From 5faffd2edddd74289846a59eb9bdb4fce23a1a19 Mon Sep 17 00:00:00 2001
From: Bart De Smet <bartde@microsoft.com>
Date: Tue, 24 Sep 2019 11:08:11 -0700
Subject: [PATCH] Remove more redundant assignments.

---
 .../Concurrency/CurrentThreadScheduler.cs            |  2 +-
 Rx.NET/Source/src/System.Reactive/EventSource.cs     |  3 +--
 .../src/System.Reactive/Internal/ExceptionHelper.cs  |  7 +++----
 .../Source/src/System.Reactive/Internal/Helpers.cs   |  2 +-
 .../src/System.Reactive/Linq/Observable/AmbMany.cs   |  2 +-
 .../System.Reactive/Linq/Observable/AppendPrepend.cs | 10 ++++++----
 .../src/System.Reactive/Linq/Observable/Case.cs      |  2 +-
 .../src/System.Reactive/Linq/Observable/Contains.cs  |  2 +-
 .../src/System.Reactive/Linq/Observable/FromEvent.cs |  2 +-
 .../src/System.Reactive/Linq/Observable/GroupBy.cs   |  2 +-
 .../System.Reactive/Linq/Observable/GroupByUntil.cs  |  2 +-
 .../Source/src/System.Reactive/Linq/Observable/If.cs |  2 +-
 .../src/System.Reactive/Linq/Observable/Max.cs       |  6 ++----
 .../src/System.Reactive/Linq/Observable/Min.cs       |  6 ++----
 .../System.Reactive/Linq/Observable/SelectMany.cs    |  8 ++++----
 .../System.Reactive/Linq/Observable/SequenceEqual.cs |  3 +--
 .../src/System.Reactive/Linq/Observable/Zip.cs       |  2 +-
 .../src/System.Reactive/Linq/QueryLanguage.Async.cs  | 12 ++++++------
 .../src/System.Reactive/Subjects/AsyncSubject.cs     |  2 +-
 .../Source/src/System.Reactive/Subjects/Subject.cs   |  2 +-
 20 files changed, 37 insertions(+), 42 deletions(-)

diff --git a/Rx.NET/Source/src/System.Reactive/Concurrency/CurrentThreadScheduler.cs b/Rx.NET/Source/src/System.Reactive/Concurrency/CurrentThreadScheduler.cs
index 3439b6e923..5426b67c36 100644
--- a/Rx.NET/Source/src/System.Reactive/Concurrency/CurrentThreadScheduler.cs
+++ b/Rx.NET/Source/src/System.Reactive/Concurrency/CurrentThreadScheduler.cs
@@ -82,7 +82,7 @@ public override IDisposable Schedule<TState>(TState state, TimeSpan dueTime, Fun
                 throw new ArgumentNullException(nameof(action));
             }
 
-            var queue = default(SchedulerQueue<TimeSpan>);
+            SchedulerQueue<TimeSpan> queue;
 
             // There is no timed task and no task is currently running
             if (!_running)
diff --git a/Rx.NET/Source/src/System.Reactive/EventSource.cs b/Rx.NET/Source/src/System.Reactive/EventSource.cs
index e31b57b91f..34539906f0 100644
--- a/Rx.NET/Source/src/System.Reactive/EventSource.cs
+++ b/Rx.NET/Source/src/System.Reactive/EventSource.cs
@@ -71,8 +71,7 @@ private void Add(Delegate handler, IDisposable disposable)
         {
             lock (_subscriptions)
             {
-                var l = new Stack<IDisposable>();
-                if (!_subscriptions.TryGetValue(handler, out l))
+                if (!_subscriptions.TryGetValue(handler, out var l))
                 {
                     _subscriptions[handler] = l = new Stack<IDisposable>();
                 }
diff --git a/Rx.NET/Source/src/System.Reactive/Internal/ExceptionHelper.cs b/Rx.NET/Source/src/System.Reactive/Internal/ExceptionHelper.cs
index 03b923675b..f36f6ee61a 100644
--- a/Rx.NET/Source/src/System.Reactive/Internal/ExceptionHelper.cs
+++ b/Rx.NET/Source/src/System.Reactive/Internal/ExceptionHelper.cs
@@ -69,14 +69,13 @@ public static bool TryAddException(ref Exception field, Exception ex)
                     return false;
                 }
 
