Rollup merge of #51104 - zackmdavis:dynamo, r=nikomatsakis

add `dyn ` to display of dynamic (trait) types

~~I'm not sure we want the `dyn` in the E0277 "trait bound [...] is not satisfied" messages ("bound" sounds like a different thing in contrast to the names of specific trait-object types like `Box<dyn Trait>`), but I'm finding the code I would need to change that hard to follow—the [display object seems to](https://github.com/rust-lang/rust/blob/f0805a4421449bd6fe3096d63820fbebe2bfcd1d/src/librustc/traits/error_reporting.rs#L600) be a [`Predicate::Trait`](https://github.com/rust-lang/rust/blob/f0805a4421449bd6fe3096d63820fbebe2bfcd1d/src/librustc/ty/mod.rs#L962) variant, whose [`Display` implementation](https://github.com/rust-lang/rust/blob/f0805a4421449bd6fe3096d63820fbebe2bfcd1d/src/librustc/util/ppaux.rs#L1309) calls `.print` on its `PolyTraitPredicate` member, [which is a type alias](https://github.com/rust-lang/rust/blob/f0805a4421449bd6fe3096d63820fbebe2bfcd1d/src/librustc/ty/mod.rs#L1112) for `ty::Binder<TraitPredicate<'tcx>>`, whose [`Display` implementation](https://github.com/rust-lang/rust/blob/f0805a4421449bd6fe3096d63820fbebe2bfcd1d/src/librustc/util/ppaux.rs#L975-L985) ... _&c._— so maybe it's time to pull-request this and see what reviewers think.~~

 Resolves #49277 (?).

r? @nikomatsakis

57 files changed, 143 insertions, 139 deletions

diff --git a/src/librustc/util/ppaux.rs b/src/librustc/util/ppaux.rs
index 3252a2cd6ab..4fe9c34c140 100644
--- a/src/librustc/util/ppaux.rs
+++ b/src/librustc/util/ppaux.rs
@@ -1062,10 +1062,14 @@ define_print! {
                 TyParam(ref param_ty) => write!(f, "{}", param_ty),
                 TyAdt(def, substs) => cx.parameterized(f, substs, def.did, &[]),
                 TyDynamic(data, r) => {
-                    data.print(f, cx)?;
                     let r = r.print_to_string(cx);
                     if !r.is_empty() {
-                        write!(f, " + {}", r)
+                        write!(f, "(")?;
+                    }
+                    write!(f, "dyn ")?;
+                    data.print(f, cx)?;
+                    if !r.is_empty() {
+                        write!(f, " + {})", r)
                     } else {
                         Ok(())
                     }
diff --git a/src/test/compile-fail/cross-borrow-trait.rs b/src/test/compile-fail/cross-borrow-trait.rs
index 847a82c0826..7c76cf475d2 100644
--- a/src/test/compile-fail/cross-borrow-trait.rs
+++ b/src/test/compile-fail/cross-borrow-trait.rs
@@ -18,6 +18,6 @@ impl Trait for Foo {}
 pub fn main() {
     let x: Box<Trait> = Box::new(Foo);
     let _y: &Trait = x; //~ ERROR E0308
-                        //~| expected type `&Trait`
-                        //~| found type `std::boxed::Box<Trait>`
+                        //~| expected type `&dyn Trait`
+                        //~| found type `std::boxed::Box<dyn Trait>`
 }
diff --git a/src/test/compile-fail/destructure-trait-ref.rs b/src/test/compile-fail/destructure-trait-ref.rs
index 09bd3a2fc57..b5acdc12ca0 100644
--- a/src/test/compile-fail/destructure-trait-ref.rs
+++ b/src/test/compile-fail/destructure-trait-ref.rs
@@ -33,23 +33,23 @@ fn main() {
     let &&x = &&(&1isize as &T);
 
     // n == m
-    let &x = &1isize as &T;      //~ ERROR type `&T` cannot be dereferenced
-    let &&x = &(&1isize as &T);  //~ ERROR type `&T` cannot be dereferenced
-    let box x = box 1isize as Box<T>; //~ ERROR type `std::boxed::Box<T>` cannot be dereferenced
+    let &x = &1isize as &T;      //~ ERROR type `&dyn T` cannot be dereferenced
+    let &&x = &(&1isize as &T);  //~ ERROR type `&dyn T` cannot be dereferenced
+    let box x = box 1isize as Box<T>; //~ ERROR type `std::boxed::Box<dyn T>` cannot be dereferenced
 
     // n > m
     let &&x = &1isize as &T;
     //~^ ERROR mismatched types
-    //~| expected type `T`
+    //~| expected type `dyn T`
     //~| found type `&_`
     //~| expected trait T, found reference
     let &&&x = &(&1isize as &T);
     //~^ ERROR mismatched types
-    //~| expected type `T`
+    //~| expected type `dyn T`
     //~| found type `&_`
     //~| expected trait T, found reference
     let box box x = box 1isize as Box<T>;
     //~^ ERROR mismatched types
-    //~| expected type `T`
+    //~| expected type `dyn T`
     //~| found type `std::boxed::Box<_>`
 }
diff --git a/src/test/compile-fail/dst-bad-assign-3.rs b/src/test/compile-fail/dst-bad-assign-3.rs
index 5bc6c6cda26..2a209a2959b 100644
--- a/src/test/compile-fail/dst-bad-assign-3.rs
+++ b/src/test/compile-fail/dst-bad-assign-3.rs
@@ -42,7 +42,7 @@ pub fn main() {
     let z: Box<ToBar> = Box::new(Bar1 {f: 36});
     f5.2 = Bar1 {f: 36};
     //~^ ERROR mismatched types
-    //~| expected type `ToBar`
+    //~| expected type `dyn ToBar`
     //~| found type `Bar1`
     //~| expected trait ToBar, found struct `Bar1`
     //~| ERROR the size for value values of type
diff --git a/src/test/compile-fail/dst-bad-assign.rs b/src/test/compile-fail/dst-bad-assign.rs
index 37b6056d1a7..e28586c4755 100644
--- a/src/test/compile-fail/dst-bad-assign.rs
+++ b/src/test/compile-fail/dst-bad-assign.rs
@@ -44,7 +44,7 @@ pub fn main() {
     let z: Box<ToBar> = Box::new(Bar1 {f: 36});
     f5.ptr = Bar1 {f: 36};
     //~^ ERROR mismatched types
-    //~| expected type `ToBar`
+    //~| expected type `dyn ToBar`
     //~| found type `Bar1`
     //~| expected trait ToBar, found struct `Bar1`
     //~| ERROR the size for value values of type
diff --git a/src/test/compile-fail/fn-trait-formatting.rs b/src/test/compile-fail/fn-trait-formatting.rs
index 6d70f54edb4..56d64d77ee2 100644
--- a/src/test/compile-fail/fn-trait-formatting.rs
+++ b/src/test/compile-fail/fn-trait-formatting.rs
@@ -16,15 +16,15 @@ fn main() {
     let _: () = (box |_: isize| {}) as Box<FnOnce(isize)>;
     //~^ ERROR mismatched types
     //~| expected type `()`
-    //~| found type `std::boxed::Box<std::ops::FnOnce(isize)>`
+    //~| found type `std::boxed::Box<dyn std::ops::FnOnce(isize)>`
     let _: () = (box |_: isize, isize| {}) as Box<Fn(isize, isize)>;
     //~^ ERROR mismatched types
     //~| expected type `()`
-    //~| found type `std::boxed::Box<std::ops::Fn(isize, isize)>`
+    //~| found type `std::boxed::Box<dyn std::ops::Fn(isize, isize)>`
     let _: () = (box || -> isize { unimplemented!() }) as Box<FnMut() -> isize>;
     //~^ ERROR mismatched types
     //~| expected type `()`
-    //~| found type `std::boxed::Box<std::ops::FnMut() -> isize>`
+    //~| found type `std::boxed::Box<dyn std::ops::FnMut() -> isize>`
 
     needs_fn(1);
     //~^ ERROR : std::ops::Fn<(isize,)>`
diff --git a/src/test/compile-fail/issue-13033.rs b/src/test/compile-fail/issue-13033.rs
index 3d9d81471cb..f1fd617717a 100644
--- a/src/test/compile-fail/issue-13033.rs
+++ b/src/test/compile-fail/issue-13033.rs
@@ -17,8 +17,8 @@ struct Baz;
 impl Foo for Baz {
     fn bar(&mut self, other: &Foo) {}
     //~^ ERROR method `bar` has an incompatible type for trait
-    //~| expected type `fn(&mut Baz, &mut Foo)`
-    //~| found type `fn(&mut Baz, &Foo)`
+    //~| expected type `fn(&mut Baz, &mut dyn Foo)`
+    //~| found type `fn(&mut Baz, &dyn Foo)`
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-20939.rs b/src/test/compile-fail/issue-20939.rs
index 88197166ee0..5282ce4bb88 100644
--- a/src/test/compile-fail/issue-20939.rs
+++ b/src/test/compile-fail/issue-20939.rs
@@ -11,6 +11,6 @@
 trait Foo {}
 
