Bad suggestion: nonminimal_bool suggests replacing !cfg!(windows) with true.

[kennytm]

Test case:

#![warn(nonminimal_bool)]
fn main() {
    let _ = !cfg!(windows);
}

Clippy will warn:

warning: this boolean expression can be simplified
 --> src/main.rs:3:13
  |
3 |     let _ = !cfg!(windows);
  |             ^^^^^^^^^^^^^^ help: try `true`
  |
note: lint level defined here
 --> src/main.rs:1:9
  |
1 | #![warn(nonminimal_bool)]
  |         ^^^^^^^^^^^^^^^
  = help: for further information visit https://github.com/Manishearth/rust-clippy/wiki#nonminimal_bool

The suggestion (try `true`) is wrong because the code will lose portability. Instead Clippy should suggest cfg!(not(windows)) or just don't emit the warning.

---

$ cargo clippy --version
0.0.143

[shssoichiro]

This is likely related to this issue: https://github.com/Manishearth/rust-clippy/issues/1877

Basically clippy is losing its mind on macros right now.

[kennytm]

Okay let's see if this will be fixed after rust-lang/rust#43179 is shipped.

[oli-obk]

Nope not fixed by it... Gotta figure out what else changed :/

[oli-obk]

It's not just clippy. Even rustc goes crazy:

while cfg!(unix) {} // better use a `loop` here, because "infinite loop" and "reasons" xD

EDIT: nevermind, it always did that :/

[mcarton]

Maybe we should suggest a fix in rustc then

[oli-obk]

rust-lang/rust#43268 done