Replace UncoeribleReceiver error message with UndispatchableReceiver

Author: mikeyhew

src/librustc/traits/object_safety.rs

@@ -64,8 +64,8 @@ impl ObjectSafetyViolation {
                 format!("method `{}` references the `Self` type in where clauses", name).into(),
             ObjectSafetyViolation::Method(name, MethodViolationCode::Generic) =>
                 format!("method `{}` has generic type parameters", name).into(),
-            ObjectSafetyViolation::Method(name, MethodViolationCode::UncoercibleReceiver) =>
-                format!("method `{}` has an uncoercible receiver type", name).into(),
+            ObjectSafetyViolation::Method(name, MethodViolationCode::UndispatchableReceiver) =>
+                format!("method `{}`'s receiver cannot be dispatched on", name).into(),
             ObjectSafetyViolation::AssociatedConst(name) =>
                 format!("the trait cannot contain associated consts like `{}`", name).into(),
         }
@@ -87,8 +87,8 @@ pub enum MethodViolationCode {
     /// e.g., `fn foo<A>()`
     Generic,
 
-    /// the self argument can't be coerced from Self=dyn Trait to Self=T where T: Trait
-    UncoercibleReceiver,
+    /// the method's receiver (`self` argument) can't be dispatched on
+    UndispatchableReceiver,
 }
 
 impl<'a, 'tcx> TyCtxt<'a, 'tcx, 'tcx> {
@@ -325,7 +325,7 @@ impl<'a, 'tcx> TyCtxt<'a, 'tcx, 'tcx> {
         // `Receiver: Unsize<Receiver[Self => dyn Trait]>`
         if receiver_ty != self.mk_self_type() {
             if !self.receiver_is_dispatchable(method, receiver_ty) {
-                return Some(MethodViolationCode::UncoercibleReceiver);
+                return Some(MethodViolationCode::UndispatchableReceiver);
             }
         }
 

src/test/ui/arbitrary-self-types-not-object-safe.stderr

@@ -4,15 +4,15 @@ error[E0038]: the trait `Foo` cannot be made into an object
 LL |     let x = Rc::new(5usize) as Rc<Foo>;
    |                                ^^^^^^^ the trait `Foo` cannot be made into an object
    |
-   = note: method `foo` has an uncoercible receiver type
+   = note: method `foo`'s receiver cannot be dispatched on
 
 error[E0038]: the trait `Foo` cannot be made into an object
   --> $DIR/arbitrary-self-types-not-object-safe.rs:40:13
    |
 LL |     let x = Rc::new(5usize) as Rc<Foo>;
    |             ^^^^^^^^^^^^^^^ the trait `Foo` cannot be made into an object
    |
-   = note: method `foo` has an uncoercible receiver type
+   = note: method `foo`'s receiver cannot be dispatched on
    = note: required because of the requirements on the impl of `std::ops::CoerceUnsized<std::rc::Rc<dyn Foo>>` for `std::rc::Rc<usize>`
 
 error: aborting due to 2 previous errors