|  | error: return types are denoted using `->` | 
|  | --> $DIR/avoid-ice-on-warning.rs:4:23 | 
|  | | | 
|  | LL | fn call_this<F>(f: F) : Fn(&str) + call_that {} | 
|  | |                       ^ | 
|  | | | 
|  | help: use `->` instead | 
|  | | | 
|  | LL - fn call_this<F>(f: F) : Fn(&str) + call_that {} | 
|  | LL + fn call_this<F>(f: F) -> Fn(&str) + call_that {} | 
|  | | | 
|  |  | 
|  | error[E0405]: cannot find trait `call_that` in this scope | 
|  | --> $DIR/avoid-ice-on-warning.rs:4:36 | 
|  | | | 
|  | LL | fn call_this<F>(f: F) : Fn(&str) + call_that {} | 
|  | |                                    ^^^^^^^^^ not found in this scope | 
|  |  | 
|  | error[E0782]: expected a type, found a trait | 
|  | --> $DIR/avoid-ice-on-warning.rs:4:25 | 
|  | | | 
|  | LL | fn call_this<F>(f: F) : Fn(&str) + call_that {} | 
|  | |                         ^^^^^^^^^^^^^^^^^^^^ | 
|  | | | 
|  | help: `Fn(&str) + call_that` is dyn-incompatible, use `impl Fn(&str) + call_that` to return an opaque type, as long as you return a single underlying type | 
|  | | | 
|  | LL | fn call_this<F>(f: F) : impl Fn(&str) + call_that {} | 
|  | |                         ++++ | 
|  |  | 
|  | error: aborting due to 3 previous errors | 
|  |  | 
|  | Some errors have detailed explanations: E0405, E0782. | 
|  | For more information about an error, try `rustc --explain E0405`. |