#![feature(rustc_attrs)] #![feature(trait_alias)] #![feature(with_negative_coherence)] trait A {} trait B {} trait AB = A + B; impl A for u32 {} impl B for u32 {} #[rustc_strict_coherence] trait C {} impl C for T {} impl C for u32 {} //~^ ERROR // FIXME it's giving an ungreat error but unsure if we care given that it's using an internal rustc // attribute and an artificial code path for testing purposes fn main() {}