From 4d4096630378477528e2d045b3805b0df8ecf830 Mon Sep 17 00:00:00 2001
From: Peter Nelson <peter1138@openttd.org>
Date: Sun, 7 Sep 2025 14:13:57 +0100
Subject: [PATCH] Codechange: Use FlatSet to store and test alternate rail/road
 types.

---
 src/newgrf/newgrf_act0_railtypes.cpp | 2 +-
 src/newgrf/newgrf_act0_roadtypes.cpp | 2 +-
 src/rail.cpp                         | 3 +--
 src/rail.h                           | 3 ++-
 src/road.cpp                         | 3 +--
 src/road.h                           | 3 ++-
 6 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/newgrf/newgrf_act0_railtypes.cpp b/src/newgrf/newgrf_act0_railtypes.cpp
index 27394f8bf4..d37a3684ec 100644
--- a/src/newgrf/newgrf_act0_railtypes.cpp
+++ b/src/newgrf/newgrf_act0_railtypes.cpp
@@ -204,7 +204,7 @@ static ChangeInfoResult RailTypeReserveInfo(uint first, uint last, int prop, Byt
 				if (type_map[id] != INVALID_RAILTYPE) {
 					int n = buf.ReadByte();
 					for (int j = 0; j != n; j++) {
-						_railtypes[type_map[id]].alternate_labels.push_back(std::byteswap(buf.ReadDWord()));
+						_railtypes[type_map[id]].alternate_labels.insert(std::byteswap(buf.ReadDWord()));
 					}
 					break;
 				}
diff --git a/src/newgrf/newgrf_act0_roadtypes.cpp b/src/newgrf/newgrf_act0_roadtypes.cpp
index 2eff6b05fd..4fa5746ce9 100644
--- a/src/newgrf/newgrf_act0_roadtypes.cpp
+++ b/src/newgrf/newgrf_act0_roadtypes.cpp
@@ -192,7 +192,7 @@ static ChangeInfoResult RoadTypeReserveInfo(uint first, uint last, int prop, Byt
 				if (type_map[id] != INVALID_ROADTYPE) {
 					int n = buf.ReadByte();
 					for (int j = 0; j != n; j++) {
-						_roadtypes[type_map[id]].alternate_labels.push_back(std::byteswap(buf.ReadDWord()));
+						_roadtypes[type_map[id]].alternate_labels.insert(std::byteswap(buf.ReadDWord()));
 					}
 					break;
 				}
diff --git a/src/rail.cpp b/src/rail.cpp
index 590676aa87..7e7174fef2 100644
--- a/src/rail.cpp
+++ b/src/rail.cpp
@@ -205,8 +205,7 @@ RailType GetRailTypeByLabel(RailTypeLabel label, bool allow_alternate_labels)
 	if (allow_alternate_labels) {
 		/* Test if any rail type defines the label as an alternate. */
 		for (RailType r = RAILTYPE_BEGIN; r != RAILTYPE_END; r++) {
-			const RailTypeInfo *rti = GetRailTypeInfo(r);
-			if (std::ranges::find(rti->alternate_labels, label) != rti->alternate_labels.end()) return r;
+			if (GetRailTypeInfo(r)->alternate_labels.contains(label)) return r;
 		}
 	}
 
diff --git a/src/rail.h b/src/rail.h
index b65f2351c8..9865f81003 100644
--- a/src/rail.h
+++ b/src/rail.h
@@ -15,6 +15,7 @@
 #include "gfx_type.h"
 #include "core/bitmath_func.hpp"
 #include "core/enum_type.hpp"
+#include "core/flatset_type.hpp"
 #include "economy_func.h"
 #include "slope_type.h"
 #include "strings_type.h"
@@ -227,7 +228,7 @@ public:
 	/**
 	 * Rail type labels this type provides in addition to the main label.
 	 */
-	std::vector<RailTypeLabel> alternate_labels;
+	FlatSet<RailTypeLabel> alternate_labels;
 
 	/**
 	 * Colour on mini-map
diff --git a/src/road.cpp b/src/road.cpp
index 51bdf1900d..590abfa07c 100644
--- a/src/road.cpp
+++ b/src/road.cpp
@@ -275,8 +275,7 @@ RoadType GetRoadTypeByLabel(RoadTypeLabel label, bool allow_alternate_labels)
 	if (allow_alternate_labels) {
 		/* Test if any road type defines the label as an alternate. */
 		for (RoadType r = ROADTYPE_BEGIN; r != ROADTYPE_END; r++) {
-			const RoadTypeInfo *rti = GetRoadTypeInfo(r);
-			if (std::ranges::find(rti->alternate_labels, label) != rti->alternate_labels.end()) return r;
+			if (GetRoadTypeInfo(r)->alternate_labels.contains(label)) return r;
 		}
 	}
 
diff --git a/src/road.h b/src/road.h
index a3c689419f..b67df0e70a 100644
--- a/src/road.h
+++ b/src/road.h
@@ -13,6 +13,7 @@
 #include "road_type.h"
 #include "gfx_type.h"
 #include "core/bitmath_func.hpp"
+#include "core/flatset_type.hpp"
 #include "strings_type.h"
 #include "timer/timer_game_calendar.h"
 #include "core/enum_type.hpp"
@@ -137,7 +138,7 @@ public:
 	/**
 	 * Road type labels this type provides in addition to the main label.
 	 */
-	std::vector<RoadTypeLabel> alternate_labels;
+	FlatSet<RoadTypeLabel> alternate_labels;
 
 	/**
 	 * Colour on mini-map