On Wed Jun 18 12:58:50 2025 +0000, Rémi Bernon wrote:
It looks like WinRT interface are simply not allowed to use anything that isn't a WinRT type. Trying to pass types from the global namespace usually fails a the IDL parsing time. Then it seems like that EventRegistrationToken is allowed, but it also doesn't show up from `Windows.Foundation` assembly or namespace in ILSpy. Its namespace is `System.Runtime.InteropServices.WindowsRuntime`, its resolution scope is 0 and and its assembly ref seems special:  
... which is something ILSpy seems to be doing on its own. Well we can leave it like that for now, but I think it would be better to ultimately do it differently, it doesn't look right to have some type name specific logic there.