issue-66596-impl-trait-for-str-const-arg.stderr

warning: the feature `const_generics` is incomplete and may cause the compiler to crash
  --> $DIR/issue-66596-impl-trait-for-str-const-arg.rs:3:12
   |
LL | #![feature(const_generics)]
   |            ^^^^^^^^^^^^^^
   |
   = note: `#[warn(incomplete_features)]` on by default