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#![warn(clippy::identity_op)]
#![allow(unused)]
#![allow(
clippy::eq_op,
clippy::no_effect,
clippy::unnecessary_operation,
clippy::op_ref,
clippy::double_parens,
clippy::uninlined_format_args,
clippy::borrow_deref_ref,
clippy::deref_addrof
)]
use std::fmt::Write as _;
const ONE: i64 = 1;
const NEG_ONE: i64 = -1;
const ZERO: i64 = 0;
struct A(String);
impl std::ops::Shl<i32> for A {
type Output = A;
fn shl(mut self, other: i32) -> Self {
let _ = write!(self.0, "{}", other);
self
}
}
struct Length(u8);
struct Meter;
impl core::ops::Mul<Meter> for u8 {
type Output = Length;
fn mul(self, _: Meter) -> Length {
Length(self)
}
}
#[rustfmt::skip]
fn main() {
let x = 0;
x;
//~^ ERROR: this operation has no effect
x;
//~^ ERROR: this operation has no effect
x + 1;
x;
//~^ ERROR: this operation has no effect
1 + x;
x - ZERO; //no error, as we skip lookups (for now)
x;
//~^ ERROR: this operation has no effect
((ZERO)) | x; //no error, as we skip lookups (for now)
x;
//~^ ERROR: this operation has no effect
x;
//~^ ERROR: this operation has no effect
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)
x;
//~^ ERROR: this operation has no effect
let u: u8 = 0;
u;
//~^ ERROR: this operation has no effect
1 << 0; // no error, this case is allowed, see issue 3430
42;
//~^ ERROR: this operation has no effect
1;
//~^ ERROR: this operation has no effect
42;
//~^ ERROR: this operation has no effect
x;
//~^ ERROR: this operation has no effect
x;
//~^ ERROR: this operation has no effect
let mut a = A(String::new());
let b = a << 0; // no error: non-integer
1 * Meter; // no error: non-integer
2;
//~^ ERROR: this operation has no effect
-2;
//~^ ERROR: this operation has no effect
2 + x;
//~^ ERROR: this operation has no effect
-2 + x;
//~^ ERROR: this operation has no effect
x + 1;
//~^ ERROR: this operation has no effect
(x + 1) % 3; // no error
4 % 3; // no error
4 % -3; // no error
// See #8724
let a = 0;
let b = true;
(if b { 1 } else { 2 });
//~^ ERROR: this operation has no effect
(if b { 1 } else { 2 }) + if b { 3 } else { 4 };
//~^ ERROR: this operation has no effect
(match a { 0 => 10, _ => 20 });
//~^ ERROR: this operation has no effect
(match a { 0 => 10, _ => 20 }) + match a { 0 => 30, _ => 40 };
//~^ ERROR: this operation has no effect
(if b { 1 } else { 2 }) + match a { 0 => 30, _ => 40 };
//~^ ERROR: this operation has no effect
(match a { 0 => 10, _ => 20 }) + if b { 3 } else { 4 };
//~^ ERROR: this operation has no effect
(if b { 1 } else { 2 });
//~^ ERROR: this operation has no effect
({ a }) + 3;
//~^ ERROR: this operation has no effect
({ a } * 2);
//~^ ERROR: this operation has no effect
(loop { let mut c = 0; if c == 10 { break c; } c += 1; }) + { a * 2 };
//~^ ERROR: this operation has no effect
fn f(_: i32) {
todo!();
}
f(a + { 8 * 5 });
//~^ ERROR: this operation has no effect
f(if b { 1 } else { 2 } + 3);
//~^ ERROR: this operation has no effect
const _: i32 = { 2 * 4 } + 3;
//~^ ERROR: this operation has no effect
const _: i32 = { 1 + 2 * 3 } + 3;
//~^ ERROR: this operation has no effect
a as usize;
//~^ ERROR: this operation has no effect
let _ = a as usize;
//~^ ERROR: this operation has no effect
({ a } as usize);
//~^ ERROR: this operation has no effect
2 * { a };
//~^ ERROR: this operation has no effect
(({ a } + 4));
//~^ ERROR: this operation has no effect
1;
//~^ ERROR: this operation has no effect
// Issue #9904
let x = 0i32;
let _: i32 = x;
//~^ ERROR: this operation has no effect
}
pub fn decide(a: bool, b: bool) -> u32 {
(if a { 1 } else { 2 }) + if b { 3 } else { 5 }
}
/// The following tests are from / for issue #12050
/// In short, the lint didn't work for coerced references,
/// e.g. let x = &0; let y = x + 0;
/// because the suggested fix was `let y = x;` but
/// it should have been `let y = *x;`
fn issue_12050() {
{
let x = &0i32;
let _: i32 = *x;
//~^ ERROR: this operation has no effect
let _: i32 = *x;
//~^ ERROR: this operation has no effect
}
{
let x = &&0i32;
let _: i32 = **x;
//~^ ERROR: this operation has no effect
let x = &&0i32;
let _: i32 = **x;
//~^ ERROR: this operation has no effect
}
{
// this is just silly
let x = &&&0i32;
let _: i32 = ***x;
//~^ ERROR: this operation has no effect
let _: i32 = ***x;
//~^ ERROR: this operation has no effect
let x = 0i32;
let _: i32 = *&x;
//~^ ERROR: this operation has no effect
let _: i32 = **&&x;
//~^ ERROR: this operation has no effect
let _: i32 = *&*&x;
//~^ ERROR: this operation has no effect
let _: i32 = **&&*&x;
//~^ ERROR: this operation has no effect
}
{
// this is getting ridiculous, but we should still see the same
// error message so let's just keep going
let x = &0i32;
let _: i32 = ***&&*&x;
//~^ ERROR: this operation has no effect
let _: i32 = ***&&*&x;
//~^ ERROR: this operation has no effect
}
}
|
