Change to use pattern matching

OpenRA.Game/Actor.cs

@@ -359,8 +359,7 @@ namespace OpenRA
 
 		public override bool Equals(object obj)
 		{
-			var o = obj as Actor;
-			return o != null && Equals(o);
+			return obj is Actor o && Equals(o);
 		}
 
 		public bool Equals(Actor other)

OpenRA.Game/Exts.cs

@@ -511,8 +511,7 @@ namespace OpenRA
 
 		public static bool IsTraitEnabled<T>(this T trait)
 		{
-			var disabledTrait = trait as IDisabledTrait;
-			return disabledTrait == null || !disabledTrait.IsTraitDisabled;
+			return !(trait is IDisabledTrait disabledTrait) || !disabledTrait.IsTraitDisabled;
 		}
 
 		public static T FirstEnabledTraitOrDefault<T>(this IEnumerable<T> ts)

OpenRA.Game/GameRules/Ruleset.cs

@@ -67,8 +67,7 @@ namespace OpenRA
 
 			foreach (var weapon in Weapons)
 			{
-				var projectileLoaded = weapon.Value.Projectile as IRulesetLoaded<WeaponInfo>;
-				if (projectileLoaded != null)
+				if (weapon.Value.Projectile is IRulesetLoaded<WeaponInfo> projectileLoaded)
 				{
 					try
 					{
@@ -82,8 +81,7 @@ namespace OpenRA
 
 				foreach (var warhead in weapon.Value.Warheads)
 				{
-					var cacher = warhead as IRulesetLoaded<WeaponInfo>;
-					if (cacher != null)
+					if (warhead is IRulesetLoaded<WeaponInfo> cacher)
 					{
 						try
 						{

OpenRA.Game/Graphics/Util.cs

@@ -41,8 +41,7 @@ namespace OpenRA.Graphics
 			// See combined.vert for documentation on the channel attribute format
 			var attribC = r.Channel == TextureChannel.RGBA ? 0x02 : ((byte)r.Channel) << 1 | 0x01;
 			attribC |= samplers.X << 6;
-			var ss = r as SpriteWithSecondaryData;
-			if (ss != null)
+			if (r is SpriteWithSecondaryData ss)
 			{
 				sl = ss.SecondaryLeft;
 				st = ss.SecondaryTop;

OpenRA.Game/Input/Hotkey.cs

@@ -81,8 +81,7 @@ namespace OpenRA
 
 		public override bool Equals(object obj)
 		{
-			var o = obj as Hotkey?;
-			return o != null && o == this;
+			return obj is Hotkey o && (Hotkey?)o == this;
 		}
 
 		public override string ToString() { return "{0} {1}".F(Key, Modifiers.ToString("F")); }

OpenRA.Game/Map/MapCache.cs

@@ -148,8 +148,7 @@ namespace OpenRA
 				{
 					foreach (var map in package.Contents)
 					{
-						var mapPackage = package.OpenPackage(map, modData.ModFiles) as IReadWritePackage;
-						if (mapPackage != null)
+						if (package.OpenPackage(map, modData.ModFiles) is IReadWritePackage mapPackage)
 							yield return mapPackage;
 					}
 				}

OpenRA.Game/Primitives/SegmentStream.cs

@@ -131,8 +131,7 @@ namespace OpenRA.Primitives
 		{
 			var offset = 0L;
 			overallBaseStream = stream;
-			var segmentStream = stream as SegmentStream;
-			if (segmentStream != null)
+			if (stream is SegmentStream segmentStream)
 				offset += segmentStream.BaseOffset + GetOverallNestedOffset(segmentStream.BaseStream, out overallBaseStream);
 			return offset;
 		}

OpenRA.Game/Primitives/float3.cs

@@ -55,8 +55,7 @@ namespace OpenRA
 
 		public override bool Equals(object obj)
 		{
-			var o = obj as float3?;
-			return o != null && o == this;
+			return obj is float3 o && (float3?)o == this;
 		}
 
 		public override string ToString() { return "{0},{1},{2}".F(X, Y, Z); }

OpenRA.Game/Support/ExceptionHandler.cs

@@ -63,13 +63,11 @@ namespace OpenRA
 
 			sb.AppendIndentedFormatLine(indent, "Exception of type `{0}`: {1}", ex.GetType().FullName, ex.Message);
 
-			var tle = ex as TypeLoadException;
-			var oom = ex as OutOfMemoryException;
-			if (tle != null)
+			if (ex is TypeLoadException tle)
 			{
 				sb.AppendIndentedFormatLine(indent, "TypeName=`{0}`", tle.TypeName);
 			}
-			else if (oom != null)
+			else if (ex is OutOfMemoryException)
 			{
 				var gcMemoryBeforeCollect = GC.GetTotalMemory(false);
 				GC.Collect();

OpenRA.Game/Widgets/Widget.cs

@@ -73,11 +73,10 @@ namespace OpenRA.Widgets
 
 		public static T LoadWidget<T>(string id, Widget parent, WidgetArgs args) where T : Widget
 		{
-			var widget = LoadWidget(id, parent, args) as T;
-			if (widget == null)
-				throw new InvalidOperationException(
-					"Widget {0} is not of type {1}".F(id, typeof(T).Name));
-			return widget;
+			if (LoadWidget(id, parent, args) is T widget)
+				return widget;
+
+			throw new InvalidOperationException("Widget {0} is not of type {1}".F(id, typeof(T).Name));
 		}
 
 		public static Widget LoadWidget(string id, Widget parent, WidgetArgs args)

OpenRA.Game/World.cs

@@ -273,8 +273,7 @@ namespace OpenRA
 
 			gameInfo.DisabledSpawnPoints = OrderManager.LobbyInfo.DisabledSpawnPoints;
 
-			var echo = OrderManager.Connection as EchoConnection;
-			var rc = echo != null ? echo.Recorder : null;
+			var rc = (OrderManager.Connection as EchoConnection)?.Recorder;
 
 			if (rc != null)
 				rc.Metadata = new ReplayMetadata(gameInfo);
@@ -326,12 +325,10 @@ namespace OpenRA
 		{
 			effects.Add(e);
 
-			var sp = e as ISpatiallyPartitionable;
-			if (sp == null)
+			if (!(e is ISpatiallyPartitionable))
 				unpartitionedEffects.Add(e);
 
-			var se = e as ISync;
-			if (se != null)
+			if (e is ISync se)
 				syncedEffects.Add(se);
 		}
 
@@ -339,12 +336,10 @@ namespace OpenRA
 		{
 			effects.Remove(e);
 
-			var sp = e as ISpatiallyPartitionable;
-			if (sp == null)
+			if (!(e is ISpatiallyPartitionable))
 				unpartitionedEffects.Remove(e);
 
-			var se = e as ISync;
-			if (se != null)
+			if (e is ISync se)
 				syncedEffects.Remove(se);
 		}