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

### What it does
Checks for explicit self-assignments.

### Why is this bad?
Self-assignments are redundant and unlikely to be
intentional.

### Known problems
If expression contains any deref coercions or
indexing operations they are assumed not to have any side effects.

### Example
```
struct Event {
    x: i32,
}

fn copy_position(a: &mut Event, b: &Event) {
    a.x = a.x;
}
```

Should be:
```
struct Event {
    x: i32,
}

fn copy_position(a: &mut Event, b: &Event) {
    a.x = b.x;
}
```
Commit	Line	Data
f2b60f7d FG	1	### What it does
	2	Checks for explicit self-assignments.
	3
	4	### Why is this bad?
	5	Self-assignments are redundant and unlikely to be
	6	intentional.
	7
	8	### Known problems
	9	If expression contains any deref coercions or
	10	indexing operations they are assumed not to have any side effects.
	11
	12	### Example
	13	```
	14	struct Event {
	15	x: i32,
	16	}
	17
	18	fn copy_position(a: &mut Event, b: &Event) {
	19	a.x = a.x;
	20	}
	21	```
	22
	23	Should be:
	24	```
	25	struct Event {
	26	x: i32,
	27	}
	28
	29	fn copy_position(a: &mut Event, b: &Event) {
	30	a.x = b.x;
	31	}
	32	```