Implicit Reborrowing lint

What it does

Detects uses of &mut T values where implicit reborrowing happens. Suggests using &mut *.

Lint Name

implicit_reborrow

Category

restriction

Advantage

The very example used in this lint request is surprising. It produces different behaviour based on whether you have let y: &mut String or just let y.

Drawbacks

None known.

Example

let x = &mut String::new();
let y: &mut String = x;
y.push_str("Hello, ");
x.push_str("world!");

Could be written as:

let x = &mut String::new();
let y: &mut String = &mut *x;
y.push_str("Hello, ");
x.push_str("world!");

The issue names the proposed implicit_reborrow lint but mentions no files, tests, or entry points. Start by reviewing how Clippy restriction lints are registered and tested; it is done when the shown implicit &mut T assignment is detected and the explicit &mut * form is accepted.