1error[E0277]: the trait bound `dyn Foo<(isize,), isize, Output = ()>: Eq<dyn Foo<(isize,), Output = ()>>` is not satisfied 2 --> $DIR/unboxed-closure-sugar-default.rs:21:5 3 | 4LL | eq::<dyn Foo<(isize,), isize, Output=()>, dyn Foo(isize)>(); 5 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Eq<dyn Foo<(isize,), Output = ()>>` is not implemented for `dyn Foo<(isize,), isize, Output = ()>` 6 | 7note: required by a bound in `eq` 8 --> $DIR/unboxed-closure-sugar-default.rs:14:40 9 | 10LL | fn eq<A: ?Sized,B: ?Sized>() where A : Eq<B> { } 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