 impl<'a> Foo for Foo+'a {}
-//~^ ERROR the object type `Foo + 'a` automatically implements the trait `Foo`
+//~^ ERROR the object type `(dyn Foo + 'a)` automatically implements the trait `Foo`
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-32963.rs b/src/test/compile-fail/issue-32963.rs
index e97e5a86a9d..24db822f89c 100644
--- a/src/test/compile-fail/issue-32963.rs
+++ b/src/test/compile-fail/issue-32963.rs
@@ -17,5 +17,5 @@ fn size_of_copy<T: Copy+?Sized>() -> usize { mem::size_of::<T>() }
 fn main() {
     size_of_copy::<Misc+Copy>();
     //~^ ERROR only auto traits can be used as additional traits in a trait object
-    //~| ERROR the trait bound `Misc: std::marker::Copy` is not satisfied
+    //~| ERROR the trait bound `dyn Misc: std::marker::Copy` is not satisfied
 }
diff --git a/src/test/compile-fail/issue-41139.rs b/src/test/compile-fail/issue-41139.rs
index 15ca151c49a..0509a4387ba 100644
--- a/src/test/compile-fail/issue-41139.rs
+++ b/src/test/compile-fail/issue-41139.rs
@@ -14,5 +14,5 @@ fn get_function<'a>() -> &'a Fn() -> Trait { panic!("") }
 
 fn main() {
     let t : &Trait = &get_function()();
-    //~^ ERROR cannot move a value of type Trait + 'static
+    //~^ ERROR cannot move a value of type (dyn Trait + 'static)
 }
diff --git a/src/test/compile-fail/issue-5153.rs b/src/test/compile-fail/issue-5153.rs
index b1d96f9b527..9b49886961d 100644
--- a/src/test/compile-fail/issue-5153.rs
+++ b/src/test/compile-fail/issue-5153.rs
@@ -18,5 +18,5 @@ impl Foo for isize {
 
 fn main() {
     (&5isize as &Foo).foo();
-    //~^ ERROR: no method named `foo` found for type `&Foo` in the current scope
+    //~^ ERROR: no method named `foo` found for type `&dyn Foo` in the current scope
 }
diff --git a/src/test/compile-fail/kindck-send-object.rs b/src/test/compile-fail/kindck-send-object.rs
index a3eb47be3ee..82b97878549 100644
--- a/src/test/compile-fail/kindck-send-object.rs
+++ b/src/test/compile-fail/kindck-send-object.rs
@@ -20,12 +20,12 @@ trait Message : Send { }
 
 fn object_ref_with_static_bound_not_ok() {
     assert_send::<&'static (Dummy+'static)>();
-    //~^ ERROR `Dummy + 'static` cannot be shared between threads safely [E0277]
+    //~^ ERROR `(dyn Dummy + 'static)` cannot be shared between threads safely [E0277]
 }
 
 fn box_object_with_no_bound_not_ok<'a>() {
     assert_send::<Box<Dummy>>();
-    //~^ ERROR `Dummy` cannot be sent between threads safely
+    //~^ ERROR `dyn Dummy` cannot be sent between threads safely
 }
 
 fn object_with_send_bound_ok() {
diff --git a/src/test/compile-fail/kindck-send-object1.rs b/src/test/compile-fail/kindck-send-object1.rs
index 673a6abc5f0..853630aa416 100644
--- a/src/test/compile-fail/kindck-send-object1.rs
+++ b/src/test/compile-fail/kindck-send-object1.rs
@@ -18,7 +18,7 @@ trait Dummy { }
 // careful with object types, who knows what they close over...
 fn test51<'a>() {
     assert_send::<&'a Dummy>();
-    //~^ ERROR `Dummy + 'a` cannot be shared between threads safely [E0277]
+    //~^ ERROR `(dyn Dummy + 'a)` cannot be shared between threads safely [E0277]
 }
 fn test52<'a>() {
     assert_send::<&'a (Dummy+Sync)>();
@@ -37,7 +37,7 @@ fn test61() {
 // them not ok
 fn test_71<'a>() {
     assert_send::<Box<Dummy+'a>>();
-    //~^ ERROR `Dummy + 'a` cannot be sent between threads safely
+    //~^ ERROR `(dyn Dummy + 'a)` cannot be sent between threads safely
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/kindck-send-object2.rs b/src/test/compile-fail/kindck-send-object2.rs
index 3a935af2000..0265f888e7c 100644
--- a/src/test/compile-fail/kindck-send-object2.rs
+++ b/src/test/compile-fail/kindck-send-object2.rs
@@ -15,12 +15,12 @@ trait Dummy { }
 
 fn test50() {
     assert_send::<&'static Dummy>();
-    //~^ ERROR `Dummy + 'static` cannot be shared between threads safely [E0277]
+    //~^ ERROR `(dyn Dummy + 'static)` cannot be shared between threads safely [E0277]
 }
 
 fn test53() {
     assert_send::<Box<Dummy>>();
-    //~^ ERROR `Dummy` cannot be sent between threads safely
+    //~^ ERROR `dyn Dummy` cannot be sent between threads safely
 }
 
 // ...unless they are properly bounded
diff --git a/src/test/compile-fail/map-types.rs b/src/test/compile-fail/map-types.rs
index 9dcf902a69f..e8ff9e817af 100644
--- a/src/test/compile-fail/map-types.rs
+++ b/src/test/compile-fail/map-types.rs
@@ -25,5 +25,5 @@ fn main() {
     let x: Box<HashMap<isize, isize>> = box HashMap::new();
     let x: Box<Map<isize, isize>> = x;
     let y: Box<Map<usize, isize>> = Box::new(x);
-    //~^ ERROR `std::boxed::Box<Map<isize, isize>>: Map<usize, isize>` is not satisfied
+    //~^ ERROR `std::boxed::Box<dyn Map<isize, isize>>: Map<usize, isize>` is not satisfied
 }
diff --git a/src/test/compile-fail/non-interger-atomic.rs b/src/test/compile-fail/non-interger-atomic.rs
index a51a9e518ce..2a6e148ca79 100644
--- a/src/test/compile-fail/non-interger-atomic.rs
+++ b/src/test/compile-fail/non-interger-atomic.rs
@@ -61,22 +61,22 @@ pub unsafe fn test_Foo_cxchg(p: &mut Foo, v: Foo) {
 
 pub unsafe fn test_Bar_load(p: &mut Bar, v: Bar) {
     intrinsics::atomic_load(p);
-    //~^ ERROR expected basic integer type, found `&std::ops::Fn()`
+    //~^ ERROR expected basic integer type, found `&dyn std::ops::Fn()`
 }
 
 pub unsafe fn test_Bar_store(p: &mut Bar, v: Bar) {
     intrinsics::atomic_store(p, v);
-    //~^ ERROR expected basic integer type, found `&std::ops::Fn()`
+    //~^ ERROR expected basic integer type, found `&dyn std::ops::Fn()`
 }
 
 pub unsafe fn test_Bar_xchg(p: &mut Bar, v: Bar) {
     intrinsics::atomic_xchg(p, v);
-    //~^ ERROR expected basic integer type, found `&std::ops::Fn()`
+    //~^ ERROR expected basic integer type, found `&dyn std::ops::Fn()`
 }
 
 pub unsafe fn test_Bar_cxchg(p: &mut Bar, v: Bar) {
     intrinsics::atomic_cxchg(p, v, v);
-    //~^ ERROR expected basic integer type, found `&std::ops::Fn()`
+    //~^ ERROR expected basic integer type, found `&dyn std::ops::Fn()`
 }
 
 pub unsafe fn test_Quux_load(p: &mut Quux, v: Quux) {
diff --git a/src/test/compile-fail/object-does-not-impl-trait.rs b/src/test/compile-fail/object-does-not-impl-trait.rs
index 8babc734c84..30f8d5e2f45 100644
--- a/src/test/compile-fail/object-does-not-impl-trait.rs
+++ b/src/test/compile-fail/object-does-not-impl-trait.rs
@@ -14,5 +14,5 @@
 trait Foo {}
 fn take_foo<F:Foo>(f: F) {}
 fn take_object(f: Box<Foo>) { take_foo(f); }
-//~^ ERROR `std::boxed::Box<Foo>: Foo` is not satisfied
+//~^ ERROR `std::boxed::Box<dyn Foo>: Foo` is not satisfied
 fn main() {}
diff --git a/src/test/compile-fail/object-safety-by-value-self-use.rs b/src/test/compile-fail/object-safety-by-value-self-use.rs
index 36356cb7d52..e575bbb6cea 100644
--- a/src/test/compile-fail/object-safety-by-value-self-use.rs
+++ b/src/test/compile-fail/object-safety-by-value-self-use.rs
@@ -22,7 +22,7 @@ trait Baz {
 }
 
