Use 'out var'.

.editorconfig

@@ -156,7 +156,7 @@ csharp_style_unused_value_expression_statement_preference = discard_variable:sil
 csharp_style_unused_value_assignment_preference = discard_variable:suggestion
 
 #Style - variable declaration
-csharp_style_inlined_variable_declaration = true:silent
+csharp_style_inlined_variable_declaration = true:warning
 csharp_style_deconstructed_variable_declaration = true:warning
 
 #Style - other C# 7.x features

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

@@ -303,8 +303,7 @@ private Pattern generateRandomPatternWithMirrored(double centreProbability, doub
 
             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);

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

@@ -225,9 +225,7 @@ private void load(RulesetStore rulesets)
                         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 @@ private void load()
                         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/Beatmaps/Formats/LegacyBeatmapDecoder.cs

@@ -293,9 +293,7 @@ private void handleEvent(string line)
         {
             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 @@ private void handleEvents(string line)
             {
                 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/IO/Legacy/SerializationReader.cs

@@ -226,9 +226,7 @@ public sealed class VersionConfigToNamespaceAssemblyObjectBinder : Serialization
 
                 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/Rulesets/Objects/Legacy/ConvertHitObjectParser.cs

@@ -177,8 +177,7 @@ public override HitObject Parse(string text)
                         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/Storyboards/Storyboard.cs

@@ -27,8 +27,7 @@ public Storyboard()
 
         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;