36 lines
1.0 KiB
C#
36 lines
1.0 KiB
C#
// Licensed to the .NET Foundation under one or more agreements.
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// The .NET Foundation licenses this file to you under the MIT License.
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// See the LICENSE file in the project root for more information.
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using System.Reactive.Disposables;
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namespace System.Reactive.Linq.ObservableImpl
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{
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internal sealed class Never<TResult> : IObservable<TResult>
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{
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/// <summary>
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/// The only instance for a TResult type: this source
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/// is completely stateless and has a constant behavior.
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/// </summary>
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internal static readonly IObservable<TResult> Default = new Never<TResult>();
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/// <summary>
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/// No need for instantiating this more than once per TResult.
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/// </summary>
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private Never()
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{
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}
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public IDisposable Subscribe(IObserver<TResult> observer)
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{
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if (observer == null)
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{
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throw new ArgumentNullException(nameof(observer));
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}
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return Disposable.Empty;
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}
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}
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}
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