Add more impls of PartialEq and PartialOrd for strings

library/alloc/src/string.rs

@@ -42,6 +42,7 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
+use core::cmp::Ordering;
 use core::error::Error;
 use core::iter::FusedIterator;
 #[cfg(not(no_global_oom_handling))]
@@ -2530,12 +2531,51 @@ macro_rules! impl_eq {
 
 impl_eq! { String, str }
 impl_eq! { String, &'a str }
+impl_eq! { String, &String }
+impl_eq! { &String, str }
 #[cfg(not(no_global_oom_handling))]
 impl_eq! { Cow<'a, str>, str }
 #[cfg(not(no_global_oom_handling))]
 impl_eq! { Cow<'a, str>, &'b str }
 #[cfg(not(no_global_oom_handling))]
 impl_eq! { Cow<'a, str>, String }
+#[cfg(not(no_global_oom_handling))]
+impl_eq! { Cow<'a, str>, &String }
+
+macro_rules! impl_ord {
+    ($lhs:ty, $rhs: ty) => {
+        #[stable(feature = "string_partialord_impls", since = "CURRENT_RUSTC_VERSION")]
+        #[allow(unused_lifetimes)]
+        impl<'a, 'b> PartialOrd<$rhs> for $lhs {
+            #[inline]
+            fn partial_cmp(&self, other: &$rhs) -> Option<Ordering> {
+                PartialOrd::partial_cmp(&self[..], &other[..])
+            }
+        }
+
+        #[stable(feature = "string_partialord_impls", since = "CURRENT_RUSTC_VERSION")]
+        #[allow(unused_lifetimes)]
+        impl<'a, 'b> PartialOrd<$lhs> for $rhs {
+            #[inline]
+            fn partial_cmp(&self, other: &$lhs) -> Option<Ordering> {
+                PartialOrd::partial_cmp(&self[..], &other[..])
+            }
+        }
+    };
+}
+
+impl_ord! { String, str }
+impl_ord! { String, &'a str }
+impl_ord! { &String, str }
+impl_ord! { String, &String }
+#[cfg(not(no_global_oom_handling))]
+impl_ord! { Cow<'a, str>, str }
+#[cfg(not(no_global_oom_handling))]
+impl_ord! { Cow<'a, str>, &'b str }
+#[cfg(not(no_global_oom_handling))]
+impl_ord! { Cow<'a, str>, String }
+#[cfg(not(no_global_oom_handling))]
+impl_ord! { Cow<'a, str>, &String }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Default for String {

library/core/src/str/traits.rs

@@ -30,6 +30,22 @@ impl PartialEq for str {
     }
 }
 
+#[stable(feature = "more_str_partialeq_impls", since = "CURRENT_RUSTC_VERSION")]
+impl PartialEq<&str> for str {
+    #[inline]
+    fn eq(&self, other: &&str) -> bool {
+        self.as_bytes() == other.as_bytes()
+    }
+}
+
+#[stable(feature = "more_str_partialeq_impls", since = "CURRENT_RUSTC_VERSION")]
+impl PartialEq<str> for &str {
+    #[inline]
+    fn eq(&self, other: &str) -> bool {
+        self.as_bytes() == other.as_bytes()
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Eq for str {}
 
@@ -48,6 +64,22 @@ impl PartialOrd for str {
     }
 }
 
+#[stable(feature = "more_str_partialord_impls", since = "CURRENT_RUSTC_VERSION")]
+impl PartialOrd<&str> for str {
+    #[inline]
+    fn partial_cmp(&self, other: &&str) -> Option<Ordering> {
+        Some(self.cmp(*other))
+    }
+}
+
+#[stable(feature = "more_str_partialord_impls", since = "CURRENT_RUSTC_VERSION")]
+impl PartialOrd<str> for &str {
+    #[inline]
+    fn partial_cmp(&self, other: &str) -> Option<Ordering> {
+        Some(self.cmp(&other))
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<I> ops::Index<I> for str
 where

