| error[E0277]: expected a `std::ops::Fn<(isize,)>` closure, found `S` |
| --> $DIR/unboxed-closures-fnmut-as-fn.rs:28:21 |
| | |
| LL | fn call_it<F:Fn(isize)->isize>(f: &F, x: isize) -> isize { |
| | ------- ---------------- required by this bound in `call_it` |
| ... |
| LL | let x = call_it(&S, 22); |
| | ^^ expected an `Fn<(isize,)>` closure, found `S` |
| | |
| = help: the trait `std::ops::Fn<(isize,)>` is not implemented for `S` |
| |
| error: aborting due to previous error |
| |
| For more information about this error, try `rustc --explain E0277`. |