 fn use_bar(t: Box<Bar>) {
-    t.bar() //~ ERROR cannot move a value of type Bar
+    t.bar() //~ ERROR cannot move a value of type (dyn Bar + 'static)
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/privacy/associated-item-privacy-type-binding.rs b/src/test/compile-fail/privacy/associated-item-privacy-type-binding.rs
index c25616c5435..6019369aa2e 100644
--- a/src/test/compile-fail/privacy/associated-item-privacy-type-binding.rs
+++ b/src/test/compile-fail/privacy/associated-item-privacy-type-binding.rs
@@ -19,19 +19,19 @@ mod priv_trait {
 
     pub macro mac1() {
         let _: Box<PubTr<AssocTy = u8>>;
-        //~^ ERROR type `priv_trait::PubTr<AssocTy=u8> + '<empty>` is private
-        //~| ERROR type `priv_trait::PubTr<AssocTy=u8> + '<empty>` is private
+        //~^ ERROR type `(dyn priv_trait::PubTr<AssocTy=u8> + '<empty>)` is private
+        //~| ERROR type `(dyn priv_trait::PubTr<AssocTy=u8> + '<empty>)` is private
         type InSignatureTy2 = Box<PubTr<AssocTy = u8>>;
-        //~^ ERROR type `priv_trait::PubTr<AssocTy=u8> + 'static` is private
+        //~^ ERROR type `(dyn priv_trait::PubTr<AssocTy=u8> + 'static)` is private
         trait InSignatureTr2: PubTr<AssocTy = u8> {}
         //~^ ERROR trait `priv_trait::PrivTr` is private
     }
     pub macro mac2() {
         let _: Box<PrivTr<AssocTy = u8>>;
-        //~^ ERROR type `priv_trait::PrivTr<AssocTy=u8> + '<empty>` is private
-        //~| ERROR type `priv_trait::PrivTr<AssocTy=u8> + '<empty>` is private
+        //~^ ERROR type `(dyn priv_trait::PrivTr<AssocTy=u8> + '<empty>)` is private
+        //~| ERROR type `(dyn priv_trait::PrivTr<AssocTy=u8> + '<empty>)` is private
         type InSignatureTy1 = Box<PrivTr<AssocTy = u8>>;
-        //~^ ERROR type `priv_trait::PrivTr<AssocTy=u8> + 'static` is private
+        //~^ ERROR type `(dyn priv_trait::PrivTr<AssocTy=u8> + 'static)` is private
         trait InSignatureTr1: PrivTr<AssocTy = u8> {}
         //~^ ERROR trait `priv_trait::PrivTr` is private
     }
diff --git a/src/test/compile-fail/private-inferred-type.rs b/src/test/compile-fail/private-inferred-type.rs
index 5af8b063c16..3ca8b1eb2ed 100644
--- a/src/test/compile-fail/private-inferred-type.rs
+++ b/src/test/compile-fail/private-inferred-type.rs
@@ -129,7 +129,7 @@ fn main() {
     m::leak_anon2(); //~ ERROR type `m::Priv` is private
     m::leak_anon3(); //~ ERROR type `m::Priv` is private
 
-    m::leak_dyn1(); //~ ERROR type `m::Trait + 'static` is private
+    m::leak_dyn1(); //~ ERROR type `(dyn m::Trait + 'static)` is private
     m::leak_dyn2(); //~ ERROR type `m::Priv` is private
     m::leak_dyn3(); //~ ERROR type `m::Priv` is private
 
diff --git a/src/test/compile-fail/trait-item-privacy.rs b/src/test/compile-fail/trait-item-privacy.rs
index be0f7dd4e1c..f8e4f0d596e 100644
--- a/src/test/compile-fail/trait-item-privacy.rs
+++ b/src/test/compile-fail/trait-item-privacy.rs
@@ -110,9 +110,9 @@ fn check_assoc_const() {
     // A, B, C are resolved as inherent items, their traits don't need to be in scope
     C::A; //~ ERROR associated constant `A` is private
           //~^ ERROR the trait `assoc_const::C` cannot be made into an object
-          //~| ERROR the trait bound `assoc_const::C: assoc_const::A` is not satisfied
+          //~| ERROR the trait bound `dyn assoc_const::C: assoc_const::A` is not satisfied
     C::B; // ERROR the trait `assoc_const::C` cannot be made into an object
-          //~^ ERROR the trait bound `assoc_const::C: assoc_const::B` is not satisfied
+          //~^ ERROR the trait bound `dyn assoc_const::C: assoc_const::B` is not satisfied
     C::C; // OK
 }
 
diff --git a/src/test/compile-fail/traits-repeated-supertrait-ambig.rs b/src/test/compile-fail/traits-repeated-supertrait-ambig.rs
index 3fc0d638dd6..559871af72e 100644
--- a/src/test/compile-fail/traits-repeated-supertrait-ambig.rs
+++ b/src/test/compile-fail/traits-repeated-supertrait-ambig.rs
@@ -33,7 +33,7 @@ impl CompareTo<u64> for i64 {
 impl CompareToInts for i64 { }
 
 fn with_obj(c: &CompareToInts) -> bool {
-    c.same_as(22) //~ ERROR `CompareToInts: CompareTo<i32>` is not satisfied
+    c.same_as(22) //~ ERROR `dyn CompareToInts: CompareTo<i32>` is not satisfied
 }
 
 fn with_trait<C:CompareToInts>(c: &C) -> bool {
@@ -41,7 +41,7 @@ fn with_trait<C:CompareToInts>(c: &C) -> bool {
 }
 
 fn with_ufcs1<C:CompareToInts>(c: &C) -> bool {
-    CompareToInts::same_as(c, 22) //~ ERROR `CompareToInts: CompareTo<i32>` is not satisfied
+    CompareToInts::same_as(c, 22) //~ ERROR `dyn CompareToInts: CompareTo<i32>` is not satisfied
 }
 
 fn with_ufcs2<C:CompareToInts>(c: &C) -> bool {
diff --git a/src/test/compile-fail/trivial_casts.rs b/src/test/compile-fail/trivial_casts.rs
index aabf0d26d5b..3f2bd2ffabf 100644
--- a/src/test/compile-fail/trivial_casts.rs
+++ b/src/test/compile-fail/trivial_casts.rs
@@ -59,25 +59,25 @@ pub fn main() {
 
     // unsize trait
     let x: &Bar = &Bar;
-    let _ = x as &Foo; //~ERROR trivial cast: `&Bar` as `&Foo`
-    let _ = x as *const Foo; //~ERROR trivial cast: `&Bar` as `*const Foo`
+    let _ = x as &Foo; //~ERROR trivial cast: `&Bar` as `&dyn Foo`
+    let _ = x as *const Foo; //~ERROR trivial cast: `&Bar` as `*const dyn Foo`
     let _: &Foo = x;
     let _: *const Foo = x;
 
     let x: &mut Bar = &mut Bar;
-    let _ = x as &mut Foo; //~ERROR trivial cast: `&mut Bar` as `&mut Foo`
-    let _ = x as *mut Foo; //~ERROR trivial cast: `&mut Bar` as `*mut Foo`
+    let _ = x as &mut Foo; //~ERROR trivial cast: `&mut Bar` as `&mut dyn Foo`
+    let _ = x as *mut Foo; //~ERROR trivial cast: `&mut Bar` as `*mut dyn Foo`
     let _: &mut Foo = x;
     let _: *mut Foo = x;
 
     let x: Box<Bar> = Box::new(Bar);
-    let _ = x as Box<Foo>; //~ERROR trivial cast: `std::boxed::Box<Bar>` as `std::boxed::Box<Foo>`
+    let _ = x as Box<Foo>; //~ERROR `std::boxed::Box<Bar>` as `std::boxed::Box<dyn Foo>`
     let x: Box<Bar> = Box::new(Bar);
     let _: Box<Foo> = x;
 
