Extend `clone_on_ref_ptr` to also work for `bytes::Bytes`

What it does

The clone_on_ref_ptr lint checks for the usage of .clone() on a reference counted pointer, preferring a user call clone via unified function syntax, e.g. Rc::clone(...). The idea being it's easier to tell that you're incrementing a reference count, and not cloning data, by using a syntax like Rc::clone(...) instead of just .clone().

It would be nice if we could extend this lint, or define a new one, to also check the bytes::Bytes type, since Bytes is essentially a reference counted chunk of memory.

Lint Name

No response

Category

restriction

Advantage

• Makes it easier to understand at a glance that you're not duplicating a chunk of bytes, instead just incrementing a reference count.

Drawbacks

• Extending clippy to cover non-std types, could open a can of worms? I'm not sure what the prior art is here.

Example

use bytes::Bytes;

let b = Bytes::from(vec![1, 2, 3, 4]);
let b1 = b.clone();

Could be written as:

use bytes::Bytes;

let b = Bytes::from(vec![1, 2, 3, 4]);
let b1 = Bytes::clone(b);

Start by reading the existing clone_on_ref_ptr lint and reviewing how bytes::Bytes implements cloning. Determine whether the existing lint should be extended or a new lint defined, then verify the chosen behavior with coverage for the example. Done means Bytes::clone(...) is recommended instead of .clone() for bytes::Bytes.