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

### What it does
Checks for casts from a signed to an unsigned numerical
type. In this case, negative values wrap around to large positive values,
which can be quite surprising in practice. However, as the cast works as
defined, this lint is `Allow` by default.

### Why is this bad?
Possibly surprising results. You can activate this lint
as a one-time check to see where numerical wrapping can arise.

### Example
```
let y: i8 = -1;
y as u128; // will return 18446744073709551615
```
Commit	Line	Data
f2b60f7d FG	1	### What it does
	2	Checks for casts from a signed to an unsigned numerical
	3	type. In this case, negative values wrap around to large positive values,
	4	which can be quite surprising in practice. However, as the cast works as
	5	defined, this lint is `Allow` by default.
	6
	7	### Why is this bad?
	8	Possibly surprising results. You can activate this lint
	9	as a one-time check to see where numerical wrapping can arise.
	10
	11	### Example
	12	```
	13	let y: i8 = -1;
	14	y as u128; // will return 18446744073709551615
	15	```