Merge pull request #6823 from huoyaoyuan/sharpen

Apply new language features

.editorconfig

@@ -111,9 +111,15 @@ csharp_preserve_single_line_statements = true
 
 #Roslyn language styles
 
+#Style - this. qualification
+dotnet_style_qualification_for_field = false:warning
+dotnet_style_qualification_for_property = false:warning
+dotnet_style_qualification_for_method = false:warning
+dotnet_style_qualification_for_event = false:warning
+
 #Style - type names
-dotnet_style_predefined_type_for_locals_parameters_members = true:silent
-dotnet_style_predefined_type_for_member_access = true:silent
+dotnet_style_predefined_type_for_locals_parameters_members = true:warning
+dotnet_style_predefined_type_for_member_access = true:warning
 csharp_style_var_when_type_is_apparent = true:none
 csharp_style_var_for_built_in_types = true:none
 csharp_style_var_elsewhere = true:silent
@@ -126,51 +132,57 @@ csharp_preferred_modifier_order = public,private,protected,internal,new,abstract
 # Skipped because roslyn cannot separate +-*/ with << >>
 
 #Style - expression bodies
-csharp_style_expression_bodied_accessors = true:silent
+csharp_style_expression_bodied_accessors = true:warning
 csharp_style_expression_bodied_constructors = false:none
-csharp_style_expression_bodied_indexers = true:silent
+csharp_style_expression_bodied_indexers = true:warning
 csharp_style_expression_bodied_methods = true:silent
-csharp_style_expression_bodied_operators = true:silent
-csharp_style_expression_bodied_properties = true:silent
+csharp_style_expression_bodied_operators = true:warning
+csharp_style_expression_bodied_properties = true:warning
+csharp_style_expression_bodied_local_functions = true:silent
 
 #Style - expression preferences
 dotnet_style_object_initializer = true:warning
 dotnet_style_collection_initializer = true:warning
 dotnet_style_prefer_inferred_anonymous_type_member_names = true:warning
-dotnet_style_prefer_auto_properties = true:silent
+dotnet_style_prefer_auto_properties = true:warning
 dotnet_style_prefer_conditional_expression_over_assignment = true:silent
 dotnet_style_prefer_conditional_expression_over_return = true:silent
-dotnet_style_prefer_compound_assignment = true:silent
+dotnet_style_prefer_compound_assignment = true:warning
 
 #Style - null/type checks
 dotnet_style_coalesce_expression = true:warning
 dotnet_style_null_propagation = true:warning
-csharp_style_pattern_matching_over_is_with_cast_check = true:silent
-csharp_style_pattern_matching_over_as_with_null_check = true:silent
+csharp_style_pattern_matching_over_is_with_cast_check = true:warning
+csharp_style_pattern_matching_over_as_with_null_check = true:warning
 csharp_style_throw_expression = true:silent
-csharp_style_conditional_delegate_call = true:suggestion
+csharp_style_conditional_delegate_call = true:warning
 
 #Style - unused
+dotnet_style_readonly_field = true:silent
 dotnet_code_quality_unused_parameters = non_public:silent
 csharp_style_unused_value_expression_statement_preference = discard_variable:silent
-csharp_style_unused_value_assignment_preference = discard_variable:silent
+csharp_style_unused_value_assignment_preference = discard_variable:warning
 
 #Style - variable declaration
-csharp_style_inlined_variable_declaration = true:silent
-csharp_style_deconstructed_variable_declaration = true:silent
+csharp_style_inlined_variable_declaration = true:warning
+csharp_style_deconstructed_variable_declaration = true:warning
 
 #Style - other C# 7.x features
-csharp_style_expression_bodied_local_functions = true:silent
 dotnet_style_prefer_inferred_tuple_names = true:warning
 csharp_prefer_simple_default_expression = true:warning
-csharp_style_pattern_local_over_anonymous_function = true:silent
+csharp_style_pattern_local_over_anonymous_function = true:warning
 dotnet_style_prefer_is_null_check_over_reference_equality_method = true:silent
 
+#Style - C# 8 features
+csharp_prefer_static_local_function = true:warning
+csharp_prefer_simple_using_statement = true:silent
+csharp_style_prefer_index_operator = false:none
+csharp_style_prefer_range_operator = false:none
+csharp_style_prefer_switch_expression = false:none
+
 #Supressing roslyn built-in analyzers
 # Suppress: EC112
 
-#Field can be readonly
-dotnet_diagnostic.IDE0044.severity = silent
 #Private method is unused
 dotnet_diagnostic.IDE0051.severity = silent
 #Private member is unused

Directory.Build.props

@@ -1,7 +1,7 @@
 <!-- Contains required properties for osu!framework projects. -->
 <Project>
   <PropertyGroup Label="C#">
-    <LangVersion>7.3</LangVersion>
+    <LangVersion>8.0</LangVersion>
   </PropertyGroup>
   <PropertyGroup>
     <ApplicationManifest>$(MSBuildThisFileDirectory)app.manifest</ApplicationManifest>

osu.Android.props

@@ -1,5 +1,6 @@
 <Project>
-<PropertyGroup>
+  <PropertyGroup>
+    <LangVersion>8.0</LangVersion>
     <OutputPath>bin\$(Configuration)</OutputPath>
     <WarningLevel>4</WarningLevel>
     <SchemaVersion>2.0</SchemaVersion>

osu.Desktop/OsuGameDesktop.cs

@@ -112,14 +112,14 @@ namespace osu.Desktop
         {
             protected override string LocateBasePath()
             {
-                bool checkExists(string p) => Directory.Exists(Path.Combine(p, "Songs"));
+                static bool checkExists(string p) => Directory.Exists(Path.Combine(p, "Songs"));
 
                 string stableInstallPath;
 
                 try
                 {
                     using (RegistryKey key = Registry.ClassesRoot.OpenSubKey("osu"))
-                        stableInstallPath = key?.OpenSubKey(@"shell\open\command")?.GetValue(String.Empty).ToString().Split('"')[1].Replace("osu!.exe", "");
+                        stableInstallPath = key?.OpenSubKey(@"shell\open\command")?.GetValue(string.Empty).ToString().Split('"')[1].Replace("osu!.exe", "");
 
                     if (checkExists(stableInstallPath))
                         return stableInstallPath;

osu.Game.Rulesets.Catch/Beatmaps/CatchBeatmapConverter.cs

@@ -8,6 +8,7 @@ using System;
 using osu.Game.Rulesets.Catch.UI;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Objects;
+using osu.Framework.Extensions.IEnumerableExtensions;
 
 namespace osu.Game.Rulesets.Catch.Beatmaps
 {
@@ -22,48 +23,44 @@ namespace osu.Game.Rulesets.Catch.Beatmaps
 
         protected override IEnumerable<CatchHitObject> ConvertHitObject(HitObject obj, IBeatmap beatmap)
         {
-            var curveData = obj as IHasCurve;
             var positionData = obj as IHasXPosition;
             var comboData = obj as IHasCombo;
-            var endTime = obj as IHasEndTime;
-            var legacyOffset = obj as IHasLegacyLastTickOffset;
 
-            if (curveData != null)
+            switch (obj)
             {
-                yield return new JuiceStream
-                {
-                    StartTime = obj.StartTime,
-                    Samples = obj.Samples,
-                    Path = curveData.Path,
-                    NodeSamples = curveData.NodeSamples,
-                    RepeatCount = curveData.RepeatCount,
-                    X = (positionData?.X ?? 0) / CatchPlayfield.BASE_WIDTH,
-                    NewCombo = comboData?.NewCombo ?? false,
-                    ComboOffset = comboData?.ComboOffset ?? 0,
-                    LegacyLastTickOffset = legacyOffset?.LegacyLastTickOffset ?? 0
-                };
-            }
-            else if (endTime != null)
-            {
-                yield return new BananaShower
-                {
-                    StartTime = obj.StartTime,
-                    Samples = obj.Samples,
-                    Duration = endTime.Duration,
-                    NewCombo = comboData?.NewCombo ?? false,
-                    ComboOffset = comboData?.ComboOffset ?? 0,
-                };
-            }
-            else
-            {
-                yield return new Fruit
-                {
-                    StartTime = obj.StartTime,
-                    Samples = obj.Samples,
-                    NewCombo = comboData?.NewCombo ?? false,
-                    ComboOffset = comboData?.ComboOffset ?? 0,
-                    X = (positionData?.X ?? 0) / CatchPlayfield.BASE_WIDTH
-                };
+                case IHasCurve curveData:
+                    return new JuiceStream
+                    {
+                        StartTime = obj.StartTime,
+                        Samples = obj.Samples,
+                        Path = curveData.Path,
+                        NodeSamples = curveData.NodeSamples,
+                        RepeatCount = curveData.RepeatCount,
+                        X = (positionData?.X ?? 0) / CatchPlayfield.BASE_WIDTH,
+                        NewCombo = comboData?.NewCombo ?? false,
+                        ComboOffset = comboData?.ComboOffset ?? 0,
+                        LegacyLastTickOffset = (obj as IHasLegacyLastTickOffset)?.LegacyLastTickOffset ?? 0
+                    }.Yield();
+
+                case IHasEndTime endTime:
+                    return new BananaShower
+                    {
+                        StartTime = obj.StartTime,
+                        Samples = obj.Samples,
+                        Duration = endTime.Duration,
+                        NewCombo = comboData?.NewCombo ?? false,
+                        ComboOffset = comboData?.ComboOffset ?? 0,
+                    }.Yield();
+
+                default:
+                    return new Fruit
+                    {
+                        StartTime = obj.StartTime,
+                        Samples = obj.Samples,
+                        NewCombo = comboData?.NewCombo ?? false,
+                        ComboOffset = comboData?.ComboOffset ?? 0,
+                        X = (positionData?.X ?? 0) / CatchPlayfield.BASE_WIDTH
+                    }.Yield();
             }
         }
 

osu.Game.Rulesets.Catch/Objects/Drawable/DrawableFruit.cs

@@ -98,7 +98,7 @@ namespace osu.Game.Rulesets.Catch.Objects.Drawable
 
             const float small_pulp = large_pulp_3 / 2;
 
-            Vector2 positionAt(float angle, float distance) => new Vector2(
+            static Vector2 positionAt(float angle, float distance) => new Vector2(
                 distance * MathF.Sin(angle * MathF.PI / 180),
                 distance * MathF.Cos(angle * MathF.PI / 180));
 

osu.Game.Rulesets.Catch/Objects/JuiceStream.cs

@@ -116,13 +116,7 @@ namespace osu.Game.Rulesets.Catch.Objects
 
         public double Duration => EndTime - StartTime;
 
-        private SliderPath path;
-
-        public SliderPath Path
-        {
-            get => path;
-            set => path = value;
-        }
+        public SliderPath Path { get; set; }
 
         public double Distance => Path.Distance;
 

osu.Game.Rulesets.Catch/UI/CatcherArea.cs

@@ -198,7 +198,7 @@ namespace osu.Game.Rulesets.Catch.UI
                 var additive = createCatcherSprite();
 
                 additive.Anchor = Anchor;
-                additive.OriginPosition = additive.OriginPosition + new Vector2(DrawWidth / 2, 0); // also temporary to align sprite correctly.
+                additive.OriginPosition += new Vector2(DrawWidth / 2, 0); // also temporary to align sprite correctly.
                 additive.Position = Position;
                 additive.Scale = Scale;
                 additive.Colour = HyperDashing ? Color4.Red : Color4.White;

osu.Game.Rulesets.Mania/Beatmaps/ManiaBeatmapConverter.cs

@@ -51,7 +51,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
 
                 if (TargetColumns >= 10)
                 {
-                    TargetColumns = TargetColumns / 2;
+                    TargetColumns /= 2;
                     Dual = true;
                 }
             }
@@ -156,37 +156,44 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
         /// <returns>The hit objects generated.</returns>
         private IEnumerable<ManiaHitObject> generateConverted(HitObject original, IBeatmap originalBeatmap)
         {
-            var endTimeData = original as IHasEndTime;
-            var distanceData = original as IHasDistance;
-            var positionData = original as IHasPosition;
-
             Patterns.PatternGenerator conversion = null;
 
