Use pattern matching

OpenRA.Game/Graphics/ModelRenderer.cs

@@ -223,8 +223,7 @@ namespace OpenRA.Graphics
 								ShadowAmbient, ShadowDiffuse, shadowPalette.TextureMidIndex, normals.TextureMidIndex);
 					}
 				}
-			}
+			}));
-			));
 
 			var screenLightVector = Util.MatrixVectorMultiply(invShadowTransform, ZVector);
 			screenLightVector = Util.MatrixVectorMultiply(cameraTransform, screenLightVector);

OpenRA.Game/Graphics/WorldRenderer.cs

@@ -177,8 +177,7 @@ namespace OpenRA.Graphics
 
 			foreach (var e in World.Effects)
 			{
-				var ea = e as IEffectAboveShroud;
+				if (!(e is IEffectAboveShroud ea))
-				if (ea == null)
 					continue;
 
 				foreach (var renderable in ea.RenderAboveShroud(this))
@@ -219,8 +218,7 @@ namespace OpenRA.Graphics
 
 			foreach (var e in World.Effects)
 			{
-				var ea = e as IEffectAnnotation;
+				if (!(e is IEffectAnnotation ea))
-				if (ea == null)
 					continue;
 
 				foreach (var renderAnnotation in ea.RenderAnnotation(this))

OpenRA.Game/Map/ActorReference.cs

@@ -87,8 +87,7 @@ namespace OpenRA
 			var ret = new MiniYaml(Type);
 			foreach (var o in initDict.Value)
 			{
-				var init = o as ActorInit;
+				if (!(o is ActorInit init) || o is ISuppressInitExport)
-				if (init == null || o is ISuppressInitExport)
 					continue;
 
 				if (initFilter != null && !initFilter(init))

OpenRA.Game/Primitives/BitSet.cs

@@ -98,7 +98,7 @@ namespace OpenRA.Primitives
 		public static bool operator !=(BitSet<T> me, BitSet<T> other) { return !(me == other); }
 
 		public bool Equals(BitSet<T> other) { return other == this; }
-		public override bool Equals(object obj) { return obj is BitSet<T> && Equals((BitSet<T>)obj); }
+		public override bool Equals(object obj) { return obj is BitSet<T> bitSet && Equals(bitSet); }
 		public override int GetHashCode() { return bits.GetHashCode(); }
 
 		public bool IsEmpty => bits == 0;

OpenRA.Game/Scripting/ScriptMemberWrapper.cs

@@ -86,8 +86,7 @@ namespace OpenRA.Scripting
 				{
 					foreach (var arg in clrArgs)
 					{
-						var table = arg as LuaValue[];
+						if (!(arg is LuaValue[] table))
-						if (table == null)
 							continue;
 
 						foreach (var value in table)

OpenRA.Mods.Cnc/Traits/Minelayer.cs

@@ -104,8 +104,8 @@ namespace OpenRA.Mods.Cnc.Traits
 			{
 				case "BeginMinefield":
 					var start = self.World.Map.CellContaining(target.CenterPosition);
-					if (self.World.OrderGenerator is MinefieldOrderGenerator)
+					if (self.World.OrderGenerator is MinefieldOrderGenerator generator)
-						((MinefieldOrderGenerator)self.World.OrderGenerator).AddMinelayer(self);
+						generator.AddMinelayer(self);
 					else
 						self.World.OrderGenerator = new MinefieldOrderGenerator(self, start, queued);
 
@@ -145,6 +145,8 @@ namespace OpenRA.Mods.Cnc.Traits
 				// A different minelayer might have started laying the field without this minelayer knowing the start
 				minefieldStart = order.ExtraLocation;
 
+#pragma warning disable IDE0019 // Use pattern matching
+
 				var movement = self.Trait<IPositionable>();
 				var mobile = movement as Mobile;
 
@@ -153,6 +155,8 @@ namespace OpenRA.Mods.Cnc.Traits
 						&& movement.CanEnterCell(c, null, BlockedByActor.Immovable) && (mobile != null && mobile.CanStayInCell(c)))
 					.OrderBy(c => (c - minefieldStart).LengthSquared).ToList();
 
