Rollup merge of #137171 - makai410:swapping-e0277, r=compiler-errors

Suggest swapping equality on E0277

Closes: #132695 .

2 files changed, 35 insertions, 0 deletions

diff --git a/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.rs b/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.rs
new file mode 100644
index 00000000000..2ebbed3c740
--- /dev/null
+++ b/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.rs
@@ -0,0 +1,11 @@
+struct T(String);
+
+impl PartialEq<String> for T {
+    fn eq(&self, other: &String) -> bool {
+        &self.0 == other
+    }
+}
+
+fn main() {
+    String::from("Girls Band Cry") == T(String::from("Girls Band Cry")); //~ can't compare `String` with `T` [E0277]
+}
diff --git a/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.stderr b/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.stderr
new file mode 100644
index 00000000000..ebe103ef19a
--- /dev/null
+++ b/tests/ui/suggestions/partialeq_suggest_swap_on_e0277.stderr
@@ -0,0 +1,24 @@
+error[E0277]: can't compare `String` with `T`
+  --> $DIR/partialeq_suggest_swap_on_e0277.rs:10:36
+   |
+LL |     String::from("Girls Band Cry") == T(String::from("Girls Band Cry"));
+   |                                    ^^ no implementation for `String == T`
+   |
+   = help: the trait `PartialEq<T>` is not implemented for `String`
+   = help: the following other types implement trait `PartialEq<Rhs>`:
+             `String` implements `PartialEq<&str>`
+             `String` implements `PartialEq<ByteStr>`
+             `String` implements `PartialEq<ByteString>`
+             `String` implements `PartialEq<Cow<'_, str>>`
+             `String` implements `PartialEq<str>`
+             `String` implements `PartialEq`
+   = note: `T` implements `PartialEq<String>`
+help: consider swapping the equality
+   |
+LL -     String::from("Girls Band Cry") == T(String::from("Girls Band Cry"));
+LL +     T(String::from("Girls Band Cry")) == String::from("Girls Band Cry");
+   |
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.