### What it does Checks for expressions like `x >= 3 && x < 8` that could be more readably expressed as `(3..8).contains(x)`. ### Why is this bad? `contains` expresses the intent better and has less failure modes (such as fencepost errors or using `||` instead of `&&`). ### Example ``` // given let x = 6; assert!(x >= 3 && x < 8); ``` Use instead: ``` assert!((3..8).contains(&x)); ```