     // functions
     fn baz(_x: i32) {}
-    let _ = &baz as &Fn(i32); //~ERROR trivial cast: `&fn(i32) {main::baz}` as `&std::ops::Fn(i32)`
+    let _ = &baz as &Fn(i32); //~ERROR `&fn(i32) {main::baz}` as `&dyn std::ops::Fn(i32)`
     let _: &Fn(i32) = &baz;
     let x = |_x: i32| {};
     let _ = &x as &Fn(i32); //~ERROR trivial cast
diff --git a/src/test/compile-fail/type-mismatch-same-crate-name.rs b/src/test/compile-fail/type-mismatch-same-crate-name.rs
index 4295d08a470..7e93f626cfc 100644
--- a/src/test/compile-fail/type-mismatch-same-crate-name.rs
+++ b/src/test/compile-fail/type-mismatch-same-crate-name.rs
@@ -33,7 +33,7 @@ fn main() {
         //~^ ERROR mismatched types
         //~| Perhaps two different versions of crate `crate_a1`
         //~| expected trait `main::a::Bar`
-        //~| expected type `std::boxed::Box<main::a::Bar + 'static>`
-        //~| found type `std::boxed::Box<main::a::Bar>`
+        //~| expected type `std::boxed::Box<(dyn main::a::Bar + 'static)>`
+        //~| found type `std::boxed::Box<dyn main::a::Bar>`
     }
 }
diff --git a/src/test/compile-fail/type-parameter-defaults-referencing-Self-ppaux.rs b/src/test/compile-fail/type-parameter-defaults-referencing-Self-ppaux.rs
index 09687724656..08988353886 100644
--- a/src/test/compile-fail/type-parameter-defaults-referencing-Self-ppaux.rs
+++ b/src/test/compile-fail/type-parameter-defaults-referencing-Self-ppaux.rs
@@ -23,5 +23,5 @@ fn main() {
     let x: i32 = 5;
     let y = x as MyAdd<i32>;
     //~^ ERROR E0038
-    //~| ERROR cast to unsized type: `i32` as `MyAdd<i32>`
+    //~| ERROR cast to unsized type: `i32` as `dyn MyAdd<i32>`
 }
diff --git a/src/test/run-pass/issue-21058.rs b/src/test/run-pass/issue-21058.rs
index 19cd1cf3df7..862439e21f4 100644
--- a/src/test/run-pass/issue-21058.rs
+++ b/src/test/run-pass/issue-21058.rs
@@ -26,5 +26,5 @@ fn main() {
         std::intrinsics::type_name::<NT>(),
         // DST
         std::intrinsics::type_name::<DST>()
-    )}, ("[u8]", "str", "std::marker::Send", "NT", "DST"));
+    )}, ("[u8]", "str", "dyn std::marker::Send", "NT", "DST"));
 }
diff --git a/src/test/ui/anonymous-higher-ranked-lifetime.stderr b/src/test/ui/anonymous-higher-ranked-lifetime.stderr
index 82f527f8cca..809d111d74e 100644
--- a/src/test/ui/anonymous-higher-ranked-lifetime.stderr
+++ b/src/test/ui/anonymous-higher-ranked-lifetime.stderr
@@ -74,7 +74,7 @@ error[E0631]: type mismatch in closure arguments
 LL |     g1(|_: (), _: ()| {}); //~ ERROR type mismatch
    |     ^^ -------------- found signature of `fn((), ()) -> _`
    |     |
-   |     expected signature of `for<'r> fn(&'r (), std::boxed::Box<for<'s> std::ops::Fn(&'s ()) + 'static>) -> _`
+   |     expected signature of `for<'r> fn(&'r (), std::boxed::Box<(dyn for<'s> std::ops::Fn(&'s ()) + 'static)>) -> _`
    |
 note: required by `g1`
   --> $DIR/anonymous-higher-ranked-lifetime.rs:33:1
@@ -102,7 +102,7 @@ error[E0631]: type mismatch in closure arguments
 LL |     g3(|_: (), _: ()| {}); //~ ERROR type mismatch
    |     ^^ -------------- found signature of `fn((), ()) -> _`
    |     |
-   |     expected signature of `for<'s> fn(&'s (), std::boxed::Box<for<'r> std::ops::Fn(&'r ()) + 'static>) -> _`
+   |     expected signature of `for<'s> fn(&'s (), std::boxed::Box<(dyn for<'r> std::ops::Fn(&'r ()) + 'static)>) -> _`
    |
 note: required by `g3`
   --> $DIR/anonymous-higher-ranked-lifetime.rs:35:1
@@ -130,7 +130,7 @@ error[E0631]: type mismatch in closure arguments
 LL |     h1(|_: (), _: (), _: (), _: ()| {}); //~ ERROR type mismatch
    |     ^^ ---------------------------- found signature of `fn((), (), (), ()) -> _`
    |     |
-   |     expected signature of `for<'r, 's> fn(&'r (), std::boxed::Box<for<'t0> std::ops::Fn(&'t0 ()) + 'static>, &'s (), for<'t0, 't1> fn(&'t0 (), &'t1 ())) -> _`
+   |     expected signature of `for<'r, 's> fn(&'r (), std::boxed::Box<(dyn for<'t0> std::ops::Fn(&'t0 ()) + 'static)>, &'s (), for<'t0, 't1> fn(&'t0 (), &'t1 ())) -> _`
    |
 note: required by `h1`
   --> $DIR/anonymous-higher-ranked-lifetime.rs:39:1
@@ -144,7 +144,7 @@ error[E0631]: type mismatch in closure arguments
 LL |     h2(|_: (), _: (), _: (), _: ()| {}); //~ ERROR type mismatch
    |     ^^ ---------------------------- found signature of `fn((), (), (), ()) -> _`
    |     |
-   |     expected signature of `for<'r, 't0> fn(&'r (), std::boxed::Box<for<'s> std::ops::Fn(&'s ()) + 'static>, &'t0 (), for<'s, 't1> fn(&'s (), &'t1 ())) -> _`
+   |     expected signature of `for<'r, 't0> fn(&'r (), std::boxed::Box<(dyn for<'s> std::ops::Fn(&'s ()) + 'static)>, &'t0 (), for<'s, 't1> fn(&'s (), &'t1 ())) -> _`
    |
 note: required by `h2`
   --> $DIR/anonymous-higher-ranked-lifetime.rs:40:1
diff --git a/src/test/ui/arbitrary-self-types-not-object-safe.stderr b/src/test/ui/arbitrary-self-types-not-object-safe.stderr
index b3f9cbc587b..ec9e65fc4c6 100644
--- a/src/test/ui/arbitrary-self-types-not-object-safe.stderr
+++ b/src/test/ui/arbitrary-self-types-not-object-safe.stderr
@@ -13,7 +13,7 @@ LL |     let x = Box::new(5usize) as Box<Foo>;
    |             ^^^^^^^^^^^^^^^^ the trait `Foo` cannot be made into an object
    |
    = note: method `foo` has a non-standard `self` type
-   = note: required because of the requirements on the impl of `std::ops::CoerceUnsized<std::boxed::Box<Foo>>` for `std::boxed::Box<usize>`
+   = note: required because of the requirements on the impl of `std::ops::CoerceUnsized<std::boxed::Box<dyn Foo>>` for `std::boxed::Box<usize>`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/cast-to-unsized-trait-object-suggestion.stderr b/src/test/ui/cast-to-unsized-trait-object-suggestion.stderr
index 67c33740f19..1e871d47284 100644
--- a/src/test/ui/cast-to-unsized-trait-object-suggestion.stderr
+++ b/src/test/ui/cast-to-unsized-trait-object-suggestion.stderr
@@ -1,4 +1,4 @@
-error[E0620]: cast to unsized type: `&{integer}` as `std::marker::Send`
+error[E0620]: cast to unsized type: `&{integer}` as `dyn std::marker::Send`
   --> $DIR/cast-to-unsized-trait-object-suggestion.rs:12:5
    |
 LL |     &1 as Send; //~ ERROR cast to unsized
@@ -6,7 +6,7 @@ LL |     &1 as Send; //~ ERROR cast to unsized
    |           |
    |           help: try casting to a reference instead: `&Send`
 
-error[E0620]: cast to unsized type: `std::boxed::Box<{integer}>` as `std::marker::Send`
+error[E0620]: cast to unsized type: `std::boxed::Box<{integer}>` as `dyn std::marker::Send`
   --> $DIR/cast-to-unsized-trait-object-suggestion.rs:13:5
    |
 LL |     Box::new(1) as Send; //~ ERROR cast to unsized
diff --git a/src/test/ui/const-unsized.stderr b/src/test/ui/const-unsized.stderr
index 2cde4aec2b5..d6fc5391ba8 100644
--- a/src/test/ui/const-unsized.stderr
+++ b/src/test/ui/const-unsized.stderr
@@ -1,10 +1,10 @@
-error[E0277]: the size for value values of type `std::fmt::Debug + std::marker::Sync + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn std::fmt::Debug + std::marker::Sync + 'static)` cannot be known at compilation time
   --> $DIR/const-unsized.rs:13:29
    |
 LL | const CONST_0: Debug+Sync = *(&0 as &(Debug+Sync));
    |                             ^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `std::fmt::Debug + std::marker::Sync + 'static`
+   = help: the trait `std::marker::Sized` is not implemented for `(dyn std::fmt::Debug + std::marker::Sync + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: constant expressions must have a statically known size
 
