Answer by Sinatr for How to queue WhenAnyValue subscriber calls containing asynchronous code?

Using this answer I've made my own SybscribeAsync extension method with parameter:

public static IDisposable SubscribeAsync<T>(this IObservable<T> source, Func<T, Task> func) =>            source.Select(o => Observable.FromAsync(_ => func(o)))                .Concat()                .Subscribe();

The method SubscribeAsync should be used instead of Subscribe(async o => ...), unless async void is not a problem (it could be).

P.S.: naming method SubscribeSynchronous like ReactiveMarbles does is the option.