Fix IDE0056

.editorconfig

@@ -141,7 +141,7 @@ dotnet_diagnostic.IDE0074.severity = silent # Requires C# 8 - TODO Consider enab
 
 # IDE0056 Use index operator
 #csharp_style_prefer_index_operator = true
-dotnet_diagnostic.IDE0056.severity = silent # Requires C# 8 - TODO Consider enabling
+dotnet_diagnostic.IDE0056.severity = warning
 
 # IDE0057 Use range operator
 #csharp_style_prefer_range_operator = true

OpenRA.Game/Graphics/RgbaColorRenderer.cs

@@ -138,7 +138,7 @@ namespace OpenRA.Graphics
 			// Segment is part of closed loop
 			if (closed)
 			{
-				var prev = points[points.Length - 1];
+				var prev = points[^1];
 				var prevDir = (start - prev) / (start - prev).XY.Length;
 				var prevCorner = width / 2 * new float3(-prevDir.Y, prevDir.X, prevDir.Z);
 				ca = IntersectionOf(start - prevCorner, prevDir, start - corner, dir);

OpenRA.Game/MiniYaml.cs

@@ -209,7 +209,7 @@ namespace OpenRA
 
 					while (levels.Count > level + 1)
 					{
-						levels[levels.Count - 1].TrimExcess();
+						levels[^1].TrimExcess();
 						levels.RemoveAt(levels.Count - 1);
 					}
 
@@ -260,7 +260,7 @@ namespace OpenRA
 					{
 						// Remove leading/trailing whitespace guards
 						var trimLeading = value[0] == '\\' && (value[1] == ' ' || value[1] == '\t') ? 1 : 0;
-						var trimTrailing = value[value.Length - 1] == '\\' && (value[value.Length - 2] == ' ' || value[value.Length - 2] == '\t') ? 1 : 0;
+						var trimTrailing = value[^1] == '\\' && (value[^2] == ' ' || value[^2] == '\t') ? 1 : 0;
 						if (trimLeading + trimTrailing > 0)
 							value = value.Slice(trimLeading, value.Length - trimLeading - trimTrailing);
 

OpenRA.Game/Support/VariableExpression.cs

@@ -719,12 +719,12 @@ namespace OpenRA.Support
 			readonly List<Expression> expressions = new List<Expression>();
 			readonly List<ExpressionType> types = new List<ExpressionType>();
 
-			public ExpressionType PeekType() { return types[types.Count - 1]; }
+			public ExpressionType PeekType() { return types[^1]; }
 
 			public Expression Peek(ExpressionType toType)
 			{
-				var fromType = types[types.Count - 1];
+				var fromType = types[^1];
-				var expression = expressions[expressions.Count - 1];
+				var expression = expressions[^1];
 				if (toType == fromType)
 					return expression;
 

OpenRA.Mods.Cnc/UtilityCommands/Glob.cs

@@ -73,13 +73,13 @@ namespace OpenRA.Mods.Cnc.UtilityCommands
 				parts.Insert(0, "." + Path.DirectorySeparatorChar);
 
 			// If the last entry ends with a directory separator, append a '*'
-			if (parts[parts.Count - 1][parts[parts.Count - 1].Length - 1] == Path.DirectorySeparatorChar
+			if (parts[^1][^1] == Path.DirectorySeparatorChar
-				|| parts[parts.Count - 1][parts[parts.Count - 1].Length - 1] == Path.AltDirectorySeparatorChar)
+				|| parts[^1][^1] == Path.AltDirectorySeparatorChar)
 				parts.Add("*");
 
 			var root = parts[0];
 			var dirs = parts.Skip(1).Take(parts.Count - 2).ToList();
-			var file = parts[parts.Count - 1];
+			var file = parts[^1];
 
 			foreach (var path in Expand(root, dirs, 0, file))
 				yield return path;
@@ -105,7 +105,7 @@ namespace OpenRA.Mods.Cnc.UtilityCommands
 				}
 				else
 				{
-					if (dir[dir.Length - 1] == Path.DirectorySeparatorChar || dir[dir.Length - 1] == Path.AltDirectorySeparatorChar)
+					if (dir[^1] == Path.DirectorySeparatorChar || dir[^1] == Path.AltDirectorySeparatorChar)
 						dir = dir.Substring(0, dir.Length - 1);
 					foreach (var subDir in Directory.EnumerateDirectories(basePath, dir, SearchOption.TopDirectoryOnly))
 						foreach (var s in Expand(subDir, dirs, dirIndex + 1, file))

