private static TSource FirstOrDefaultInternal <TSource>(IObservable <TSource> source, bool throwOnEmpty)
{
using var consumer = new FirstBlocking <TSource>();
using (source.Subscribe(consumer))
{
consumer.Wait();
}
consumer._error?.Throw();
if (throwOnEmpty && !consumer._hasValue)
{
throw new InvalidOperationException(Strings_Linq.NO_ELEMENTS);
}
return(consumer._value);
}
private static TSource FirstOrDefaultInternal <TSource>(IObservable <TSource> source, bool throwOnEmpty)
{
using (var consumer = new FirstBlocking <TSource>())
{
using (var d = source.Subscribe(consumer))
{
consumer.SetUpstream(d);
if (consumer.CurrentCount != 0)
{
consumer.Wait();
}
}
consumer._error.ThrowIfNotNull();
if (throwOnEmpty && !consumer._hasValue)
{
throw new InvalidOperationException(Strings_Linq.NO_ELEMENTS);
}
return(consumer._value);
}
}