-            if (distanceData != null)
+            switch (original)
             {
-                var generator = new DistanceObjectPatternGenerator(Random, original, beatmap, lastPattern, originalBeatmap);
-                conversion = generator;
-
-                for (double time = original.StartTime; !Precision.DefinitelyBigger(time, generator.EndTime); time += generator.SegmentDuration)
+                case IHasDistance _:
                 {
-                    recordNote(time, positionData?.Position ?? Vector2.Zero);
-                    computeDensity(time);
+                    var generator = new DistanceObjectPatternGenerator(Random, original, beatmap, lastPattern, originalBeatmap);
+                    conversion = generator;
+
+                    var positionData = original as IHasPosition;
+
+                    for (double time = original.StartTime; !Precision.DefinitelyBigger(time, generator.EndTime); time += generator.SegmentDuration)
+                    {
+                        recordNote(time, positionData?.Position ?? Vector2.Zero);
+                        computeDensity(time);
+                    }
+
+                    break;
                 }
-            }
-            else if (endTimeData != null)
-            {
-                conversion = new EndTimeObjectPatternGenerator(Random, original, beatmap, originalBeatmap);
 
-                recordNote(endTimeData.EndTime, new Vector2(256, 192));
-                computeDensity(endTimeData.EndTime);
-            }
-            else if (positionData != null)
-            {
-                computeDensity(original.StartTime);
+                case IHasEndTime endTimeData:
+                {
+                    conversion = new EndTimeObjectPatternGenerator(Random, original, beatmap, originalBeatmap);
 
-                conversion = new HitObjectPatternGenerator(Random, original, beatmap, lastPattern, lastTime, lastPosition, density, lastStair, originalBeatmap);
+                    recordNote(endTimeData.EndTime, new Vector2(256, 192));
+                    computeDensity(endTimeData.EndTime);
+                    break;
+                }
 
-                recordNote(original.StartTime, positionData.Position);
+                case IHasPosition positionData:
+                {
+                    computeDensity(original.StartTime);
+
+                    conversion = new HitObjectPatternGenerator(Random, original, beatmap, lastPattern, lastTime, lastPosition, density, lastStair, originalBeatmap);
+
+                    recordNote(original.StartTime, positionData.Position);
+                    break;
+                }
             }
 
             if (conversion == null)
@@ -219,14 +226,13 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
 
             private Pattern generate()
             {
-                var endTimeData = HitObject as IHasEndTime;
                 var positionData = HitObject as IHasXPosition;
 
                 int column = GetColumn(positionData?.X ?? 0);
 
                 var pattern = new Pattern();
 
-                if (endTimeData != null)
+                if (HitObject is IHasEndTime endTimeData)
                 {
                     pattern.Add(new HoldNote
                     {
@@ -237,7 +243,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
                         Tail = { Samples = sampleInfoListAt(endTimeData.EndTime) },
                     });
                 }
-                else if (positionData != null)
+                else if (HitObject is IHasXPosition)
                 {
                     pattern.Add(new Note
                     {
@@ -257,9 +263,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps
             /// <returns></returns>
             private IList<HitSampleInfo> sampleInfoListAt(double time)
             {
-                var curveData = HitObject as IHasCurve;
-
-                if (curveData == null)
+                if (!(HitObject is IHasCurve curveData))
                     return HitObject.Samples;
 
                 double segmentTime = (curveData.EndTime - HitObject.StartTime) / curveData.SpanCount();

osu.Game.Rulesets.Mania/Beatmaps/Patterns/Legacy/DistanceObjectPatternGenerator.cs

@@ -364,7 +364,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
                     break;
             }
 
-            bool isDoubleSample(HitSampleInfo sample) => sample.Name == HitSampleInfo.HIT_CLAP || sample.Name == HitSampleInfo.HIT_FINISH;
+            static bool isDoubleSample(HitSampleInfo sample) => sample.Name == HitSampleInfo.HIT_CLAP || sample.Name == HitSampleInfo.HIT_FINISH;
 
             bool canGenerateTwoNotes = !convertType.HasFlag(PatternType.LowProbability);
             canGenerateTwoNotes &= HitObject.Samples.Any(isDoubleSample) || sampleInfoListAt(HitObject.StartTime).Any(isDoubleSample);
@@ -474,9 +474,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
         /// <returns></returns>
         private IList<HitSampleInfo> sampleInfoListAt(double time)
         {
-            var curveData = HitObject as IHasCurve;
-
-            if (curveData == null)
+            if (!(HitObject is IHasCurve curveData))
                 return HitObject.Samples;
 
             double segmentTime = (EndTime - HitObject.StartTime) / spanCount;

osu.Game.Rulesets.Mania/Beatmaps/Patterns/Legacy/HitObjectPatternGenerator.cs

@@ -12,6 +12,7 @@ using osu.Game.Rulesets.Mania.MathUtils;
 using osu.Game.Rulesets.Mania.Objects;
 using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Objects.Types;
+using osu.Framework.Extensions.IEnumerableExtensions;
 
 namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
 {
@@ -88,15 +89,10 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
 
         public override IEnumerable<Pattern> Generate()
         {
-            yield return generate();
-        }
-
-        private Pattern generate()
-        {
-            var pattern = new Pattern();
-
-            try
+            Pattern generateCore()
             {
+                var pattern = new Pattern();
+
                 if (TotalColumns == 1)
                 {
                     addToPattern(pattern, 0);
@@ -168,54 +164,56 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
                 }
 
                 if (convertType.HasFlag(PatternType.KeepSingle))
-                    return pattern = generateRandomNotes(1);
+                    return generateRandomNotes(1);
 
                 if (convertType.HasFlag(PatternType.Mirror))
                 {
                     if (ConversionDifficulty > 6.5)
-                        return pattern = generateRandomPatternWithMirrored(0.12, 0.38, 0.12);
+                        return generateRandomPatternWithMirrored(0.12, 0.38, 0.12);
                     if (ConversionDifficulty > 4)
-                        return pattern = generateRandomPatternWithMirrored(0.12, 0.17, 0);
+                        return generateRandomPatternWithMirrored(0.12, 0.17, 0);
 
-                    return pattern = generateRandomPatternWithMirrored(0.12, 0, 0);
+                    return generateRandomPatternWithMirrored(0.12, 0, 0);
                 }
 
                 if (ConversionDifficulty > 6.5)
                 {
                     if (convertType.HasFlag(PatternType.LowProbability))
-                        return pattern = generateRandomPattern(0.78, 0.42, 0, 0);
+                        return generateRandomPattern(0.78, 0.42, 0, 0);
 
-                    return pattern = generateRandomPattern(1, 0.62, 0, 0);
+                    return generateRandomPattern(1, 0.62, 0, 0);
                 }
 
                 if (ConversionDifficulty > 4)
                 {
                     if (convertType.HasFlag(PatternType.LowProbability))
-                        return pattern = generateRandomPattern(0.35, 0.08, 0, 0);
+                        return generateRandomPattern(0.35, 0.08, 0, 0);
 
-                    return pattern = generateRandomPattern(0.52, 0.15, 0, 0);
+                    return generateRandomPattern(0.52, 0.15, 0, 0);
                 }
 
                 if (ConversionDifficulty > 2)
                 {
                     if (convertType.HasFlag(PatternType.LowProbability))
-                        return pattern = generateRandomPattern(0.18, 0, 0, 0);
+                        return generateRandomPattern(0.18, 0, 0, 0);
 
-                    return pattern = generateRandomPattern(0.45, 0, 0, 0);
+                    return generateRandomPattern(0.45, 0, 0, 0);
                 }
 
-                return pattern = generateRandomPattern(0, 0, 0, 0);
+                return generateRandomPattern(0, 0, 0, 0);
             }
-            finally
+
+            var p = generateCore();
+
+            foreach (var obj in p.HitObjects)
             {
-                foreach (var obj in pattern.HitObjects)
-                {
-                    if (convertType.HasFlag(PatternType.Stair) && obj.Column == TotalColumns - 1)
-                        StairType = PatternType.ReverseStair;
-                    if (convertType.HasFlag(PatternType.ReverseStair) && obj.Column == RandomStart)
-                        StairType = PatternType.Stair;
-                }
+                if (convertType.HasFlag(PatternType.Stair) && obj.Column == TotalColumns - 1)
+                    StairType = PatternType.ReverseStair;
+                if (convertType.HasFlag(PatternType.ReverseStair) && obj.Column == RandomStart)
+                    StairType = PatternType.Stair;
             }
+
+            return p.Yield();
         }
 
         /// <summary>
@@ -303,8 +301,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
 
             var pattern = new Pattern();
 
-            bool addToCentre;
-            int noteCount = getRandomNoteCountMirrored(centreProbability, p2, p3, out addToCentre);
+            int noteCount = getRandomNoteCountMirrored(centreProbability, p2, p3, out var addToCentre);
 
             int columnLimit = (TotalColumns % 2 == 0 ? TotalColumns : TotalColumns - 1) / 2;
             int nextColumn = GetRandomColumn(upperBound: columnLimit);
@@ -384,8 +381,6 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
         /// <returns>The amount of notes to be generated. The note to be added to the centre column will NOT be part of this count.</returns>
         private int getRandomNoteCountMirrored(double centreProbability, double p2, double p3, out bool addToCentre)
         {
-            addToCentre = false;
-
             switch (TotalColumns)
             {
                 case 2:

osu.Game.Rulesets.Mania/Beatmaps/Patterns/Legacy/PatternGenerator.cs

@@ -147,9 +147,9 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns.Legacy
         protected int FindAvailableColumn(int initialColumn, int? lowerBound = null, int? upperBound = null, Func<int, int> nextColumn = null, [InstantHandle] Func<int, bool> validation = null,
                                           params Pattern[] patterns)
         {
-            lowerBound = lowerBound ?? RandomStart;
-            upperBound = upperBound ?? TotalColumns;
-            nextColumn = nextColumn ?? (_ => GetRandomColumn(lowerBound, upperBound));
+            lowerBound ??= RandomStart;
+            upperBound ??= TotalColumns;
+            nextColumn ??= (_ => GetRandomColumn(lowerBound, upperBound));
 
