[swift-evolution] [RFC] "Library Evolution Support in Swift ('Resilience')"

[Joe Groff]

Regarding @inlineable, I think having the equivalent of __attribute__((always_inline)) is important. As proposed, an inlineable function may factor out helpers into internal-with-availability helpers, but then those helpers are still required to exist for old clients even if a new implementation of the inlineable function is factored differently. Such deep refactorings of inlineable code are not ideal, of course, but it's happened in the past in C++ standard libraries, and seems like freedom we'd want to reserve for the inlineable layer of Swift's own standard library.

-Joe