| error[E0271]: type mismatch resolving `impl !Fn<(u32,)> == ()` | |
| --> $DIR/opaque-type-unsatisfied-fn-bound.rs:5:17 | |
| | | |
| LL | fn produce() -> impl !Fn<(u32,)> {} | |
| | ^^^^^^^^^^^^^^^^ types differ | |
| error: aborting due to 1 previous error | |
| For more information about this error, try `rustc --explain E0271`. |