ArrayVector does not respond to QI for IIterable<T>

[tristanlabelle]

The Swift-implemented ArrayVector class implements IIterable<T> but does not respond to QI for it from WinRT callers.

The problem is that the wrapper class for a given IVector<T> interface implements its vtable's QueryInterface by delegating to CustomQueryInterface, but ArrayVector<T> cannot implement queryInterface for IIterable<T> because the IIDs and wrapper types it would need to create depend on T. It could possibly generate the correct IID based on T, but it instantiating the matching wrapper type would be complex.

[rayman-zhao]

I'm not sure if this issue caused failed to set itemsSource property of BreadcrumbBar/AutoSuggestBox etc. items controls?

The itemsSource property required IVector parameter, it can accept winrt::single_threaded_observable_vectorwinrt::hstring of C++/WinRT. But passing Array[String].toVector() will crash the app.exe. So that stops using these controls.

It will be really appreciated if any help or hint. Thank you.