error: generic parameters may not be used in const operations --> $DIR/outer-lifetime-in-const-generic-default.rs:4:17 | LL | let x: &'a (); | ^^ cannot perform const operation using `'a` | = note: lifetime parameters may not be used in const expressions = help: add `#![feature(generic_const_exprs)]` to allow generic const expressions error: aborting due to 1 previous error