             // Check for the initial column
             if (isValid(initialColumn))

osu.Game.Rulesets.Mania/Edit/ManiaSelectionHandler.cs

@@ -55,7 +55,7 @@ namespace osu.Game.Rulesets.Mania.Edit
 
             // Flip the vertical coordinate space when scrolling downwards
             if (scrollingInfo.Direction.Value == ScrollingDirection.Down)
-                targetPosition = targetPosition - referenceParent.DrawHeight;
+                targetPosition -= referenceParent.DrawHeight;
 
             float movementDelta = targetPosition - reference.DrawableObject.Position.Y;
 

osu.Game.Rulesets.Mania/UI/ManiaPlayfield.cs

@@ -96,7 +96,7 @@ namespace osu.Game.Rulesets.Mania.UI
 
             foreach (var stage in stages)
             {
-                sum = sum + stage.Columns.Count;
+                sum += stage.Columns.Count;
                 if (sum > column)
                     return stage;
             }

osu.Game.Rulesets.Osu.Tests/OsuBeatmapConversionTest.cs

@@ -40,7 +40,7 @@ namespace osu.Game.Rulesets.Osu.Tests
                     break;
             }
 
-            ConvertValue createConvertValue(OsuHitObject obj) => new ConvertValue
+            static ConvertValue createConvertValue(OsuHitObject obj) => new ConvertValue
             {
                 StartTime = obj.StartTime,
                 EndTime = obj.GetEndTime(),

osu.Game.Rulesets.Osu.Tests/TestSceneHitCircle.cs

@@ -45,7 +45,7 @@ namespace osu.Game.Rulesets.Osu.Tests
 
         private Drawable testSingle(float circleSize, bool auto = false, double timeOffset = 0, Vector2? positionOffset = null)
         {
-            positionOffset = positionOffset ?? Vector2.Zero;
+            positionOffset ??= Vector2.Zero;
 
             var circle = new HitCircle
             {

osu.Game.Rulesets.Osu.Tests/TestSceneSlider.cs

@@ -148,9 +148,9 @@ namespace osu.Game.Rulesets.Osu.Tests
             AddAssert("repeat samples updated", () => ((Slider)slider.HitObject).NestedHitObjects.OfType<RepeatPoint>().All(assertSamples));
             AddAssert("tail has no samples", () => ((Slider)slider.HitObject).TailCircle.Samples.Count == 0);
 
-            bool assertTickSamples(SliderTick tick) => tick.Samples.Single().Name == "slidertick";
+            static bool assertTickSamples(SliderTick tick) => tick.Samples.Single().Name == "slidertick";
 
-            bool assertSamples(HitObject hitObject)
+            static bool assertSamples(HitObject hitObject)
             {
                 return hitObject.Samples.Any(s => s.Name == HitSampleInfo.HIT_CLAP)
                        && hitObject.Samples.Any(s => s.Name == HitSampleInfo.HIT_WHISTLE);
@@ -183,8 +183,9 @@ namespace osu.Game.Rulesets.Osu.Tests
             AddAssert("repeat samples not updated", () => ((Slider)slider.HitObject).NestedHitObjects.OfType<RepeatPoint>().All(assertSamples));
             AddAssert("tail has no samples", () => ((Slider)slider.HitObject).TailCircle.Samples.Count == 0);
 
-            bool assertTickSamples(SliderTick tick) => tick.Samples.Single().Name == "slidertick";
-            bool assertSamples(HitObject hitObject) => hitObject.Samples.All(s => s.Name != HitSampleInfo.HIT_CLAP && s.Name != HitSampleInfo.HIT_WHISTLE);
+            static bool assertTickSamples(SliderTick tick) => tick.Samples.Single().Name == "slidertick";
+
+            static bool assertSamples(HitObject hitObject) => hitObject.Samples.All(s => s.Name != HitSampleInfo.HIT_CLAP && s.Name != HitSampleInfo.HIT_WHISTLE);
         }
 
         private Drawable testSimpleBig(int repeats = 0) => createSlider(2, repeats: repeats);
@@ -379,8 +380,7 @@ namespace osu.Game.Rulesets.Osu.Tests
 
         private void onNewResult(DrawableHitObject judgedObject, JudgementResult result)
         {
-            var osuObject = judgedObject as DrawableOsuHitObject;
-            if (osuObject == null)
+            if (!(judgedObject is DrawableOsuHitObject osuObject))
                 return;
 
             OsuSpriteText text;

osu.Game.Rulesets.Osu/Beatmaps/OsuBeatmapConverter.cs

@@ -9,6 +9,7 @@ using System.Collections.Generic;
 using osu.Game.Rulesets.Objects.Types;
 using System;
 using osu.Game.Rulesets.Osu.UI;
+using osu.Framework.Extensions.IEnumerableExtensions;
 
 namespace osu.Game.Rulesets.Osu.Beatmaps
 {
@@ -23,52 +24,48 @@ namespace osu.Game.Rulesets.Osu.Beatmaps
 
         protected override IEnumerable<OsuHitObject> ConvertHitObject(HitObject original, IBeatmap beatmap)
         {
-            var curveData = original as IHasCurve;
-            var endTimeData = original as IHasEndTime;
             var positionData = original as IHasPosition;
             var comboData = original as IHasCombo;
-            var legacyOffset = original as IHasLegacyLastTickOffset;
 
-            if (curveData != null)
+            switch (original)
             {
-                yield return new Slider
-                {
-                    StartTime = original.StartTime,
-                    Samples = original.Samples,
-                    Path = curveData.Path,
-                    NodeSamples = curveData.NodeSamples,
-                    RepeatCount = curveData.RepeatCount,
-                    Position = positionData?.Position ?? Vector2.Zero,
-                    NewCombo = comboData?.NewCombo ?? false,
-                    ComboOffset = comboData?.ComboOffset ?? 0,
-                    LegacyLastTickOffset = legacyOffset?.LegacyLastTickOffset,
-                    // prior to v8, speed multipliers don't adjust for how many ticks are generated over the same distance.
-                    // this results in more (or less) ticks being generated in <v8 maps for the same time duration.
-                    TickDistanceMultiplier = beatmap.BeatmapInfo.BeatmapVersion < 8 ? 1f / beatmap.ControlPointInfo.DifficultyPointAt(original.StartTime).SpeedMultiplier : 1
-                };
-            }
-            else if (endTimeData != null)
-            {
-                yield return new Spinner
-                {
-                    StartTime = original.StartTime,
-                    Samples = original.Samples,
-                    EndTime = endTimeData.EndTime,
-                    Position = positionData?.Position ?? OsuPlayfield.BASE_SIZE / 2,
-                    NewCombo = comboData?.NewCombo ?? false,
-                    ComboOffset = comboData?.ComboOffset ?? 0,
-                };
-            }
-            else
-            {
-                yield return new HitCircle
-                {
-                    StartTime = original.StartTime,
-                    Samples = original.Samples,
-                    Position = positionData?.Position ?? Vector2.Zero,
-                    NewCombo = comboData?.NewCombo ?? false,
-                    ComboOffset = comboData?.ComboOffset ?? 0,
-                };
+                case IHasCurve curveData:
+                    return new Slider
+                    {
+                        StartTime = original.StartTime,
+                        Samples = original.Samples,
+                        Path = curveData.Path,
+                        NodeSamples = curveData.NodeSamples,
+                        RepeatCount = curveData.RepeatCount,
+                        Position = positionData?.Position ?? Vector2.Zero,
+                        NewCombo = comboData?.NewCombo ?? false,
+                        ComboOffset = comboData?.ComboOffset ?? 0,
+                        LegacyLastTickOffset = (original as IHasLegacyLastTickOffset)?.LegacyLastTickOffset,
+                        // prior to v8, speed multipliers don't adjust for how many ticks are generated over the same distance.
+                        // this results in more (or less) ticks being generated in <v8 maps for the same time duration.
+                        TickDistanceMultiplier = beatmap.BeatmapInfo.BeatmapVersion < 8 ? 1f / beatmap.ControlPointInfo.DifficultyPointAt(original.StartTime).SpeedMultiplier : 1
+                    }.Yield();
+
+                case IHasEndTime endTimeData:
+                    return new Spinner
+                    {
+                        StartTime = original.StartTime,
+                        Samples = original.Samples,
+                        EndTime = endTimeData.EndTime,
+                        Position = positionData?.Position ?? OsuPlayfield.BASE_SIZE / 2,
+                        NewCombo = comboData?.NewCombo ?? false,
+                        ComboOffset = comboData?.ComboOffset ?? 0,
+                    }.Yield();
+
+                default:
+                    return new HitCircle
+                    {
+                        StartTime = original.StartTime,
+                        Samples = original.Samples,
+                        Position = positionData?.Position ?? Vector2.Zero,
+                        NewCombo = comboData?.NewCombo ?? false,
+                        ComboOffset = comboData?.ComboOffset ?? 0,
+                    }.Yield();
             }
         }
 

osu.Game.Rulesets.Osu/Difficulty/Preprocessing/OsuDifficultyHitObject.cs

@@ -103,7 +103,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
                 if (progress % 2 >= 1)
                     progress = 1 - progress % 1;
                 else
-                    progress = progress % 1;
+                    progress %= 1;
 
                 // ReSharper disable once PossibleInvalidOperationException (bugged in current r# version)
                 var diff = slider.StackedPosition + slider.Path.PositionAt(progress) - slider.LazyEndPosition.Value;

osu.Game.Rulesets.Osu/Edit/Blueprints/Sliders/Components/PathControlPointVisualiser.cs

@@ -130,7 +130,7 @@ namespace osu.Game.Rulesets.Osu.Edit.Blueprints.Sliders.Components
                 newControlPoints[i] = newControlPoints[i] - first;
 
             // The slider's position defines the position of the first control point, and all further control points are relative to that point
-            slider.Position = slider.Position + first;
+            slider.Position += first;
 
             // Since pieces are re-used, they will not point to the deleted control points while remaining selected
             foreach (var piece in Pieces)

osu.Game.Rulesets.Osu/Mods/OsuModHardRock.cs

@@ -22,8 +22,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 
             osuObject.Position = new Vector2(osuObject.Position.X, OsuPlayfield.BASE_SIZE.Y - osuObject.Y);
 
-            var slider = hitObject as Slider;
-            if (slider == null)
+            if (!(hitObject is Slider slider))
                 return;
 
             slider.NestedHitObjects.OfType<SliderTick>().ForEach(h => h.Position = new Vector2(h.Position.X, OsuPlayfield.BASE_SIZE.Y - h.Position.Y));

osu.Game.Rulesets.Osu/Mods/OsuModHidden.cs

@@ -25,7 +25,7 @@ namespace osu.Game.Rulesets.Osu.Mods
 
         public override void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables)
         {
-            void adjustFadeIn(OsuHitObject h) => h.TimeFadeIn = h.TimePreempt * fade_in_duration_multiplier;
+            static void adjustFadeIn(OsuHitObject h) => h.TimeFadeIn = h.TimePreempt * fade_in_duration_multiplier;
 
             foreach (var d in drawables.OfType<DrawableOsuHitObject>())
             {

osu.Game.Rulesets.Osu/Objects/Drawables/DrawableOsuHitObject.cs

@@ -37,7 +37,7 @@ namespace osu.Game.Rulesets.Osu.Objects.Drawables
         protected sealed override double InitialLifetimeOffset => HitObject.TimePreempt;
 
         private OsuInputManager osuActionInputManager;
-        internal OsuInputManager OsuActionInputManager => osuActionInputManager ?? (osuActionInputManager = GetContainingInputManager() as OsuInputManager);
+        internal OsuInputManager OsuActionInputManager => osuActionInputManager ??= GetContainingInputManager() as OsuInputManager;
 
         protected virtual void Shake(double maximumLength) => shakeContainer.Shake(maximumLength);
 

osu.Game.Rulesets.Taiko/Beatmaps/TaikoBeatmapConverter.cs

@@ -73,127 +73,133 @@ namespace osu.Game.Rulesets.Taiko.Beatmaps
 
         protected override IEnumerable<TaikoHitObject> ConvertHitObject(HitObject obj, IBeatmap beatmap)
         {
-            var distanceData = obj as IHasDistance;
-            var repeatsData = obj as IHasRepeats;
-            var endTimeData = obj as IHasEndTime;
-            var curveData = obj as IHasCurve;
-
             // Old osu! used hit sounding to determine various hit type information
             IList<HitSampleInfo> samples = obj.Samples;
 
             bool strong = samples.Any(s => s.Name == HitSampleInfo.HIT_FINISH);
 
