error[E0658]: const trait impls are experimental --> $DIR/feature-gate.rs:9:6 | LL | impl const T for S {} | ^^^^^ | = note: see issue #67792 for more information = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable error: aborting due to previous error For more information about this error, try `rustc --explain E0658`.