Auto merge of #9096 - Jarcho:needless_borrow_subs, r=Manishearth

[rust.git] / tests / ui / needless_borrow.rs

diff --git a/tests/ui/needless_borrow.rs b/tests/ui/needless_borrow.rs
index 3e416a0eb84aaa6ea38a285f0cefa7ca911e2904..3ae4722a1f8985e414ea3a9d49f85ccb397bf770 100644 (file)
--- a/tests/ui/needless_borrow.rs
+++ b/tests/ui/needless_borrow.rs
@@ -1,5 +1,7 @@
 // run-rustfix
 
+#![feature(lint_reasons)]
+
 #[warn(clippy::all, clippy::needless_borrow)]
 #[allow(unused_variables, clippy::unnecessary_mut_passed)]
 fn main() {
@@ -60,7 +62,18 @@ fn main() {
         0 => &mut x,
         _ => &mut *x,
     };
-
+    let y: &mut i32 = match 0 {
+        // Lint here. The type given above triggers auto-borrow.
+        0 => &mut x,
+        _ => &mut *x,
+    };
+    fn ref_mut_i32(_: &mut i32) {}
+    ref_mut_i32(match 0 {
+        // Lint here. The type given above triggers auto-borrow.
+        0 => &mut x,
+        _ => &mut *x,
+    });
+    // use 'x' after to make sure it's still usable in the fixed code.
     *x = 5;
 
     let s = String::new();
@@ -72,6 +85,48 @@ fn main() {
     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)]
@@ -96,3 +151,10 @@ trait Trait {}
 impl<'a> Trait for &'a str {}
 
 fn h(_: &dyn Trait) {}
+
+#[allow(dead_code)]
+fn check_expect_suppression() {
+    let a = 5;
+    #[expect(clippy::needless_borrow)]
+    let _ = x(&&a);
+}