-                var b = default(Exception);
+                Exception b;
 
                 if (current == null)
                 {
                     b = ex;
                 }
-                else
-                if (current is AggregateException a)
+                else if (current is AggregateException a)
                 {
                     var list = new List<Exception>(a.InnerExceptions)
                     {
@@ -88,6 +87,7 @@ public static bool TryAddException(ref Exception field, Exception ex)
                 {
                     b = new AggregateException(current, ex);
                 }
+
                 if (Interlocked.CompareExchange(ref field, b, current) == current)
                 {
                     return true;
@@ -102,7 +102,6 @@ private sealed class TerminatedException : Exception
         {
             internal TerminatedException() : base("No further exceptions")
             {
-
             }
         }
     }
diff --git a/Rx.NET/Source/src/System.Reactive/Internal/Helpers.cs b/Rx.NET/Source/src/System.Reactive/Internal/Helpers.cs
index d69c4e76e1..04faf186eb 100644
--- a/Rx.NET/Source/src/System.Reactive/Internal/Helpers.cs
+++ b/Rx.NET/Source/src/System.Reactive/Internal/Helpers.cs
@@ -25,7 +25,7 @@ internal static class Helpers
 
         public static IObservable<T> Unpack<T>(IObservable<T> source)
         {
-            var hasOpt = default(bool);
+            bool hasOpt;
 
             do
             {
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/AmbMany.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/AmbMany.cs
index e559d5188e..2d2c845ad6 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/AmbMany.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/AmbMany.cs
@@ -36,8 +36,8 @@ public AmbManyEnumerable(IEnumerable<IObservable<T>> sources)
         protected override IDisposable Run(IObserver<T> observer)
         {
             var sourcesEnumerable = _sources;
-            var sources = default(IObservable<T>[]);
 
+            IObservable<T>[] sources;
             try
             {
                 sources = sourcesEnumerable.ToArray();
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/AppendPrepend.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/AppendPrepend.cs
index bd87771fd5..b805f4af73 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/AppendPrepend.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/AppendPrepend.cs
@@ -35,8 +35,9 @@ public SingleBase(IObservable<TSource> source, TSource value, bool append)
             public IAppendPrepend Append(TSource value)
             {
                 var prev = new Node<TSource>(_value);
-                var appendNode = default(Node<TSource>);
-                var prependNode = default(Node<TSource>);
+
+                Node<TSource> appendNode;
+                Node<TSource> prependNode = null;
 
                 if (_append)
                 {
@@ -54,8 +55,9 @@ public IAppendPrepend Append(TSource value)
             public IAppendPrepend Prepend(TSource value)
             {
                 var prev = new Node<TSource>(_value);
-                var appendNode = default(Node<TSource>);
-                var prependNode = default(Node<TSource>);
+
+                Node<TSource> appendNode = null;
+                Node<TSource> prependNode;
 
                 if (_append)
                 {
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Case.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Case.cs
index 49e01796af..ec53110b83 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Case.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Case.cs
@@ -42,7 +42,7 @@ public _(IObserver<TResult> observer)
 
             public void Run(Case<TValue, TResult> parent)
             {
-                var result = default(IObservable<TResult>);
+                IObservable<TResult> result;
                 try
                 {
                     result = parent.Eval();
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Contains.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Contains.cs
index 9229881a6b..42205a448d 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Contains.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Contains.cs
@@ -37,7 +37,7 @@ public _(Contains<TSource> parent, IObserver<bool> observer)
 
             public override void OnNext(TSource value)
             {
-                var res = false;
+                bool res;
                 try
                 {
                     res = _comparer.Equals(value, _value);
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/FromEvent.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/FromEvent.cs
index 5fc592b508..3fe6270cd9 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/FromEvent.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/FromEvent.cs
@@ -327,7 +327,7 @@ private void Initialize()
 