@@ -18,13 +18,13 @@ LL | const CONST_FOO: str = *"foo";
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: constant expressions must have a statically known size
 
-error[E0277]: the size for value values of type `std::fmt::Debug + std::marker::Sync + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn std::fmt::Debug + std::marker::Sync + 'static)` cannot be known at compilation time
   --> $DIR/const-unsized.rs:19:31
    |
 LL | static STATIC_1: Debug+Sync = *(&1 as &(Debug+Sync));
    |                               ^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `std::fmt::Debug + std::marker::Sync + 'static`
+   = help: the trait `std::marker::Sized` is not implemented for `(dyn std::fmt::Debug + std::marker::Sync + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: constant expressions must have a statically known size
 
diff --git a/src/test/ui/did_you_mean/bad-assoc-ty.stderr b/src/test/ui/did_you_mean/bad-assoc-ty.stderr
index 169a12ef92e..33792d4f5b3 100644
--- a/src/test/ui/did_you_mean/bad-assoc-ty.stderr
+++ b/src/test/ui/did_you_mean/bad-assoc-ty.stderr
@@ -92,7 +92,7 @@ error[E0223]: ambiguous associated type
 LL | type G = 'static + (Send)::AssocTy;
    |          ^^^^^^^^^^^^^^^^^^^^^^^^^ ambiguous associated type
    |
-   = note: specify the type using the syntax `<std::marker::Send + 'static as Trait>::AssocTy`
+   = note: specify the type using the syntax `<(dyn std::marker::Send + 'static) as Trait>::AssocTy`
 
 error[E0223]: ambiguous associated type
   --> $DIR/bad-assoc-ty.rs:43:10
@@ -100,7 +100,7 @@ error[E0223]: ambiguous associated type
 LL | type H = Fn(u8) -> (u8)::Output;
    |          ^^^^^^^^^^^^^^^^^^^^^^ ambiguous associated type
    |
-   = note: specify the type using the syntax `<std::ops::Fn(u8) -> u8 + 'static as Trait>::Output`
+   = note: specify the type using the syntax `<(dyn std::ops::Fn(u8) -> u8 + 'static) as Trait>::Output`
 
 error: aborting due to 15 previous errors
 
diff --git a/src/test/ui/error-codes/E0033-teach.stderr b/src/test/ui/error-codes/E0033-teach.stderr
index c74485781c1..2fac6080f49 100644
--- a/src/test/ui/error-codes/E0033-teach.stderr
+++ b/src/test/ui/error-codes/E0033-teach.stderr
@@ -12,11 +12,11 @@ LL |     let trait_obj: &SomeTrait = SomeTrait;
    |
    = note: method `foo` has no receiver
 
-error[E0033]: type `&SomeTrait` cannot be dereferenced
+error[E0033]: type `&dyn SomeTrait` cannot be dereferenced
   --> $DIR/E0033-teach.rs:23:9
    |
 LL |     let &invalid = trait_obj;
-   |         ^^^^^^^^ type `&SomeTrait` cannot be dereferenced
+   |         ^^^^^^^^ type `&dyn SomeTrait` cannot be dereferenced
    |
    = note: This error indicates that a pointer to a trait type cannot be implicitly dereferenced by a pattern. Every trait defines a type, but because the size of trait implementors isn't fixed, this type has no compile-time size. Therefore, all accesses to trait types must be through pointers. If you encounter this error you should try to avoid dereferencing the pointer.
            
diff --git a/src/test/ui/error-codes/E0033.stderr b/src/test/ui/error-codes/E0033.stderr
index a1e72d6f669..5d789566beb 100644
--- a/src/test/ui/error-codes/E0033.stderr
+++ b/src/test/ui/error-codes/E0033.stderr
@@ -12,11 +12,11 @@ LL |     let trait_obj: &SomeTrait = SomeTrait;
    |
    = note: method `foo` has no receiver
 
-error[E0033]: type `&SomeTrait` cannot be dereferenced
+error[E0033]: type `&dyn SomeTrait` cannot be dereferenced
   --> $DIR/E0033.rs:21:9
    |
 LL |     let &invalid = trait_obj;
-   |         ^^^^^^^^ type `&SomeTrait` cannot be dereferenced
+   |         ^^^^^^^^ type `&dyn SomeTrait` cannot be dereferenced
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/error-codes/E0657.stderr b/src/test/ui/error-codes/E0657.stderr
index 23b9666de3c..fb7f88d5ca9 100644
--- a/src/test/ui/error-codes/E0657.stderr
+++ b/src/test/ui/error-codes/E0657.stderr
@@ -16,7 +16,7 @@ error[E0308]: mismatched types
 LL |     () //~ ERROR mismatched types
    |     ^^ expected struct `std::boxed::Box`, found ()
    |
-   = note: expected type `std::boxed::Box<Id<_> + 'static>`
+   = note: expected type `std::boxed::Box<(dyn Id<_> + 'static)>`
               found type `()`
 
 error[E0308]: mismatched types
@@ -25,7 +25,7 @@ error[E0308]: mismatched types
 LL |         () //~ ERROR mismatched types
    |         ^^ expected struct `std::boxed::Box`, found ()
    |
-   = note: expected type `std::boxed::Box<Id<_> + 'static>`
+   = note: expected type `std::boxed::Box<(dyn Id<_> + 'static)>`
               found type `()`
 
 error: aborting due to 4 previous errors
diff --git a/src/test/ui/fat-ptr-cast.stderr b/src/test/ui/fat-ptr-cast.stderr
index cf1dcfcb8ad..778a4cf1fa0 100644
--- a/src/test/ui/fat-ptr-cast.stderr
+++ b/src/test/ui/fat-ptr-cast.stderr
@@ -52,7 +52,7 @@ error[E0607]: cannot cast thin pointer `*const i32` to fat pointer `*const [i32]
 LL |     q as *const [i32]; //~ ERROR cannot cast
    |     ^^^^^^^^^^^^^^^^^
 
-error[E0606]: casting `usize` as `*mut Trait + 'static` is invalid
+error[E0606]: casting `usize` as `*mut (dyn Trait + 'static)` is invalid
   --> $DIR/fat-ptr-cast.rs:32:37
    |
 LL |     let t: *mut (Trait + 'static) = 0 as *mut _; //~ ERROR casting
diff --git a/src/test/ui/feature-gate-trivial_bounds.stderr b/src/test/ui/feature-gate-trivial_bounds.stderr
index db280f2d1f7..19a6a863795 100644
--- a/src/test/ui/feature-gate-trivial_bounds.stderr
+++ b/src/test/ui/feature-gate-trivial_bounds.stderr
@@ -98,7 +98,7 @@ LL | struct TwoStrs(str, str) where str: Sized; //~ ERROR
    = help: see issue #48214
    = help: add #![feature(trivial_bounds)] to the crate attributes to enable
 
-error[E0277]: the size for value values of type `A + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn A + 'static)` cannot be known at compilation time
   --> $DIR/feature-gate-trivial_bounds.rs:65:1
    |
 LL | / fn unsized_local() where Dst<A>: Sized { //~ ERROR
@@ -106,9 +106,9 @@ LL | |     let x: Dst<A> = *(Box::new(Dst { x: 1 }) as Box<Dst<A>>);
 LL | | }
    | |_^ doesn't have a size known at compile-time
    |
-   = help: within `Dst<A + 'static>`, the trait `std::marker::Sized` is not implemented for `A + 'static`
+   = help: within `Dst<(dyn A + 'static)>`, the trait `std::marker::Sized` is not implemented for `(dyn A + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
-   = note: required because it appears within the type `Dst<A + 'static>`
+   = note: required because it appears within the type `Dst<(dyn A + 'static)>`
    = help: see issue #48214
    = help: add #![feature(trivial_bounds)] to the crate attributes to enable
 
