Codechange: Remove FOR_EACH_SET_BIT

src/core/bitmath_func.hpp

@@ -345,20 +345,55 @@ static inline T ROR(const T x, const uint8 n)
 	)                                                                               \
 		if ((___FESBE_bits & 1) != 0)
 
-/**
- * Do an operation for each set set bit in a value.
- *
- * This macros is used to do an operation for each set
- * bit in a variable. The first parameter is a variable
- * that is used as the bit position counter.
- * The second parameter is an expression of the bits
- * we need to iterate over. This expression will be
- * evaluated once.
- *
- * @param bitpos_var   The position counter variable.
- * @param bitset_value The value which we check for set bits.
- */
-#define FOR_EACH_SET_BIT(bitpos_var, bitset_value) FOR_EACH_SET_BIT_EX(uint, bitpos_var, uint, bitset_value)
+ /**
+ * Iterable ensemble of each set bit in a value.
+ * @tparam Tbitpos Type of the position variable.
+ * @tparam Tbitset Type of the bitset value.
+*/
+template <typename Tbitpos = uint, typename Tbitset = uint>
+struct SetBitIterator {
+	struct Iterator {
+		typedef Tbitpos value_type;
+		typedef value_type *pointer;
+		typedef value_type &reference;
+		typedef size_t difference_type;
+		typedef std::forward_iterator_tag iterator_category;
+
+		explicit Iterator(Tbitset bitset) : bitset(bitset), bitpos(static_cast<Tbitpos>(0))
+		{
+			this->Validate();
+		}
+
+		bool operator==(const Iterator &other) const
+		{
+			return this->bitset == other.bitset && (this->bitset == 0 || this->bitpos == other.bitpos);
+		}
+		bool operator!=(const Iterator &other) const { return !(*this == other); }
+		Tbitpos operator*() const { return this->bitpos; }
+		Iterator & operator++() { this->Next(); this->Validate(); return *this; }
+
+	private:
+		Tbitset bitset;
+		Tbitpos bitpos;
+		void Validate()
+		{
+			while (this->bitset != 0 && (this->bitset & 1) == 0) this->Next();
+		}
+		void Next()
+		{
+			this->bitset = static_cast<Tbitset>(this->bitset >> 1);
+			this->bitpos++;
+		}
+	};
+
+	SetBitIterator(Tbitset bitset) : bitset(bitset) {}
+	Iterator begin() { return Iterator(this->bitset); }
+	Iterator end() { return Iterator(static_cast<Tbitset>(0)); }
+	bool empty() { return this->begin() == this->end(); }
+
+private:
+	Tbitset bitset;
+};
 
 #if defined(__APPLE__)
 	/* Make endian swapping use Apple's macros to increase speed

src/goal_gui.cpp

@@ -336,9 +336,8 @@ struct GoalQuestionWindow : public Window {
 		this->question = stredup(question);
 
 		/* Figure out which buttons we have to enable. */
-		uint bit;
 		int n = 0;
-		FOR_EACH_SET_BIT(bit, button_mask) {
+		for (uint bit : SetBitIterator(button_mask)) {
 			if (bit >= GOAL_QUESTION_BUTTON_COUNT) break;
 			this->button[n++] = bit;
 			if (n == 3) break;

src/newgrf.cpp

@@ -961,8 +961,7 @@ static bool ReadSpriteLayout(ByteReader *buf, uint num_building_sprites, bool us
 static CargoTypes TranslateRefitMask(uint32 refit_mask)
 {
 	CargoTypes result = 0;
-	uint8 bit;
-	FOR_EACH_SET_BIT(bit, refit_mask) {
+	for (uint8 bit : SetBitIterator(refit_mask)) {
 		CargoID cargo = GetCargoTranslation(bit, _cur.grffile, true);
 		if (cargo != CT_INVALID) SetBit(result, cargo);
 	}

