error[E0107]: trait takes 0 generic arguments but 1 generic argument was supplied --> $DIR/unboxed-closure-sugar-wrong-trait.rs:5:8 | LL | fn f isize>(x: F) {} | ^^^^^------- help: remove these parenthetical generics | | | expected 0 generic arguments | note: trait defined here, with 0 generic parameters --> $DIR/unboxed-closure-sugar-wrong-trait.rs:3:7 | LL | trait Trait {} | ^^^^^ error[E0220]: associated type `Output` not found for `Trait` --> $DIR/unboxed-closure-sugar-wrong-trait.rs:5:24 | LL | fn f isize>(x: F) {} | ^^^^^ associated type `Output` not found error: aborting due to 2 previous errors Some errors have detailed explanations: E0107, E0220. For more information about an error, try `rustc --explain E0107`.