diff --git a/src/test/ui/fmt/send-sync.stderr b/src/test/ui/fmt/send-sync.stderr
index 807b499155b..0d9239d7227 100644
--- a/src/test/ui/fmt/send-sync.stderr
+++ b/src/test/ui/fmt/send-sync.stderr
@@ -1,11 +1,11 @@
-error[E0277]: `*mut std::ops::Fn() + 'static` cannot be shared between threads safely
+error[E0277]: `*mut (dyn std::ops::Fn() + 'static)` cannot be shared between threads safely
   --> $DIR/send-sync.rs:18:5
    |
 LL |     send(format_args!("{:?}", c)); //~ ERROR E0277
-   |     ^^^^ `*mut std::ops::Fn() + 'static` cannot be shared between threads safely
+   |     ^^^^ `*mut (dyn std::ops::Fn() + 'static)` cannot be shared between threads safely
    |
-   = help: within `[std::fmt::ArgumentV1<'_>]`, the trait `std::marker::Sync` is not implemented for `*mut std::ops::Fn() + 'static`
-   = note: required because it appears within the type `std::marker::PhantomData<*mut std::ops::Fn() + 'static>`
+   = help: within `[std::fmt::ArgumentV1<'_>]`, the trait `std::marker::Sync` is not implemented for `*mut (dyn std::ops::Fn() + 'static)`
+   = note: required because it appears within the type `std::marker::PhantomData<*mut (dyn std::ops::Fn() + 'static)>`
    = note: required because it appears within the type `core::fmt::Void`
    = note: required because it appears within the type `&core::fmt::Void`
    = note: required because it appears within the type `std::fmt::ArgumentV1<'_>`
@@ -18,14 +18,14 @@ note: required by `send`
 LL | fn send<T: Send>(_: T) {}
    | ^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: `*mut std::ops::Fn() + 'static` cannot be shared between threads safely
+error[E0277]: `*mut (dyn std::ops::Fn() + 'static)` cannot be shared between threads safely
   --> $DIR/send-sync.rs:19:5
    |
 LL |     sync(format_args!("{:?}", c)); //~ ERROR E0277
-   |     ^^^^ `*mut std::ops::Fn() + 'static` cannot be shared between threads safely
+   |     ^^^^ `*mut (dyn std::ops::Fn() + 'static)` cannot be shared between threads safely
    |
-   = help: within `std::fmt::Arguments<'_>`, the trait `std::marker::Sync` is not implemented for `*mut std::ops::Fn() + 'static`
-   = note: required because it appears within the type `std::marker::PhantomData<*mut std::ops::Fn() + 'static>`
+   = help: within `std::fmt::Arguments<'_>`, the trait `std::marker::Sync` is not implemented for `*mut (dyn std::ops::Fn() + 'static)`
+   = note: required because it appears within the type `std::marker::PhantomData<*mut (dyn std::ops::Fn() + 'static)>`
    = note: required because it appears within the type `core::fmt::Void`
    = note: required because it appears within the type `&core::fmt::Void`
    = note: required because it appears within the type `std::fmt::ArgumentV1<'_>`
diff --git a/src/test/ui/in-band-lifetimes/impl/dyn-trait.stderr b/src/test/ui/in-band-lifetimes/impl/dyn-trait.stderr
index 201470abe67..07b86228f61 100644
--- a/src/test/ui/in-band-lifetimes/impl/dyn-trait.stderr
+++ b/src/test/ui/in-band-lifetimes/impl/dyn-trait.stderr
@@ -10,8 +10,8 @@ note: first, the lifetime cannot outlive the lifetime 'a as defined on the funct
 LL | fn with_dyn_debug_static<'a>(x: Box<dyn Debug + 'a>) {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: ...so that the expression is assignable:
-           expected std::boxed::Box<std::fmt::Debug>
-              found std::boxed::Box<std::fmt::Debug + 'a>
+           expected std::boxed::Box<dyn std::fmt::Debug>
+              found std::boxed::Box<(dyn std::fmt::Debug + 'a)>
    = note: but, the lifetime must be valid for the static lifetime...
    = note: ...so that the types are compatible:
            expected StaticTrait
diff --git a/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr b/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr
index 37b586e1e3b..169369c304e 100644
--- a/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr
+++ b/src/test/ui/in-band-lifetimes/mismatched_trait_impl-2.stderr
@@ -13,8 +13,8 @@ LL | |     }
    | |_____^
    = note: ...but the lifetime must also be valid for the static lifetime...
    = note: ...so that the method type is compatible with trait:
-           expected fn(&Struct) -> &Trait + 'static
-              found fn(&Struct) -> &Trait
+           expected fn(&Struct) -> &(dyn Trait + 'static)
+              found fn(&Struct) -> &dyn Trait
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issue-17441.rs b/src/test/ui/issue-17441.rs
index c7b07701461..5432d5f5ed9 100644
--- a/src/test/ui/issue-17441.rs
+++ b/src/test/ui/issue-17441.rs
@@ -13,10 +13,10 @@ fn main() {
     //~^ ERROR cast to unsized type: `&[usize; 2]` as `[usize]`
 
     let _bar = Box::new(1_usize) as std::fmt::Debug;
-    //~^ ERROR cast to unsized type: `std::boxed::Box<usize>` as `std::fmt::Debug`
+    //~^ ERROR cast to unsized type: `std::boxed::Box<usize>` as `dyn std::fmt::Debug`
 
     let _baz = 1_usize as std::fmt::Debug;
-    //~^ ERROR cast to unsized type: `usize` as `std::fmt::Debug`
+    //~^ ERROR cast to unsized type: `usize` as `dyn std::fmt::Debug`
 
     let _quux = [1_usize, 2] as [usize];
     //~^ ERROR cast to unsized type: `[usize; 2]` as `[usize]`
diff --git a/src/test/ui/issue-17441.stderr b/src/test/ui/issue-17441.stderr
index 80ba49cce1a..6c7e883f9f9 100644
--- a/src/test/ui/issue-17441.stderr
+++ b/src/test/ui/issue-17441.stderr
@@ -10,7 +10,7 @@ help: consider using an implicit coercion to `&[usize]` instead
 LL |     let _foo = &[1_usize, 2] as [usize];
    |                ^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0620]: cast to unsized type: `std::boxed::Box<usize>` as `std::fmt::Debug`
+error[E0620]: cast to unsized type: `std::boxed::Box<usize>` as `dyn std::fmt::Debug`
   --> $DIR/issue-17441.rs:15:16
    |
 LL |     let _bar = Box::new(1_usize) as std::fmt::Debug;
@@ -18,7 +18,7 @@ LL |     let _bar = Box::new(1_usize) as std::fmt::Debug;
    |                                     |
    |                                     help: try casting to a `Box` instead: `Box<std::fmt::Debug>`
 
-error[E0620]: cast to unsized type: `usize` as `std::fmt::Debug`
+error[E0620]: cast to unsized type: `usize` as `dyn std::fmt::Debug`
   --> $DIR/issue-17441.rs:18:16
    |
 LL |     let _baz = 1_usize as std::fmt::Debug;
diff --git a/src/test/ui/issue-20692.stderr b/src/test/ui/issue-20692.stderr
index 1316773f6b7..156ebd920f0 100644
--- a/src/test/ui/issue-20692.stderr
+++ b/src/test/ui/issue-20692.stderr
@@ -13,7 +13,7 @@ LL |     let _ = x
    |             ^ the trait `Array` cannot be made into an object
    |
    = note: the trait cannot require that `Self : Sized`
-   = note: required because of the requirements on the impl of `std::ops::CoerceUnsized<&Array>` for `&T`
+   = note: required because of the requirements on the impl of `std::ops::CoerceUnsized<&dyn Array>` for `&T`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/lint-ctypes.rs b/src/test/ui/lint-ctypes.rs
index 4b20001457f..7f22dc8739e 100644
--- a/src/test/ui/lint-ctypes.rs
+++ b/src/test/ui/lint-ctypes.rs
@@ -59,7 +59,7 @@ extern {
     pub fn char_type(p: char); //~ ERROR uses type `char`
     pub fn i128_type(p: i128); //~ ERROR uses type `i128`
     pub fn u128_type(p: u128); //~ ERROR uses type `u128`
-    pub fn trait_type(p: &Clone); //~ ERROR uses type `std::clone::Clone`
+    pub fn trait_type(p: &Clone); //~ ERROR uses type `dyn std::clone::Clone`
     pub fn tuple_type(p: (i32, i32)); //~ ERROR uses type `(i32, i32)`
     pub fn tuple_type2(p: I32Pair); //~ ERROR uses type `(i32, i32)`
     pub fn zero_size(p: ZeroSize); //~ ERROR struct has no fields
diff --git a/src/test/ui/lint-ctypes.stderr b/src/test/ui/lint-ctypes.stderr
index 76b500e7d23..d1ef3a7a19c 100644
--- a/src/test/ui/lint-ctypes.stderr
+++ b/src/test/ui/lint-ctypes.stderr
@@ -73,10 +73,10 @@ error: `extern` block uses type `u128` which is not FFI-safe: 128-bit integers d
 LL |     pub fn u128_type(p: u128); //~ ERROR uses type `u128`
    |                         ^^^^
 
