namespace System.Reactive.Linq.ObservableImpl { internal sealed class AverageInt32 : Producer<double, AverageInt32._> { internal sealed class _ : Sink<int, double> { private long _sum; private long _count; public _(IObserver<double> observer) : base(observer) { _sum = 0; _count = 0; } public override void OnNext(int value) { checked { try { _sum += value; _count++; } catch (Exception error) { ForwardOnError(error); } } } public override void OnCompleted() { if (_count > 0) { ForwardOnNext((double)_sum / (double)_count); ForwardOnCompleted(); } else ForwardOnError(new InvalidOperationException(Strings_Linq.NO_ELEMENTS)); } } private readonly IObservable<int> _source; public AverageInt32(IObservable<int> source) { _source = source; } protected override _ CreateSink(IObserver<double> observer) { return new _(observer); } protected override void Run(_ sink) { sink.Run(_source); } } }