Lint for unused arguments starting with a _

[yaahc]

In response to this comment

I think the idea here would be to recommend removal of arguments that are ignored and never referenced.

On the flip side, I'm wondering if it would make sense to also lint for used arguments starting _ which recommends removing the _, because that came up in the same review.

[yaahc]

@flip1995

[flip1995]

Yes I would suggest to make the unused _arg lint a pedantic lint (it can actually make sense to have such an unused arg: StackOverflow) and the used _arg lint a style lint.

[yaahc]

I'm gonna go ahead and take care of this issue as well.

[JurrianFahner]

@rustbot claim

[JurrianFahner]

@rustbot release-assignment

[Zhonghe-zhao]

I'd like to work on this issue. Could I claim it?

[samueltardieu]

I'd like to work on this issue. Could I claim it?

Sure!

[Zhonghe-zhao]

@rustbot claim