-error: `extern` block uses type `std::clone::Clone` which is not FFI-safe: trait objects have no C equivalent
+error: `extern` block uses type `dyn std::clone::Clone` which is not FFI-safe: trait objects have no C equivalent
   --> $DIR/lint-ctypes.rs:62:26
    |
-LL |     pub fn trait_type(p: &Clone); //~ ERROR uses type `std::clone::Clone`
+LL |     pub fn trait_type(p: &Clone); //~ ERROR uses type `dyn std::clone::Clone`
    |                          ^^^^^^
 
 error: `extern` block uses type `(i32, i32)` which is not FFI-safe: tuples have unspecified layout
diff --git a/src/test/ui/lub-glb/old-lub-glb-object.stderr b/src/test/ui/lub-glb/old-lub-glb-object.stderr
index 6a69e7cc717..79442bd108a 100644
--- a/src/test/ui/lub-glb/old-lub-glb-object.stderr
+++ b/src/test/ui/lub-glb/old-lub-glb-object.stderr
@@ -9,8 +9,8 @@ LL | |         _ => y,
 LL | |     };
    | |_____^ expected bound lifetime parameter 'a, found concrete lifetime
    |
-   = note: expected type `&for<'a, 'b> Foo<&'a u8, &'b u8>`
-              found type `&for<'a> Foo<&'a u8, &'a u8>`
+   = note: expected type `&dyn for<'a, 'b> Foo<&'a u8, &'b u8>`
+              found type `&dyn for<'a> Foo<&'a u8, &'a u8>`
    = note: this was previously accepted by the compiler but has been phased out
    = note: for more information, see https://github.com/rust-lang/rust/issues/45852
 
diff --git a/src/test/ui/mismatched_types/cast-rfc0401.stderr b/src/test/ui/mismatched_types/cast-rfc0401.stderr
index feaf492837f..9335795f6b8 100644
--- a/src/test/ui/mismatched_types/cast-rfc0401.stderr
+++ b/src/test/ui/mismatched_types/cast-rfc0401.stderr
@@ -162,13 +162,13 @@ error[E0607]: cannot cast thin pointer `*const u8` to fat pointer `*const [u8]`
 LL |     let _ = v as *const [u8]; //~ ERROR cannot cast
    |             ^^^^^^^^^^^^^^^^
 
-error[E0606]: casting `&Foo` as `*const str` is invalid
+error[E0606]: casting `&dyn Foo` as `*const str` is invalid
   --> $DIR/cast-rfc0401.rs:64:13
    |
 LL |     let _ = foo as *const str; //~ ERROR is invalid
    |             ^^^^^^^^^^^^^^^^^
 
-error[E0606]: casting `&Foo` as `*mut str` is invalid
+error[E0606]: casting `&dyn Foo` as `*mut str` is invalid
   --> $DIR/cast-rfc0401.rs:65:13
    |
 LL |     let _ = foo as *mut str; //~ ERROR is invalid
@@ -200,7 +200,7 @@ LL |     let _ = fat_sv as usize; //~ ERROR is invalid
    |
    = help: cast through a thin pointer first
 
-error[E0606]: casting `*const Foo` as `*const [u16]` is invalid
+error[E0606]: casting `*const dyn Foo` as `*const [u16]` is invalid
   --> $DIR/cast-rfc0401.rs:78:13
    |
 LL |     let _ = cf as *const [u16]; //~ ERROR is invalid
@@ -208,7 +208,7 @@ LL |     let _ = cf as *const [u16]; //~ ERROR is invalid
    |
    = note: vtable kinds may not match
 
-error[E0606]: casting `*const Foo` as `*const Bar` is invalid
+error[E0606]: casting `*const dyn Foo` as `*const dyn Bar` is invalid
   --> $DIR/cast-rfc0401.rs:79:13
    |
 LL |     let _ = cf as *const Bar; //~ ERROR is invalid
@@ -224,7 +224,7 @@ LL |     let _ = fat_v as *const Foo; //~ ERROR the size for value values of typ
    |
    = help: the trait `std::marker::Sized` is not implemented for `[u8]`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
-   = note: required for the cast to the object type `Foo`
+   = note: required for the cast to the object type `dyn Foo`
 
 error[E0277]: the size for value values of type `str` cannot be known at compilation time
   --> $DIR/cast-rfc0401.rs:72:13
@@ -234,7 +234,7 @@ LL |     let _ = a as *const Foo; //~ ERROR the size for value values of type
    |
    = help: the trait `std::marker::Sized` is not implemented for `str`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
-   = note: required for the cast to the object type `Foo`
+   = note: required for the cast to the object type `dyn Foo`
 
 error[E0606]: casting `&{float}` as `f32` is invalid
   --> $DIR/cast-rfc0401.rs:81:30
diff --git a/src/test/ui/mismatched_types/issue-19109.stderr b/src/test/ui/mismatched_types/issue-19109.stderr
index c838c617ae4..018ea941d12 100644
--- a/src/test/ui/mismatched_types/issue-19109.stderr
+++ b/src/test/ui/mismatched_types/issue-19109.stderr
@@ -2,12 +2,12 @@ error[E0308]: mismatched types
   --> $DIR/issue-19109.rs:14:5
    |
 LL | fn function(t: &mut Trait) {
-   |                            - help: try adding a return type: `-> *mut Trait`
+   |                            - help: try adding a return type: `-> *mut dyn Trait`
 LL |     t as *mut Trait
    |     ^^^^^^^^^^^^^^^ expected (), found *-ptr
    |
    = note: expected type `()`
-              found type `*mut Trait`
+              found type `*mut dyn Trait`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/mismatched_types/trait-bounds-cant-coerce.stderr b/src/test/ui/mismatched_types/trait-bounds-cant-coerce.stderr
index bbe9053430a..15c9fd6bf8f 100644
--- a/src/test/ui/mismatched_types/trait-bounds-cant-coerce.stderr
+++ b/src/test/ui/mismatched_types/trait-bounds-cant-coerce.stderr
@@ -4,8 +4,8 @@ error[E0308]: mismatched types
 LL |     a(x); //~ ERROR mismatched types [E0308]
    |       ^ expected trait `Foo + std::marker::Send`, found trait `Foo`
    |
-   = note: expected type `std::boxed::Box<Foo + std::marker::Send + 'static>`
-              found type `std::boxed::Box<Foo + 'static>`
+   = note: expected type `std::boxed::Box<(dyn Foo + std::marker::Send + 'static)>`
+              found type `std::boxed::Box<(dyn Foo + 'static)>`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/nll/ty-outlives/projection-no-regions-closure.stderr b/src/test/ui/nll/ty-outlives/projection-no-regions-closure.stderr
index 3689ca74adb..e0705113577 100644
--- a/src/test/ui/nll/ty-outlives/projection-no-regions-closure.stderr
+++ b/src/test/ui/nll/ty-outlives/projection-no-regions-closure.stderr
@@ -20,7 +20,7 @@ LL |     with_signature(x, |mut y| Box::new(y.next()))
                '_#1r,
                T,
                i32,
-               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<Anything + '_#2r>
+               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<(dyn Anything + '_#2r)>
            ]
    = note: number of external vids: 3
    = note: where <T as std::iter::Iterator>::Item: '_#2r
@@ -60,7 +60,7 @@ LL |     with_signature(x, |mut y| Box::new(y.next()))
                '_#1r,
                T,
                i32,
-               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<Anything + '_#2r>
+               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<(dyn Anything + '_#2r)>
            ]
    = note: number of external vids: 3
    = note: where <T as std::iter::Iterator>::Item: '_#2r
@@ -92,7 +92,7 @@ LL |     with_signature(x, |mut y| Box::new(y.next()))
                '_#2r,
                T,
                i32,
-               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<Anything + '_#3r>
+               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<(dyn Anything + '_#3r)>
            ]
    = note: number of external vids: 4
    = note: where <T as std::iter::Iterator>::Item: '_#3r
@@ -134,7 +134,7 @@ LL |     with_signature(x, |mut y| Box::new(y.next()))
                '_#2r,
                T,
                i32,
-               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<Anything + '_#3r>
+               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<(dyn Anything + '_#3r)>
            ]
    = note: number of external vids: 4
    = note: where <T as std::iter::Iterator>::Item: '_#3r
diff --git a/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-return-type.stderr b/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-return-type.stderr
index 59a8a39a7b0..39ad96cc6cd 100644
--- a/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-return-type.stderr
+++ b/src/test/ui/nll/ty-outlives/ty-param-closure-outlives-from-return-type.stderr
@@ -20,7 +20,7 @@ LL |     with_signature(x, |y| y)
                '_#1r,
                T,
                i32,
-               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<std::fmt::Debug + '_#2r>
+               extern "rust-call" fn((std::boxed::Box<T>,)) -> std::boxed::Box<(dyn std::fmt::Debug + '_#2r)>
            ]
    = note: number of external vids: 3
    = note: where T: '_#2r
diff --git a/src/test/ui/resolve/issue-5035-2.stderr b/src/test/ui/resolve/issue-5035-2.stderr
index efcd0b36248..72bd270165f 100644
--- a/src/test/ui/resolve/issue-5035-2.stderr
+++ b/src/test/ui/resolve/issue-5035-2.stderr
@@ -1,10 +1,10 @@
-error[E0277]: the size for value values of type `I + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn I + 'static)` cannot be known at compilation time
   --> $DIR/issue-5035-2.rs:14:8
    |
 LL | fn foo(_x: K) {}
    |        ^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `I + 'static`
+   = help: the trait `std::marker::Sized` is not implemented for `(dyn I + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: all local variables must have a statically known size
 
