ifs_same_cond bails out on equal methods that return bool

[matthiaskrgr]

Summary

apparently we detect boolan expressions of the form x == y but we don't detect fn(&self) -> bool ones???
I get it that this can be iffy if sideeffects are involved but in this example the fn does not even need &mut self :/

Could we somehow warn here for const-fns at least maybe?

Lint Name

ifs_same_cond

Reproducer

I tried this code:

pub fn main() {
    let a = Some(32);
    if let Some(32) = a {
        let b = String::from("x");
        if b.contains("ah") { // same as
            eprintln!("AAA");
        } else if b.contains("ah") { // here
            println!("AAA");
        }
    }
}

I expected to see this happen:
clippy warning

Instead, this happened:

Version

rustc 1.69.0-nightly (dc1d9d50f 2023-01-31)
binary: rustc
commit-hash: dc1d9d50fba2f6a1ccab8748a0050cde38253f60
commit-date: 2023-01-31
host: x86_64-unknown-linux-gnu
release: 1.69.0-nightly
LLVM version: 15.0.7

[J-ZhengLi]

claim first, question it later~ @rustbot claim