OccupiedCells and TargetableCells must return arrays, not just enumerables.

This allows callers to efficiently enumerate these returned collections without the allocation and overhead imposed by the IEnumerable interface. All implementations were already returning arrays, so this only required a signature change.

OpenRA.Game/Traits/TraitsInterfaces.cs

@@ -203,7 +203,7 @@ namespace OpenRA.Traits
 	{
 		WPos CenterPosition { get; }
 		CPos TopLeft { get; }
-		IEnumerable<Pair<CPos, SubCell>> OccupiedCells();
+		Pair<CPos, SubCell>[] OccupiedCells();
 	}
 
 	public static class IOccupySpaceExts

OpenRA.Mods.Cnc/Traits/TDGunboat.cs

@@ -136,7 +136,7 @@ namespace OpenRA.Mods.Cnc.Traits
 			get { return Util.ApplyPercentageModifiers(Info.Speed, speedModifiers); }
 		}
 
-		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { return new[] { Pair.New(TopLeft, SubCell.FullCell) }; }
+		public Pair<CPos, SubCell>[] OccupiedCells() { return new[] { Pair.New(TopLeft, SubCell.FullCell) }; }
 
 		WVec MoveStep(int facing)
 		{

OpenRA.Mods.Common/ShroudExts.cs

@@ -15,11 +15,9 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common
 {
-	using OccupiedCells = IEnumerable<Pair<CPos, SubCell>>;
-
 	public static class ShroudExts
 	{
-		public static bool AnyExplored(this Shroud shroud, OccupiedCells cells)
+		public static bool AnyExplored(this Shroud shroud, Pair<CPos, SubCell>[] cells)
 		{
 			// PERF: Avoid LINQ.
 			foreach (var cell in cells)
@@ -29,7 +27,7 @@ namespace OpenRA.Mods.Common
 			return false;
 		}
 
-		public static bool AnyVisible(this Shroud shroud, OccupiedCells cells)
+		public static bool AnyVisible(this Shroud shroud, Pair<CPos, SubCell>[] cells)
 		{
 			// PERF: Avoid LINQ.
 			foreach (var cell in cells)

OpenRA.Mods.Common/Traits/Air/Aircraft.cs

@@ -460,7 +460,7 @@ namespace OpenRA.Mods.Common.Traits
 			get { return Util.ApplyPercentageModifiers(Info.Speed, speedModifiers); }
 		}
 
-		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { return NoCells; }
+		public Pair<CPos, SubCell>[] OccupiedCells() { return NoCells; }
 
 		public WVec FlyStep(int facing)
 		{

OpenRA.Mods.Common/Traits/Buildings/Building.cs

@@ -291,9 +291,9 @@ namespace OpenRA.Mods.Common.Traits
 			SkipMakeAnimation = init.Contains<SkipMakeAnimsInit>();
 		}
 
-		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { return occupiedCells; }
+		public Pair<CPos, SubCell>[] OccupiedCells() { return occupiedCells; }
 
-		IEnumerable<Pair<CPos, SubCell>> ITargetableCells.TargetableCells() { return targetableCells; }
+		Pair<CPos, SubCell>[] ITargetableCells.TargetableCells() { return targetableCells; }
 
 		void INotifyCreated.Created(Actor self)
 		{

OpenRA.Mods.Common/Traits/Crates/Crate.cs

@@ -160,7 +160,7 @@ namespace OpenRA.Mods.Common.Traits
 		}
 
 		public CPos TopLeft { get { return Location; } }
-		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { return new[] { Pair.New(Location, SubCell.FullCell) }; }
+		public Pair<CPos, SubCell>[] OccupiedCells() { return new[] { Pair.New(Location, SubCell.FullCell) }; }
 
 		public WPos CenterPosition { get; private set; }
 

OpenRA.Mods.Common/Traits/Husk.cs

@@ -77,7 +77,7 @@ namespace OpenRA.Mods.Common.Traits
 				self.QueueActivity(new Drag(self, CenterPosition, finalPosition, distance / dragSpeed));
 		}
 
-		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { return new[] { Pair.New(TopLeft, SubCell.FullCell) }; }
+		public Pair<CPos, SubCell>[] OccupiedCells() { return new[] { Pair.New(TopLeft, SubCell.FullCell) }; }
 		public bool IsLeavingCell(CPos location, SubCell subCell = SubCell.Any) { return false; }
 		public SubCell GetValidSubCell(SubCell preferred = SubCell.Any) { return SubCell.FullCell; }
 		public SubCell GetAvailableSubCell(CPos cell, SubCell preferredSubCell = SubCell.Any, Actor ignoreActor = null, bool checkTransientActors = true)

OpenRA.Mods.Common/Traits/Immobile.cs

@@ -35,7 +35,7 @@ namespace OpenRA.Mods.Common.Traits
 	{
 		[Sync] readonly CPos location;
 		[Sync] readonly WPos position;
-		readonly IEnumerable<Pair<CPos, SubCell>> occupied;
+		readonly Pair<CPos, SubCell>[] occupied;
 
 		public Immobile(ActorInitializer init, ImmobileInfo info)
 		{
@@ -50,7 +50,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public CPos TopLeft { get { return location; } }
 		public WPos CenterPosition { get { return position; } }
-		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { return occupied; }
+		public Pair<CPos, SubCell>[] OccupiedCells() { return occupied; }
 
 		void INotifyAddedToWorld.AddedToWorld(Actor self)
 		{

OpenRA.Mods.Common/Traits/Mobile.cs

@@ -665,7 +665,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public CPos TopLeft { get { return ToCell; } }
 
-		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells()
+		public Pair<CPos, SubCell>[] OccupiedCells()
 		{
 			if (FromCell == ToCell)
 				return new[] { Pair.New(FromCell, FromSubCell) };

OpenRA.Mods.Common/TraitsInterfaces.cs

@@ -383,7 +383,7 @@ namespace OpenRA.Mods.Common.Traits
 	[RequireExplicitImplementation]
 	public interface ITargetableCells
 	{
-		IEnumerable<Pair<CPos, SubCell>> TargetableCells();
+		Pair<CPos, SubCell>[] TargetableCells();
 	}
 
 	[RequireExplicitImplementation]