I think I need a "multiplatform-getting-started" channel, because this sounds like a very simple question. It probably shows I don't understand. Where, and how, do I include a properly platform specific implementation of a function? I've got a class "GuTime" marked as expected in /shared/src/commonMain. The Android version seems happy in /shared/src/commonAndroid, or probably even /app/src/<etc>, but what about the iOS version? iOS doesn't have "systemtime" so I need an iOS route. I can't put that in /shared/src/commonIOS (can I?), and trying to put an "actual" class in /iOS/ complains about "actual". Yes, I know there's a Kotlin time package on the way, but how "alpha" is it? And that would only help for this specific issue.

this is the usual directory structure for multiplatform module. inside every dir you keep the same package structure and then the expect/actual should work just fine (of course if you don;t need tests, you can only keep the 3 "main" dirs)

Thanks @Michal Klimczak. I do have that, isn't that simply for the shared module (Kotlin) code, though? Everything I've seen (eg KaMPKit) specifies separate modules for the platform specific code. I don't understand how to link iOS/Swift results into the rest of the shared code. In this example my data controllers sometimes need the time. In Android I get it from the System object. In iOS I seem to need to get a TimeInterval, but how do I feed that back to my shared code?

You basicsly have at least 3 codebases (may be in one repo, may be in several). One is ios swift code. One is android module. One is shared module. The shared and android module may be in the same project or in separate. Now expect/actual only refers to the shared module which has these subdirectories which I have shown on screenshot. In "actual" in iosMain you can use objectivec classes, the ios Foundation framework, objc libraries even.

Ok, thanks (again), that should get me going 🙂