src/test/ui/const-generics/unused-const-param.stderr

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