Tweak output

compiler/rustc_infer/src/traits/error_reporting/mod.rs

@@ -137,17 +137,17 @@ pub fn report_object_safety_error<'tcx>(
                 .iter()
                 .map(|t| {
                     with_no_trimmed_paths!(format!(
-                        "\n - {}",
+                        "  {}",
                         tcx.type_of(*t).instantiate_identity(),
                     ))
                 })
                 .collect::<Vec<_>>();
             err.help(format!(
                 "the following types implement the trait, consider defining an enum where each \
                  variant holds one of these types, implementing `{}` for this new enum and using \
-                 it instead:{}",
+                 it instead:\n{}",
                 trait_str,
-                types.join(""),
+                types.join("\n"),
             ));
         }
     }

tests/ui/generic-associated-types/gat-in-trait-path.base.stderr

@@ -13,8 +13,8 @@ LL |     type A<'a> where Self: 'a;
    |          ^ ...because it contains the generic associated type `A`
    = help: consider moving `A` to another trait
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `Foo` for this new enum and using it instead:
-            - Fooy
-            - Fooer<T>
+             Fooy
+             Fooer<T>
 
 error: aborting due to previous error
 

tests/ui/generic-associated-types/issue-79422.base.stderr

@@ -29,8 +29,8 @@ LL |     type VRefCont<'a>: RefCont<'a, V> where Self: 'a;
    |          ^^^^^^^^ ...because it contains the generic associated type `VRefCont`
    = help: consider moving `VRefCont` to another trait
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `MapLike` for this new enum and using it instead:
-            - std::collections::BTreeMap<K, V>
-            - Source
+             std::collections::BTreeMap<K, V>
+             Source
 
 error[E0038]: the trait `MapLike` cannot be made into an object
   --> $DIR/issue-79422.rs:44:13
@@ -47,8 +47,8 @@ LL |     type VRefCont<'a>: RefCont<'a, V> where Self: 'a;
    |          ^^^^^^^^ ...because it contains the generic associated type `VRefCont`
    = help: consider moving `VRefCont` to another trait
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `MapLike` for this new enum and using it instead:
-            - std::collections::BTreeMap<K, V>
-            - Source
+             std::collections::BTreeMap<K, V>
+             Source
    = note: required for the cast from `Box<BTreeMap<u8, u8>>` to `Box<dyn MapLike<u8, u8, VRefCont = (dyn RefCont<'_, u8> + 'static)>>`
 
 error: aborting due to 3 previous errors

tests/ui/impl-trait/object-unsafe-trait-in-return-position-dyn-trait.stderr

@@ -12,8 +12,8 @@ LL | trait NotObjectSafe {
 LL |     fn foo() -> Self;
    |        ^^^ ...because associated function `foo` has no `self` parameter
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `NotObjectSafe` for this new enum and using it instead:
-            - A
-            - B
+             A
+             B
 help: consider turning `foo` into a method by giving it a `&self` argument
    |
 LL |     fn foo(&self) -> Self;
@@ -37,8 +37,8 @@ LL | trait NotObjectSafe {
 LL |     fn foo() -> Self;
    |        ^^^ ...because associated function `foo` has no `self` parameter
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `NotObjectSafe` for this new enum and using it instead:
-            - A
-            - B
+             A
+             B
 help: consider turning `foo` into a method by giving it a `&self` argument
    |
 LL |     fn foo(&self) -> Self;

tests/ui/traits/test-2.stderr

@@ -43,8 +43,8 @@ LL | trait bar { fn dup(&self) -> Self; fn blah<X>(&self); }
    = help: consider moving `dup` to another trait
    = help: consider moving `blah` to another trait
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `bar` for this new enum and using it instead:
-            - i32
-            - u32
+             i32
+             u32
 
 error[E0038]: the trait `bar` cannot be made into an object
   --> $DIR/test-2.rs:13:5
@@ -63,8 +63,8 @@ LL | trait bar { fn dup(&self) -> Self; fn blah<X>(&self); }
    = help: consider moving `dup` to another trait
    = help: consider moving `blah` to another trait
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `bar` for this new enum and using it instead:
-            - i32
-            - u32
+             i32
+             u32
 
 error[E0038]: the trait `bar` cannot be made into an object
   --> $DIR/test-2.rs:13:6
@@ -83,8 +83,8 @@ LL | trait bar { fn dup(&self) -> Self; fn blah<X>(&self); }
    = help: consider moving `dup` to another trait
    = help: consider moving `blah` to another trait
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `bar` for this new enum and using it instead:
-            - i32
-            - u32
+             i32
+             u32
    = note: required for the cast from `Box<{integer}>` to `Box<dyn bar>`
 
 error: aborting due to 5 previous errors

tests/ui/wf/wf-unsafe-trait-obj-match.stderr

@@ -30,8 +30,8 @@ LL | trait Trait: Sized {}
    |       |
    |       this trait cannot be made into an object...
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `Trait` for this new enum and using it instead:
-            - S
-            - R
+             S
+             R
    = note: required for the cast from `&S` to `&dyn Trait`
 
 error[E0038]: the trait `Trait` cannot be made into an object
@@ -52,8 +52,8 @@ LL | trait Trait: Sized {}
    |       |
    |       this trait cannot be made into an object...
    = help: the following types implement the trait, consider defining an enum where each variant holds one of these types, implementing `Trait` for this new enum and using it instead:
-            - S
-            - R
+             S
+             R
    = note: required for the cast from `&R` to `&dyn Trait`
 
 error: aborting due to 3 previous errors