error[E0658]: const trait impls are experimental
  --> $DIR/feature-gate.rs:9:6
   |
LL | impl const T for S {}
   |      ^^^^^
   |
   = note: see issue #67792 <https://github.com/rust-lang/rust/issues/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`.