1 // Licensed to the .NET Foundation under one or more agreements. 2 // The .NET Foundation licenses this file to you under the MIT license. 3 // See the LICENSE file in the project root for more information. 4 5 namespace System 6 { 7 public interface IObserver<in T> 8 { OnNext(T value)9 void OnNext(T value); OnError(Exception error)10 void OnError(Exception error); OnCompleted()11 void OnCompleted(); 12 } 13 } 14