Refactor classes to structs

OpenRA.Game/Map/CellRegion.cs

@@ -117,7 +117,7 @@ namespace OpenRA
 			return GetEnumerator();
 		}
 
-		public sealed class CellRegionEnumerator : IEnumerator<CPos>
+		public struct CellRegionEnumerator : IEnumerator<CPos>
 		{
 			readonly CellRegion r;
 
@@ -128,9 +128,11 @@ namespace OpenRA
 			CPos current;
 
 			public CellRegionEnumerator(CellRegion region)
+				: this()
 			{
 				r = region;
 				Reset();
+				current = new MPos(u, v).ToCPos(r.gridType);
 			}
 
 			public bool MoveNext()

OpenRA.Game/Map/ProjectedCellRegion.cs

@@ -76,7 +76,7 @@ namespace OpenRA
 			return GetEnumerator();
 		}
 
-		public sealed class ProjectedCellRegionEnumerator : IEnumerator<PPos>
+		public struct ProjectedCellRegionEnumerator : IEnumerator<PPos>
 		{
 			readonly ProjectedCellRegion r;
 
@@ -86,9 +86,11 @@ namespace OpenRA
 			PPos current;
 
 			public ProjectedCellRegionEnumerator(ProjectedCellRegion region)
+				: this()
 			{
 				r = region;
 				Reset();
+				current = new PPos(u, v);
 			}
 
 			public bool MoveNext()

OpenRA.Game/TraitDictionary.cs

@@ -179,13 +179,14 @@ namespace OpenRA
 				System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { return GetEnumerator(); }
 			}
 
-			class MultipleEnumerator : IEnumerator<T>
+			struct MultipleEnumerator : IEnumerator<T>
 			{
 				readonly List<Actor> actors;
 				readonly List<T> traits;
 				readonly uint actor;
 				int index;
 				public MultipleEnumerator(TraitContainer<T> container, uint actor)
+					: this()
 				{
 					actors = container.actors;
 					traits = container.traits;
@@ -236,7 +237,7 @@ namespace OpenRA
 				}
 			}
 
-			class AllEnumerable : IEnumerable<TraitPair<T>>
+			struct AllEnumerable : IEnumerable<TraitPair<T>>
 			{
 				readonly TraitContainer<T> container;
 				public AllEnumerable(TraitContainer<T> container) { this.container = container; }
@@ -244,12 +245,13 @@ namespace OpenRA
 				System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { return GetEnumerator(); }
 			}
 
-			class AllEnumerator : IEnumerator<TraitPair<T>>
+			struct AllEnumerator : IEnumerator<TraitPair<T>>
 			{
 				readonly List<Actor> actors;
 				readonly List<T> traits;
 				int index;
 				public AllEnumerator(TraitContainer<T> container)
+					: this()
 				{
 					actors = container.actors;
 					traits = container.traits;