#include "label_type.hpp"
+#include "../string_func.h"
+
+#include "../safeguards.h"
+
+/**
+ * Get the label as a \c std::string.
+ * If the label is all \c std::isgraph characters, it will return these characters as string,
+ * otherwise it will format it as a 8-digit hexadecimal.
+ * @return The label as string.
+ */
+std::string BaseLabel::AsString() const
+{
+	if (std::ranges::all_of(*this, [](uint8_t c) { return std::isgraph(c); })) {
+		return std::string{reinterpret_cast<const char *>(this->data()), this->size()};
+	}
+
+	return FormatArrayAsHex(*this);
+}

src/core/label_type.hpp

@@ -0,0 +1,72 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
+ */
+
+/** @file label_type.hpp A type for 4 character labels/tags/ids in files that should be read/shown as is. */
+
+#ifndef LABEL_TYPE_HPP
+#define LABEL_TYPE_HPP
+
+/** Base for a four character label/tag/id. */
+struct BaseLabel : std::array<uint8_t, 4> {
+	/**
+	 * Check whether the label is empty.
+	 * @return \c true iff the label is empty, i.e. all zeros.
+	 */
+	constexpr inline bool Empty() const
+	{
+		return std::ranges::all_of(*this, [](uint8_t b) { return b == 0; });
+	};
+
+	/**
+	 * Get the label as a \c std::string.
+	 * If the label is all \c std::isgraph characters, it will return these characters as string,
+	 * otherwise it will format it as a 8-digit hexadecimal.
+	 * @return The label as string.
+	 */
+	std::string AsString() const;
+};
+
+/**
+ * A four character label/tag/id.
+ * @tparam Tag Type to distinguish labels/tags/ids of different types.
+ */
+template <typename Tag>
+struct Label : BaseLabel {
+	/** Create an empty label, i.e. all zeros. */
+	constexpr Label()
+	{
+		std::ranges::fill(*this, 0);
+	}
+
+	/**
+	 * Create a label with the given 4 letter character string.
+	 * @param label The label value.
+	 * @note This defines 5 characters, but the 5th character is assumed to null-terminator.
+	 */
+	constexpr Label(const char (&label)[5])
+	{
+		std::copy(label, label + this->size(), this->begin());
+	}
+
+	/**
+	 * Create a label with the given 4 bytes.
+	 * @param label The label value.
+	 */
+	constexpr Label(const uint8_t (&label)[4])
+	{
+		std::copy(label, label + this->size(), this->begin());
+	}
+
+	/**
+	 * Default spaceship operator.
+	 * @param other The label to compare to.
+	 * @return The comparison ordering.
+	 */
+	constexpr std::strong_ordering operator<=>(const Label<Tag> &other) const = default;
+};
+
+#endif /* LABEL_TYPE_HPP */

src/newgrf/newgrf_act0_objects.cpp

@@ -96,7 +96,7 @@ static ChangeInfoResult ObjectChangeInfo(uint first, uint last, int prop, ByteRe
 		}
 
 		switch (prop) {
-			case 0x08: { // Class ID
+			case 0x08: // Class ID
 				/* Allocate space for this object. */
 				if (spec == nullptr) {
 					spec = std::make_unique<ObjectSpec>();
@@ -104,16 +104,12 @@ static ChangeInfoResult ObjectChangeInfo(uint first, uint last, int prop, ByteRe
 					spec->size = OBJECT_SIZE_1X1; // Default for NewGRFs that manage to not set it (1x1)
 				}
 
-				/* Swap classid because we read it in BE. */
-				uint32_t classid = buf.ReadDWord();
-				spec->class_index = ObjectClass::Allocate(std::byteswap(classid));
+				spec->class_index = ObjectClass::Allocate(buf.ReadLabel<ObjectClass::GlobalID>());
 				break;
-			}
 
-			case 0x09: { // Class name
+			case 0x09: // Class name
 				AddStringForMapping(GRFStringID{buf.ReadWord()}, [spec = spec.get()](StringID str) { ObjectClass::Get(spec->class_index)->name = str; });
 				break;
-			}
 
 			case 0x0A: // Object name
 				AddStringForMapping(GRFStringID{buf.ReadWord()}, &spec->name);

src/newgrf/newgrf_act0_roadstops.cpp

@@ -88,15 +88,13 @@ static ChangeInfoResult RoadStopChangeInfo(uint first, uint last, int prop, Byte
 		}
 
 		switch (prop) {
-			case 0x08: { // Road Stop Class ID
+			case 0x08: // Road Stop Class ID
 				if (rs == nullptr) {
 					rs = std::make_unique<RoadStopSpec>();
 				}
 
-				uint32_t classid = buf.ReadDWord();
-				rs->class_index = RoadStopClass::Allocate(std::byteswap(classid));
+				rs->class_index = RoadStopClass::Allocate(buf.ReadLabel<RoadStopClass::GlobalID>());
 				break;
-			}
 
 			case 0x09: // Road stop type
 				rs->stop_type = (RoadStopAvailabilityType)buf.ReadByte();

src/newgrf/newgrf_act0_stations.cpp

@@ -49,17 +49,14 @@ static ChangeInfoResult StationChangeInfo(uint first, uint last, int prop, ByteR
 		}
 
 		switch (prop) {
-			case 0x08: { // Class ID
+			case 0x08: // Class ID
 				/* Property 0x08 is special; it is where the station is allocated */
 				if (statspec == nullptr) {
 					statspec = std::make_unique<StationSpec>();
 				}
 
-				/* Swap classid because we read it in BE meaning WAYP or DFLT */
-				uint32_t classid = buf.ReadDWord();
-				statspec->class_index = StationClass::Allocate(std::byteswap(classid));
+				statspec->class_index = StationClass::Allocate(buf.ReadLabel<StationClass::GlobalID>());
 				break;
-			}
 
 			case 0x09: { // Define sprite layout
 				uint16_t tiles = buf.ReadExtendedByte();

src/newgrf/newgrf_bytereader.h

@@ -10,6 +10,7 @@
 #ifndef NEWGRF_BYTEREADER_H
 #define NEWGRF_BYTEREADER_H
 
+#include "../core/label_type.hpp"
 #include "../core/string_consumer.hpp"
 
 class OTTDByteReaderSignal { };
@@ -94,6 +95,18 @@ public:
 		return this->consumer.ReadUntilChar('\0', StringConsumer::SKIP_ONE_SEPARATOR);
 	}
 