+#pragma warning restore IDE0019 // Use pattern matching
+
 				self.QueueActivity(order.Queued, new LayMines(self, minefield));
 				self.ShowTargetLines();
 			}
@@ -305,6 +309,8 @@ namespace OpenRA.Mods.Cnc.Traits
 				var minefield = GetMinefieldCells(minefieldStart, lastMousePos,
 					minelayers.Max(m => m.Info.TraitInfo<MinelayerInfo>().MinefieldDepth));
 
+#pragma warning disable IDE0019 // Use pattern matching
+
 				var movement = minelayer.Trait<IPositionable>();
 				var mobile = movement as Mobile;
 				var pal = wr.Palette(TileSet.TerrainPaletteInternalName);
@@ -335,6 +341,8 @@ namespace OpenRA.Mods.Cnc.Traits
 					}
 
 					yield return new SpriteRenderable(tile, world.Map.CenterOfCell(c), WVec.Zero, -511, pal, 1f, alpha, float3.Ones, TintModifiers.IgnoreWorldTint, true);
+
+#pragma warning restore IDE0019 // Use pattern matching
 				}
 			}
 

OpenRA.Mods.Common/Activities/Move/Move.cs

@@ -309,8 +309,7 @@ namespace OpenRA.Mods.Common.Activities
 		{
 			foreach (var actor in self.World.ActorMap.GetActorsAt(cell))
 			{
-				var move = actor.OccupiesSpace as Mobile;
+				if (!(actor.OccupiesSpace is Mobile move) || !move.IsTraitEnabled() || !move.IsLeaving())
-				if (move == null || !move.IsTraitEnabled() || !move.IsLeaving())
 					return false;
 			}
 

OpenRA.Mods.Common/Traits/Attack/AttackBase.cs

@@ -155,8 +155,7 @@ namespace OpenRA.Mods.Common.Traits
 				return false;
 
 			// PERF: Mobile implements IPositionable, so we can use 'as' to save a trait look-up here.
-			var mobile = positionable as Mobile;
+			if (positionable is Mobile mobile && !mobile.CanInteractWithGroundLayer(self))
-			if (mobile != null && !mobile.CanInteractWithGroundLayer(self))
 				return false;
 
 			return true;

OpenRA.Mods.Common/UtilityCommands/CheckMissingSprites.cs

@@ -55,8 +55,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 						{
 							foreach (var sequence in kv.Value.Sequences(image))
 							{
-								var s = kv.Value.GetSequence(image, sequence) as FileNotFoundSequence;
+								if (!(kv.Value.GetSequence(image, sequence) is FileNotFoundSequence s))
-								if (s == null)
 									continue;
 
 								Console.WriteLine("\tSequence `{0}.{1}` references sprite `{2}` that does not exist.", image, sequence, s.Filename);

OpenRA.Mods.Common/Widgets/Logic/Editor/ActorEditLogic.cs

@@ -260,9 +260,8 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 					foreach (var o in options)
 					{
-						if (o is EditorActorCheckbox)
+						if (o is EditorActorCheckbox co)
 						{
-							var co = (EditorActorCheckbox)o;
 							var checkboxContainer = checkboxOptionTemplate.Clone();
 							checkboxContainer.Bounds.Y = initContainer.Bounds.Height;
 							initContainer.Bounds.Height += checkboxContainer.Bounds.Height;
@@ -283,9 +282,8 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 							initContainer.AddChild(checkboxContainer);
 						}
-						else if (o is EditorActorSlider)
+						else if (o is EditorActorSlider so)
 						{
-							var so = (EditorActorSlider)o;
 							var sliderContainer = sliderOptionTemplate.Clone();
 							sliderContainer.Bounds.Y = initContainer.Bounds.Height;
 							initContainer.Bounds.Height += sliderContainer.Bounds.Height;
@@ -319,9 +317,8 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 							initContainer.AddChild(sliderContainer);
 						}
-						else if (o is EditorActorDropdown)
+						else if (o is EditorActorDropdown ddo)
 						{
-							var ddo = (EditorActorDropdown)o;
 							var dropdownContainer = dropdownOptionTemplate.Clone();
 							dropdownContainer.Bounds.Y = initContainer.Bounds.Height;
 							initContainer.Bounds.Height += dropdownContainer.Bounds.Height;

