I have class:
class base_event;
Several classes derive from it:
class event_1 : base_event;
class event_2 : base_event;
I have an observable:
observable<base_event> o
;
I would like to subscribe to o and get event_1 and event_2 seperately.
o.of_type(event_1).subscribe([](event_1& e){});
o.of_type(event_2).subscribe([](event_2& e){});
Is there a way to create the of_type operator like this?
One way to express of_type
is to use
o.filter([](const shared_ptr<base_event>& be){
return dynamic_cast<event_1*>(be.get()) != nullptr;
})
.map([](const shared_ptr<base_event>& be){
return static_pointer_cast<event_1>(be);
})
Another is to use
.map([](const shared_ptr<base_event>& be){
auto event = dynamic_pointer_cast<event_1>(be);
if (event == nullptr) { return empty<event_1>().as_dynamic();}
return just<event_1>(event).as_dynamic();
})
.concat()
I prefer the first one.