+	/**
+	 * Read a label.
+	 * @return The read label.
+	 */
+	template <typename T> requires std::is_base_of_v<BaseLabel, T>
+	T ReadLabel()
+	{
+		T label{};
+		std::ranges::copy(this->consumer.Read(label.size()), label.data());
+		return label;
+	}
+
 	size_t Remaining() const
 	{
 		return this->consumer.GetBytesLeft();

src/newgrf_airport.cpp

@@ -30,10 +30,10 @@
 template <>
 /* static */ void AirportClass::InsertDefaults()
 {
-	AirportClass::Get(AirportClass::Allocate('SMAL'))->name = STR_AIRPORT_CLASS_SMALL;
-	AirportClass::Get(AirportClass::Allocate('LARG'))->name = STR_AIRPORT_CLASS_LARGE;
-	AirportClass::Get(AirportClass::Allocate('HUB_'))->name = STR_AIRPORT_CLASS_HUB;
-	AirportClass::Get(AirportClass::Allocate('HELI'))->name = STR_AIRPORT_CLASS_HELIPORTS;
+	AirportClass::Get(AirportClass::Allocate("SMAL"))->name = STR_AIRPORT_CLASS_SMALL;
+	AirportClass::Get(AirportClass::Allocate("LARG"))->name = STR_AIRPORT_CLASS_LARGE;
+	AirportClass::Get(AirportClass::Allocate("HUB_"))->name = STR_AIRPORT_CLASS_HUB;
+	AirportClass::Get(AirportClass::Allocate("HELI"))->name = STR_AIRPORT_CLASS_HELIPORTS;
 }
 
 template <>

src/newgrf_class.h

@@ -10,6 +10,7 @@
 #ifndef NEWGRF_CLASS_H
 #define NEWGRF_CLASS_H
 
+#include "core/label_type.hpp"
 #include "newgrf_type.h"
 #include "strings_type.h"
 
@@ -45,12 +46,17 @@ private:
 public:
 	using spec_type = Tspec;
 	using index_type = Tindex;
+	using GlobalID = Label<NewGRFClass<Tspec, Tindex>>; ///< Type for the global identifier of the class.
 
-	uint32_t global_id; ///< Global ID for class, e.g. 'DFLT', 'WAYP', etc.
-	StringID name;    ///< Name of this class.
+	GlobalID global_id; ///< Global ID for class, e.g. 'DFLT', 'WAYP', etc.
+	StringID name; ///< Name of this class.
 
-	/* Public constructor as emplace_back needs access. */
-	NewGRFClass(uint32_t global_id, StringID name) : global_id(global_id), name(name) { }
+	/**
+	 * Create the class.
+	 * @param global_id The globally unique identifier of the class.
+	 * @param name The name of the class.
+	 */
+	NewGRFClass(GlobalID global_id, StringID name) : global_id(global_id), name(name) { }
 
 	/**
 	 * Get read-only span of specs of this class.
@@ -90,7 +96,7 @@ public:
 	bool IsUIAvailable(uint index) const;
 
 	static void Reset();
-	static Tindex Allocate(uint32_t global_id);
+	static Tindex Allocate(GlobalID global_id);
 	static void Assign(Tspec *spec);
 	static uint GetClassCount();
 	static uint GetUIClassCount();

src/newgrf_class_func.h

@@ -29,7 +29,7 @@ void NewGRFClass<Tspec, Tindex>::Reset()
  *       second time, this first allocation will be given.
  */
 template <typename Tspec, typename Tindex>
-Tindex NewGRFClass<Tspec, Tindex>::Allocate(uint32_t global_id)
+Tindex NewGRFClass<Tspec, Tindex>::Allocate(GlobalID global_id)
 {
 	auto found = std::ranges::find(NewGRFClass::classes, global_id, &NewGRFClass::global_id);
 

src/newgrf_object.cpp

@@ -136,8 +136,8 @@ void ResetObjects()
 	}
 
 	/* Set class for originals. */
-	_object_specs[OBJECT_LIGHTHOUSE].class_index = ObjectClass::Allocate('LTHS');
-	_object_specs[OBJECT_TRANSMITTER].class_index = ObjectClass::Allocate('TRNS');
+	_object_specs[OBJECT_LIGHTHOUSE].class_index = ObjectClass::Allocate("LTHS");
+	_object_specs[OBJECT_TRANSMITTER].class_index = ObjectClass::Allocate("TRNS");
 
 	/* Reset any overrides that have been set. */
 	_object_mngr.ResetOverride();
@@ -146,8 +146,8 @@ void ResetObjects()
 template <>
 /* static */ void ObjectClass::InsertDefaults()
 {
-	ObjectClass::Get(ObjectClass::Allocate('LTHS'))->name = STR_OBJECT_CLASS_LTHS;
-	ObjectClass::Get(ObjectClass::Allocate('TRNS'))->name = STR_OBJECT_CLASS_TRNS;
+	ObjectClass::Get(ObjectClass::Allocate("LTHS"))->name = STR_OBJECT_CLASS_LTHS;
+	ObjectClass::Get(ObjectClass::Allocate("TRNS"))->name = STR_OBJECT_CLASS_TRNS;
 }
 
 template <>

src/newgrf_roadstop.h

@@ -25,9 +25,6 @@ struct TileInfo;
 /** The maximum amount of roadstops a single GRF is allowed to add */
 static const int NUM_ROADSTOPS_PER_GRF = UINT16_MAX - 1;
 
-static const uint32_t ROADSTOP_CLASS_LABEL_DEFAULT = 'DFLT';
-static const uint32_t ROADSTOP_CLASS_LABEL_WAYPOINT = 'WAYP';
-
 /** Class IDs for stations. */
 using RoadStopClassID = PoolID<uint16_t, struct RoadStopClassIDTag, UINT16_MAX, UINT16_MAX>;
 
@@ -164,6 +161,9 @@ struct RoadStopSpec : NewGRFSpecBase<RoadStopClassID> {
 
 using RoadStopClass = NewGRFClass<RoadStopSpec, RoadStopClassID>;
 
+static const RoadStopClass::GlobalID ROADSTOP_CLASS_LABEL_DEFAULT{"DFLT"}; ///< Class label for default road stops.
+static const RoadStopClass::GlobalID ROADSTOP_CLASS_LABEL_WAYPOINT{"WAYP"}; ///< Class label for default road waypoints.
+
 std::optional<SpriteLayoutProcessor> GetRoadStopLayout(TileInfo *ti, const RoadStopSpec *spec, BaseStation *st, StationType type, int view, std::span<int32_t> regs100 = {});
 void DrawRoadStopTile(int x, int y, RoadType roadtype, const RoadStopSpec *spec, StationType type, int view);
 
@@ -191,7 +191,7 @@ void RoadStopUpdateCachedTriggers(BaseStation *st);
  */
 inline bool IsWaypointClass(const RoadStopClass &cls)
 {
-	return cls.global_id == ROADSTOP_CLASS_LABEL_WAYPOINT || GB(cls.global_id, 24, 8) == UINT8_MAX;
+	return cls.global_id == ROADSTOP_CLASS_LABEL_WAYPOINT || cls.global_id[0] == UINT8_MAX;
 }
 
 #endif /* NEWGRF_ROADSTATION_H */

src/newgrf_station.h

@@ -98,9 +98,6 @@ struct StationResolverObject : public SpecializedResolverObject<StationRandomTri
 	uint32_t GetDebugID() const override;
 };
 
-static const uint32_t STATION_CLASS_LABEL_DEFAULT = 'DFLT';
-static const uint32_t STATION_CLASS_LABEL_WAYPOINT = 'WAYP';
-
 /** Class IDs for stations. */
 using StationClassID = PoolID<uint16_t, struct StationClassIDTag, UINT16_MAX, UINT16_MAX>;
 
