While The C++ Interop Workgroup and The Language Workgroup have provided great feedback, I'd like to also ask for the wider community's thoughts and feedback. Please feel free to add comments to the GitHub pull request or to this thread. Thanks in advance.
Broadly, this feels like similar goals to Google’s Carbon which I think is great.
Yes. Interestingly enough, Google actually started this effort and wrote the first Manifesto (vision) for C++ and Swift interoperability.
While the goals here are generally similar to Carbon, there are some subtle differences, both in how much and how automatically we want to import, and the sacrifices this necessarily entails. That begin said, Carbon's interop story seems to be mostly a set of lofty goals. Their interop design document is mostly a "TODO," and from talking with Chandler it seems that they are prioritizing other parts of the language's development.
Whether these goals can be met, or are even implementable, is yet to be seen. I think there is a dichotomy when designing a successor language around interoperability; either the language will need to maintain those unfortunate constructs in the name of interoperability, or the language can be more strict and maintain strong idioms on the pain of automatic and complete interoperability. This vision proposes that Swift strike a balance closer to the latter. It seems that Carbon leans closer to the former.
In any case, languages take a long time to develop. If programmers want to move away from C++ in this decade, or if they want a language with modern features, such as memory safety, library evolution, error handling, etc., Swift will be a better option then Carbon.