Create a completed Task

Question

I want to create a completed Task (not Task). Is there something built into .NET to do this?

A related question: Create a complete

Answer 1

My preferred method for doing this is to call Task.WhenAll() with no arguments. The MSDN documentation states that "If the supplied array/enumerable contains no tasks, the returned task will immediately transition to a RanToCompletion state before it's returned to the caller.". That sounds like what you want.

Update: I found the source over at Microsoft's Reference Source; there you can see that Task.WhenAll contains the following:

return (tasks.Length == 0) ? // take shortcut if there are no tasks upon which to wait
            Task.CompletedTask :
            new WhenAllPromise(tasks);

So Task.CompletedTask is indeed internal, but it is exposed by calling WhenAll() with no arguments.