Use var where appropriate.

Rx.NET/Source/src/System.Reactive/Disposables/RefCountDisposable.cs

@@ -107,7 +107,7 @@ namespace System.Reactive.Disposables
                 }
 
                 // how many active disposables are there?
-                int active = cnt & 0x7FFFFFFF;
+                var active = cnt & 0x7FFFFFFF;
 
                 // keep the active count but set the dispose marker of bit 31
                 var u = int.MinValue | active;

Rx.NET/Source/src/System.Reactive/Linq/Observable/AmbMany.cs

@@ -66,7 +66,7 @@ namespace System.Reactive.Linq.ObservableImpl
         {
             this.downstream = downstream;
             var o = new InnerObserver[n];
-            for (int i = 0; i < n; i++)
+            for (var i = 0; i < n; i++)
             {
                 o[i] = new InnerObserver(this, i);
             }

Rx.NET/Source/src/System.Reactive/Linq/Observable/CombineLatest.cs

@@ -283,7 +283,7 @@ namespace System.Reactive.Linq.ObservableImpl
             else
             {
                 var allOthersDone = true;
-                for (int i = 0; i < _isDone.Length; i++)
+                for (var i = 0; i < _isDone.Length; i++)
                 {
                     if (i != index && !_isDone[i])
                     {
@@ -421,7 +421,7 @@ namespace System.Reactive.Linq.ObservableImpl
                 _hasValueAll = false;
 
                 _values = new List<TSource>(N);
-                for (int i = 0; i < N; i++)
+                for (var i = 0; i < N; i++)
                     _values.Add(default(TSource));
 
                 _isDone = new bool[N];
@@ -430,7 +430,7 @@ namespace System.Reactive.Linq.ObservableImpl
 
                 _gate = new object();
 
-                for (int i = 0; i < N; i++)
+                for (var i = 0; i < N; i++)
                 {
                     var j = i;
 

Rx.NET/Source/src/System.Reactive/Linq/Observable/RetryWhen.cs

@@ -220,7 +220,7 @@ namespace System.Reactive.Linq.ObservableImpl
                 return;
             }
 
-            int missed = 1;
+            var missed = 1;
 
             for (; ; )
             {

Rx.NET/Source/src/System.Reactive/Linq/Observable/Zip.cs

@@ -431,7 +431,7 @@ namespace System.Reactive.Linq.ObservableImpl
             else
             {
                 var allOthersDone = true;
-                for (int i = 0; i < _isDone.Length; i++)
+                for (var i = 0; i < _isDone.Length; i++)
                 {
                     if (i != index && !_isDone[i])
                     {
@@ -581,7 +581,7 @@ namespace System.Reactive.Linq.ObservableImpl
                 var N = srcs.Length;
 
                 _queues = new Queue<TSource>[N];
-                for (int i = 0; i < N; i++)
+                for (var i = 0; i < N; i++)
                     _queues[i] = new Queue<TSource>();
 
                 _isDone = new bool[N];
@@ -590,7 +590,7 @@ namespace System.Reactive.Linq.ObservableImpl
 
                 if (Interlocked.CompareExchange(ref _subscriptions, subscriptions, null) == null)
                 {
-                    for (int i = 0; i < N; i++)
+                    for (var i = 0; i < N; i++)
                     {
                         var o = new SourceObserver(this, i);
                         Disposable.SetSingle(ref subscriptions[i], srcs[i].SubscribeSafe(o));
@@ -605,7 +605,7 @@ namespace System.Reactive.Linq.ObservableImpl
                     var subscriptions = Interlocked.Exchange(ref _subscriptions, Disposed);
                     if (subscriptions != null)
                     {
-                        for (int i = 0; i < subscriptions.Length; i++)
+                        for (var i = 0; i < subscriptions.Length; i++)
                         {
                             Disposable.TryDispose(ref subscriptions[i]);
                         }

Rx.NET/Source/src/System.Reactive/Subjects/AsyncSubject.cs

@@ -263,7 +263,7 @@ namespace System.Reactive.Subjects
 
                 var j = -1;
 
-                for (int i = 0; i < n; i++)
+                for (var i = 0; i < n; i++)
                 {
                     if (a[i] == inner)
                     {