using System.Collections.Generic; namespace System.Reactive.Linq.ObservableImpl { internal sealed class Concat<TSource> : Producer<TSource, Concat<TSource>._>, IConcatenatable<TSource> { internal sealed class _ : ConcatSink<TSource> { public _(IObserver<TSource> observer) : base(observer) { } } private readonly IEnumerable<IObservable<TSource>> _sources; public Concat(IEnumerable<IObservable<TSource>> sources) { _sources = sources; } protected override _ CreateSink(IObserver<TSource> observer) { return new _(observer); } protected override void Run(_ sink) { sink.Run(_sources); } public IEnumerable<IObservable<TSource>> GetSources() { return _sources; } } }