namespace System.Reactive.Linq.ObservableImpl { internal sealed class AverageSingleNullable : Producer<float?, AverageSingleNullable._> { 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 { if (value.HasValue) { _sum += (double)value.Value; checked { _count++; } } } catch (Exception error) { ForwardOnError(error); } } public override void OnCompleted() { if (_count > 0) ForwardOnNext((float)(_sum / (double)_count)); else ForwardOnNext(null); ForwardOnCompleted(); } } private readonly IObservable<float?> _source; public AverageSingleNullable(IObservable<float?> source) { _source = source; } protected override _ CreateSink(IObserver<float?> observer) { return new _(observer); } protected override void Run(_ sink) { sink.Run(_source); } } }