unique_ptr does not have an implied fence. atomic<unique_ptr> is what you need if you need a fence. many might argue for shared_ptr but, while it does have a fe

unique_ptr does not have an implied fence. atomic<unique_ptr> is what you need if you need a fence. many might argue for shared_ptr but, while it does have a fence, it does _not_ have the same semantics as unique_ptr i don't think the problem is libc++ or libstdc++. the problem is, indeed, that KDE is using the unique_ptr after and/or during its lifetime expiration. the immediate fix is indeed as patched, but a better fix would be better management of object lifetimes. good luck getting that done in anything using Qt though