removed replacen

Author: Kivooeo

compiler/rustc_hir_typeck/src/cast.rs

@@ -501,12 +501,15 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                             .must_apply_modulo_regions()
                         {
                             label = false;
-                            if !self.cast_ty.is_primitive() {
-                                let type_to_cast = self.cast_ty.to_string().replacen('<', "::<", 1);
+                            if let ty::Adt(def, args) = self.cast_ty.kind() {
                                 err.span_suggestion_verbose(
                                     self.span,
                                     "consider using the `From` trait instead",
-                                    format!("{}::from({})", type_to_cast, snippet),
+                                    format!(
+                                        "{}::from({})",
+                                        fcx.tcx.value_path_str_with_args(def.did(), args),
+                                        snippet
+                                    ),
                                     Applicability::MaybeIncorrect,
                                 );
                             } else {
@@ -516,7 +519,7 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                                     format!("{}::from({})", self.cast_ty, snippet),
                                     Applicability::MaybeIncorrect,
                                 );
-                            }
+                            };
                         }
                     }
 

tests/ui/issues/issue-16048.stderr

@@ -11,14 +11,9 @@ error[E0605]: non-primitive cast: `Foo<'a>` as `T`
   --> $DIR/issue-16048.rs:24:16
    |
 LL |         return *self as T;
-   |                ^^^^^^^^^^
+   |                ^^^^^^^^^^ help: consider using the `From` trait instead: `T::from(*self)`
    |
    = note: an `as` expression can only be used to convert between primitive types or to coerce to a specific trait object
-help: consider using the `From` trait instead
-   |
-LL -         return *self as T;
-LL +         return T::from(*self);
-   |
 
 error: aborting due to 2 previous errors