mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-13 09:05:00 +00:00
250 lines
5.0 KiB
Rust
250 lines
5.0 KiB
Rust
#![feature(lint_reasons)]
|
|
#![allow(
|
|
unused,
|
|
clippy::uninlined_format_args,
|
|
clippy::unnecessary_mut_passed,
|
|
clippy::unnecessary_to_owned,
|
|
clippy::unnecessary_literal_unwrap
|
|
)]
|
|
#![warn(clippy::needless_borrow)]
|
|
|
|
fn main() {
|
|
let a = 5;
|
|
let ref_a = &a;
|
|
let _ = x(&a); // no warning
|
|
let _ = x(&a); // warn
|
|
|
|
let mut b = 5;
|
|
mut_ref(&mut b); // no warning
|
|
mut_ref(&mut b); // warn
|
|
|
|
let s = &String::from("hi");
|
|
let s_ident = f(&s); // should not error, because `&String` implements Copy, but `String` does not
|
|
let g_val = g(&Vec::new()); // should not error, because `&Vec<T>` derefs to `&[T]`
|
|
let vec = Vec::new();
|
|
let vec_val = g(&vec); // should not error, because `&Vec<T>` derefs to `&[T]`
|
|
h(&"foo"); // should not error, because the `&&str` is required, due to `&Trait`
|
|
let garbl = match 42 {
|
|
44 => &a,
|
|
45 => {
|
|
println!("foo");
|
|
&a
|
|
},
|
|
46 => &a,
|
|
47 => {
|
|
println!("foo");
|
|
loop {
|
|
println!("{}", a);
|
|
if a == 25 {
|
|
break ref_a;
|
|
}
|
|
}
|
|
},
|
|
_ => panic!(),
|
|
};
|
|
|
|
let _ = x(&a);
|
|
let _ = x(&a);
|
|
let _ = x(&mut b);
|
|
let _ = x(ref_a);
|
|
{
|
|
let b = &mut b;
|
|
x(b);
|
|
}
|
|
|
|
// Issue #8191
|
|
let mut x = 5;
|
|
let mut x = &mut x;
|
|
|
|
mut_ref(x);
|
|
mut_ref(x);
|
|
let y: &mut i32 = x;
|
|
let y: &mut i32 = x;
|
|
|
|
let y = match 0 {
|
|
// Don't lint. Removing the borrow would move 'x'
|
|
0 => &mut x,
|
|
_ => &mut *x,
|
|
};
|
|
let y: &mut i32 = match 0 {
|
|
// Lint here. The type given above triggers auto-borrow.
|
|
0 => x,
|
|
_ => &mut *x,
|
|
};
|
|
fn ref_mut_i32(_: &mut i32) {}
|
|
ref_mut_i32(match 0 {
|
|
// Lint here. The type given above triggers auto-borrow.
|
|
0 => x,
|
|
_ => &mut *x,
|
|
});
|
|
// use 'x' after to make sure it's still usable in the fixed code.