-            if (distanceData != null)
+            switch (obj)
             {
-                // Number of spans of the object - one for the initial length and for each repeat
-                int spans = repeatsData?.SpanCount() ?? 1;
-
-                TimingControlPoint timingPoint = beatmap.ControlPointInfo.TimingPointAt(obj.StartTime);
-                DifficultyControlPoint difficultyPoint = beatmap.ControlPointInfo.DifficultyPointAt(obj.StartTime);
-
-                double speedAdjustment = difficultyPoint.SpeedMultiplier;
-                double speedAdjustedBeatLength = timingPoint.BeatLength / speedAdjustment;
-
-                // The true distance, accounting for any repeats. This ends up being the drum roll distance later
-                double distance = distanceData.Distance * spans * legacy_velocity_multiplier;
-
-                // The velocity of the taiko hit object - calculated as the velocity of a drum roll
-                double taikoVelocity = taiko_base_distance * beatmap.BeatmapInfo.BaseDifficulty.SliderMultiplier / speedAdjustedBeatLength;
-                // The duration of the taiko hit object
-                double taikoDuration = distance / taikoVelocity;
-
-                // The velocity of the osu! hit object - calculated as the velocity of a slider
-                double osuVelocity = osu_base_scoring_distance * beatmap.BeatmapInfo.BaseDifficulty.SliderMultiplier / speedAdjustedBeatLength;
-                // The duration of the osu! hit object
-                double osuDuration = distance / osuVelocity;
-
-                // osu-stable always uses the speed-adjusted beatlength to determine the velocities, but
-                // only uses it for tick rate if beatmap version < 8
-                if (beatmap.BeatmapInfo.BeatmapVersion >= 8)
-                    speedAdjustedBeatLength *= speedAdjustment;
-
-                // If the drum roll is to be split into hit circles, assume the ticks are 1/8 spaced within the duration of one beat
-                double tickSpacing = Math.Min(speedAdjustedBeatLength / beatmap.BeatmapInfo.BaseDifficulty.SliderTickRate, taikoDuration / spans);
-
-                if (!isForCurrentRuleset && tickSpacing > 0 && osuDuration < 2 * speedAdjustedBeatLength)
+                case IHasDistance distanceData:
                 {
-                    List<IList<HitSampleInfo>> allSamples = curveData != null ? curveData.NodeSamples : new List<IList<HitSampleInfo>>(new[] { samples });
+                    // Number of spans of the object - one for the initial length and for each repeat
+                    int spans = (obj as IHasRepeats)?.SpanCount() ?? 1;
 
-                    int i = 0;
+                    TimingControlPoint timingPoint = beatmap.ControlPointInfo.TimingPointAt(obj.StartTime);
+                    DifficultyControlPoint difficultyPoint = beatmap.ControlPointInfo.DifficultyPointAt(obj.StartTime);
 
-                    for (double j = obj.StartTime; j <= obj.StartTime + taikoDuration + tickSpacing / 8; j += tickSpacing)
+                    double speedAdjustment = difficultyPoint.SpeedMultiplier;
+                    double speedAdjustedBeatLength = timingPoint.BeatLength / speedAdjustment;
+
+                    // The true distance, accounting for any repeats. This ends up being the drum roll distance later
+                    double distance = distanceData.Distance * spans * legacy_velocity_multiplier;
+
+                    // The velocity of the taiko hit object - calculated as the velocity of a drum roll
+                    double taikoVelocity = taiko_base_distance * beatmap.BeatmapInfo.BaseDifficulty.SliderMultiplier / speedAdjustedBeatLength;
+                    // The duration of the taiko hit object
+                    double taikoDuration = distance / taikoVelocity;
+
+                    // The velocity of the osu! hit object - calculated as the velocity of a slider
+                    double osuVelocity = osu_base_scoring_distance * beatmap.BeatmapInfo.BaseDifficulty.SliderMultiplier / speedAdjustedBeatLength;
+                    // The duration of the osu! hit object
+                    double osuDuration = distance / osuVelocity;
+
+                    // osu-stable always uses the speed-adjusted beatlength to determine the velocities, but
+                    // only uses it for tick rate if beatmap version < 8
+                    if (beatmap.BeatmapInfo.BeatmapVersion >= 8)
+                        speedAdjustedBeatLength *= speedAdjustment;
+
+                    // If the drum roll is to be split into hit circles, assume the ticks are 1/8 spaced within the duration of one beat
+                    double tickSpacing = Math.Min(speedAdjustedBeatLength / beatmap.BeatmapInfo.BaseDifficulty.SliderTickRate, taikoDuration / spans);
+
+                    if (!isForCurrentRuleset && tickSpacing > 0 && osuDuration < 2 * speedAdjustedBeatLength)
                     {
-                        IList<HitSampleInfo> currentSamples = allSamples[i];
-                        bool isRim = currentSamples.Any(s => s.Name == HitSampleInfo.HIT_CLAP || s.Name == HitSampleInfo.HIT_WHISTLE);
-                        strong = currentSamples.Any(s => s.Name == HitSampleInfo.HIT_FINISH);
+                        List<IList<HitSampleInfo>> allSamples = obj is IHasCurve curveData ? curveData.NodeSamples : new List<IList<HitSampleInfo>>(new[] { samples });
 
-                        if (isRim)
-                        {
-                            yield return new RimHit
-                            {
-                                StartTime = j,
-                                Samples = currentSamples,
-                                IsStrong = strong
-                            };
-                        }
-                        else
-                        {
-                            yield return new CentreHit
-                            {
-                                StartTime = j,
-                                Samples = currentSamples,
-                                IsStrong = strong
-                            };
-                        }
+                        int i = 0;
 
-                        i = (i + 1) % allSamples.Count;
+                        for (double j = obj.StartTime; j <= obj.StartTime + taikoDuration + tickSpacing / 8; j += tickSpacing)
+                        {
+                            IList<HitSampleInfo> currentSamples = allSamples[i];
+                            bool isRim = currentSamples.Any(s => s.Name == HitSampleInfo.HIT_CLAP || s.Name == HitSampleInfo.HIT_WHISTLE);
+                            strong = currentSamples.Any(s => s.Name == HitSampleInfo.HIT_FINISH);
+
+                            if (isRim)
+                            {
+                                yield return new RimHit
+                                {
+                                    StartTime = j,
+                                    Samples = currentSamples,
+                                    IsStrong = strong
+                                };
+                            }
+                            else
+                            {
+                                yield return new CentreHit
+                                {
+                                    StartTime = j,
+                                    Samples = currentSamples,
+                                    IsStrong = strong
+                                };
+                            }
+
+                            i = (i + 1) % allSamples.Count;
+                        }
                     }
-                }
-                else
-                {
-                    yield return new DrumRoll
+                    else
                     {
-                        StartTime = obj.StartTime,
-                        Samples = obj.Samples,
-                        IsStrong = strong,
-                        Duration = taikoDuration,
-                        TickRate = beatmap.BeatmapInfo.BaseDifficulty.SliderTickRate == 3 ? 3 : 4
-                    };
-                }
-            }
-            else if (endTimeData != null)
-            {
-                double hitMultiplier = BeatmapDifficulty.DifficultyRange(beatmap.BeatmapInfo.BaseDifficulty.OverallDifficulty, 3, 5, 7.5) * swell_hit_multiplier;
+                        yield return new DrumRoll
+                        {
+                            StartTime = obj.StartTime,
+                            Samples = obj.Samples,
+                            IsStrong = strong,
+                            Duration = taikoDuration,
+                            TickRate = beatmap.BeatmapInfo.BaseDifficulty.SliderTickRate == 3 ? 3 : 4
+                        };
+                    }
 
-                yield return new Swell
-                {
-                    StartTime = obj.StartTime,
-                    Samples = obj.Samples,
-                    Duration = endTimeData.Duration,
-                    RequiredHits = (int)Math.Max(1, endTimeData.Duration / 1000 * hitMultiplier)
-                };
-            }
-            else
-            {
-                bool isRim = samples.Any(s => s.Name == HitSampleInfo.HIT_CLAP || s.Name == HitSampleInfo.HIT_WHISTLE);
-
-                if (isRim)
-                {
-                    yield return new RimHit
-                    {
-                        StartTime = obj.StartTime,
-                        Samples = obj.Samples,
-                        IsStrong = strong
-                    };
+                    break;
                 }
-                else
+
+                case IHasEndTime endTimeData:
                 {
-                    yield return new CentreHit
+                    double hitMultiplier = BeatmapDifficulty.DifficultyRange(beatmap.BeatmapInfo.BaseDifficulty.OverallDifficulty, 3, 5, 7.5) * swell_hit_multiplier;
+
+                    yield return new Swell
                     {
                         StartTime = obj.StartTime,
                         Samples = obj.Samples,
-                        IsStrong = strong
+                        Duration = endTimeData.Duration,
+                        RequiredHits = (int)Math.Max(1, endTimeData.Duration / 1000 * hitMultiplier)
                     };
+
+                    break;
+                }
+
+                default:
+                {
+                    bool isRim = samples.Any(s => s.Name == HitSampleInfo.HIT_CLAP || s.Name == HitSampleInfo.HIT_WHISTLE);
+
+                    if (isRim)
+                    {
+                        yield return new RimHit
+                        {
+                            StartTime = obj.StartTime,
+                            Samples = obj.Samples,
+                            IsStrong = strong
+                        };
+                    }
+                    else
+                    {
+                        yield return new CentreHit
+                        {
+                            StartTime = obj.StartTime,
+                            Samples = obj.Samples,
+                            IsStrong = strong
+                        };
+                    }
+
+                    break;
                 }
             }
         }

osu.Game.Rulesets.Taiko/Objects/Drawables/Pieces/TaikoPiece.cs

@@ -10,27 +10,15 @@ namespace osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces
 {
     public class TaikoPiece : BeatSyncedContainer, IHasAccentColour
     {
-        private Color4 accentColour;
-
         /// <summary>
         /// The colour of the inner circle and outer glows.
         /// </summary>
-        public virtual Color4 AccentColour
-        {
-            get => accentColour;
-            set => accentColour = value;
-        }
-
-        private bool kiaiMode;
+        public virtual Color4 AccentColour { get; set; }
 
         /// <summary>
         /// Whether Kiai mode effects are enabled for this circle piece.
         /// </summary>
-        public virtual bool KiaiMode
-        {
-            get => kiaiMode;
-            set => kiaiMode = value;
-        }
+        public virtual bool KiaiMode { get; set; }
 
         public TaikoPiece()
         {

osu.Game.Rulesets.Taiko/Replays/TaikoAutoGenerator.cs

@@ -43,76 +43,83 @@ namespace osu.Game.Rulesets.Taiko.Replays
                 IHasEndTime endTimeData = h as IHasEndTime;
                 double endTime = endTimeData?.EndTime ?? h.StartTime;
 