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

@@ -202,7 +202,7 @@ namespace OpenRA.Mods.Common.Activities
 			if (path.Count == 0)
 				return null;
 
-			var nextCell = path[path.Count - 1];
+			var nextCell = path[^1];
 
 			// Something else might have moved us, so the path is no longer valid.
 			if (!Util.AreAdjacentCells(mobile.ToCell, nextCell))
@@ -280,7 +280,7 @@ namespace OpenRA.Mods.Common.Activities
 				if (newPath.Count != 0)
 				{
 					path = newPath;
-					var newCell = path[path.Count - 1];
+					var newCell = path[^1];
 					path.RemoveAt(path.Count - 1);
 
 					return (newCell, mobile.GetAvailableSubCell(nextCell, mobile.FromSubCell, ignoreActor));

OpenRA.Mods.Common/HitShapes/Polygon.cs

@@ -53,7 +53,7 @@ namespace OpenRA.Mods.Common.HitShapes
 			combatOverlayVertsTop = Points.Select(p => new WVec(p.X, p.Y, VerticalTopOffset)).ToArray();
 			combatOverlayVertsBottom = Points.Select(p => new WVec(p.X, p.Y, VerticalBottomOffset)).ToArray();
 			squares = new int[Points.Length];
-			squares[0] = (Points[0] - Points[Points.Length - 1]).LengthSquared;
+			squares[0] = (Points[0] - Points[^1]).LengthSquared;
 			for (var i = 1; i < Points.Length; i++)
 				squares[i] = (Points[i] - Points[i - 1]).LengthSquared;
 		}
@@ -89,7 +89,7 @@ namespace OpenRA.Mods.Common.HitShapes
 			if (Points.PolygonContains(p))
 				return new WDist(z);
 
-			var min2 = DistanceSquaredFromLineSegment(p, Points[Points.Length - 1], Points[0], squares[0]);
+			var min2 = DistanceSquaredFromLineSegment(p, Points[^1], Points[0], squares[0]);
 			for (var i = 1; i < Points.Length; i++)
 			{
 				var d2 = DistanceSquaredFromLineSegment(p, Points[i - 1], Points[i], squares[i]);

OpenRA.Mods.Common/Traits/Conditions/GrantConditionOnAttack.cs

@@ -144,7 +144,7 @@ namespace OpenRA.Mods.Common.Traits
 			shotsFired++;
 			var requiredShots = tokens.Count < Info.RequiredShotsPerInstance.Length
 				? Info.RequiredShotsPerInstance[tokens.Count]
-				: Info.RequiredShotsPerInstance[Info.RequiredShotsPerInstance.Length - 1];
+				: Info.RequiredShotsPerInstance[^1];
 
 			if (shotsFired >= requiredShots)
 			{

OpenRA.Mods.Common/Traits/World/WarheadDebugOverlay.cs

@@ -35,7 +35,7 @@ namespace OpenRA.Mods.Common.Traits
 			public readonly Color Color;
 			public int Time;
 
-			public WDist OuterRange => Range[Range.Length - 1];
+			public WDist OuterRange => Range[^1];
 
 			public WHImpact(WPos pos, WDist[] range, int time, Color color)
 			{

OpenRA.Mods.Common/Util.cs

@@ -148,7 +148,7 @@ namespace OpenRA.Mods.Common
 			}
 
 			if (items.Length > 0)
-				yield return items[items.Length - 1];
+				yield return items[^1];
 		}
 
 		static IEnumerable<CPos> Neighbours(CPos c, bool allowDiagonal)

