Suggest: documents about working according to msrv in web site.

[kyoto7250]

Description

clippy has rules that change behavior depending on msrv.

• Change the content of warnings

  • ex. [`map_clone`] changes the message if msrv < 1.36.

• Stop warnings

  • ex. [`filter_map_next] ignore the rule if msrv < 1.30

Their behavior depends on the internal implementation, and currently we have no way to know them except by reading the source code.

The web site indicates that the msrv option is available, but does not say how the behavior is changed as a result of adding the option.

I think it would be more user-friendly to have a document that describes how clippy's behavior changes depending on the value of msrv.

Thank you in advance.

---

example.

# https://rust-lang.github.io/rust-clippy/master/#map_clone
Configuration
This lint has the following configuration variables:
- msrv: Option<String>: The minimum rust version that the project supports (defaults to None)
  • if msrv >= 1.36, this rule suggests using `copied`.
  • if msrv < 1.36, this rule suggets using `cloned`, because `copied` was estabilished in 1.36.

Version

No response

Additional Labels

No response

[xFrednet]

AFAIK, most lints simply don't lint when the current msrv is too low for them, but there are some that change the suggestion. I also thought about including the msrv version that the lint checks for in the lint description. (Similar to your suggestion)

The current metadata collection takes the lint description and appends the configuration documentation to the end. Creating a documentation like you suggested would be nice, but also require some addition to this system. If someone wants to do this, I'm happy to point them into the right direction or mentor them 🙃. Another option would be to document this behavior simply in the lint description. Some lints already do this AFAIK, by saying something like: "Since Rust 1.X.0 it's possible to use abc which generally performs better"