-                Swell swell = h as Swell;
-                DrumRoll drumRoll = h as DrumRoll;
-                Hit hit = h as Hit;
-
-                if (swell != null)
+                switch (h)
                 {
-                    int d = 0;
-                    int count = 0;
-                    int req = swell.RequiredHits;
-                    double hitRate = Math.Min(swell_hit_speed, swell.Duration / req);
-
-                    for (double j = h.StartTime; j < endTime; j += hitRate)
+                    case Swell swell:
                     {
-                        TaikoAction action;
+                        int d = 0;
+                        int count = 0;
+                        int req = swell.RequiredHits;
+                        double hitRate = Math.Min(swell_hit_speed, swell.Duration / req);
 
-                        switch (d)
+                        for (double j = h.StartTime; j < endTime; j += hitRate)
                         {
-                            default:
-                            case 0:
-                                action = TaikoAction.LeftCentre;
-                                break;
+                            TaikoAction action;
 
-                            case 1:
-                                action = TaikoAction.LeftRim;
-                                break;
+                            switch (d)
+                            {
+                                default:
+                                case 0:
+                                    action = TaikoAction.LeftCentre;
+                                    break;
 
-                            case 2:
-                                action = TaikoAction.RightCentre;
-                                break;
+                                case 1:
+                                    action = TaikoAction.LeftRim;
+                                    break;
 
-                            case 3:
-                                action = TaikoAction.RightRim;
+                                case 2:
+                                    action = TaikoAction.RightCentre;
+                                    break;
+
+                                case 3:
+                                    action = TaikoAction.RightRim;
+                                    break;
+                            }
+
+                            Frames.Add(new TaikoReplayFrame(j, action));
+                            d = (d + 1) % 4;
+                            if (++count == req)
                                 break;
                         }
 
-                        Frames.Add(new TaikoReplayFrame(j, action));
-                        d = (d + 1) % 4;
-                        if (++count == req)
-                            break;
-                    }
-                }
-                else if (drumRoll != null)
-                {
-                    foreach (var tick in drumRoll.NestedHitObjects.OfType<DrumRollTick>())
-                    {
-                        Frames.Add(new TaikoReplayFrame(tick.StartTime, hitButton ? TaikoAction.LeftCentre : TaikoAction.RightCentre));
-                        hitButton = !hitButton;
-                    }
-                }
-                else if (hit != null)
-                {
-                    TaikoAction[] actions;
-
-                    if (hit is CentreHit)
-                    {
-                        actions = h.IsStrong
-                            ? new[] { TaikoAction.LeftCentre, TaikoAction.RightCentre }
-                            : new[] { hitButton ? TaikoAction.LeftCentre : TaikoAction.RightCentre };
-                    }
-                    else
-                    {
-                        actions = h.IsStrong
-                            ? new[] { TaikoAction.LeftRim, TaikoAction.RightRim }
-                            : new[] { hitButton ? TaikoAction.LeftRim : TaikoAction.RightRim };
+                        break;
                     }
 
-                    Frames.Add(new TaikoReplayFrame(h.StartTime, actions));
+                    case DrumRoll drumRoll:
+                    {
+                        foreach (var tick in drumRoll.NestedHitObjects.OfType<DrumRollTick>())
+                        {
+                            Frames.Add(new TaikoReplayFrame(tick.StartTime, hitButton ? TaikoAction.LeftCentre : TaikoAction.RightCentre));
+                            hitButton = !hitButton;
+                        }
+
+                        break;
+                    }
+
+                    case Hit hit:
+                    {
+                        TaikoAction[] actions;
+
+                        if (hit is CentreHit)
+                        {
+                            actions = h.IsStrong
+                                ? new[] { TaikoAction.LeftCentre, TaikoAction.RightCentre }
+                                : new[] { hitButton ? TaikoAction.LeftCentre : TaikoAction.RightCentre };
+                        }
+                        else
+                        {
+                            actions = h.IsStrong
+                                ? new[] { TaikoAction.LeftRim, TaikoAction.RightRim }
+                                : new[] { hitButton ? TaikoAction.LeftRim : TaikoAction.RightRim };
+                        }
+
+                        Frames.Add(new TaikoReplayFrame(h.StartTime, actions));
+                        break;
+                    }
+
+                    default:
+                        throw new InvalidOperationException("Unknown hit object type.");
                 }
-                else
-                    throw new InvalidOperationException("Unknown hit object type.");
 
                 var nextHitObject = GetNextObject(i); // Get the next object that requires pressing the same button
 

osu.Game.Tests/Beatmaps/Formats/LegacyBeatmapDecoderTest.cs

@@ -413,7 +413,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
                 Assert.AreEqual("soft-hitnormal8", getTestableSampleInfo(hitObjects[4]).LookupNames.First());
             }
 
-            HitSampleInfo getTestableSampleInfo(HitObject hitObject) => hitObject.SampleControlPoint.ApplyTo(hitObject.Samples[0]);
+            static HitSampleInfo getTestableSampleInfo(HitObject hitObject) => hitObject.SampleControlPoint.ApplyTo(hitObject.Samples[0]);
         }
 
         [Test]
@@ -431,7 +431,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
                 Assert.AreEqual("normal-hitnormal3", getTestableSampleInfo(hitObjects[2]).LookupNames.First());
             }
 
-            HitSampleInfo getTestableSampleInfo(HitObject hitObject) => hitObject.SampleControlPoint.ApplyTo(hitObject.Samples[0]);
+            static HitSampleInfo getTestableSampleInfo(HitObject hitObject) => hitObject.SampleControlPoint.ApplyTo(hitObject.Samples[0]);
         }
 
         [Test]
@@ -451,7 +451,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
                 Assert.AreEqual(70, getTestableSampleInfo(hitObjects[3]).Volume);
             }
 
-            HitSampleInfo getTestableSampleInfo(HitObject hitObject) => hitObject.SampleControlPoint.ApplyTo(hitObject.Samples[0]);
+            static HitSampleInfo getTestableSampleInfo(HitObject hitObject) => hitObject.SampleControlPoint.ApplyTo(hitObject.Samples[0]);
         }
 
         [Test]

osu.Game.Tests/Beatmaps/Formats/ParsingTest.cs

@@ -59,7 +59,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
         {
             try
             {
-                var _ = int.Parse(input);
+                _ = int.Parse(input);
             }
             catch (Exception e)
             {

osu.Game.Tests/NonVisual/Filtering/FilterQueryParserTest.cs

@@ -87,7 +87,7 @@ namespace osu.Game.Tests.NonVisual.Filtering
             Assert.IsNull(filterCriteria.BPM.Max);
         }
 
-        private static object[] lengthQueryExamples =
+        private static readonly object[] length_query_examples =
         {
             new object[] { "6ms", TimeSpan.FromMilliseconds(6), TimeSpan.FromMilliseconds(1) },
             new object[] { "23s", TimeSpan.FromSeconds(23), TimeSpan.FromSeconds(1) },
@@ -97,7 +97,7 @@ namespace osu.Game.Tests.NonVisual.Filtering
         };
 
         [Test]
-        [TestCaseSource(nameof(lengthQueryExamples))]
+        [TestCaseSource(nameof(length_query_examples))]
         public void TestApplyLengthQueries(string lengthQuery, TimeSpan expectedLength, TimeSpan scale)
         {
             string query = $"length={lengthQuery} time";

osu.Game.Tests/Visual/Gameplay/TestSceneSkinnableDrawable.cs

@@ -335,16 +335,14 @@ namespace osu.Game.Tests.Visual.Gameplay
 
         private class TestSkinComponent : ISkinComponent
         {
-            private readonly string name;
-
             public TestSkinComponent(string name)
             {
-                this.name = name;
+                LookupName = name;
             }
 
             public string ComponentGroup => string.Empty;
 
-            public string LookupName => name;
+            public string LookupName { get; }
         }
     }
 }

osu.Game.Tests/Visual/Online/TestSceneBeatmapSetOverlaySuccessRate.cs

@@ -64,7 +64,7 @@ namespace osu.Game.Tests.Visual.Online
             AddStep("set second set", () => successRate.Beatmap = secondBeatmap);
             AddAssert("ratings set", () => successRate.Graph.Metrics == secondBeatmap.Metrics);
 
-            BeatmapInfo createBeatmap() => new BeatmapInfo
+            static BeatmapInfo createBeatmap() => new BeatmapInfo
             {
                 Metrics = new BeatmapMetrics
                 {

osu.Game.Tournament/Components/SongBar.cs

@@ -259,7 +259,7 @@ namespace osu.Game.Tournament.Components
                 Margin = new MarginPadding { Horizontal = 15, Vertical = 1 };
                 AutoSizeAxes = Axes.Both;
 
-                void cp(SpriteText s, Color4 colour)
+                static void cp(SpriteText s, Color4 colour)
                 {
                     s.Colour = colour;
                     s.Font = OsuFont.GetFont(weight: FontWeight.Bold, size: 15);
@@ -267,7 +267,7 @@ namespace osu.Game.Tournament.Components
 
                 for (var i = 0; i < tuples.Length; i++)
                 {
-                    var tuple = tuples[i];
+                    var (heading, content) = tuples[i];
 
                     if (i > 0)
                     {
@@ -278,9 +278,9 @@ namespace osu.Game.Tournament.Components
                         });
                     }
 
-                    AddText(new OsuSpriteText { Text = tuple.heading }, s => cp(s, OsuColour.Gray(0.33f)));
+                    AddText(new OsuSpriteText { Text = heading }, s => cp(s, OsuColour.Gray(0.33f)));
                     AddText(" ", s => cp(s, OsuColour.Gray(0.33f)));
-                    AddText(new OsuSpriteText { Text = tuple.content }, s => cp(s, OsuColour.Gray(0.5f)));
+                    AddText(new OsuSpriteText { Text = content }, s => cp(s, OsuColour.Gray(0.5f)));
                 }
             }
         }

osu.Game.Tournament/IPC/FileBasedIPC.cs

@@ -152,7 +152,7 @@ namespace osu.Game.Tournament.IPC
         {
             protected override string LocateBasePath()
             {
-                bool checkExists(string p)
+                static bool checkExists(string p)
                 {
                     return File.Exists(Path.Combine(p, "ipc.txt"));
                 }
@@ -180,7 +180,7 @@ namespace osu.Game.Tournament.IPC
                     try
                     {
                         using (RegistryKey key = Registry.ClassesRoot.OpenSubKey("osu"))
-                            stableInstallPath = key?.OpenSubKey(@"shell\open\command")?.GetValue(String.Empty).ToString().Split('"')[1].Replace("osu!.exe", "");
+                            stableInstallPath = key?.OpenSubKey(@"shell\open\command")?.GetValue(string.Empty).ToString().Split('"')[1].Replace("osu!.exe", "");
 
                         if (checkExists(stableInstallPath))
                             return stableInstallPath;

osu.Game.Tournament/Screens/Drawings/Components/ScrollingTeamContainer.cs

@@ -125,9 +125,7 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
 
                         foreach (var c in Children)
                         {
-                            var stc = c as ScrollingTeam;
-
-                            if (stc == null)
+                            if (!(c is ScrollingTeam stc))
                                 continue;
 
