error: this closure returns the unit type which also implements Ord
  --> $DIR/unit_return_expecting_ord.rs:18:25
   |
LL |     structs.sort_by_key(|s| {
   |                         ^^^
   |
help: probably caused by this trailing semicolon
  --> $DIR/unit_return_expecting_ord.rs:19:24
   |
LL |         double(s.field);
   |                        ^
   = note: `-D clippy::unit-return-expecting-ord` implied by `-D warnings`

error: this closure returns the unit type which also implements PartialOrd
  --> $DIR/unit_return_expecting_ord.rs:22:30
   |
LL |     structs.is_sorted_by_key(|s| {
   |                              ^^^
   |
help: probably caused by this trailing semicolon
  --> $DIR/unit_return_expecting_ord.rs:23:24
   |
LL |         double(s.field);
   |                        ^

error: this closure returns the unit type which also implements PartialOrd
  --> $DIR/unit_return_expecting_ord.rs:25:30
   |
LL |     structs.is_sorted_by_key(|s| {
   |                              ^^^

error: this closure returns the unit type which also implements Ord
  --> $DIR/unit_return_expecting_ord.rs:35:25
   |
LL |     structs.sort_by_key(|s| unit(s.field));
   |                         ^^^

error: aborting due to 4 previous errors