namespace System.Reactive.Linq.ObservableImpl { internal sealed class AverageSingle : Producer<float, AverageSingle._> { internal sealed class _ : IdentitySink<float> { private double _sum; private long _count; public _(IObserver<float> observer) : base(observer) { _sum = 0; _count = 0; } public override void OnNext(float value) { try { _sum += (double)value; checked { _count++; } } catch (Exception error) { ForwardOnError(error); } } public override void OnCompleted() { if (_count > 0) { ForwardOnNext((float)(_sum / (double)_count)); ForwardOnCompleted(); } else ForwardOnError(new InvalidOperationException(Strings_Linq.NO_ELEMENTS)); } } private readonly IObservable<float> _source; public AverageSingle(IObservable<float> source) { _source = source; } protected override _ CreateSink(IObserver<float> observer) { return new _(observer); } protected override void Run(_ sink) { sink.Run(_source); } } }