                             if (closest == null)
@@ -203,15 +201,13 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
 
             foreach (var c in Children)
             {
-                ScrollingTeam st = c as ScrollingTeam;
-
-                if (st == null)
-                    continue;
-
-                if (st.Team == team)
+                if (c is ScrollingTeam st)
                 {
-                    st.FadeOut(200);
-                    st.Expire();
+                    if (st.Team == team)
+                    {
+                        st.FadeOut(200);
+                        st.Expire();
+                    }
                 }
             }
         }
@@ -295,14 +291,13 @@ namespace osu.Game.Tournament.Screens.Drawings.Components
         {
             foreach (var c in Children)
             {
-                ScrollingTeam st = c as ScrollingTeam;
-                if (st == null)
-                    continue;
-
-                if (st.Selected)
+                if (c is ScrollingTeam st)
                 {
-                    st.Selected = false;
-                    RemoveTeam(st.Team);
+                    if (st.Selected)
+                    {
+                        st.Selected = false;
+                        RemoveTeam(st.Team);
+                    }
                 }
             }
         }

osu.Game.Tournament/Screens/Editors/RoundEditorScreen.cs

@@ -225,9 +225,7 @@ namespace osu.Game.Tournament.Screens.Editors
                         beatmapId.Value = Model.ID.ToString();
                         beatmapId.BindValueChanged(idString =>
                         {
-                            int parsed;
-
-                            int.TryParse(idString.NewValue, out parsed);
+                            int.TryParse(idString.NewValue, out var parsed);
 
                             Model.ID = parsed;
 

osu.Game.Tournament/Screens/Editors/TeamEditorScreen.cs

@@ -267,9 +267,7 @@ namespace osu.Game.Tournament.Screens.Editors
                         userId.Value = user.Id.ToString();
                         userId.BindValueChanged(idString =>
                         {
-                            long parsed;
-
-                            long.TryParse(idString.NewValue, out parsed);
+                            long.TryParse(idString.NewValue, out var parsed);
 
                             user.Id = parsed;
 

osu.Game.Tournament/Screens/Ladder/Components/ProgressionPath.cs

@@ -26,7 +26,7 @@ namespace osu.Game.Tournament.Screens.Ladder.Components
         {
             base.LoadComplete();
 
-            Vector2 getCenteredVector(Vector2 top, Vector2 bottom) => new Vector2(top.X, top.Y + (bottom.Y - top.Y) / 2);
+            static Vector2 getCenteredVector(Vector2 top, Vector2 bottom) => new Vector2(top.X, top.Y + (bottom.Y - top.Y) / 2);
 
             var q1 = Source.ScreenSpaceDrawQuad;
             var q2 = Destination.ScreenSpaceDrawQuad;

osu.Game.Tournament/Screens/Ladder/LadderDragContainer.cs

@@ -35,7 +35,7 @@ namespace osu.Game.Tournament.Screens.Ladder
         {
             var newScale = Math.Clamp(scale + e.ScrollDelta.Y / 15 * scale, min_scale, max_scale);
 
-            this.MoveTo(target = target - e.MousePosition * (newScale - scale), 2000, Easing.OutQuint);
+            this.MoveTo(target -= e.MousePosition * (newScale - scale), 2000, Easing.OutQuint);
             this.ScaleTo(scale = newScale, 2000, Easing.OutQuint);
 
             return true;

osu.Game.Tournament/Screens/MapPool/MapPoolScreen.cs

@@ -120,7 +120,7 @@ namespace osu.Game.Tournament.Screens.MapPool
             pickColour = colour;
             pickType = choiceType;
 
-            Color4 setColour(bool active) => active ? Color4.White : Color4.Gray;
+            static Color4 setColour(bool active) => active ? Color4.White : Color4.Gray;
 
             buttonRedBan.Colour = setColour(pickColour == TeamColour.Red && pickType == ChoiceType.Ban);
             buttonBlueBan.Colour = setColour(pickColour == TeamColour.Blue && pickType == ChoiceType.Ban);

osu.Game/Beatmaps/BeatmapManager_WorkingBeatmap.cs

@@ -84,7 +84,7 @@ namespace osu.Game.Beatmaps
             {
                 try
                 {
-                    return (trackStore ?? (trackStore = AudioManager.GetTrackStore(store))).Get(getPathForFile(Metadata.AudioFile));
+                    return (trackStore ??= AudioManager.GetTrackStore(store)).Get(getPathForFile(Metadata.AudioFile));
                 }
                 catch
                 {

osu.Game/Beatmaps/ControlPoints/ControlPoint.cs

@@ -14,7 +14,7 @@ namespace osu.Game.Beatmaps.ControlPoints
 
         private ControlPointGroup controlPointGroup;
 
-        public void AttachGroup(ControlPointGroup pointGroup) => this.controlPointGroup = pointGroup;
+        public void AttachGroup(ControlPointGroup pointGroup) => controlPointGroup = pointGroup;
 
         public int CompareTo(ControlPoint other) => Time.CompareTo(other.Time);
 

osu.Game/Beatmaps/Formats/LegacyBeatmapDecoder.cs

@@ -293,9 +293,7 @@ namespace osu.Game.Beatmaps.Formats
         {
             string[] split = line.Split(',');
 
-            EventType type;
-
-            if (!Enum.TryParse(split[0], out type))
+            if (!Enum.TryParse(split[0], out EventType type))
                 throw new InvalidDataException($@"Unknown event type: {split[0]}");
 
             switch (type)

osu.Game/Beatmaps/Formats/LegacyStoryboardDecoder.cs

@@ -83,9 +83,7 @@ namespace osu.Game.Beatmaps.Formats
             {
                 storyboardSprite = null;
 
-                EventType type;
-
-                if (!Enum.TryParse(split[0], out type))
+                if (!Enum.TryParse(split[0], out EventType type))
                     throw new InvalidDataException($@"Unknown event type: {split[0]}");
 
                 switch (type)

osu.Game/Beatmaps/WorkingBeatmap.cs

@@ -150,7 +150,7 @@ namespace osu.Game.Beatmaps
 
         public bool BeatmapLoaded => beatmapLoadTask?.IsCompleted ?? false;
 
-        public Task<IBeatmap> LoadBeatmapAsync() => (beatmapLoadTask ?? (beatmapLoadTask = Task.Factory.StartNew(() =>
+        public Task<IBeatmap> LoadBeatmapAsync() => beatmapLoadTask ??= Task.Factory.StartNew(() =>
         {
             // Todo: Handle cancellation during beatmap parsing
             var b = GetBeatmap() ?? new Beatmap();
@@ -162,7 +162,7 @@ namespace osu.Game.Beatmaps
             b.BeatmapInfo = BeatmapInfo;
 
             return b;
-        }, beatmapCancellation.Token, TaskCreationOptions.LongRunning, TaskScheduler.Default)));
+        }, beatmapCancellation.Token, TaskCreationOptions.LongRunning, TaskScheduler.Default);
 
         public IBeatmap Beatmap
         {

osu.Game/Configuration/DatabasedConfigManager.cs

@@ -36,7 +36,7 @@ namespace osu.Game.Configuration
         protected override void PerformLoad()
         {
             databasedSettings = settings.Query(ruleset?.ID, variant);
-            legacySettingsExist = databasedSettings.Any(s => int.TryParse(s.Key, out var _));
+            legacySettingsExist = databasedSettings.Any(s => int.TryParse(s.Key, out _));
         }
 
         protected override bool PerformSave()

osu.Game/Graphics/UserInterface/PercentageCounter.cs

@@ -41,7 +41,7 @@ namespace osu.Game.Graphics.UserInterface
 
         public override void Increment(double amount)
         {
-            Current.Value = Current.Value + amount;
+            Current.Value += amount;
         }
     }
 }

osu.Game/Graphics/UserInterface/ScoreCounter.cs

@@ -55,7 +55,7 @@ namespace osu.Game.Graphics.UserInterface
 
         public override void Increment(double amount)
         {
-            Current.Value = Current.Value + amount;
+            Current.Value += amount;
         }
     }
 }

osu.Game/Graphics/UserInterface/SimpleComboCounter.cs

@@ -33,7 +33,7 @@ namespace osu.Game.Graphics.UserInterface
 
         public override void Increment(int amount)
         {
-            Current.Value = Current.Value + amount;
+            Current.Value += amount;
         }
     }
 }

osu.Game/IO/Legacy/SerializationReader.cs

@@ -226,9 +226,7 @@ namespace osu.Game.IO.Legacy
 
                 public override Type BindToType(string assemblyName, string typeName)
                 {
-                    Type typeToDeserialize;
-
-                    if (cache.TryGetValue(assemblyName + typeName, out typeToDeserialize))
+                    if (cache.TryGetValue(assemblyName + typeName, out var typeToDeserialize))
                         return typeToDeserialize;
 
                     List<Type> tmpTypes = new List<Type>();

osu.Game/Online/API/Requests/Responses/CommentBundle.cs

@@ -50,17 +50,14 @@ namespace osu.Game.Online.API.Requests.Responses
         [JsonProperty(@"user_votes")]
         private List<long> userVotes
         {
-            set
+            set => value.ForEach(v =>
             {
-                value.ForEach(v =>
+                Comments.ForEach(c =>
                 {
-                    Comments.ForEach(c =>
-                    {
-                        if (v == c.Id)
-                            c.IsVoted = true;
-                    });
+                    if (v == c.Id)
+                        c.IsVoted = true;
                 });
-            }
+            });
         }
 
         private List<User> users;

osu.Game/Online/Leaderboards/LeaderboardScore.cs

@@ -288,17 +288,15 @@ namespace osu.Game.Online.Leaderboards
         private class ScoreComponentLabel : Container, IHasTooltip
         {
             private const float icon_size = 20;
-
-            private readonly string name;
             private readonly FillFlowContainer content;
 
             public override bool Contains(Vector2 screenSpacePos) => content.Contains(screenSpacePos);
 
-            public string TooltipText => name;
+            public string TooltipText { get; }
 
             public ScoreComponentLabel(LeaderboardScoreStatistic statistic)
             {
-                name = statistic.Name;
+                TooltipText = statistic.Name;
                 AutoSizeAxes = Axes.Both;
 
                 Child = content = new FillFlowContainer

osu.Game/OsuGameBase.cs

@@ -74,8 +74,6 @@ namespace osu.Game
 
         protected Storage Storage { get; set; }
 
-        private Bindable<WorkingBeatmap> beatmap; // cached via load() method
-
         [Cached]
         [Cached(typeof(IBindable<RulesetInfo>))]
         protected readonly Bindable<RulesetInfo> Ruleset = new Bindable<RulesetInfo>();
@@ -85,7 +83,7 @@ namespace osu.Game
         [Cached(Type = typeof(IBindable<IReadOnlyList<Mod>>))]
         protected readonly Bindable<IReadOnlyList<Mod>> Mods = new Bindable<IReadOnlyList<Mod>>(Array.Empty<Mod>());
 
-        protected Bindable<WorkingBeatmap> Beatmap => beatmap;
+        protected Bindable<WorkingBeatmap> Beatmap { get; private set; } // cached via load() method
 
         private Bindable<bool> fpsDisplayVisible;
 
@@ -201,16 +199,16 @@ namespace osu.Game
             // this adds a global reduction of track volume for the time being.
             Audio.Tracks.AddAdjustment(AdjustableProperty.Volume, new BindableDouble(0.8));
 