|
|
*x = 5;
|
|
|
|
let s = String::new();
|
|
// let _ = (&s).len();
|
|
// let _ = (&s).capacity();
|
|
// let _ = (&&s).capacity();
|
|
|
|
let x = (1, 2);
|
|
let _ = x.0;
|
|
let x = &x as *const (i32, i32);
|
|
let _ = unsafe { (*x).0 };
|
|
|
|
// Issue #8367
|
|
trait Foo {
|
|
fn foo(self);
|
|
}
|
|
impl Foo for &'_ () {
|
|
fn foo(self) {}
|
|
}
|
|
(&()).foo(); // Don't lint. `()` doesn't implement `Foo`
|
|
(&()).foo();
|
|
|
|
impl Foo for i32 {
|
|
fn foo(self) {}
|
|
}
|
|
impl Foo for &'_ i32 {
|
|
fn foo(self) {}
|
|
}
|
|
(&5).foo(); // Don't lint. `5` will call `<i32 as Foo>::foo`
|
|
(&5).foo();
|
|
|
|
trait FooRef {
|
|
fn foo_ref(&self);
|
|
}
|
|
impl FooRef for () {
|
|
fn foo_ref(&self) {}
|
|
}
|
|
impl FooRef for &'_ () {
|
|
fn foo_ref(&self) {}
|
|
}
|
|
(&&()).foo_ref(); // Don't lint. `&()` will call `<() as FooRef>::foo_ref`
|
|
|
|
struct S;
|
|
impl From<S> for u32 {
|
|
fn from(s: S) -> Self {
|
|
(&s).into()
|
|
}
|
|
}
|
|
impl From<&S> for u32 {
|
|
fn from(s: &S) -> Self {
|
|
0
|
|
}
|
|
}
|
|
}
|
|
|
|
#[allow(clippy::needless_borrowed_reference)]
|
|
fn x(y: &i32) -> i32 {
|
|
*y
|
|
}
|
|
|
|
fn mut_ref(y: &mut i32) {
|
|
*y = 5;
|
|
}
|
|
|
|
fn f<T: Copy>(y: &T) -> T {
|
|
*y
|
|
}
|
|
|
|
fn g(y: &[u8]) -> u8 {
|
|
y[0]
|
|
}
|
|
|
|
trait Trait {}
|
|
|
|
impl<'a> Trait for &'a str {}
|
|
|
|
fn h(_: &dyn Trait) {}
|
|
|
|
fn check_expect_suppression() {
|
|
let a = 5;
|
|
#[expect(clippy::needless_borrow)]
|
|
let _ = x(&&a);
|
|
}
|
|
|
|
mod issue9160 {
|
|
pub struct S<F> {
|
|
f: F,
|
|
}
|
|
|
|
impl<T, F> S<F>
|
|
where
|
|
F: Fn() -> T,
|
|
{
|
|
fn calls_field(&self) -> T {
|
|
(self.f)()
|
|
}
|
|
}
|
|
|
|
impl<T, F> S<F>
|
|
where
|
|
F: FnMut() -> T,
|
|
{
|
|
fn calls_mut_field(&mut self) -> T {
|
|
(self.f)()
|
|
}
|
|
}
|
|
}
|
|
|
|
fn issue9383() {
|
|
// Should not lint because unions need explicit deref when accessing field
|
|
use std::mem::ManuallyDrop;
|
|
|
|
#[derive(Clone, Copy)]
|
|
struct Wrap<T>(T);
|
|
impl<T> core::ops::Deref for Wrap<T> {
|
|
type Target = T;
|
|
fn deref(&self) -> &T {
|
|
&self.0
|
|
}
|
|
}
|
|
impl<T> core::ops::DerefMut for Wrap<T> {
|
|
fn deref_mut(&mut self) -> &mut T {
|
|
&mut self.0
|
|
}
|
|
}
|
|
|
|
union U<T: Copy> {
|
|
u: T,
|
|
}
|
|
|
|
#[derive(Clone, Copy)]
|
|
struct Foo {
|
|
x: u32,
|
|
}
|
|
|
|
unsafe {
|
|
let mut x = U {
|
|
u: ManuallyDrop::new(Foo { x: 0 }),
|
|
};
|
|
let _ = &mut (&mut x.u).x;
|
|
let _ = &mut { x.u }.x;
|
|
let _ = &mut ({ &mut x.u }).x;
|
|
|
|
let mut x = U {
|
|
u: Wrap(ManuallyDrop::new(Foo { x: 0 })),
|
|
};
|
|
let _ = &mut (&mut x.u).x;
|
|
let _ = &mut { x.u }.x;
|
|
let _ = &mut ({ &mut x.u }).x;
|
|
|
|
let mut x = U { u: Wrap(Foo { x: 0 }) };
|
|
let _ = &mut x.u.x;
|
|
let _ = &mut { x.u }.x;
|
|
let _ = &mut ({ &mut x.u }).x;
|
|
}
|
|
}
|
|
|
|
mod issue_10253 {
|
|
struct S;
|
|
trait X {
|
|
fn f<T>(&self);
|
|
}
|
|
impl X for &S {
|
|
fn f<T>(&self) {}
|
|
}
|
|
fn f() {
|
|
(&S).f::<()>();
|
|
}
|
|
}
|