I really struggle to imagine an organisation that shepherds a large and venerable C++ codebase migrating over to Swift.
For all of C++'s faults, it is an extremely stable and vendor-independent language. The kind of organisation that's running on some C++ monolith from 1995 is not going to voluntarily let Apple become a massive business risk in return for marginally nicer DX.
(Yes, Swift is OSS now, but Apple pays the bills and sets the direction, and no one is seriously going to maintain a fork.)
I saw organizations in the past do that with Java and .NET, moving away from C++.
It is perfectly feasable for companies that are full commited into Apple ecosystem.
I think Apple is largely doing this for themselves.
Maybe not, but an Objective-C++ codebase might be a good candidate.
Do you have projects with huge code bases of Obj-C++ in mind?
I guess, some Mac apps? In that case I think most platform independent "guts" would be in C or C++, and the Obj-C++ part is tied to the frameworks, so the devs would have to rewrite it anyway.
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