@@ -188,6 +185,9 @@ struct StationSpec : NewGRFSpecBase<StationClassID> {
 /** Class containing information relating to station classes. */
 using StationClass = NewGRFClass<StationSpec, StationClassID>;
 
+static const StationClass::GlobalID STATION_CLASS_LABEL_DEFAULT{"DFLT"}; ///< Class label for default rail station.
+static const StationClass::GlobalID STATION_CLASS_LABEL_WAYPOINT{"WAYP"}; ///< Class label for default rail waypoints.
+
 const StationSpec *GetStationSpec(TileIndex t);
 
 /**
@@ -208,7 +208,7 @@ inline uint16_t GetStationLayoutKey(uint8_t platforms, uint8_t length)
  */
 inline bool IsWaypointClass(const StationClass &cls)
 {
-	return cls.global_id == STATION_CLASS_LABEL_WAYPOINT || GB(cls.global_id, 24, 8) == UINT8_MAX;
+	return cls.global_id == STATION_CLASS_LABEL_WAYPOINT || cls.global_id[0] == UINT8_MAX;
 }
 
 /* Evaluate a tile's position within a station, and return the result a bitstuffed format. */

src/saveload/ai_sl.cpp

@@ -73,7 +73,7 @@ static void SaveReal_AIPL(int arg)
 }
 
 struct AIPLChunkHandler : ChunkHandler {
-	AIPLChunkHandler() : ChunkHandler('AIPL', ChunkType::Table) {}
+	AIPLChunkHandler() : ChunkHandler("AIPL", ChunkType::Table) {}
 
 	void Load() const override
 	{

src/saveload/airport_sl.cpp

@@ -15,11 +15,11 @@
 #include "../safeguards.h"
 
 struct APIDChunkHandler : NewGRFMappingChunkHandler {
-	APIDChunkHandler() : NewGRFMappingChunkHandler('APID', _airport_mngr) {}
+	APIDChunkHandler() : NewGRFMappingChunkHandler("APID", _airport_mngr) {}
 };
 
 struct ATIDChunkHandler : NewGRFMappingChunkHandler {
-	ATIDChunkHandler() : NewGRFMappingChunkHandler('ATID', _airporttile_mngr) {}
+	ATIDChunkHandler() : NewGRFMappingChunkHandler("ATID", _airporttile_mngr) {}
 };
 
 static const ATIDChunkHandler ATID;

src/saveload/animated_tile_sl.cpp

@@ -23,7 +23,7 @@ static const SaveLoad _animated_tile_desc[] = {
 };
 
 struct ANITChunkHandler : ChunkHandler {
-	ANITChunkHandler() : ChunkHandler('ANIT', ChunkType::Table) {}
+	ANITChunkHandler() : ChunkHandler("ANIT", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/autoreplace_sl.cpp

@@ -26,7 +26,7 @@ static const SaveLoad _engine_renew_desc[] = {
 };
 
 struct ERNWChunkHandler : ChunkHandler {
-	ERNWChunkHandler() : ChunkHandler('ERNW', ChunkType::Table) {}
+	ERNWChunkHandler() : ChunkHandler("ERNW", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/cargomonitor_sl.cpp

@@ -45,7 +45,7 @@ static CargoMonitorID FixupCargoMonitor(CargoMonitorID number)
 
 /** #_cargo_deliveries monitoring map. */
 struct CMDLChunkHandler : ChunkHandler {
-	CMDLChunkHandler() : ChunkHandler('CMDL', ChunkType::Table) {}
+	CMDLChunkHandler() : ChunkHandler("CMDL", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -88,7 +88,7 @@ struct CMDLChunkHandler : ChunkHandler {
 
 /** #_cargo_pickups monitoring map. */
 struct CMPUChunkHandler : ChunkHandler {
-	CMPUChunkHandler() : ChunkHandler('CMPU', ChunkType::Table) {}
+	CMPUChunkHandler() : ChunkHandler("CMPU", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/cargopacket_sl.cpp

@@ -143,7 +143,7 @@ SaveLoadTable GetCargoPacketDesc()
 }
 
 struct CAPAChunkHandler : ChunkHandler {
-	CAPAChunkHandler() : ChunkHandler('CAPA', ChunkType::Table) {}
+	CAPAChunkHandler() : ChunkHandler("CAPA", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/cheat_sl.cpp

@@ -39,7 +39,7 @@ static const SaveLoad _cheats_desc[] = {
 
 
 struct CHTSChunkHandler : ChunkHandler {
-	CHTSChunkHandler() : ChunkHandler('CHTS', ChunkType::Table) {}
+	CHTSChunkHandler() : ChunkHandler("CHTS", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/company_sl.cpp

@@ -551,7 +551,7 @@ static const SaveLoad _company_desc[] = {
 };
 
 struct PLYRChunkHandler : ChunkHandler {
-	PLYRChunkHandler() : ChunkHandler('PLYR', ChunkType::Table) {}
+	PLYRChunkHandler() : ChunkHandler("PLYR", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/depot_sl.cpp

@@ -30,7 +30,7 @@ static const SaveLoad _depot_desc[] = {
 };
 
 struct DEPTChunkHandler : ChunkHandler {
-	DEPTChunkHandler() : ChunkHandler('DEPT', ChunkType::Table) {}
+	DEPTChunkHandler() : ChunkHandler("DEPT", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/economy_sl.cpp

@@ -19,7 +19,7 @@
 
 /** Prices in pre 126 savegames */
 struct PRICChunkHandler : ChunkHandler {
-	PRICChunkHandler() : ChunkHandler('PRIC', ChunkType::ReadOnly) {}
+	PRICChunkHandler() : ChunkHandler("PRIC", ChunkType::ReadOnly) {}
 
 	void Load() const override
 	{
@@ -32,7 +32,7 @@ struct PRICChunkHandler : ChunkHandler {
 
 /** Cargo payment rates in pre 126 savegames */
 struct CAPRChunkHandler : ChunkHandler {
-	CAPRChunkHandler() : ChunkHandler('CAPR', ChunkType::ReadOnly) {}
+	CAPRChunkHandler() : ChunkHandler("CAPR", ChunkType::ReadOnly) {}
 
 	void Load() const override
 	{
@@ -58,7 +58,7 @@ static const SaveLoad _economy_desc[] = {
 
 /** Economy variables */
 struct ECMYChunkHandler : ChunkHandler {
-	ECMYChunkHandler() : ChunkHandler('ECMY', ChunkType::Table) {}
+	ECMYChunkHandler() : ChunkHandler("ECMY", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -89,7 +89,7 @@ static const SaveLoad _cargopayment_desc[] = {
 };
 
 struct CAPYChunkHandler : ChunkHandler {
-	CAPYChunkHandler() : ChunkHandler('CAPY', ChunkType::Table) {}
+	CAPYChunkHandler() : ChunkHandler("CAPY", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/engine_sl.cpp