OpenRA.Mods.Common/Widgets/Logic/Editor/SaveMapLogic.cs

@@ -92,8 +92,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 				foreach (var kv in modData.MapCache.MapLocations)
 				{
-					var folder = kv.Key as Folder;
+					if (!(kv.Key is Folder folder))
-					if (folder == null)
 						continue;
 
 					try

OpenRA.Mods.Common/Widgets/Logic/GameSaveBrowserLogic.cs

@@ -226,8 +226,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				games[games.IndexOf(oldPath)] = newPath;
 				foreach (var c in gameList.Children)
 				{
-					var item = c as ScrollItemWidget;
+					if (!(c is ScrollItemWidget item) || item.ItemKey != oldPath)
-					if (item == null || item.ItemKey != oldPath)
 						continue;
 
 					item.ItemKey = newPath;

OpenRA.Mods.Common/Widgets/Logic/Ingame/ClassicProductionLogic.cs

@@ -133,8 +133,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 					// Select the first active tab
 					foreach (var b in typesContainer.Children)
 					{
-						var button = b as ProductionTypeButtonWidget;
+						if (!(b is ProductionTypeButtonWidget button) || button.IsDisabled())
-						if (button == null || button.IsDisabled())
 							continue;
 
 						button.OnClick();

OpenRA.Mods.Common/Widgets/Logic/Installation/InstallFromDiscLogic.cs

@@ -207,74 +207,74 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 						switch (i.Key)
 						{
 							case "copy":
-							{
-								var sourceDir = Path.Combine(path, i.Value.Value);
-								foreach (var node in i.Value.Nodes)
 								{
-									var sourcePath = Path.Combine(sourceDir, node.Value.Value);
+									var sourceDir = Path.Combine(path, i.Value.Value);
-									var targetPath = Platform.ResolvePath(node.Key);
+									foreach (var node in i.Value.Nodes)
-									if (File.Exists(targetPath))
 									{
-										Log.Write("install", "Ignoring installed file " + targetPath);
+										var sourcePath = Path.Combine(sourceDir, node.Value.Value);
-										continue;
+										var targetPath = Platform.ResolvePath(node.Key);
+										if (File.Exists(targetPath))
+										{
+											Log.Write("install", "Ignoring installed file " + targetPath);
+											continue;
+										}
+
+										Log.Write("install", $"Copying {sourcePath} -> {targetPath}");
+										extracted.Add(targetPath);
+										Directory.CreateDirectory(Path.GetDirectoryName(targetPath));
+
+										using (var source = File.OpenRead(sourcePath))
+										using (var target = File.OpenWrite(targetPath))
+										{
+											var displayFilename = Path.GetFileName(targetPath);
+											var length = source.Length;
+
+											Action<long> onProgress = null;
+											if (length < ShowPercentageThreshold)
+												message = "Copying " + displayFilename;
+											else
+												onProgress = b => message = $"Copying {displayFilename} ({100 * b / length}%)";
+
+											CopyStream(source, target, length, onProgress);
+										}
 									}
 
-									Log.Write("install", $"Copying {sourcePath} -> {targetPath}");
+									break;
-									extracted.Add(targetPath);
-									Directory.CreateDirectory(Path.GetDirectoryName(targetPath));
-
-									using (var source = File.OpenRead(sourcePath))
-									using (var target = File.OpenWrite(targetPath))
-									{
-										var displayFilename = Path.GetFileName(targetPath);
-										var length = source.Length;
-
-										Action<long> onProgress = null;
-										if (length < ShowPercentageThreshold)
-											message = "Copying " + displayFilename;
-										else
-											onProgress = b => message = $"Copying {displayFilename} ({100 * b / length}%)";
-
-										CopyStream(source, target, length, onProgress);
-									}
 								}
 
