error[E0658]: const trait impls are experimental --> $DIR/feature-gate.rs:10:6 | 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[E0658]: `const_trait` is a temporary placeholder for marking a trait that is suitable for `const` `impls` and all default bodies as `const`, which may be removed or renamed in the future. --> $DIR/feature-gate.rs:8:1 | LL | #[const_trait] | ^^^^^^^^^^^^^^ | = note: see issue #67792 for more information = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0658`.