src/newgrf_station.cpp

@@ -812,8 +812,7 @@ bool DrawStationTile(int x, int y, RailType railtype, Axis axis, StationClassID
 		/* Sprite layout which needs preprocessing */
 		bool separate_ground = HasBit(statspec->flags, SSF_SEPARATE_GROUND);
 		uint32 var10_values = layout->PrepareLayout(total_offset, rti->fallback_railtype, 0, 0, separate_ground);
-		uint8 var10;
-		FOR_EACH_SET_BIT(var10, var10_values) {
+		for (uint8 var10 : SetBitIterator(var10_values)) {
 			uint32 var10_relocation = GetCustomStationRelocation(statspec, nullptr, INVALID_TILE, var10);
 			layout->ProcessRegisters(var10, var10_relocation, separate_ground);
 		}

src/settings.cpp

@@ -354,9 +354,8 @@ void OneOfManySettingDesc::FormatValue(char *buf, const char *last, const void *
 void ManyOfManySettingDesc::FormatValue(char *buf, const char *last, const void *object) const
 {
 	uint bitmask = (uint)this->Read(object);
-	uint id = 0;
 	bool first = true;
-	FOR_EACH_SET_BIT(id, bitmask) {
+	for (uint id : SetBitIterator(bitmask)) {
 		if (!first) buf = strecpy(buf, "|", last);
 		buf = this->FormatSingleValue(buf, last, id);
 		first = false;

src/station_cmd.cpp

@@ -2993,8 +2993,7 @@ draw_default_foundation:
 			/* Sprite layout which needs preprocessing */
 			bool separate_ground = HasBit(statspec->flags, SSF_SEPARATE_GROUND);
 			uint32 var10_values = layout->PrepareLayout(total_offset, rti->fallback_railtype, 0, 0, separate_ground);
-			uint8 var10;
-			FOR_EACH_SET_BIT(var10, var10_values) {
+			for (uint8 var10 : SetBitIterator(var10_values)) {
 				uint32 var10_relocation = GetCustomStationRelocation(statspec, st, ti->tile, var10);
 				layout->ProcessRegisters(var10, var10_relocation, separate_ground);
 			}

src/station_gui.cpp

@@ -560,8 +560,7 @@ public:
 					ToggleBit(this->facilities, widget - WID_STL_TRAIN);
 					this->ToggleWidgetLoweredState(widget);
 				} else {
-					uint i;
-					FOR_EACH_SET_BIT(i, this->facilities) {
+					for (uint i : SetBitIterator(this->facilities)) {
 						this->RaiseWidget(i + WID_STL_TRAIN);
 					}
 					this->facilities = 1 << (widget - WID_STL_TRAIN);

src/town_gui.cpp

@@ -84,8 +84,7 @@ private:
 	static int GetNthSetBit(uint32 bits, int n)
 	{
 		if (n >= 0) {
-			uint i;
-			FOR_EACH_SET_BIT(i, bits) {
+			for (uint i : SetBitIterator(bits)) {
 				n--;
 				if (n < 0) return i;
 			}

src/water_cmd.cpp

@@ -1246,8 +1246,7 @@ void TileLoop_Water(TileIndex tile)
 
 		case FLOOD_DRYUP: {
 			Slope slope_here = GetFoundationSlope(tile) & ~SLOPE_HALFTILE_MASK & ~SLOPE_STEEP;
-			uint dir;
-			FOR_EACH_SET_BIT(dir, _flood_from_dirs[slope_here]) {
+			for (uint dir : SetBitIterator(_flood_from_dirs[slope_here])) {
 				TileIndex dest = tile + TileOffsByDir((Direction)dir);
 				if (!IsValidTile(dest)) continue;
 
@@ -1285,8 +1284,7 @@ void ConvertGroundTilesIntoWaterTiles()
 					break;
 
 				default:
-					uint dir;
-					FOR_EACH_SET_BIT(dir, _flood_from_dirs[slope & ~SLOPE_STEEP]) {
+					for (uint dir : SetBitIterator(_flood_from_dirs[slope & ~SLOPE_STEEP])) {
 						TileIndex dest = TileAddByDir(tile, (Direction)dir);
 						Slope slope_dest = GetTileSlope(dest) & ~SLOPE_STEEP;
 						if (slope_dest == SLOPE_FLAT || IsSlopeWithOneCornerRaised(slope_dest)) {