Merge #6148

6148: Fix trait object hir formatting behind pointer and references r=matklad a=Veykril

Fixes #6064

Co-authored-by: Lukas Wirth <lukastw97@gmail.com>

Author: bors[bot]

crates/hir_ty/src/display.rs

@@ -221,7 +221,16 @@ impl HirDisplay for ApplicationTy {
             }
             TypeCtor::RawPtr(m) => {
                 let t = self.parameters.as_single();
-                write!(f, "*{}{}", m.as_keyword_for_ptr(), t.display(f.db))?;
+                let ty_display = t.display(f.db);
+
+                write!(f, "*{}", m.as_keyword_for_ptr())?;
+                if matches!(t, Ty::Dyn(predicates) if predicates.len() > 1) {
+                    write!(f, "(")?;
+                    write!(f, "{}", ty_display)?;
+                    write!(f, ")")?;
+                } else {
+                    write!(f, "{}", ty_display)?;
+                }
             }
             TypeCtor::Ref(m) => {
                 let t = self.parameters.as_single();
@@ -230,7 +239,15 @@ impl HirDisplay for ApplicationTy {
                 } else {
                     t.display(f.db)
                 };
-                write!(f, "&{}{}", m.as_keyword_for_ref(), ty_display)?;
+
+                write!(f, "&{}", m.as_keyword_for_ref())?;
+                if matches!(t, Ty::Dyn(predicates) if predicates.len() > 1) {
+                    write!(f, "(")?;
+                    write!(f, "{}", ty_display)?;
+                    write!(f, ")")?;
+                } else {
+                    write!(f, "{}", ty_display)?;
+                }
             }
             TypeCtor::Never => write!(f, "!")?,
             TypeCtor::Tuple { .. } => {
@@ -636,14 +653,14 @@ impl HirDisplay for GenericPredicate {
 
 impl HirDisplay for Obligation {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
-        Ok(match self {
-            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db))?,
+        match self {
+            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db)),
             Obligation::Projection(proj) => write!(
                 f,
                 "Normalize({} => {})",
                 proj.projection_ty.display(f.db),
                 proj.ty.display(f.db)
-            )?,
-        })
+            ),
+        }
     }
 }

crates/ide/src/inlay_hints.rs

@@ -1023,6 +1023,40 @@ mod collections {
         type Item=T;
     }
 }
+"#,
+        );
+    }
+
+    #[test]
+    fn multi_dyn_trait_bounds() {
+        check_with_config(
+            InlayHintsConfig {
+                type_hints: true,
+                parameter_hints: false,
+                chaining_hints: false,
+                max_length: None,
+            },
+            r#"
+//- /main.rs crate:main
+pub struct Vec<T> {}
+
+impl<T> Vec<T> {
+    pub fn new() -> Self { Vec {} }
+}
+
+pub struct Box<T> {}
+
+trait Display {}
+trait Sync {}
+
+fn main() {
+    let _v = Vec::<Box<&(dyn Display + Sync)>>::new();
+      //^^ Vec<Box<&(dyn Display + Sync)>>
+    let _v = Vec::<Box<*const (dyn Display + Sync)>>::new();
+      //^^ Vec<Box<*const (dyn Display + Sync)>>
+    let _v = Vec::<Box<dyn Display + Sync>>::new();
+      //^^ Vec<Box<dyn Display + Sync>>
+}
 "#,
         );
     }