rust-clippy/tests/ui/identity_op.rs

const ONE: i64 = 1;
const NEG_ONE: i64 = -1;
const ZERO: i64 = 0;

#[allow(
    clippy::eq_op,
    clippy::no_effect,
    clippy::unnecessary_operation,
    clippy::double_parens
)]
#[warn(clippy::identity_op)]
#[rustfmt::skip]
fn main() {
    let x = 0;

    x + 0;
    x + (1 - 1);
    x + 1;
    0 + x;
    1 + x;
    x - ZERO; //no error, as we skip lookups (for now)
    x | (0);
    ((ZERO)) | x; //no error, as we skip lookups (for now)

    x * 1;
    1 * x;
    x / ONE; //no error, as we skip lookups (for now)

    x / 2; //no false positive

    x & NEG_ONE; //no error, as we skip lookups (for now)
    -1 & x;

    let u: u8 = 0;
    u & 255;
}