Codechange: Use std::array for cached town zone radius.

src/town.h

@@ -42,7 +42,7 @@ struct TownCache {
 	uint32_t population;                        ///< Current population of people
 	TrackedViewportSign sign;                 ///< Location of name sign, UpdateVirtCoord updates this
 	PartOfSubsidy part_of_subsidy;            ///< Is this town a source/destination of a subsidy?
-	uint32_t squared_town_zone_radius[HZB_END]; ///< UpdateTownRadius updates this given the house count
+	std::array<uint32_t, HZB_END> squared_town_zone_radius; ///< UpdateTownRadius updates this given the house count
 	BuildingCounts<uint16_t> building_counts;   ///< The number of each type of building in the town
 };
 

src/town_cmd.cpp

@@ -1902,7 +1902,7 @@ static bool GrowTown(Town *t)
  */
 void UpdateTownRadius(Town *t)
 {
-	static const uint32_t _town_squared_town_zone_radius_data[23][HZB_END] = {
+	static const std::array<std::array<uint32_t, HZB_END>, 23> _town_squared_town_zone_radius_data = {{
 		{  4,  0,  0,  0,  0}, // 0
 		{ 16,  0,  0,  0,  0},
 		{ 25,  0,  0,  0,  0},
@@ -1926,10 +1926,10 @@ void UpdateTownRadius(Town *t)
 		{121, 81,  0, 49, 25}, // 80
 		{121, 81,  0, 49, 25},
 		{121, 81,  0, 49, 36}, // 88
-	};
+	}};
 
-	if (t->cache.num_houses < 92) {
-		memcpy(t->cache.squared_town_zone_radius, _town_squared_town_zone_radius_data[t->cache.num_houses / 4], sizeof(t->cache.squared_town_zone_radius));
+	if (t->cache.num_houses < std::size(_town_squared_town_zone_radius_data) * 4) {
+		t->cache.squared_town_zone_radius = _town_squared_town_zone_radius_data[t->cache.num_houses / 4];
 	} else {
 		int mass = t->cache.num_houses / 8;
 		/* Actually we are proportional to sqrt() but that's right because we are covering an area.