Right, I knew I should have said "without shenanigans". The difference is that editions are a first-class, supported mechanism for managing interoperability be

Right, I knew I should have said "without shenanigans". The difference is that editions are a first-class, supported mechanism for managing interoperability between code targeting different "standards versions". It's not up to the user and the linker to conspire so that things work out, it's part of the language, and you don't need to limit your public interfaces / generic code to the lowest version. (I don't know if this is the best policy? It seems like it could be a big burden on implementations in the long run.)