@@ -62,7 +62,7 @@ Engine *GetTempDataEngine(EngineID index, VehicleType type, uint16_t local_id)
 }
 
 struct ENGNChunkHandler : ChunkHandler {
-	ENGNChunkHandler() : ChunkHandler('ENGN', ChunkType::Table) {}
+	ENGNChunkHandler() : ChunkHandler("ENGN", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -135,7 +135,7 @@ void ResetTempEngineData()
 }
 
 struct ENGSChunkHandler : ChunkHandler {
-	ENGSChunkHandler() : ChunkHandler('ENGS', ChunkType::ReadOnly) {}
+	ENGSChunkHandler() : ChunkHandler("ENGS", ChunkType::ReadOnly) {}
 
 	void Load() const override
 	{
@@ -162,7 +162,7 @@ static const SaveLoad _engine_id_mapping_desc[] = {
 };
 
 struct EIDSChunkHandler : ChunkHandler {
-	EIDSChunkHandler() : ChunkHandler('EIDS', ChunkType::Table) {}
+	EIDSChunkHandler() : ChunkHandler("EIDS", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/game_sl.cpp

@@ -52,7 +52,7 @@ static void SaveReal_GSDT(int)
 }
 
 struct GSDTChunkHandler : ChunkHandler {
-	GSDTChunkHandler() : ChunkHandler('GSDT', ChunkType::Table) {}
+	GSDTChunkHandler() : ChunkHandler("GSDT", ChunkType::Table) {}
 
 	void Load() const override
 	{
@@ -153,7 +153,7 @@ static const SaveLoad _game_language_desc[] = {
 };
 
 struct GSTRChunkHandler : ChunkHandler {
-	GSTRChunkHandler() : ChunkHandler('GSTR', ChunkType::Table) {}
+	GSTRChunkHandler() : ChunkHandler("GSTR", ChunkType::Table) {}
 
 	void Load() const override
 	{

src/saveload/gamelog_sl.cpp

@@ -375,7 +375,7 @@ static const SaveLoad _gamelog_desc[] = {
 };
 
 struct GLOGChunkHandler : ChunkHandler {
-	GLOGChunkHandler() : ChunkHandler('GLOG', ChunkType::Table) {}
+	GLOGChunkHandler() : ChunkHandler("GLOG", ChunkType::Table) {}
 
 	void LoadCommon(Gamelog &gamelog) const
 	{

src/saveload/goal_sl.cpp

@@ -26,7 +26,7 @@ static const SaveLoad _goals_desc[] = {
 };
 
 struct GOALChunkHandler : ChunkHandler {
-	GOALChunkHandler() : ChunkHandler('GOAL', ChunkType::Table) {}
+	GOALChunkHandler() : ChunkHandler("GOAL", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/group_sl.cpp

@@ -30,7 +30,7 @@ static const SaveLoad _group_desc[] = {
 };
 
 struct GRPSChunkHandler : ChunkHandler {
-	GRPSChunkHandler() : ChunkHandler('GRPS', ChunkType::Table) {}
+	GRPSChunkHandler() : ChunkHandler("GRPS", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/industry_sl.cpp

@@ -211,7 +211,7 @@ static const SaveLoad _industry_desc[] = {
 };
 
 struct INDYChunkHandler : ChunkHandler {
-	INDYChunkHandler() : ChunkHandler('INDY', ChunkType::Table) {}
+	INDYChunkHandler() : ChunkHandler("INDY", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -303,11 +303,11 @@ struct INDYChunkHandler : ChunkHandler {
 };
 
 struct IIDSChunkHandler : NewGRFMappingChunkHandler {
-	IIDSChunkHandler() : NewGRFMappingChunkHandler('IIDS', _industry_mngr) {}
+	IIDSChunkHandler() : NewGRFMappingChunkHandler("IIDS", _industry_mngr) {}
 };
 
 struct TIDSChunkHandler : NewGRFMappingChunkHandler {
-	TIDSChunkHandler() : NewGRFMappingChunkHandler('TIDS', _industile_mngr) {}
+	TIDSChunkHandler() : NewGRFMappingChunkHandler("TIDS", _industile_mngr) {}
 };
 
 /** Description of the data to save and load in #IndustryBuildData. */
@@ -317,7 +317,7 @@ static const SaveLoad _industry_builder_desc[] = {
 
 /** Industry builder. */
 struct IBLDChunkHandler : ChunkHandler {
-	IBLDChunkHandler() : ChunkHandler('IBLD', ChunkType::Table) {}
+	IBLDChunkHandler() : ChunkHandler("IBLD", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -348,7 +348,7 @@ static const SaveLoad _industrytype_builder_desc[] = {
 
 /** Industry-type build data. */
 struct ITBLChunkHandler : ChunkHandler {
-	ITBLChunkHandler() : ChunkHandler('ITBL', ChunkType::Table) {}
+	ITBLChunkHandler() : ChunkHandler("ITBL", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/labelmaps_sl.cpp

@@ -34,7 +34,7 @@ void AfterLoadLabelMaps()
 }
 
 struct RAILChunkHandler : ChunkHandler {
-	RAILChunkHandler() : ChunkHandler('RAIL', ChunkType::Table) {}
+	RAILChunkHandler() : ChunkHandler("RAIL", ChunkType::Table) {}
 
 	static inline const SaveLoad description[] = {
 		SLE_VAR(LabelObject<RailTypeLabel>, label, VarTypes::U32),
@@ -69,7 +69,7 @@ struct RAILChunkHandler : ChunkHandler {
 };
 
 struct ROTTChunkHandler : ChunkHandler {
-	ROTTChunkHandler() : ChunkHandler('ROTT', ChunkType::Table) {}
+	ROTTChunkHandler() : ChunkHandler("ROTT", ChunkType::Table) {}
 
 	static inline const SaveLoad description[] = {
 		SLE_VAR(LabelObject<RoadTypeLabel>, label, VarTypes::U32),

src/saveload/league_sl.cpp

@@ -27,7 +27,7 @@ static const SaveLoad _league_table_elements_desc[] = {
 };
 
 struct LEAEChunkHandler : ChunkHandler {
-	LEAEChunkHandler() : ChunkHandler('LEAE', ChunkType::Table) {}
+	LEAEChunkHandler() : ChunkHandler("LEAE", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -58,7 +58,7 @@ static const SaveLoad _league_tables_desc[] = {
 };
 
 struct LEATChunkHandler : ChunkHandler {
-	LEATChunkHandler() : ChunkHandler('LEAT', ChunkType::Table) {}
+	LEATChunkHandler() : ChunkHandler("LEAT", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/linkgraph_sl.cpp

@@ -259,7 +259,7 @@ void AfterLoadLinkGraphs()
  * All link graphs.
  */
 struct LGRPChunkHandler : ChunkHandler {
-	LGRPChunkHandler() : ChunkHandler('LGRP', ChunkType::Table) {}
+	LGRPChunkHandler() : ChunkHandler("LGRP", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -287,7 +287,7 @@ struct LGRPChunkHandler : ChunkHandler {
  * All link graph jobs.
  */
 struct LGRJChunkHandler : ChunkHandler {
-	LGRJChunkHandler() : ChunkHandler('LGRJ', ChunkType::Table) {}
+	LGRJChunkHandler() : ChunkHandler("LGRJ", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -315,7 +315,7 @@ struct LGRJChunkHandler : ChunkHandler {
  * Link graph schedule.
  */
 struct LGRSChunkHandler : ChunkHandler {
-	LGRSChunkHandler() : ChunkHandler('LGRS', ChunkType::Table) {}
+	LGRSChunkHandler() : ChunkHandler("LGRS", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/map_sl.cpp