-								break;
-							}
-
 							case "extract-raw":
-							{
+								{
-								ExtractFromPackage(ExtractionType.Raw, path, i.Value, extracted, m => message = m);
+									ExtractFromPackage(ExtractionType.Raw, path, i.Value, extracted, m => message = m);
-								break;
+									break;
-							}
+								}
 
 							case "extract-blast":
-							{
+								{
-								ExtractFromPackage(ExtractionType.Blast, path, i.Value, extracted, m => message = m);
+									ExtractFromPackage(ExtractionType.Blast, path, i.Value, extracted, m => message = m);
-								break;
+									break;
-							}
+								}
 
 							case "extract-mscab":
-							{
+								{
-								ExtractFromMSCab(path, i.Value, extracted, m => message = m);
+									ExtractFromMSCab(path, i.Value, extracted, m => message = m);
-								break;
+									break;
-							}
+								}
 
 							case "extract-iscab":
-							{
+								{
-								ExtractFromISCab(path, i.Value, extracted, m => message = m);
+									ExtractFromISCab(path, i.Value, extracted, m => message = m);
-								break;
+									break;
-							}
+								}
 
 							case "delete":
-							{
+								{
-								// Yaml path may be specified relative to a named directory (e.g. ^SupportDir) or the detected disc path
+									// Yaml path may be specified relative to a named directory (e.g. ^SupportDir) or the detected disc path
-								var sourcePath = i.Value.Value.StartsWith("^") ? Platform.ResolvePath(i.Value.Value) : Path.Combine(path, i.Value.Value);
+									var sourcePath = i.Value.Value.StartsWith("^") ? Platform.ResolvePath(i.Value.Value) : Path.Combine(path, i.Value.Value);
 
-								Log.Write("debug", "Deleting {0}", sourcePath);
+									Log.Write("debug", "Deleting {0}", sourcePath);
-								File.Delete(sourcePath);
+									File.Delete(sourcePath);
-								break;
+									break;
-							}
+								}
 
 							default:
 								Log.Write("debug", "Unknown installation command {0} - ignoring", i.Key);
@@ -479,8 +479,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 				foreach (var prefix in source.RegistryPrefixes)
 				{
-					var path = Microsoft.Win32.Registry.GetValue(prefix + source.RegistryKey, source.RegistryValue, null) as string;
+					if (!(Microsoft.Win32.Registry.GetValue(prefix + source.RegistryKey, source.RegistryValue, null) is string path))
-					if (path == null)
 						continue;
 
 					if (source.Type == ModContent.SourceType.RegistryDirectoryFromFile)
@@ -530,7 +529,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 								return false;
 						}
 						else if (CryptoUtil.SHA1Hash(fileStream) != kv.Value.Value)
-								return false;
+							return false;
 					}
 				}
 			}

OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyOptionsLogic.cs

@@ -89,8 +89,8 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 					row.Bounds.Y = optionsContainer.Bounds.Height;
 					optionsContainer.Bounds.Height += row.Bounds.Height;
 					foreach (var child in row.Children)
-						if (child is CheckboxWidget)
+						if (child is CheckboxWidget childCheckbox)
-							checkboxColumns.Enqueue((CheckboxWidget)child);
+							checkboxColumns.Enqueue(childCheckbox);
 
 					optionsContainer.AddChild(row);
 				}
@@ -118,8 +118,8 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 					row.Bounds.Y = optionsContainer.Bounds.Height;
 					optionsContainer.Bounds.Height += row.Bounds.Height;
 					foreach (var child in row.Children)
-						if (child is DropDownButtonWidget)
+						if (child is DropDownButtonWidget dropDown)
-							dropdownColumns.Enqueue((DropDownButtonWidget)child);
+							dropdownColumns.Enqueue(dropDown);
 
 					optionsContainer.AddChild(row);
 				}