| error[E0282]: type annotations needed | |
| --> $DIR/issue-23041.rs:6:22 | |
| | | |
| LL | b.downcast_ref::<fn(_)->_>(); | |
| | ^^^^^^^^ cannot infer type of the type parameter `T` declared on the method `downcast_ref` | |
| error: aborting due to 1 previous error | |
| For more information about this error, try `rustc --explain E0282`. |