@@ -27,7 +27,7 @@ static const SaveLoad _map_desc[] = {
 };
 
 struct MAPSChunkHandler : ChunkHandler {
-	MAPSChunkHandler() : ChunkHandler('MAPS', ChunkType::Table) {}
+	MAPSChunkHandler() : ChunkHandler("MAPS", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -67,7 +67,7 @@ struct MAPSChunkHandler : ChunkHandler {
 static const uint MAP_SL_BUF_SIZE = 4096;
 
 struct MAPTChunkHandler : ChunkHandler {
-	MAPTChunkHandler() : ChunkHandler('MAPT', ChunkType::Riff) {}
+	MAPTChunkHandler() : ChunkHandler("MAPT", ChunkType::Riff) {}
 
 	void Load() const override
 	{
@@ -94,7 +94,7 @@ struct MAPTChunkHandler : ChunkHandler {
 };
 
 struct MAPHChunkHandler : ChunkHandler {
-	MAPHChunkHandler() : ChunkHandler('MAPH', ChunkType::Riff) {}
+	MAPHChunkHandler() : ChunkHandler("MAPH", ChunkType::Riff) {}
 
 	void Load() const override
 	{
@@ -121,7 +121,7 @@ struct MAPHChunkHandler : ChunkHandler {
 };
 
 struct MAPOChunkHandler : ChunkHandler {
-	MAPOChunkHandler() : ChunkHandler('MAPO', ChunkType::Riff) {}
+	MAPOChunkHandler() : ChunkHandler("MAPO", ChunkType::Riff) {}
 
 	void Load() const override
 	{
@@ -148,7 +148,7 @@ struct MAPOChunkHandler : ChunkHandler {
 };
 
 struct MAP2ChunkHandler : ChunkHandler {
-	MAP2ChunkHandler() : ChunkHandler('MAP2', ChunkType::Riff) {}
+	MAP2ChunkHandler() : ChunkHandler("MAP2", ChunkType::Riff) {}
 
 	void Load() const override
 	{
@@ -178,7 +178,7 @@ struct MAP2ChunkHandler : ChunkHandler {
 };
 
 struct M3LOChunkHandler : ChunkHandler {
-	M3LOChunkHandler() : ChunkHandler('M3LO', ChunkType::Riff) {}
+	M3LOChunkHandler() : ChunkHandler("M3LO", ChunkType::Riff) {}
 
 	void Load() const override
 	{
@@ -205,7 +205,7 @@ struct M3LOChunkHandler : ChunkHandler {
 };
 
 struct M3HIChunkHandler : ChunkHandler {
-	M3HIChunkHandler() : ChunkHandler('M3HI', ChunkType::Riff) {}
+	M3HIChunkHandler() : ChunkHandler("M3HI", ChunkType::Riff) {}
 
 	void Load() const override
 	{
@@ -232,7 +232,7 @@ struct M3HIChunkHandler : ChunkHandler {
 };
 
 struct MAP5ChunkHandler : ChunkHandler {
-	MAP5ChunkHandler() : ChunkHandler('MAP5', ChunkType::Riff) {}
+	MAP5ChunkHandler() : ChunkHandler("MAP5", ChunkType::Riff) {}
 
 	void Load() const override
 	{
@@ -259,7 +259,7 @@ struct MAP5ChunkHandler : ChunkHandler {
 };
 
 struct MAPEChunkHandler : ChunkHandler {
-	MAPEChunkHandler() : ChunkHandler('MAPE', ChunkType::Riff) {}
+	MAPEChunkHandler() : ChunkHandler("MAPE", ChunkType::Riff) {}
 
 	void Load() const override
 	{
@@ -299,7 +299,7 @@ struct MAPEChunkHandler : ChunkHandler {
 };
 
 struct MAP7ChunkHandler : ChunkHandler {
-	MAP7ChunkHandler() : ChunkHandler('MAP7', ChunkType::Riff) {}
+	MAP7ChunkHandler() : ChunkHandler("MAP7", ChunkType::Riff) {}
 
 	void Load() const override
 	{
@@ -326,7 +326,7 @@ struct MAP7ChunkHandler : ChunkHandler {
 };
 
 struct MAP8ChunkHandler : ChunkHandler {
-	MAP8ChunkHandler() : ChunkHandler('MAP8', ChunkType::Riff) {}
+	MAP8ChunkHandler() : ChunkHandler("MAP8", ChunkType::Riff) {}
 
 	void Load() const override
 	{

src/saveload/misc_sl.cpp

@@ -121,7 +121,7 @@ static const SaveLoad _date_check_desc[] = {
  * @note currently some unrelated stuff is just put here.
  */
 struct DATEChunkHandler : ChunkHandler {
-	DATEChunkHandler() : ChunkHandler('DATE', ChunkType::Table) {}
+	DATEChunkHandler() : ChunkHandler("DATE", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -165,7 +165,7 @@ static const SaveLoad _view_desc[] = {
 };
 
 struct VIEWChunkHandler : ChunkHandler {
-	VIEWChunkHandler() : ChunkHandler('VIEW', ChunkType::Table) {}
+	VIEWChunkHandler() : ChunkHandler("VIEW", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/newgrf_sl.cpp

@@ -62,7 +62,7 @@ void NewGRFMappingChunkHandler::Load() const
 }
 
 struct NGRFChunkHandler : ChunkHandler {
-	NGRFChunkHandler() : ChunkHandler('NGRF', ChunkType::Table) {}
+	NGRFChunkHandler() : ChunkHandler("NGRF", ChunkType::Table) {}
 
 	static inline std::array<uint32_t, GRFConfig::MAX_NUM_PARAMS> param;
 	static inline uint8_t num_params;

src/saveload/newgrf_sl.h

@@ -13,10 +13,16 @@
 #include "../newgrf_commons.h"
 #include "saveload.h"
 
+/** Chunk handler for data of the OverrideManagerBase. */
 struct NewGRFMappingChunkHandler : ChunkHandler {
-	OverrideManagerBase &mapping;
+	OverrideManagerBase &mapping; ///< The override manager to save/load.
 
