1 files changed, 53 insertions, 0 deletions

diff --git a/Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/IsEmpty.cs b/Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/IsEmpty.cs
new file mode 100644
index 0000000..674c6f8
--- /dev/null
+++ b/Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/IsEmpty.cs
@@ -0,0 +1,53 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+#if !NO_PERF
+using System;
+
+namespace System.Reactive.Linq.Observαble
+{
+    class IsEmpty<TSource> : Producer<bool>
+    {
+        private readonly IObservable<TSource> _source;
+
+        public IsEmpty(IObservable<TSource> source)
+        {
+            _source = source;
+        }
+
+        protected override IDisposable Run(IObserver<bool> observer, IDisposable cancel, Action<IDisposable> setSink)
+        {
+            var sink = new _(observer, cancel);
+            setSink(sink);
+            return _source.SubscribeSafe(sink);
+        }
+
+        class _ : Sink<bool>, IObserver<TSource>
+        {
+            public _(IObserver<bool> observer, IDisposable cancel)
+                : base(observer, cancel)
+            {
+            }
+
+            public void OnNext(TSource value)
+            {
+                base._observer.OnNext(false);
+                base._observer.OnCompleted();
+                base.Dispose();
+            }
+
+            public void OnError(Exception error)
+            {
+                base._observer.OnError(error);
+                base.Dispose();
+            }
+
+            public void OnCompleted()
+            {
+                base._observer.OnNext(true);
+                base._observer.OnCompleted();
+                base.Dispose();
+            }
+        }
+    }
+}
+#endif
\ No newline at end of file