warning: the feature `min_generic_const_args` is incomplete and may not be safe to use and/or cause compiler crashes
  --> $DIR/unexpected-fn-item-in-array.rs:3:12
   |
LL | #![feature(min_generic_const_args)]
   |            ^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #132980 <https://github.com/rust-lang/rust/issues/132980> for more information
   = note: `#[warn(incomplete_features)]` on by default

error: the constant `fn_item` is not of type `usize`
  --> $DIR/unexpected-fn-item-in-array.rs:8:6
   |
LL | impl A<[usize; fn_item]> for () {}
   |      ^^^^^^^^^^^^^^^^^^^ expected `usize`, found fn item
   |
   = note: the length of array `[usize; fn_item]` must be type `usize`

error: aborting due to 1 previous error; 1 warning emitted