src/bootstrap/src/core/build_steps/clippy.rs

@@ -77,7 +77,8 @@ pub fn get_clippy_rules_in_order(all_args: &[String], config: &LintConfig) -> Ve
             let rule = format!("{prefix}{v}");
             // Arguments added by bootstrap in LintConfig won't show up in the all_args list, so
             // put them at the end of the command line.
-            let position = all_args.iter().position(|t| t == &rule || t == v).unwrap_or(usize::MAX);
+            let position =
+                all_args.iter().position(|t| t == rule.as_str() || t == v).unwrap_or(usize::MAX);
             result.push((position, rule));
         });
     }

src/tools/clippy/clippy_lints/src/operators/cmp_owned.rs

@@ -98,12 +98,12 @@ fn check_op(cx: &LateContext<'_>, expr: &Expr<'_>, other: &Expr<'_>, left: bool)
             let arg_snip = snippet(cx, arg_span, "..");
             let expr_snip;
             let eq_impl;
-            if with_deref.is_implemented() {
-                expr_snip = format!("*{arg_snip}");
-                eq_impl = with_deref;
-            } else {
+            if without_deref.is_implemented() {
                 expr_snip = arg_snip.to_string();
                 eq_impl = without_deref;
+            } else {
+                expr_snip = format!("*{arg_snip}");
+                eq_impl = with_deref;
             }
 
             let span;

src/tools/clippy/tests/ui/iter_overeager_cloned.fixed

@@ -13,13 +13,13 @@ fn main() {
 
     let _: Option<String> = vec.iter().chain(vec.iter()).next().cloned();
 
-    let _: usize = vec.iter().filter(|x| x == &"2").count();
+    let _: usize = vec.iter().filter(|x| x == "2").count();
 
     let _: Vec<_> = vec.iter().take(2).cloned().collect();
 
     let _: Vec<_> = vec.iter().skip(2).cloned().collect();
 
-    let _ = vec.iter().filter(|x| x == &"2").nth(2).cloned();
+    let _ = vec.iter().filter(|x| x == "2").nth(2).cloned();
 
     let _ = [Some(Some("str".to_string())), Some(Some("str".to_string()))]
         .iter()
@@ -46,7 +46,7 @@ fn main() {
         iter: impl Iterator<Item = &'a (&'a u32, String)> + 'a,
         target: String,
     ) -> impl Iterator<Item = (&'a u32, String)> + 'a {
-        iter.filter(move |&(&a, b)| a == 1 && b == &target).cloned()
+        iter.filter(move |&(&a, b)| a == 1 && b == target).cloned()
     }
 
     {
@@ -57,7 +57,7 @@ fn main() {
         }
 
         fn bar<'a>(iter: impl Iterator<Item = &'a S<'a>> + 'a, target: String) -> impl Iterator<Item = S<'a>> + 'a {
-            iter.filter(move |&S { a, b }| **a == 1 && b == &target).cloned()
+            iter.filter(move |&S { a, b }| **a == 1 && b == target).cloned()
         }
     }
 

src/tools/clippy/tests/ui/iter_overeager_cloned.rs

@@ -47,7 +47,7 @@ fn main() {
         iter: impl Iterator<Item = &'a (&'a u32, String)> + 'a,
         target: String,
     ) -> impl Iterator<Item = (&'a u32, String)> + 'a {
-        iter.cloned().filter(move |(&a, b)| a == 1 && b == &target)
+        iter.cloned().filter(move |(&a, b)| a == 1 && b == target)
     }
 
     {
@@ -58,7 +58,7 @@ fn main() {
         }
 
         fn bar<'a>(iter: impl Iterator<Item = &'a S<'a>> + 'a, target: String) -> impl Iterator<Item = S<'a>> + 'a {
-            iter.cloned().filter(move |S { a, b }| **a == 1 && b == &target)
+            iter.cloned().filter(move |S { a, b }| **a == 1 && b == target)
         }
     }
 

src/tools/clippy/tests/ui/iter_overeager_cloned.stderr

@@ -28,6 +28,17 @@ LL |     let _: usize = vec.iter().filter(|x| x == &"2").cloned().count();
    = note: `-D clippy::redundant-clone` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::redundant_clone)]`
 
