aaron.ballman added a comment. In D143891#4122668 <https://reviews.llvm.org/D143891#4122668>, @royjacobson wrote:
> In D143891#4122660 <https://reviews.llvm.org/D143891#4122660>, @aaron.ballman > wrote: > >> This is an ABI breaking change, isn't it? (The type trait now returns >> something different than it did before, which could change instantiations or >> object layout.) > > Technically it is, but it only affects code that relies on constrained > default constructors, which we're only going to support in Clang 16. So if we > backport this to 16 it's not very problematic. Hmmm, if it's true that this only changes the behavior of a type with a constrained default constructor, then I think it's fine despite being an ABI break (we never claimed full support for concepts, so anyone relying on a particular behavior was mistaken to do that). I can't quite convince myself this doesn't impact other cases though -- the logic for computing triviality is nontrivial itself (pun intended), so I'm really only concerned that `__is_trivial` and friends return a different value for a non-constrained type. However, I also can't come up with a test case whose behavior changes either. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D143891/new/ https://reviews.llvm.org/D143891 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
