@DougGregor Thanks for merging. However, @dabrahams's recent Unmanaged proposal may subsume this one. (I haven't read it yet, but will soon.)

Ah, indeed. If it does "manage" to subsume this one (har har), we'll just mark this as subsumed. It looks like @dabrahams proposal still uses COpaquePointer.

Largely because we can’t give just UnsafePointer<Void> an init taking an UnsafeReference. But I have a larger concern that pointers to Void and incomplete types are not in any sense “unsafe” (once you restrict the interface as appropriate for incomplete types), and so maybe we want OpaquePointer<T> for these.

@dabrahams We can, if we use a protocol extension (we'd need to introduce a throwaway protocol though).

@gribozavr Oh, yes, that's an evil hack.