-	NewGRFMappingChunkHandler(uint32_t id, OverrideManagerBase &mapping) : ChunkHandler(id, ChunkType::Table), mapping(mapping) {}
+	/**
+	 * Create the handler.
+	 * @param id The identifier of the chunk
+	 * @param mapping The override manager to save/load.
+	 */
+	NewGRFMappingChunkHandler(ChunkId id, OverrideManagerBase &mapping) : ChunkHandler(id, ChunkType::Table), mapping(mapping) {}
 	void Save() const override;
 	void Load() const override;
 };

src/saveload/object_sl.cpp

@@ -30,7 +30,7 @@ static const SaveLoad _object_desc[] = {
 };
 
 struct OBJSChunkHandler : ChunkHandler {
-	OBJSChunkHandler() : ChunkHandler('OBJS', ChunkType::Table) {}
+	OBJSChunkHandler() : ChunkHandler("OBJS", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -67,7 +67,7 @@ struct OBJSChunkHandler : ChunkHandler {
 };
 
 struct OBIDChunkHandler : NewGRFMappingChunkHandler {
-	OBIDChunkHandler() : NewGRFMappingChunkHandler('OBID', _object_mngr) {}
+	OBIDChunkHandler() : NewGRFMappingChunkHandler("OBID", _object_mngr) {}
 };
 
 static const OBIDChunkHandler OBID;

src/saveload/order_sl.cpp

@@ -159,7 +159,7 @@ SaveLoadTable GetOrderDescription()
 }
 
 struct ORDRChunkHandler : ChunkHandler {
-	ORDRChunkHandler() : ChunkHandler('ORDR', ChunkType::ReadOnly) {}
+	ORDRChunkHandler() : ChunkHandler("ORDR", ChunkType::ReadOnly) {}
 
 	void Load() const override
 	{
@@ -249,7 +249,7 @@ SaveLoadTable GetOrderListDescription()
 }
 
 struct ORDLChunkHandler : ChunkHandler {
-	ORDLChunkHandler() : ChunkHandler('ORDL', ChunkType::Table) {}
+	ORDLChunkHandler() : ChunkHandler("ORDL", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -320,7 +320,7 @@ SaveLoadTable GetOrderBackupDescription()
 }
 
 struct BKORChunkHandler : ChunkHandler {
-	BKORChunkHandler() : ChunkHandler('BKOR', ChunkType::Table) {}
+	BKORChunkHandler() : ChunkHandler("BKOR", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/randomizer_sl.cpp

@@ -19,7 +19,7 @@ static const SaveLoad _randomizer_desc[] = {
 };
 
 struct SRNDChunkHandler : ChunkHandler {
-	SRNDChunkHandler() : ChunkHandler('SRND', ChunkType::Table)
+	SRNDChunkHandler() : ChunkHandler("SRND", ChunkType::Table)
 	{}
 
 	void Save() const override

src/saveload/saveload.cpp

@@ -458,6 +458,17 @@ static inline void SlWriteUint64(uint64_t x)
 	SlWriteUint32(static_cast<uint32_t>(x));
 }
 
+/**
+ * Read the \c ChunkId.
+ * @return The read \c ChunkId.
+ */
+static inline ChunkId SlReadChunkId()
+{
+	ChunkId label{};
+	for (uint8_t &b : label) b = SlReadByte();
+	return label;
+}
+
 /**
  * Read in the header descriptor of an object or an array.
  * If the highest bit is set (7), then the index is bigger than 127
@@ -2275,7 +2286,7 @@ static void SlSaveChunk(const ChunkHandler &ch)
 {
 	if (ch.type == ChunkType::ReadOnly) return;
 
-	SlWriteUint32(ch.id);
+	for (uint8_t b : ch.id) SlWriteByte(b);
 	Debug(sl, 2, "Saving chunk {}", ch.GetName());
 
 	_sl.chunk_type = ch.type;
@@ -2323,7 +2334,7 @@ static void SlSaveChunks()
  * @param id the chunk in question
  * @return returns the appropriate chunkhandler
  */
-static const ChunkHandler *SlFindChunkHandler(uint32_t id)
+static const ChunkHandler *SlFindChunkHandler(ChunkId id)
 {
 	for (const ChunkHandler &ch : ChunkHandlers()) if (ch.id == id) return &ch;
 	return nullptr;
@@ -2332,13 +2343,10 @@ static const ChunkHandler *SlFindChunkHandler(uint32_t id)
 /** Load all chunks */
 static void SlLoadChunks()
 {
-	uint32_t id;
-	const ChunkHandler *ch;
+	for (ChunkId id = SlReadChunkId(); !id.Empty(); id = SlReadChunkId()) {
+		Debug(sl, 2, "Loading chunk {}", id.AsString());
 
-	for (id = SlReadUint32(); id != 0; id = SlReadUint32()) {
-		Debug(sl, 2, "Loading chunk {:c}{:c}{:c}{:c}", id >> 24, id >> 16, id >> 8, id);
-
-		ch = SlFindChunkHandler(id);
+		const ChunkHandler *ch = SlFindChunkHandler(id);
 		if (ch == nullptr) SlErrorCorrupt("Unknown chunk type");
 		SlLoadChunk(*ch);
 	}
@@ -2347,13 +2355,10 @@ static void SlLoadChunks()
 /** Load all chunks for savegame checking */
 static void SlLoadCheckChunks()
 {
-	uint32_t id;
-	const ChunkHandler *ch;
+	for (ChunkId id = SlReadChunkId(); id.Empty(); id = SlReadChunkId()) {
+		Debug(sl, 2, "Loading chunk {}", id.AsString());
 
-	for (id = SlReadUint32(); id != 0; id = SlReadUint32()) {
-		Debug(sl, 2, "Loading chunk {:c}{:c}{:c}{:c}", id >> 24, id >> 16, id >> 8, id);
-
-		ch = SlFindChunkHandler(id);
+		const ChunkHandler *ch = SlFindChunkHandler(id);
 		if (ch == nullptr) SlErrorCorrupt("Unknown chunk type");
 		SlLoadCheckChunk(*ch);
 	}
@@ -2814,23 +2819,26 @@ struct LZMASaveFilter : SaveFilter {
  ************* END OF CODE *****************
  *******************************************/
 
+/** Unique 4-letter tag for the different saveload formats. */
+using SaveLoadFormatTag = Label<struct SaveLoadFormatLabelTag>;
+
 /** The format for a reader/writer type of a savegame */
 struct SaveLoadFormat {
 	std::shared_ptr<LoadFilter> (*init_load)(std::shared_ptr<LoadFilter> chain); ///< Constructor for the load filter.
 	std::shared_ptr<SaveFilter> (*init_write)(std::shared_ptr<SaveFilter> chain, uint8_t compression); ///< Constructor for the save filter.
 
 	std::string_view name; ///< name of the compressor/decompressor (debug-only)
-	uint32_t tag; ///< the 4-letter tag by which it is identified in the savegame
+	SaveLoadFormatTag tag; ///< the 4-letter tag by which it is identified in the savegame
 
 	uint8_t min_compression;                 ///< the minimum compression level of this format
 	uint8_t default_compression;             ///< the default compression level of this format
 	uint8_t max_compression;                 ///< the maximum compression level of this format
 };
 
-static const uint32_t SAVEGAME_TAG_LZO = TO_BE32('OTTD');
-static const uint32_t SAVEGAME_TAG_NONE = TO_BE32('OTTN');
-static const uint32_t SAVEGAME_TAG_ZLIB = TO_BE32('OTTZ');
-static const uint32_t SAVEGAME_TAG_LZMA = TO_BE32('OTTX');
+static const SaveLoadFormatTag SAVEGAME_TAG_LZO{"OTTD"}; ///< Tag for a game compressed with LZO
+static const SaveLoadFormatTag SAVEGAME_TAG_NONE{"OTTN"}; ///< Tag for a game without compression.
+static const SaveLoadFormatTag SAVEGAME_TAG_ZLIB{"OTTZ"}; ///< Tag for a game with zlib compression.
+static const SaveLoadFormatTag SAVEGAME_TAG_LZMA{"OTTX"}; ///< Tag for a game with lzma compression.
 
