| error[E0277]: expected a `FnMut(_, char)` closure, found `()` | |
| --> $DIR/issue-23966.rs:2:32 | |
| | | |
| LL | "".chars().fold(|_, _| (), ()); | |
| | ---- ^^ expected an `FnMut(_, char)` closure, found `()` | |
| | | | |
| | required by a bound introduced by this call | |
| | | |
| = help: the trait `FnMut(_, char)` is not implemented for `()` | |
| note: required by a bound in `fold` | |
| --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL | |
| error: aborting due to 1 previous error | |
| For more information about this error, try `rustc --explain E0277`. |