1error[E0277]: the trait bound `dyn Foo<(char,), Output = ()>: Eq<dyn Foo<(), Output = ()>>` is not satisfied 2 --> $DIR/unboxed-closure-sugar-equiv.rs:44:11 3 | 4LL | dyn Foo(char) >(); 5 | ^^^^^^^^^^^^^ the trait `Eq<dyn Foo<(), Output = ()>>` is not implemented for `dyn Foo<(char,), Output = ()>` 6 | 7note: required by a bound in `eq` 8 --> $DIR/unboxed-closure-sugar-equiv.rs:16:28 9 | 10LL | fn eq<A: ?Sized,B: ?Sized +Eq<A>>() { } 11 | ^^^^^ required by this bound in `eq` 12 13error: aborting due to previous error 14 15For more information about this error, try `rustc --explain E0277`. 16