error: expected one of `,` or `>`, found `+`
  --> $DIR/const-expression-parameter.rs:13:22
   |
LL |     i32_identity::<1 + 2>();
   |                      ^ expected one of `,` or `>` here

warning: the feature `const_generics` is incomplete and may cause the compiler to crash
  --> $DIR/const-expression-parameter.rs:1:12
   |
LL | #![feature(const_generics)]
   |            ^^^^^^^^^^^^^^
   |
   = note: `#[warn(incomplete_features)]` on by default

error: aborting due to previous error