3 ms·

I think the issue is that a variable's type can't be set by the outside (via the template parameter ViewType) and by the inside (to be of type EmptyView) at the

I think the issue is that a variable's type can't be set by the outside (via the template parameter ViewType) and by the inside (to be of type EmptyView) at the same time. You have to decide. Your workaround is to use the AnyView type I guess. Or a conditional with either EmptyView or the template type (displayed). What would be the name of the feature that allows you to use a default template type if no argument is given to figure out the type to use?

Razengan 7y ago
> Your workaround is to use the AnyView type I guess. Yes, I made the init generic instead of the type, and made the property an AnyView, but I've read that AnyView may decrease performance (probably because of reasons discussed in this post's article.)
- DelightOne 7y ago
  True. You could work around it by conditionally extending your ViewContainer to have a default constructor (init()), if the type is EmptyView. Then you can write var viewContainer2 = ViewContainer<EmptyView>() But that's probably not what you want is it. Default generic arguments aren't implemented yet, see (https://stackoverflow.com/questions/42015081/can-i-assign-a-default-type-to-generic-type-t-in-swift https://stackoverflow.com/questions/42015081/can-i-assign-a-...). It would have possibly removed the <EmptyView> aspect. So you always have to give a type to ViewContainer, if you provide no way for the compiler to infer it.
  - Razengan 7y ago
    > var viewContainer2 = ViewContainer<EmptyView>() Yes, that would be a workaround for myself, but for a game engine's API, it'd be ugly to require users to write that every time. :) And there are cases where they might not even know the type.
    - DelightOne 7y ago
      It seems the compiler might be smarter than I thought he is (see a poster above), if so I learnt something new. :) And it seems I didn't understand your problem, you wanting a variable that can change it's type instead of just some syntactic sugar, hmm.

Razengan 7y ago

> Your workaround is to use the AnyView type I guess. Yes, I made the init generic instead of the type, and made the property an AnyView, but I've read that AnyView may decrease performance (probably because of reasons discussed in this post's article.)

DelightOne 7y ago
True. You could work around it by conditionally extending your ViewContainer to have a default constructor (init()), if the type is EmptyView. Then you can write var viewContainer2 = ViewContainer<EmptyView>() But that's probably not what you want is it. Default generic arguments aren't implemented yet, see (https://stackoverflow.com/questions/42015081/can-i-assign-a-default-type-to-generic-type-t-in-swift https://stackoverflow.com/questions/42015081/can-i-assign-a-...). It would have possibly removed the <EmptyView> aspect. So you always have to give a type to ViewContainer, if you provide no way for the compiler to infer it.
- Razengan 7y ago
  > var viewContainer2 = ViewContainer<EmptyView>() Yes, that would be a workaround for myself, but for a game engine's API, it'd be ugly to require users to write that every time. :) And there are cases where they might not even know the type.
  - DelightOne 7y ago
    It seems the compiler might be smarter than I thought he is (see a poster above), if so I learnt something new. :) And it seems I didn't understand your problem, you wanting a variable that can change it's type instead of just some syntactic sugar, hmm.