Lint for functions/variables/etc using the same name as a type (str, u32, ...)

[joshtriplett]

Code

fn func(u32: u32) {
    println!("{u32}");
}

fn main() {
    let u32 = 42;
    func(u32);

    let closure = |str: &str| {
        println!("{}", str.len());
    };
    closure("hello");
}

Current output

(none)

Desired output

warning: variable `u32` should use a name that doesn't conflict with a standard type
 --> src/main.rs:1:9
  |
1 | fn func(u32: u32) {
  |         ^^^ help: rename the identifier

Rationale and extra context

It's confusing to read code where str (or another standard type name) is used as an identifier. It also produces misleading syntax highlighting.

Other cases

Rust Version

rustc 1.83.0 (90b35a623 2024-11-26)
binary: rustc
commit-hash: 90b35a6239c3d8bdabc530a6a0816f7ff89a0aaf
commit-date: 2024-11-26
host: x86_64-unknown-linux-gnu
release: 1.83.0
LLVM version: 19.1.1

Anything else?

No response

[Noratrieb]

I don't like it, in my opinion str is a perfectly clear name for a string variable. Rust didn't make primitives keywords, so I don't see a reason why we shouldn't use the names. I don't think syntax highlighters should highlight primitive types in a special way, which would avoid this problem (r-a's highlighter doesn't).
I think this should be a pedantic clippy lint at most, I wouldn't want this to be a rustc lint.