Description
From #303, where supporting unions was discussed.
I still don't have a good handle on the community's thoughts on this—in nix we test against Rust 1.1 and up with an open issue to decide on a policy. I see that libc tests on 1.0 and up, which is an implicit version support policy. Is there an explicit one? I skimmed the README and RFC, but didn't spot anything obvious about it.
This will come up again once one of the bitfield RFCs get accepted and implemented, so it's worth thinking and being clearly explicit about.
For both unions and bitfields, it's a user code ergonomics and correctness win to have libc export as complete definitions of structs as possible.
I hope that the language survey will give an idea of how many people are on older language versions, so we can have a bit more of an idea of what dropping support would mean.