             private void AddHandler(TDelegate onNext)
             {
-                var removeHandler = default(IDisposable);
+                IDisposable removeHandler;
                 try
                 {
                     removeHandler = _parent.AddHandler(onNext);
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/GroupBy.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/GroupBy.cs
index 8aac426248..9b6f604934 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/GroupBy.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/GroupBy.cs
@@ -77,7 +77,7 @@ public override void OnNext(TSource value)
                 }
 
                 var fireNewMapEntry = false;
-                var writer = default(Subject<TElement>);
+                Subject<TElement> writer;
                 try
                 {
                     //
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/GroupByUntil.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/GroupByUntil.cs
index 0250527f98..47dbd5d00b 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/GroupByUntil.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/GroupByUntil.cs
@@ -319,7 +319,7 @@ public TValue GetOrAdd(TKey key, Func<TValue> valueFactory, out bool added)
         {
             added = false;
 
-            var value = default(TValue);
+            TValue value;
             var newValue = default(TValue);
             var hasNewValue = false;
             while (true)
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/If.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/If.cs
index 069f44fa71..60244e438b 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/If.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/If.cs
@@ -36,7 +36,7 @@ public _(If<TResult> parent, IObserver<TResult> observer)
 
             public void Run()
             {
-                var result = default(IObservable<TResult>);
+                IObservable<TResult> result;
                 try
                 {
                     result = _parent.Eval();
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Max.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Max.cs
index 47cbd0721f..cecf9b2fb9 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Max.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Max.cs
@@ -46,8 +46,7 @@ public override void OnNext(TSource value)
             {
                 if (_hasValue)
                 {
-                    var comparison = 0;
-
+                    int comparison;
                     try
                     {
                         comparison = _comparer.Compare(value, _lastValue);
@@ -103,8 +102,7 @@ public override void OnNext(TSource value)
                     }
                     else
                     {
-                        var comparison = 0;
-
+                        int comparison;
                         try
                         {
                             comparison = _comparer.Compare(value, _lastValue);
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Min.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Min.cs
index 92d70de11b..7241489adf 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Min.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Min.cs
@@ -46,8 +46,7 @@ public override void OnNext(TSource value)
             {
                 if (_hasValue)
                 {
-                    var comparison = 0;
-
+                    int comparison;
                     try
                     {
                         comparison = _comparer.Compare(value, _lastValue);
@@ -108,8 +107,7 @@ public override void OnNext(TSource value)
                     }
                     else
                     {
-                        var comparison = 0;
-
+                        int comparison;
                         try
                         {
                             comparison = _comparer.Compare(value, _lastValue);
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/SelectMany.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/SelectMany.cs
index 7bfd6c737d..8d3241ab70 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/SelectMany.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/SelectMany.cs
@@ -381,7 +381,7 @@ public override void OnNext(TSource value)
                         return;
                     }
 
-                    var e = default(IEnumerator<TCollection>);
+                    IEnumerator<TCollection> e;
                     try
                     {
                         e = xs.GetEnumerator();
@@ -470,7 +470,7 @@ public override void OnNext(TSource value)
                         return;
                     }
 
-                    var e = default(IEnumerator<TCollection>);
+                    IEnumerator<TCollection> e;
                     try
                     {
                         e = xs.GetEnumerator();
@@ -1333,7 +1333,7 @@ public override void OnNext(TSource value)
                         return;
                     }
 
-                    var e = default(IEnumerator<TResult>);
+                    IEnumerator<TResult> e;
                     try
                     {
                         e = xs.GetEnumerator();
@@ -1416,7 +1416,7 @@ public override void OnNext(TSource value)
                         return;
                     }
 
-                    var e = default(IEnumerator<TResult>);
+                    IEnumerator<TResult> e;
                     try
                     {
                         e = xs.GetEnumerator();
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/SequenceEqual.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/SequenceEqual.cs
index c1421ecfef..14f3912c10 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/SequenceEqual.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/SequenceEqual.cs
@@ -314,8 +314,7 @@ public override void OnNext(TSource value)
 
                 public override void OnCompleted()
                 {
-                    var hasNext = false;
-
+                    bool hasNext;
                     try
                     {
                         hasNext = _enumerator.MoveNext();
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Zip.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Zip.cs
index 62adeafd61..e8258aa6b6 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Zip.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Zip.cs
@@ -322,7 +322,7 @@ protected override void Dispose(bool disposing)
 