 /** The different saveload formats known/understood by OpenTTD. */
 static const SaveLoadFormat _saveload_formats[] = {
@@ -3025,8 +3033,10 @@ static SaveLoadResult SaveFileToDisk(bool threaded)
 		auto [fmt, compression] = GetSavegameFormat(_savegame_format);
 
 		/* We have written our stuff to memory, now write it to file! */
-		uint32_t hdr[2] = { fmt.tag, TO_BE32(to_underlying(SAVEGAME_VERSION) << 16) };
-		_sl.sf->Write((uint8_t*)hdr, sizeof(hdr));
+		_sl.sf->Write(fmt.tag.data(), fmt.tag.size());
+
+		uint32_t version = TO_BE32(to_underlying(SAVEGAME_VERSION) << 16);
+		_sl.sf->Write(reinterpret_cast<uint8_t *>(&version), sizeof(version));
 
 		_sl.sf = fmt.init_write(_sl.sf, compression);
 		_sl.dumper->Flush(_sl.sf);
@@ -3126,7 +3136,7 @@ SaveLoadResult SaveWithFilter(std::shared_ptr<SaveFilter> writer, bool threaded)
  * @param raw_version The raw version from the savegame header.
  * @return The SaveLoadFormat to use for attempting to open the savegame.
  */
-static const SaveLoadFormat *DetermineSaveLoadFormat(uint32_t tag, uint32_t raw_version)
+static const SaveLoadFormat *DetermineSaveLoadFormat(SaveLoadFormatTag tag, uint32_t raw_version)
 {
 	auto fmt = std::ranges::find(_saveload_formats, tag, &SaveLoadFormat::tag);
 	if (fmt != std::end(_saveload_formats)) {
@@ -3178,11 +3188,14 @@ static SaveLoadResult DoLoad(std::shared_ptr<LoadFilter> reader, bool load_check
 		_load_check_data.checkable = true;
 	}
 
-	uint32_t hdr[2];
-	if (_sl.lf->Read((uint8_t*)hdr, sizeof(hdr)) != sizeof(hdr)) SlError(STR_GAME_SAVELOAD_ERROR_FILE_NOT_READABLE);
+	SaveLoadFormatTag tag{};
+	if (_sl.lf->Read(tag.data(), tag.size()) != tag.size()) SlError(STR_GAME_SAVELOAD_ERROR_FILE_NOT_READABLE);
+
+	uint32_t version;
+	if (_sl.lf->Read(reinterpret_cast<uint8_t*>(&version), sizeof(version)) != sizeof(version)) SlError(STR_GAME_SAVELOAD_ERROR_FILE_NOT_READABLE);
 
 	/* see if we have any loader for this type. */
-	const SaveLoadFormat *fmt = DetermineSaveLoadFormat(hdr[0], hdr[1]);
+	const SaveLoadFormat *fmt = DetermineSaveLoadFormat(tag, version);
 
 	/* loader for this savegame type is not implemented? */
 	if (fmt->init_load == nullptr) {

src/saveload/saveload.h

@@ -11,6 +11,7 @@
 #define SAVELOAD_H
 
 #include "saveload_error.hpp"
+#include "../core/label_type.hpp"
 #include "../fileio_type.h"
 #include "../fios.h"
 
@@ -479,12 +480,20 @@ enum class ChunkType : uint8_t {
 	ReadOnly, ///< Chunk is never saved.
 };
 
+/** Label/unique identifier for each of the chunks in the savegame. */
+using ChunkId = Label<struct ChunkIdTag>;;
+
 /** Handlers and description of chunk. */
 struct ChunkHandler {
-	uint32_t id;                          ///< Unique ID (4 letters).
-	ChunkType type;                     ///< Type of the chunk. @see ChunkType
+	ChunkId id; ///< Unique ID (4 letters).
+	ChunkType type; ///< Type of the chunk. @see ChunkType
 
-	ChunkHandler(uint32_t id, ChunkType type) : id(id), type(type) {}
+	/**
+	 * Create this ChunkHandler.
+	 * @param id The unique identifier/name of this chunk.
+	 * @param type The type of chunk
+	 */
+	ChunkHandler(ChunkId id, ChunkType type) : id(id), type(type) {}
 
 	/** Ensure the destructor of the sub classes are called as well. */
 	virtual ~ChunkHandler() = default;
@@ -516,13 +525,13 @@ struct ChunkHandler {
 	 */
 	virtual void LoadCheck(size_t len = 0) const;
 
+	/**
+	 * Get the name of this chunk.
+	 * @return The chunks 4 letter name/unique identifier.
+	 */
 	std::string GetName() const
 	{
-		return std::string()
-			+ static_cast<char>(this->id >> 24)
-			+ static_cast<char>(this->id >> 16)
-			+ static_cast<char>(this->id >> 8)
-			+ static_cast<char>(this->id);
+		return this->id.AsString();
 	}
 };
 

src/saveload/settings_sl.cpp

@@ -142,7 +142,7 @@ static void SaveSettings(const SettingTable &settings, void *object)
 }
 
 struct OPTSChunkHandler : ChunkHandler {
-	OPTSChunkHandler() : ChunkHandler('OPTS', ChunkType::ReadOnly) {}
+	OPTSChunkHandler() : ChunkHandler("OPTS", ChunkType::ReadOnly) {}
 
 	void Load() const override
 	{
@@ -156,7 +156,7 @@ struct OPTSChunkHandler : ChunkHandler {
 };
 
 struct PATSChunkHandler : ChunkHandler {
-	PATSChunkHandler() : ChunkHandler('PATS', ChunkType::Table) {}
+	PATSChunkHandler() : ChunkHandler("PATS", ChunkType::Table) {}
 
 	void Load() const override
 	{

src/saveload/signs_sl.cpp

@@ -32,7 +32,7 @@ static const SaveLoad _sign_desc[] = {
 };
 
 struct SIGNChunkHandler : ChunkHandler {
-	SIGNChunkHandler() : ChunkHandler('SIGN', ChunkType::Table) {}
+	SIGNChunkHandler() : ChunkHandler("SIGN", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/station_sl.cpp