-            beatmap = new NonNullableBindable<WorkingBeatmap>(defaultBeatmap);
-            beatmap.BindValueChanged(b => ScheduleAfterChildren(() =>
+            Beatmap = new NonNullableBindable<WorkingBeatmap>(defaultBeatmap);
+            Beatmap.BindValueChanged(b => ScheduleAfterChildren(() =>
             {
                 // compare to last beatmap as sometimes the two may share a track representation (optimisation, see WorkingBeatmap.TransferTo)
                 if (b.OldValue?.TrackLoaded == true && b.OldValue?.Track != b.NewValue?.Track)
                     b.OldValue.RecycleTrack();
             }));
 
-            dependencies.CacheAs<IBindable<WorkingBeatmap>>(beatmap);
-            dependencies.CacheAs(beatmap);
+            dependencies.CacheAs<IBindable<WorkingBeatmap>>(Beatmap);
+            dependencies.CacheAs(Beatmap);
 
             FileStore.Cleanup();
 

osu.Game/Overlays/BeatmapSet/BasicStats.cs

@@ -91,10 +91,9 @@ namespace osu.Game.Overlays.BeatmapSet
 
         private class Statistic : Container, IHasTooltip
         {
-            private readonly string name;
             private readonly OsuSpriteText value;
 
-            public string TooltipText => name;
+            public string TooltipText { get; }
 
             public string Value
             {
@@ -104,7 +103,7 @@ namespace osu.Game.Overlays.BeatmapSet
 
             public Statistic(IconUsage icon, string name)
             {
-                this.name = name;
+                TooltipText = name;
                 RelativeSizeAxes = Axes.X;
                 AutoSizeAxes = Axes.Y;
 

osu.Game/Overlays/BeatmapSet/Scores/ScoresContainer.cs

@@ -45,31 +45,28 @@ namespace osu.Game.Overlays.BeatmapSet.Scores
 
         protected APILegacyScores Scores
         {
-            set
+            set => Schedule(() =>
             {
-                Schedule(() =>
+                topScoresContainer.Clear();
+
+                if (value?.Scores.Any() != true)
                 {
-                    topScoresContainer.Clear();
+                    scoreTable.Scores = null;
+                    scoreTable.Hide();
+                    return;
+                }
 
-                    if (value?.Scores.Any() != true)
-                    {
-                        scoreTable.Scores = null;
-                        scoreTable.Hide();
-                        return;
-                    }
+                scoreTable.Scores = value.Scores;
+                scoreTable.Show();
 
-                    scoreTable.Scores = value.Scores;
-                    scoreTable.Show();
+                var topScore = value.Scores.First();
+                var userScore = value.UserScore;
 
-                    var topScore = value.Scores.First();
-                    var userScore = value.UserScore;
+                topScoresContainer.Add(new DrawableTopScore(topScore));
 
-                    topScoresContainer.Add(new DrawableTopScore(topScore));
-
-                    if (userScore != null && userScore.Score.OnlineScoreID != topScore.OnlineScoreID)
-                        topScoresContainer.Add(new DrawableTopScore(userScore.Score, userScore.Position));
-                });
-            }
+                if (userScore != null && userScore.Score.OnlineScoreID != topScore.OnlineScoreID)
+                    topScoresContainer.Add(new DrawableTopScore(userScore.Score, userScore.Position));
+            });
         }
 
         public ScoresContainer()

osu.Game/Overlays/Chat/ChatLine.cs

@@ -58,9 +58,8 @@ namespace osu.Game.Overlays.Chat
 
         private Message message;
         private OsuSpriteText username;
-        private LinkFlowContainer contentFlow;
 
-        public LinkFlowContainer ContentFlow => contentFlow;
+        public LinkFlowContainer ContentFlow { get; private set; }
 
         public Message Message
         {
@@ -164,7 +163,7 @@ namespace osu.Game.Overlays.Chat
                     Padding = new MarginPadding { Left = MessagePadding + HorizontalPadding },
                     Children = new Drawable[]
                     {
-                        contentFlow = new LinkFlowContainer(t =>
+                        ContentFlow = new LinkFlowContainer(t =>
                         {
                             t.Shadow = false;
 
@@ -206,8 +205,8 @@ namespace osu.Game.Overlays.Chat
             // remove non-existent channels from the link list
             message.Links.RemoveAll(link => link.Action == LinkAction.OpenChannel && chatManager?.AvailableChannels.Any(c => c.Name == link.Argument) != true);
 
-            contentFlow.Clear();
-            contentFlow.AddLinks(message.DisplayContent, message.Links);
+            ContentFlow.Clear();
+            ContentFlow.AddLinks(message.DisplayContent, message.Links);
         }
 
         private class MessageSender : OsuClickableContainer, IHasContextMenu

osu.Game/Overlays/Chat/Selection/ChannelSelectionOverlay.cs

@@ -22,7 +22,7 @@ namespace osu.Game.Overlays.Chat.Selection
 {
     public class ChannelSelectionOverlay : WaveOverlayContainer
     {
-        public static readonly float WIDTH_PADDING = 170;
+        public const float WIDTH_PADDING = 170;
 
         private const float transition_duration = 500;
 

osu.Game/Overlays/Chat/Tabs/ChannelTabControl.cs

@@ -14,7 +14,7 @@ namespace osu.Game.Overlays.Chat.Tabs
 {
     public class ChannelTabControl : OsuTabControl<Channel>
     {
-        public static readonly float SHEAR_WIDTH = 10;
+        public const float SHEAR_WIDTH = 10;
 
         public Action<Channel> OnRequestLeave;
 

osu.Game/Overlays/Dialog/PopupDialog.cs

@@ -21,8 +21,8 @@ namespace osu.Game.Overlays.Dialog
 {
     public abstract class PopupDialog : VisibilityContainer
     {
-        public static readonly float ENTER_DURATION = 500;
-        public static readonly float EXIT_DURATION = 200;
+        public const float ENTER_DURATION = 500;
+        public const float EXIT_DURATION = 200;
 
         private readonly Vector2 ringSize = new Vector2(100f);
         private readonly Vector2 ringMinifiedSize = new Vector2(20f);

osu.Game/Overlays/KeyBinding/VariantBindingsSubsection.cs

@@ -7,8 +7,7 @@ namespace osu.Game.Overlays.KeyBinding
 {
     public class VariantBindingsSubsection : KeyBindingsSubsection
     {
-        protected override string Header => variantName;
-        private readonly string variantName;
+        protected override string Header { get; }
 
         public VariantBindingsSubsection(RulesetInfo ruleset, int variant)
             : base(variant)
@@ -17,7 +16,7 @@ namespace osu.Game.Overlays.KeyBinding
 
             var rulesetInstance = ruleset.CreateInstance();
 
-            variantName = rulesetInstance.GetVariantName(variant);
+            Header = rulesetInstance.GetVariantName(variant);
             Defaults = rulesetInstance.GetDefaultKeyBindings(variant);
         }
     }

osu.Game/Overlays/SearchableList/SearchableListOverlay.cs

@@ -13,7 +13,7 @@ namespace osu.Game.Overlays.SearchableList
 {
     public abstract class SearchableListOverlay : FullscreenOverlay
     {
-        public static readonly float WIDTH_PADDING = 80;
+        public const float WIDTH_PADDING = 80;
     }
 
     public abstract class SearchableListOverlay<T, U, S> : SearchableListOverlay

osu.Game/Overlays/Settings/Sections/General/LoginSettings.cs

@@ -297,10 +297,8 @@ namespace osu.Game.Overlays.Settings.Sections.General
             {
                 set
                 {
-                    var h = Header as UserDropdownHeader;
-                    if (h == null) return;
-
-                    h.StatusColour = value;
+                    if (Header is UserDropdownHeader h)
+                        h.StatusColour = value;
                 }
             }
 

osu.Game/Overlays/VolumeOverlay.cs

@@ -30,8 +30,7 @@ namespace osu.Game.Overlays
 
         private readonly BindableDouble muteAdjustment = new BindableDouble();
 
-        private readonly Bindable<bool> isMuted = new Bindable<bool>();
-        public Bindable<bool> IsMuted => isMuted;
+        public Bindable<bool> IsMuted { get; } = new Bindable<bool>();
 
         [BackgroundDependencyLoader]
         private void load(AudioManager audio, OsuColour colours)
@@ -66,7 +65,7 @@ namespace osu.Game.Overlays
                         muteButton = new MuteButton
                         {
                             Margin = new MarginPadding { Top = 100 },
-                            Current = { BindTarget = isMuted }
+                            Current = { BindTarget = IsMuted }
                         }
                     }
                 },
@@ -76,7 +75,7 @@ namespace osu.Game.Overlays
             volumeMeterEffect.Bindable.BindTo(audio.VolumeSample);
             volumeMeterMusic.Bindable.BindTo(audio.VolumeTrack);
 
-            isMuted.BindValueChanged(muted =>
+            IsMuted.BindValueChanged(muted =>
             {
                 if (muted.NewValue)
                     audio.AddAdjustment(AdjustableProperty.Volume, muteAdjustment);

osu.Game/Rulesets/Objects/Legacy/ConvertHitObjectParser.cs

@@ -116,7 +116,7 @@ namespace osu.Game.Rulesets.Objects.Legacy
                 }
 
                 // osu-stable special-cased colinear perfect curves to a CurveType.Linear
-                bool isLinear(Vector2[] p) => Precision.AlmostEquals(0, (p[1].Y - p[0].Y) * (p[2].X - p[0].X) - (p[1].X - p[0].X) * (p[2].Y - p[0].Y));
+                static bool isLinear(Vector2[] p) => Precision.AlmostEquals(0, (p[1].Y - p[0].Y) * (p[2].X - p[0].X) - (p[1].X - p[0].X) * (p[2].Y - p[0].Y));
 
                 if (points.Length == 3 && pathType == PathType.PerfectCurve && isLinear(points))
                     pathType = PathType.Linear;
@@ -177,8 +177,7 @@ namespace osu.Game.Rulesets.Objects.Legacy
                         if (i >= adds.Length)
                             break;
 
-                        int sound;
-                        int.TryParse(adds[i], out sound);
+                        int.TryParse(adds[i], out var sound);
                         nodeSoundTypes[i] = (LegacySoundType)sound;
                     }
                 }

osu.Game/Rulesets/Objects/SliderPath.cs

@@ -129,7 +129,7 @@ namespace osu.Game.Rulesets.Objects
 
             isInitialised = true;
 
-            controlPoints = controlPoints ?? Array.Empty<Vector2>();
+            controlPoints ??= Array.Empty<Vector2>();
             calculatedPath = new List<Vector2>();
             cumulativeLength = new List<double>();
 

osu.Game/Rulesets/UI/Scrolling/DrawableScrollingRuleset.cs

@@ -147,13 +147,9 @@ namespace osu.Game.Rulesets.UI.Scrolling
             // Generate the timing points, making non-timing changes use the previous timing change and vice-versa
             var timingChanges = allPoints.Select(c =>
             {
-                var timingPoint = c as TimingControlPoint;
-                var difficultyPoint = c as DifficultyControlPoint;
-
-                if (timingPoint != null)
+                if (c is TimingControlPoint timingPoint)
                     lastTimingPoint = timingPoint;
-
-                if (difficultyPoint != null)
+                else if (c is DifficultyControlPoint difficultyPoint)
                     lastDifficultyPoint = difficultyPoint;
 
                 return new MultiplierControlPoint(c.Time)

osu.Game/Screens/Backgrounds/BackgroundScreenCustom.cs

@@ -17,10 +17,10 @@ namespace osu.Game.Screens.Backgrounds
 
         public override bool Equals(BackgroundScreen other)
         {
-            var backgroundScreenCustom = other as BackgroundScreenCustom;
-            if (backgroundScreenCustom == null) return false;
+            if (other is BackgroundScreenCustom backgroundScreenCustom)
+                return base.Equals(other) && textureName == backgroundScreenCustom.textureName;
 