OpenRA.Mods.Common/UtilityCommands/ConvertSpriteToPngCommand.cs

@@ -39,9 +39,9 @@ namespace OpenRA.Mods.Common.UtilityCommands
 			if (args.Contains("--noshadow"))
 			{
 				Array.Resize(ref shadowIndex, shadowIndex.Length + 3);
-				shadowIndex[shadowIndex.Length - 1] = 1;
+				shadowIndex[^1] = 1;
-				shadowIndex[shadowIndex.Length - 2] = 3;
+				shadowIndex[^2] = 3;
-				shadowIndex[shadowIndex.Length - 3] = 4;
+				shadowIndex[^3] = 4;
 			}
 
 			var palette = new ImmutablePalette(args[2], new[] { 0 }, shadowIndex);

OpenRA.Mods.Common/Warheads/SpreadDamageWarhead.cs

@@ -58,7 +58,7 @@ namespace OpenRA.Mods.Common.Warheads
 			if (debugVis != null && debugVis.CombatGeometry)
 				firedBy.World.WorldActor.Trait<WarheadDebugOverlay>().AddImpact(pos, effectiveRange, DebugOverlayColor);
 
-			foreach (var victim in firedBy.World.FindActorsOnCircle(pos, effectiveRange[effectiveRange.Length - 1]))
+			foreach (var victim in firedBy.World.FindActorsOnCircle(pos, effectiveRange[^1]))
 			{
 				if (!IsValidAgainst(victim, firedBy))
 					continue;
@@ -99,7 +99,7 @@ namespace OpenRA.Mods.Common.Warheads
 				}
 
 				// The range to target is more than the range the warhead covers, so GetDamageFalloff() is going to give us 0 and we're going to do 0 damage anyway, so bail early.
-				if (falloffDistance > effectiveRange[effectiveRange.Length - 1].Length)
+				if (falloffDistance > effectiveRange[^1].Length)
 					continue;
 
 				var localModifiers = args.DamageModifiers.Append(GetDamageFalloff(falloffDistance));

OpenRA.Mods.Common/Widgets/TextNotificationsDisplayWidget.cs

@@ -61,7 +61,7 @@ namespace OpenRA.Mods.Common.Widgets
 			if (!IsVisible() || Children.Count == 0)
 				return;
 
-			var mostRecentMessageOverflows = Bounds.Height < Children[Children.Count - 1].Bounds.Height;
+			var mostRecentMessageOverflows = Bounds.Height < Children[^1].Bounds.Height;
 
 			if (mostRecentMessageOverflows && HideOverflow)
 				Game.Renderer.EnableScissor(overflowDrawBounds);
@@ -91,7 +91,7 @@ namespace OpenRA.Mods.Common.Widgets
 				foreach (var line in Children)
 					line.Bounds.Y -= notificationWidget.Bounds.Height + ItemSpacing;
 
-				var lastLine = Children[Children.Count - 1];
+				var lastLine = Children[^1];
 				notificationWidget.Bounds.Y = lastLine.Bounds.Bottom + ItemSpacing;
 			}
 
@@ -107,7 +107,7 @@ namespace OpenRA.Mods.Common.Widgets
 			if (Children.Count == 0)
 				return;
 
-			var mostRecentChild = Children[Children.Count - 1];
+			var mostRecentChild = Children[^1];
 
 			RemoveChild(mostRecentChild);
 			expirations.RemoveAt(expirations.Count - 1);

OpenRA.Mods.D2k/Traits/AttractsWorms.cs

@@ -68,7 +68,7 @@ namespace OpenRA.Mods.D2k.Traits
 			var length = distance.Length;
 
 			// Actor is too far to hear anything.
-			if (length > effectiveRange[effectiveRange.Length - 1].Length)
+			if (length > effectiveRange[^1].Length)
 				return WVec.Zero;
 
 			var direction = 1024 * distance / length;

OpenRA.Utility/Program.cs

@@ -169,7 +169,7 @@ namespace OpenRA
 				return;
 
 			var args = descParts.Take(descParts.Length - 1).JoinWith(" ");
-			var desc = descParts[descParts.Length - 1];
+			var desc = descParts[^1];
 
 			Console.WriteLine($"  {key} {args}{Environment.NewLine}  {desc}{Environment.NewLine}");
 		}