I tried to create a TaskFactory instance with TaskContinuationOptions.RunContinuationsAsynchronously, so that I am sure that tasks created will have their continuations run asynchronously. However, this doesn’t seem to be possible as I get an ArgumentOutOfRangeException.

TaskFactory tf = new TaskFactory(TaskCreationOptions.None, 
    TaskContinuationOptions.RunContinuationsAsynchronously);
//ArgumentOutOfRangeException: Specified argument was out of the range of valid values. (Parameter 'continuationOptions')

Now I think what I wanted to achieve is done by using TaskCreationOptions.RunContinuationsAsynchronously and not TaskContinuationOptions.RunContinuationsAsynchronously. This aside. I couldn’t find list of invalid options or why they are invalid in the docs.

So, why is TaskContinuationOptions.RunContinuationsAsynchronously an invalid option for TaskFactory?