-            return base.Equals(other) && textureName == backgroundScreenCustom.textureName;
+            return false;
         }
     }
 }

osu.Game/Screens/Menu/Disclaimer.cs

@@ -1,7 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using System;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -93,7 +92,7 @@ namespace osu.Game.Screens.Menu
             textFlow.AddParagraph("Things may not work as expected", t => t.Font = t.Font.With(size: 20));
             textFlow.NewParagraph();
 
-            Action<SpriteText> format = t => t.Font = OsuFont.GetFont(size: 15, weight: FontWeight.SemiBold);
+            static void format(SpriteText t) => t.Font = OsuFont.GetFont(size: 15, weight: FontWeight.SemiBold);
 
             textFlow.AddParagraph("Detailed bug reports are welcomed via github issues.", format);
             textFlow.NewParagraph();

osu.Game/Screens/Multi/Ranking/Pages/RoomLeaderboardPage.cs

@@ -1,7 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using System;
 using System.Collections.Generic;
 using Microsoft.EntityFrameworkCore.Internal;
 using osu.Framework.Allocation;
@@ -77,12 +76,13 @@ namespace osu.Game.Screens.Multi.Ranking.Pages
 
         private void scoresLoaded(IEnumerable<APIRoomScoreInfo> scores)
         {
-            Action<SpriteText> gray = s => s.Colour = colours.GrayC;
-            Action<SpriteText> white = s =>
+            void gray(SpriteText s) => s.Colour = colours.GrayC;
+
+            void white(SpriteText s)
             {
                 s.Font = s.Font.With(size: s.Font.Size * 1.4f);
                 s.Colour = colours.GrayF;
-            };
+            }
 
             rankText.AddText(name + "\n", white);
             rankText.AddText("You are placed ", gray);

osu.Game/Screens/Play/GameplayClockContainer.cs

@@ -68,7 +68,7 @@ namespace osu.Game.Screens.Play
             this.beatmap = beatmap;
             this.mods = mods;
             this.gameplayStartTime = gameplayStartTime;
-            this.firstHitObjectTime = beatmap.Beatmap.HitObjects.First().StartTime;
+            firstHitObjectTime = beatmap.Beatmap.HitObjects.First().StartTime;
 
             RelativeSizeAxes = Axes.Both;
 

osu.Game/Screens/Play/HUD/ComboCounter.cs

@@ -114,7 +114,7 @@ namespace osu.Game.Screens.Play.HUD
         /// <param name="amount"></param>
         public void Increment(int amount = 1)
         {
-            Current.Value = Current.Value + amount;
+            Current.Value += amount;
         }
 
         /// <summary>

osu.Game/Screens/Play/HUD/ComboResultCounter.cs

@@ -26,7 +26,7 @@ namespace osu.Game.Screens.Play.HUD
 
         public override void Increment(long amount)
         {
-            Current.Value = Current.Value + amount;
+            Current.Value += amount;
         }
     }
 }

osu.Game/Screens/Select/BeatmapCarousel.cs

@@ -79,7 +79,7 @@ namespace osu.Game.Screens.Select
             newRoot.Filter(activeCriteria);
 
             // preload drawables as the ctor overhead is quite high currently.
-            var _ = newRoot.Drawables;
+            _ = newRoot.Drawables;
 
             root = newRoot;
             if (selectedBeatmapSet != null && !beatmapSets.Contains(selectedBeatmapSet.BeatmapSet))

osu.Game/Screens/Select/BeatmapDetailAreaTabControl.cs

@@ -17,7 +17,7 @@ namespace osu.Game.Screens.Select
 {
     public class BeatmapDetailAreaTabControl : Container
     {
-        public static readonly float HEIGHT = 24;
+        public const float HEIGHT = 24;
         private readonly OsuTabControlCheckbox modsCheckbox;
         private readonly OsuTabControl<BeatmapDetailTab> tabs;
         private readonly Container tabsContainer;

osu.Game/Screens/Select/FooterButton.cs

@@ -17,7 +17,7 @@ namespace osu.Game.Screens.Select
 {
     public class FooterButton : OsuClickableContainer
     {
-        public static readonly float SHEAR_WIDTH = 7.5f;
+        public const float SHEAR_WIDTH = 7.5f;
 
         protected static readonly Vector2 SHEAR = new Vector2(SHEAR_WIDTH / Footer.HEIGHT, 0);
 

osu.Game/Skinning/SkinManager.cs

@@ -96,7 +96,7 @@ namespace osu.Game.Skinning
             else
             {
                 model.Name = model.Name.Replace(".osk", "");
-                model.Creator = model.Creator ?? "Unknown";
+                model.Creator ??= "Unknown";
             }
         }
 

osu.Game/Skinning/SkinnableSound.cs

@@ -96,8 +96,8 @@ namespace osu.Game.Skinning
 
                     if (adjustments != null)
                     {
-                        foreach (var adjustment in adjustments)
-                            ch.AddAdjustment(adjustment.property, adjustment.bindable);
+                        foreach (var (property, bindable) in adjustments)
+                            ch.AddAdjustment(property, bindable);
                     }
                 }
 

osu.Game/Skinning/SkinnableSprite.cs

@@ -28,14 +28,12 @@ namespace osu.Game.Skinning
 
         private class SpriteComponent : ISkinComponent
         {
-            private readonly string textureName;
-
             public SpriteComponent(string textureName)
             {
-                this.textureName = textureName;
+                LookupName = textureName;
             }
 
-            public string LookupName => textureName;
+            public string LookupName { get; }
         }
     }
 }

osu.Game/Storyboards/Drawables/DrawableStoryboard.cs

@@ -16,8 +16,7 @@ namespace osu.Game.Storyboards.Drawables
     {
         public Storyboard Storyboard { get; private set; }
 
-        private readonly Container<DrawableStoryboardLayer> content;
-        protected override Container<DrawableStoryboardLayer> Content => content;
+        protected override Container<DrawableStoryboardLayer> Content { get; }
 
         protected override Vector2 DrawScale => new Vector2(Parent.DrawHeight / 480);
 
@@ -49,7 +48,7 @@ namespace osu.Game.Storyboards.Drawables
             Anchor = Anchor.Centre;
             Origin = Anchor.Centre;
 
-            AddInternal(content = new Container<DrawableStoryboardLayer>
+            AddInternal(Content = new Container<DrawableStoryboardLayer>
             {
                 Size = new Vector2(640, 480),
                 Anchor = Anchor.Centre,

osu.Game/Storyboards/Storyboard.cs

@@ -29,8 +29,7 @@ namespace osu.Game.Storyboards
 
         public StoryboardLayer GetLayer(string name)
         {
-            StoryboardLayer layer;
-            if (!layers.TryGetValue(name, out layer))
+            if (!layers.TryGetValue(name, out var layer))
                 layers[name] = layer = new StoryboardLayer(name, layers.Values.Min(l => l.Depth) - 1);
 
             return layer;

osu.Game/Tests/Visual/OsuTestScene.cs

@@ -219,7 +219,7 @@ namespace osu.Game.Tests.Visual
 
                 public IEnumerable<string> GetAvailableResources() => throw new NotImplementedException();
 
-                public Track GetVirtual(double length = Double.PositiveInfinity)
+                public Track GetVirtual(double length = double.PositiveInfinity)
                 {
                     var track = new TrackVirtualManual(referenceClock) { Length = length };
                     AddItem(track);

osu.Game/Users/User.cs

@@ -129,7 +129,7 @@ namespace osu.Game.Users
         [JsonProperty]
         private string[] playstyle
         {
-            set { PlayStyles = value?.Select(str => Enum.Parse(typeof(PlayStyle), str, true)).Cast<PlayStyle>().ToArray(); }
+            set => PlayStyles = value?.Select(str => Enum.Parse(typeof(PlayStyle), str, true)).Cast<PlayStyle>().ToArray();
         }
 
         public PlayStyle[] PlayStyles;

osu.iOS.props

@@ -1,5 +1,6 @@
 <Project>
   <PropertyGroup>
+    <LangVersion>8.0</LangVersion>
     <ProjectTypeGuids>{FEACFBD2-3405-455C-9665-78FE426C6842};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <IPhoneResourcePrefix>Resources</IPhoneResourcePrefix>
     <RestoreProjectStyle>PackageReference</RestoreProjectStyle>

osu.sln.DotSettings

@@ -17,6 +17,7 @@
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ArrangeTypeMemberModifiers/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ArrangeTypeModifiers/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=AssignedValueIsNeverUsed/@EntryIndexedValue">HINT</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=AssignmentIsFullyDiscarded/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=AssignNullToNotNullAttribute/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=AutoPropertyCanBeMadeGetOnly_002EGlobal/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=AutoPropertyCanBeMadeGetOnly_002ELocal/@EntryIndexedValue">HINT</s:String>
@@ -63,11 +64,14 @@
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertIfToOrExpression/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertNullableToShortForm/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertPropertyToExpressionBody/@EntryIndexedValue">WARNING</s:String>
-	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertToAutoProperty/@EntryIndexedValue">HINT</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertToAutoProperty/@EntryIndexedValue">WARNING</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertToAutoPropertyWhenPossible/@EntryIndexedValue">WARNING</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertToAutoPropertyWithPrivateSetter/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertToConstant_002ELocal/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertToLambdaExpression/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertToLocalFunction/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertToStaticClass/@EntryIndexedValue">WARNING</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ConvertToUsingDeclaration/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=DoubleNegationOperator/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=EmptyGeneralCatchClause/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=EnforceDoWhileStatementBraces/@EntryIndexedValue">WARNING</s:String>
@@ -116,6 +120,7 @@
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ParameterHidesMember/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ParameterOnlyUsedForPreconditionCheck_002EGlobal/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=ParameterOnlyUsedForPreconditionCheck_002ELocal/@EntryIndexedValue">HINT</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=PatternAlwaysOfType/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=PossibleInterfaceMemberAmbiguity/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=PossibleMultipleEnumeration/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=PrivateVariableCanBeMadeReadonly/@EntryIndexedValue">WARNING</s:String>
@@ -130,7 +135,6 @@
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=RedundantCommaInEnumDeclaration/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=RedundantCommaInInitializer/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=RedundantEmptyObjectCreationArgumentList/@EntryIndexedValue">WARNING</s:String>
-	
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=RedundantExplicitParamsArrayCreation/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=RedundantImmediateDelegateInvocation/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=RedundantLambdaSignatureParentheses/@EntryIndexedValue">WARNING</s:String>
@@ -209,12 +213,13 @@
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UnusedMember_002ELocal/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UnusedMethodReturnValue_002EGlobal/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UnusedMethodReturnValue_002ELocal/@EntryIndexedValue">HINT</s:String>
-	
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UnusedParameter_002EGlobal/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UnusedParameter_002ELocal/@EntryIndexedValue">HINT</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseAwaitUsing/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseCollectionCountProperty/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseFormatSpecifierInFormatString/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseFormatSpecifierInInterpolation/@EntryIndexedValue">WARNING</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseIndexFromEndExpression/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseNameofExpression/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseNegatedPatternMatching/@EntryIndexedValue"></s:String>
 	<s:Boolean x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseNegatedPatternMatching/@EntryIndexRemoved">True</s:Boolean>