[rustc.git] / src / tools / clippy / src / docs / unit_return_expecting_ord.txt

### What it does
Checks for functions that expect closures of type
Fn(...) -> Ord where the implemented closure returns the unit type.
The lint also suggests to remove the semi-colon at the end of the statement if present.

### Why is this bad?
Likely, returning the unit type is unintentional, and
could simply be caused by an extra semi-colon. Since () implements Ord
it doesn't cause a compilation error.
This is the same reasoning behind the unit_cmp lint.

### Known problems
If returning unit is intentional, then there is no
way of specifying this without triggering needless_return lint

### Example
```
let mut twins = vec!((1, 1), (2, 2));
twins.sort_by_key(|x| { x.1; });
```
Commit	Line	Data
f2b60f7d FG	1	### What it does
	2	Checks for functions that expect closures of type
	3	Fn(...) -> Ord where the implemented closure returns the unit type.
	4	The lint also suggests to remove the semi-colon at the end of the statement if present.
	5
	6	### Why is this bad?
	7	Likely, returning the unit type is unintentional, and
	8	could simply be caused by an extra semi-colon. Since () implements Ord
	9	it doesn't cause a compilation error.
	10	This is the same reasoning behind the unit_cmp lint.
	11
	12	### Known problems
	13	If returning unit is intentional, then there is no
	14	way of specifying this without triggering needless_return lint
	15
	16	### Example
	17	```
	18	let mut twins = vec!((1, 1), (2, 2));
	19	twins.sort_by_key(\|x\| { x.1; });
	20	```