+error: taken reference of right operand
+  --> tests/ui/iter_overeager_cloned.rs:16:42
+   |
+LL |     let _: usize = vec.iter().filter(|x| x == &"2").cloned().count();
+   |                                          ^^^^^----
+   |                                               |
+   |                                               help: use the right value directly: `"2"`
+   |
+   = note: `-D clippy::op-ref` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::op_ref)]`
+
 error: unnecessarily eager cloning of iterator items
   --> tests/ui/iter_overeager_cloned.rs:18:21
    |
@@ -52,6 +63,14 @@ LL |     let _ = vec.iter().filter(|x| x == &"2").cloned().nth(2);
    |                                             |
    |                                             help: try: `.nth(2).cloned()`
 
+error: taken reference of right operand
+  --> tests/ui/iter_overeager_cloned.rs:22:35
+   |
+LL |     let _ = vec.iter().filter(|x| x == &"2").cloned().nth(2);
+   |                                   ^^^^^----
+   |                                        |
+   |                                        help: use the right value directly: `"2"`
+
 error: unnecessarily eager cloning of iterator items
   --> tests/ui/iter_overeager_cloned.rs:24:13
    |
@@ -119,18 +138,18 @@ LL |         let _ = vec.iter().cloned().find(f);
 error: unnecessarily eager cloning of iterator items
   --> tests/ui/iter_overeager_cloned.rs:50:9
    |
-LL |         iter.cloned().filter(move |(&a, b)| a == 1 && b == &target)
-   |         ^^^^-------------------------------------------------------
+LL |         iter.cloned().filter(move |(&a, b)| a == 1 && b == target)
+   |         ^^^^------------------------------------------------------
    |             |
-   |             help: try: `.filter(move |&(&a, b)| a == 1 && b == &target).cloned()`
+   |             help: try: `.filter(move |&(&a, b)| a == 1 && b == target).cloned()`
 
 error: unnecessarily eager cloning of iterator items
   --> tests/ui/iter_overeager_cloned.rs:61:13
    |
-LL |             iter.cloned().filter(move |S { a, b }| **a == 1 && b == &target)
-   |             ^^^^------------------------------------------------------------
+LL |             iter.cloned().filter(move |S { a, b }| **a == 1 && b == target)
+   |             ^^^^-----------------------------------------------------------
    |                 |
-   |                 help: try: `.filter(move |&S { a, b }| **a == 1 && b == &target).cloned()`
+   |                 help: try: `.filter(move |&S { a, b }| **a == 1 && b == target).cloned()`
 
 error: unneeded cloning of iterator items
   --> tests/ui/iter_overeager_cloned.rs:65:13
@@ -164,5 +183,5 @@ LL |     let _ = vec.iter().cloned().any(|x| x.len() == 1);
    |                       |
    |                       help: try: `.any(|x| x.len() == 1)`
 
-error: aborting due to 19 previous errors
+error: aborting due to 21 previous errors
 

src/tools/clippy/tests/ui/op_ref.fixed

@@ -18,7 +18,7 @@ fn main() {
     let a = "a".to_string();
     let b = "a";
 
-    if b < &a {
+    if b < a {
         println!("OK");
     }
 

src/tools/clippy/tests/ui/op_ref.stderr

@@ -11,6 +11,14 @@ help: use the values directly
 LL |     let foo = 5 - 6;
    |               ~   ~
 
+error: taken reference of right operand
+  --> tests/ui/op_ref.rs:21:8
+   |
+LL |     if b < &a {
+   |        ^^^^--
+   |            |
+   |            help: use the right value directly: `a`
+
 error: taken reference of right operand
   --> tests/ui/op_ref.rs:58:13
    |
@@ -35,5 +43,5 @@ LL |         let _ = two + &three;
    |                       |
    |                       help: use the right value directly: `three`
 
