Rustaceans at the border

Nothing particularly remarkable in how it's done. Generous use of vtables, thunks converting parameters by coping them, putting the return value on the heap. (I wonder if they considered a separate return value stack?) Thunks in vtables is novel - I haven't seen that before

But mostly it's stuff we've all done manually at some point. Android's compatibility libraries are the same thing done manually, on steroids. Is the major difference is seems to be Swift does it by default, making it automagic it with some nice tooling?