The docs for eina_future_as_value need to explain why the returned Eina_Value is of type Eina_promise instead of Eina_Future as the method name seems to suggest.
The discussion started in D8334#151205.
There is a method called eina_promise_as_value() which takes an Eina_Promise and wraps it in an Eina_Value.
And then there is eina_future_as_value() which indeed takes an Eina_Future and produces an Eina_Value. but the value does not wrap an Eina_Future but an Eina_Promise which gets fulfilled at the same time the original future does.
Therefore, eina_future_as_value() seems a bit misleading.