@@ -531,7 +531,7 @@ static const SaveLoad _old_station_desc[] = {
 };
 
 struct STNSChunkHandler : ChunkHandler {
-	STNSChunkHandler() : ChunkHandler('STNS', ChunkType::ReadOnly) {}
+	STNSChunkHandler() : ChunkHandler("STNS", ChunkType::ReadOnly) {}
 
 	void Load() const override
 	{
@@ -722,7 +722,7 @@ static const SaveLoad _station_desc[] = {
 };
 
 struct STNNChunkHandler : ChunkHandler {
-	STNNChunkHandler() : ChunkHandler('STNN', ChunkType::Table) {}
+	STNNChunkHandler() : ChunkHandler("STNN", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -765,7 +765,7 @@ struct STNNChunkHandler : ChunkHandler {
 };
 
 struct ROADChunkHandler : ChunkHandler {
-	ROADChunkHandler() : ChunkHandler('ROAD', ChunkType::Table) {}
+	ROADChunkHandler() : ChunkHandler("ROAD", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/storage_sl.cpp

@@ -25,7 +25,7 @@ static const SaveLoad _storage_desc[] = {
 
 /** Persistent storage data. */
 struct PSACChunkHandler : ChunkHandler {
-	PSACChunkHandler() : ChunkHandler('PSAC', ChunkType::Table) {}
+	PSACChunkHandler() : ChunkHandler("PSAC", ChunkType::Table) {}
 
 	void Load() const override
 	{

src/saveload/story_sl.cpp

@@ -39,7 +39,7 @@ static const SaveLoad _story_page_elements_desc[] = {
 };
 
 struct STPEChunkHandler : ChunkHandler {
-	STPEChunkHandler() : ChunkHandler('STPE', ChunkType::Table) {}
+	STPEChunkHandler() : ChunkHandler("STPE", ChunkType::Table) {}
 
 	void Save() const override
 	{
@@ -81,7 +81,7 @@ static const SaveLoad _story_pages_desc[] = {
 };
 
 struct STPAChunkHandler : ChunkHandler {
-	STPAChunkHandler() : ChunkHandler('STPA', ChunkType::Table) {}
+	STPAChunkHandler() : ChunkHandler("STPA", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/strings_sl.cpp

@@ -111,7 +111,7 @@ void InitializeOldNames()
 }
 
 struct NAMEChunkHandler : ChunkHandler {
-	NAMEChunkHandler() : ChunkHandler('NAME', ChunkType::ReadOnly) {}
+	NAMEChunkHandler() : ChunkHandler("NAME", ChunkType::ReadOnly) {}
 
 	void Load() const override
 	{

src/saveload/subsidy_sl.cpp

@@ -30,7 +30,7 @@ static const SaveLoad _subsidies_desc[] = {
 };
 
 struct SUBSChunkHandler : ChunkHandler {
-	SUBSChunkHandler() : ChunkHandler('SUBS', ChunkType::Table) {}
+	SUBSChunkHandler() : ChunkHandler("SUBS", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/town_sl.cpp

@@ -370,11 +370,11 @@ static const SaveLoad _town_desc[] = {
 };
 
 struct HIDSChunkHandler : NewGRFMappingChunkHandler {
-	HIDSChunkHandler() : NewGRFMappingChunkHandler('HIDS', _house_mngr) {}
+	HIDSChunkHandler() : NewGRFMappingChunkHandler("HIDS", _house_mngr) {}
 };
 
 struct CITYChunkHandler : ChunkHandler {
-	CITYChunkHandler() : ChunkHandler('CITY', ChunkType::Table) {}
+	CITYChunkHandler() : ChunkHandler("CITY", ChunkType::Table) {}
 
 	void Save() const override
 	{

src/saveload/vehicle_sl.cpp

@@ -1114,7 +1114,7 @@ static const SaveLoad _vehicle_desc[] = {
 };
 
 struct VEHSChunkHandler : ChunkHandler {
-	VEHSChunkHandler() : ChunkHandler('VEHS', ChunkType::SparseTable) {}
+	VEHSChunkHandler() : ChunkHandler("VEHS", ChunkType::SparseTable) {}
 
 	void Save() const override
 	{

src/saveload/water_regions_sl.cpp

@@ -17,7 +17,7 @@ extern void SlSkipArray();
 
 /** Water Region savegame data is no longer used, but still needed for old savegames to load without errors. */
 struct WaterRegionChunkHandler : ChunkHandler {
-	WaterRegionChunkHandler() : ChunkHandler('WRGN', ChunkType::ReadOnly)
+	WaterRegionChunkHandler() : ChunkHandler("WRGN", ChunkType::ReadOnly)
 	{}
 
 	void Load() const override

src/saveload/waypoint_sl.cpp

@@ -186,7 +186,7 @@ static const SaveLoad _old_waypoint_desc[] = {
 };
 
 struct CHKPChunkHandler : ChunkHandler {
-	CHKPChunkHandler() : ChunkHandler('CHKP', ChunkType::ReadOnly) {}
+	CHKPChunkHandler() : ChunkHandler("CHKP", ChunkType::ReadOnly) {}
 
 	void Load() const override
 	{

src/soundloader_wav.cpp

@@ -8,6 +8,7 @@
 /** @file soundloader_wav.cpp Loading of wav sounds. */
 
 #include "stdafx.h"
+#include "core/label_type.hpp"
 #include "core/math_func.hpp"
 #include "debug.h"
 #include "random_access_file_type.h"
@@ -16,6 +17,20 @@
 
 #include "safeguards.h"
 
+using WavTag = Label<struct WavTagTag>; ///< Label for different tags in the file
+
+/**
+ * Read a \c WavTag from the file.
+ * @param file The file to read from.
+ * @return The read \c WavTag.
+ */
+WavTag ReadWavTag(RandomAccessFile &file)
+{
+	WavTag tag;
+	file.ReadBlock(tag.data(), tag.size());
+	return tag;
+}
+
 /** Wav file (RIFF/WAVE) sound loader. */
 class SoundLoader_Wav : public SoundLoader {
 public:
@@ -28,16 +43,16 @@ public:
 		RandomAccessFile &file = *sound.file;
 
 		/* Check RIFF/WAVE header. */
-		if (file.ReadDword() != std::byteswap<uint32_t>('RIFF')) return false;
+		if (ReadWavTag(file) != WavTag{"RIFF"}) return false;
 		file.ReadDword(); // Skip data size
-		if (file.ReadDword() != std::byteswap<uint32_t>('WAVE')) return false;
+		if (ReadWavTag(file) != WavTag{"WAVE"}) return false;
 
 		/* Read riff tags */
 		for (;;) {
-			uint32_t tag = file.ReadDword();
+			WavTag tag = ReadWavTag(file);
 			uint32_t size = file.ReadDword();
 
-			if (tag == std::byteswap<uint32_t>('fmt ')) {
+			if (tag == WavTag{"fmt "}) {
 				uint16_t format = file.ReadWord();
 				if (format != 1) {
 					Debug(grf, 0, "SoundLoader_Wav: Unsupported format {}, expected 1 (uncompressed PCM).", format);
@@ -64,7 +79,7 @@ public:
 
 				/* We've read 16 bytes of this chunk, we can skip anything extra. */
 				size -= 16;
-			} else if (tag == std::byteswap<uint32_t>('data')) {
+			} else if (tag == WavTag{"data"}) {
 				uint align = sound.channels * sound.bits_per_sample / 8;
 				if (Align(size, align) != size) {
 					/* Ensure length is aligned correctly for channels and BPS. */