#![feature(staged_api)] #[stable(feature = "x", since = "1")] struct StableType; #[unstable(feature = "x", issue = "none")] struct UnstableType; #[stable(feature = "x", since = "1")] trait StableTrait {} #[unstable(feature = "x", issue = "none")] trait UnstableTrait {} #[unstable(feature = "x", issue = "none")] impl UnstableTrait for UnstableType {} #[unstable(feature = "x", issue = "none")] impl StableTrait for UnstableType {} #[unstable(feature = "x", issue = "none")] impl UnstableTrait for StableType {} #[unstable(feature = "x", issue = "none")] //~^ ERROR an `#[unstable]` annotation here has no effect [ineffective_unstable_trait_impl] impl StableTrait for StableType {} fn main() {}