error: unnecessary parentheses around type --> $DIR/issue-105061.rs:12:6 | LL | ((for<'a> fn(Inv<'a>)),): Trait, | ^ ^ | note: the lint level is defined here --> $DIR/issue-105061.rs:2:9 | LL | #![deny(warnings)] | ^^^^^^^^ = note: `#[deny(unused_parens)]` implied by `#[deny(warnings)]` help: remove these parentheses | LL - ((for<'a> fn(Inv<'a>)),): Trait, LL + (for<'a> fn(Inv<'a>),): Trait, | error: aborting due to 1 previous error