How to upcast object contained in Java 8 Optional?

Question

Is there an efficient way to perform upcasting while using an Optional object. Here is a sample code:

class A{}
class B extends A{}

B func(){
    //do somet         


        

Answer 1

The cleanest way to do this I think would be Optional a = func2().flatMap(Optional::of) or Optional a = func2().map(Function.identity()) because both do not require casting and only use existing functionality.