1 files changed, 76 insertions, 0 deletions
diff --git a/Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/Contains.cs b/Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/Contains.cs
new file mode 100644
index 0000000..b26e2d4
--- /dev/null
+++ b/Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/Contains.cs
@@ -0,0 +1,76 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+#if !NO_PERF
+using System;
+using System.Collections.Generic;
+
+namespace System.Reactive.Linq.Observαble
+{
+    class Contains<TSource> : Producer<bool>
+    {
+        private readonly IObservable<TSource> _source;
+        private readonly TSource _value;
+        private readonly IEqualityComparer<TSource> _comparer;
+
+        public Contains(IObservable<TSource> source, TSource value, IEqualityComparer<TSource> comparer)
+        {
+            _source = source;
+            _value = value;
+            _comparer = comparer;
+        }
+
+        protected override IDisposable Run(IObserver<bool> observer, IDisposable cancel, Action<IDisposable> setSink)
+        {
+            var sink = new _(this, observer, cancel);
+            setSink(sink);
+            return _source.SubscribeSafe(sink);
+        }
+
+        class _ : Sink<bool>, IObserver<TSource>
+        {
+            private readonly Contains<TSource> _parent;
+
+            public _(Contains<TSource> parent, IObserver<bool> observer, IDisposable cancel)
+                : base(observer, cancel)
+            {
+                _parent = parent;
+            }
+
+            public void OnNext(TSource value)
+            {
+                var res = false;
+                try
+                {
+                    res = _parent._comparer.Equals(value, _parent._value);
+                }
+                catch (Exception ex)
+                {
+                    base._observer.OnError(ex);
+                    base.Dispose();
+                    return;
+                }
+
+                if (res)
+                {
+                    base._observer.OnNext(true);
+                    base._observer.OnCompleted();
+                    base.Dispose();
+                }
+            }
+
+            public void OnError(Exception error)
+            {
+                base._observer.OnError(error);
+                base.Dispose();
+            }
+
+            public void OnCompleted()
+            {
+                base._observer.OnNext(false);
+                base._observer.OnCompleted();
+                base.Dispose();
+            }
+        }
+    }
+}
+#endif
+\ No newline at end of file