warning: the feature `const_generics` is incomplete and may cause the compiler to crash
  --> $DIR/const-fn-with-const-param.rs:1:12
   |
LL | #![feature(const_generics)]
   |            ^^^^^^^^^^^^^^

error: const parameters are not permitted in `const fn`
  --> $DIR/const-fn-with-const-param.rs:4:1
   |
LL | / const fn const_u32_identity<const X: u32>() -> u32 {
LL | |
LL | |     X
LL | | }
   | |_^

error: aborting due to previous error