-error: aborting due to 4 previous errors
+error: aborting due to 5 previous errors
 

tests/ui/binop/binary-op-suggest-deref.rs

@@ -67,9 +67,7 @@ fn baz() {
     let string_ref = &owned;
     let partial = "foobar";
     _ = string_ref == partial[..3];
-    //~^ERROR can't compare `&String` with `str` [E0277]
     _ = partial[..3] == string_ref;
-    //~^ERROR can't compare `str` with `&String` [E0277]
 }
 
 fn qux() {

tests/ui/binop/binary-op-suggest-deref.stderr

@@ -271,32 +271,8 @@ note: an implementation of `PartialEq<&&{integer}>` might be missing for `Foo`
 LL |     struct Foo;
    |     ^^^^^^^^^^ must implement `PartialEq<&&{integer}>`
 
-error[E0277]: can't compare `&String` with `str`
-  --> $DIR/binary-op-suggest-deref.rs:69:20
-   |
-LL |     _ = string_ref == partial[..3];
-   |                    ^^ no implementation for `&String == str`
-   |
-   = help: the trait `PartialEq<str>` is not implemented for `&String`
-help: consider dereferencing here
-   |
-LL |     _ = *string_ref == partial[..3];
-   |         +
-
-error[E0277]: can't compare `str` with `&String`
-  --> $DIR/binary-op-suggest-deref.rs:71:22
-   |
-LL |     _ = partial[..3] == string_ref;
-   |                      ^^ no implementation for `str == &String`
-   |
-   = help: the trait `PartialEq<&String>` is not implemented for `str`
-help: consider dereferencing here
-   |
-LL |     _ = partial[..3] == *string_ref;
-   |                         +
-
 error[E0277]: no implementation for `i32 & str`
-  --> $DIR/binary-op-suggest-deref.rs:78:17
+  --> $DIR/binary-op-suggest-deref.rs:76:17
    |
 LL |     let _ = FOO & (*"Sized".to_string().into_boxed_str());
    |                 ^ no implementation for `i32 & str`
@@ -309,14 +285,14 @@ LL |     let _ = FOO & (*"Sized".to_string().into_boxed_str());
              `i32` implements `BitAnd`
 
 error[E0277]: the size for values of type `str` cannot be known at compilation time
-  --> $DIR/binary-op-suggest-deref.rs:78:17
+  --> $DIR/binary-op-suggest-deref.rs:76:17
    |
 LL |     let _ = FOO & (*"Sized".to_string().into_boxed_str());
    |                 ^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `str`
 
-error: aborting due to 24 previous errors
+error: aborting due to 22 previous errors
 
 Some errors have detailed explanations: E0277, E0308, E0369.
 For more information about an error, try `rustc --explain E0277`.

tests/ui/inference/issue-72616.stderr

@@ -8,12 +8,15 @@ LL |         if String::from("a") == "a".try_into().unwrap() {}
    |
    = note: cannot satisfy `String: PartialEq<_>`
    = help: the following types implement trait `PartialEq<Rhs>`:
+             `&String` implements `PartialEq<Cow<'_, str>>`
+             `&String` implements `PartialEq<String>`
+             `&String` implements `PartialEq<str>`
+             `String` implements `PartialEq<&String>`
              `String` implements `PartialEq<&str>`
              `String` implements `PartialEq<ByteStr>`
              `String` implements `PartialEq<ByteString>`
              `String` implements `PartialEq<Cow<'_, str>>`
-             `String` implements `PartialEq<str>`
-             `String` implements `PartialEq`
+           and 2 others
 help: try using a fully qualified path to specify the expected types
    |
 LL |         if String::from("a") == <&str as TryInto<T>>::try_into("a").unwrap() {}