### What it does Checks for use of `&Box` anywhere in the code. Check the [Box documentation](https://doc.rust-lang.org/std/boxed/index.html) for more information. ### Why is this bad? A `&Box` parameter requires the function caller to box `T` first before passing it to a function. Using `&T` defines a concrete type for the parameter and generalizes the function, this would also auto-deref to `&T` at the function call site if passed a `&Box`. ### Example ``` fn foo(bar: &Box) { ... } ``` Better: ``` fn foo(bar: &T) { ... } ```