Expression of type 'System.Func`1[System.Threading.Tasks.Task]' cannot be used for return type 'System.Threading.Tasks.Task'

Question

So, I'm using the below assignment:

Expression<Func<Task>> a = Expression.Lambda<Func<Task>>(() => Task.CompletedTask);

And it results in the error mentioned in the thread subject:

Expression of type 'System.Func`1[System.Threading.Tasks.Task]' cannot be used for return type 'System.Threading.Tasks.Task'

I have no idea what I'm doing wrong...

Answer 1

Try removing the Expression.Lambda , compiler should be able to figure out the conversions itself:

Expression<Func<Task>> a = () => Task.CompletedTask;