                 public override void OnNext(TFirst value)
                 {
-                    var hasNext = false;
+                    bool hasNext;
                     try
                     {
                         hasNext = _rightEnumerator.MoveNext();
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/QueryLanguage.Async.cs b/Rx.NET/Source/src/System.Reactive/Linq/QueryLanguage.Async.cs
index 579fde407c..f84e4233d8 100644
--- a/Rx.NET/Source/src/System.Reactive/Linq/QueryLanguage.Async.cs
+++ b/Rx.NET/Source/src/System.Reactive/Linq/QueryLanguage.Async.cs
@@ -670,7 +670,7 @@ public virtual IObservable<TSource> StartAsync<TSource>(Func<Task<TSource>> func
 
         private IObservable<TSource> StartAsyncImpl<TSource>(Func<Task<TSource>> functionAsync, IScheduler scheduler)
         {
-            var task = default(Task<TSource>);
+            Task<TSource> task;
             try
             {
                 task = functionAsync();
@@ -702,7 +702,7 @@ private IObservable<TSource> StartAsyncImpl<TSource>(Func<CancellationToken, Tas
         {
             var cancellable = new CancellationDisposable();
 
-            var task = default(Task<TSource>);
+            Task<TSource> task;
             try
             {
                 task = functionAsync(cancellable.Token);
@@ -712,7 +712,7 @@ private IObservable<TSource> StartAsyncImpl<TSource>(Func<CancellationToken, Tas
                 return Throw<TSource>(exception);
             }
 
-            var result = default(IObservable<TSource>);
+            IObservable<TSource> result;
 
             if (scheduler != null)
             {
@@ -773,7 +773,7 @@ public virtual IObservable<Unit> StartAsync(Func<Task> actionAsync, IScheduler s
 
         private IObservable<Unit> StartAsyncImpl(Func<Task> actionAsync, IScheduler scheduler)
         {
-            var task = default(Task);
+            Task task;
             try
             {
                 task = actionAsync();
@@ -805,7 +805,7 @@ private IObservable<Unit> StartAsyncImpl(Func<CancellationToken, Task> actionAsy
         {
             var cancellable = new CancellationDisposable();
 
-            var task = default(Task);
+            Task task;
             try
             {
                 task = actionAsync(cancellable.Token);
@@ -815,7 +815,7 @@ private IObservable<Unit> StartAsyncImpl(Func<CancellationToken, Task> actionAsy
                 return Throw<Unit>(exception);
             }
 
-            var result = default(IObservable<Unit>);
+            IObservable<Unit> result;
 
             if (scheduler != null)
             {
diff --git a/Rx.NET/Source/src/System.Reactive/Subjects/AsyncSubject.cs b/Rx.NET/Source/src/System.Reactive/Subjects/AsyncSubject.cs
index 98a826d5d5..b800d18f20 100644
--- a/Rx.NET/Source/src/System.Reactive/Subjects/AsyncSubject.cs
+++ b/Rx.NET/Source/src/System.Reactive/Subjects/AsyncSubject.cs
@@ -274,7 +274,7 @@ private void Remove(AsyncSubjectDisposable inner)
                     break;
                 }
 
-                var b = default(AsyncSubjectDisposable[]);
+                AsyncSubjectDisposable[] b;
                 if (n == 1)
                 {
                     b = Array.Empty<AsyncSubjectDisposable>();
diff --git a/Rx.NET/Source/src/System.Reactive/Subjects/Subject.cs b/Rx.NET/Source/src/System.Reactive/Subjects/Subject.cs
index 4888524cf4..4b7e1009fa 100644
--- a/Rx.NET/Source/src/System.Reactive/Subjects/Subject.cs
+++ b/Rx.NET/Source/src/System.Reactive/Subjects/Subject.cs
@@ -225,7 +225,7 @@ private void Unsubscribe(SubjectDisposable observer)
                     break;
                 }
 
-                var b = default(SubjectDisposable[]);
+                SubjectDisposable[] b;
                 if (n == 1)
                 {
                     b = Array.Empty<SubjectDisposable>();