1error[E0658]: the precise format of `Fn`-family traits' type parameters is subject to change 2 --> $DIR/unboxed-closure-sugar-not-used-on-fn.rs:3:17 3 | 4LL | fn bar1(x: &dyn Fn<(), Output=()>) { 5 | ^^^^^^^^^^^^^^^^^ help: use parenthetical notation instead: `Fn() -> ()` 6 | 7 = note: see issue #29625 <https://github.com/rust-lang/rust/issues/29625> for more information 8 = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable 9 10error[E0658]: the precise format of `Fn`-family traits' type parameters is subject to change 11 --> $DIR/unboxed-closure-sugar-not-used-on-fn.rs:7:28 12 | 13LL | fn bar2<T>(x: &T) where T: Fn<()> { 14 | ^^^^^^ help: use parenthetical notation instead: `Fn() -> ()` 15 | 16 = note: see issue #29625 <https://github.com/rust-lang/rust/issues/29625> for more information 17 = help: add `#![feature(unboxed_closures)]` to the crate attributes to enable 18 19error: aborting due to 2 previous errors 20 21For more information about this error, try `rustc --explain E0658`. 22