diff --git a/src/test/ui/span/borrowck-object-mutability.nll.stderr b/src/test/ui/span/borrowck-object-mutability.nll.stderr
index cf615eed556..b318e778f87 100644
--- a/src/test/ui/span/borrowck-object-mutability.nll.stderr
+++ b/src/test/ui/span/borrowck-object-mutability.nll.stderr
@@ -2,7 +2,7 @@ error[E0596]: cannot borrow immutable item `*x` as mutable
   --> $DIR/borrowck-object-mutability.rs:19:5
    |
 LL | fn borrowed_receiver(x: &Foo) {
-   |                         ---- help: consider changing this to be a mutable reference: `&mut Foo`
+   |                         ---- help: consider changing this to be a mutable reference: `&mut dyn Foo`
 LL |     x.borrowed();
 LL |     x.borrowed_mut(); //~ ERROR cannot borrow
    |     ^ `x` is a `&` reference, so the data it refers to cannot be borrowed as mutable
diff --git a/src/test/ui/suggestions/confuse-field-and-method/issue-2392.stderr b/src/test/ui/suggestions/confuse-field-and-method/issue-2392.stderr
index bd5efcd9fee..9049ffd4090 100644
--- a/src/test/ui/suggestions/confuse-field-and-method/issue-2392.stderr
+++ b/src/test/ui/suggestions/confuse-field-and-method/issue-2392.stderr
@@ -75,7 +75,7 @@ LL |     w.wrap.not_closure();
    |
    = help: did you mean to write `w.wrap.not_closure` instead of `w.wrap.not_closure(...)`?
 
-error[E0599]: no method named `closure` found for type `Obj<std::boxed::Box<std::boxed::FnBox<(), Output=u32> + 'static>>` in the current scope
+error[E0599]: no method named `closure` found for type `Obj<std::boxed::Box<(dyn std::boxed::FnBox<(), Output=u32> + 'static)>>` in the current scope
   --> $DIR/issue-2392.rs:72:24
    |
 LL | struct Obj<F> where F: FnOnce() -> u32 {
diff --git a/src/test/ui/trivial-bounds-inconsistent-sized.stderr b/src/test/ui/trivial-bounds-inconsistent-sized.stderr
index ee2ff7d7861..e18018c6f0c 100644
--- a/src/test/ui/trivial-bounds-inconsistent-sized.stderr
+++ b/src/test/ui/trivial-bounds-inconsistent-sized.stderr
@@ -6,7 +6,7 @@ LL | struct S(str, str) where str: Sized;
    |
    = note: #[warn(trivial_bounds)] on by default
 
-warning: Trait bound for<'a> T<A + 'a>: std::marker::Sized does not depend on any type or lifetime parameters
+warning: Trait bound for<'a> T<(dyn A + 'a)>: std::marker::Sized does not depend on any type or lifetime parameters
   --> $DIR/trivial-bounds-inconsistent-sized.rs:26:1
    |
 LL | / fn unsized_local() where for<'a> T<A + 'a>: Sized {
diff --git a/src/test/ui/trivial-bounds-inconsistent.stderr b/src/test/ui/trivial-bounds-inconsistent.stderr
index ee3c7518294..85b16b17042 100644
--- a/src/test/ui/trivial-bounds-inconsistent.stderr
+++ b/src/test/ui/trivial-bounds-inconsistent.stderr
@@ -78,7 +78,7 @@ warning: Trait bound str: std::marker::Sized does not depend on any type or life
 LL | struct TwoStrs(str, str) where str: Sized;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-warning: Trait bound for<'a> Dst<A + 'a>: std::marker::Sized does not depend on any type or lifetime parameters
+warning: Trait bound for<'a> Dst<(dyn A + 'a)>: std::marker::Sized does not depend on any type or lifetime parameters
   --> $DIR/trivial-bounds-inconsistent.rs:65:1
    |
 LL | / fn unsized_local() where for<'a> Dst<A + 'a>: Sized {
diff --git a/src/test/ui/underscore-lifetime/dyn-trait-underscore.stderr b/src/test/ui/underscore-lifetime/dyn-trait-underscore.stderr
index 98249d3f2b5..cb545ca008d 100644
--- a/src/test/ui/underscore-lifetime/dyn-trait-underscore.stderr
+++ b/src/test/ui/underscore-lifetime/dyn-trait-underscore.stderr
@@ -19,8 +19,8 @@ LL |     Box::new(items.iter()) //~ ERROR cannot infer an appropriate lifetime
    |              ^^^^^
    = note: but, the lifetime must be valid for the static lifetime...
    = note: ...so that the expression is assignable:
-           expected std::boxed::Box<std::iter::Iterator<Item=&T> + 'static>
-              found std::boxed::Box<std::iter::Iterator<Item=&T>>
+           expected std::boxed::Box<(dyn std::iter::Iterator<Item=&T> + 'static)>
+              found std::boxed::Box<dyn std::iter::Iterator<Item=&T>>
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/unsized-enum2.stderr b/src/test/ui/unsized-enum2.stderr
index ff2aa1d1ef9..1f30c815d30 100644
--- a/src/test/ui/unsized-enum2.stderr
+++ b/src/test/ui/unsized-enum2.stderr
@@ -82,43 +82,43 @@ LL |     VH{u: isize, x: [u32]},
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: no field of an enum variant may have a dynamically sized type
 
-error[E0277]: the size for value values of type `Foo + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn Foo + 'static)` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:63:8
    |
 LL |     VM(Foo),
    |        ^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Foo + 'static`
+   = help: the trait `std::marker::Sized` is not implemented for `(dyn Foo + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: no field of an enum variant may have a dynamically sized type
 
-error[E0277]: the size for value values of type `Bar + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn Bar + 'static)` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:65:8
    |
 LL |     VN{x: Bar},
    |        ^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `Bar + 'static`
+   = help: the trait `std::marker::Sized` is not implemented for `(dyn Bar + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: no field of an enum variant may have a dynamically sized type
 
-error[E0277]: the size for value values of type `FooBar + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn FooBar + 'static)` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:67:15
    |
 LL |     VO(isize, FooBar),
    |               ^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `FooBar + 'static`
+   = help: the trait `std::marker::Sized` is not implemented for `(dyn FooBar + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: no field of an enum variant may have a dynamically sized type
 
-error[E0277]: the size for value values of type `BarFoo + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn BarFoo + 'static)` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:69:18
    |
 LL |     VP{u: isize, x: BarFoo},
    |                  ^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `std::marker::Sized` is not implemented for `BarFoo + 'static`
+   = help: the trait `std::marker::Sized` is not implemented for `(dyn BarFoo + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: no field of an enum variant may have a dynamically sized type
 
@@ -162,46 +162,46 @@ LL |     VT{u: isize, x: <&'static [i32] as Deref>::Target},
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: no field of an enum variant may have a dynamically sized type
 
-error[E0277]: the size for value values of type `PathHelper1 + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn PathHelper1 + 'static)` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:53:8
    |
 LL |     VI(Path1),
    |        ^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Path1`, the trait `std::marker::Sized` is not implemented for `PathHelper1 + 'static`
+   = help: within `Path1`, the trait `std::marker::Sized` is not implemented for `(dyn PathHelper1 + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: required because it appears within the type `Path1`
    = note: no field of an enum variant may have a dynamically sized type
 
-error[E0277]: the size for value values of type `PathHelper2 + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn PathHelper2 + 'static)` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:55:8
    |
 LL |     VJ{x: Path2},
    |        ^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Path2`, the trait `std::marker::Sized` is not implemented for `PathHelper2 + 'static`
+   = help: within `Path2`, the trait `std::marker::Sized` is not implemented for `(dyn PathHelper2 + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: required because it appears within the type `Path2`
    = note: no field of an enum variant may have a dynamically sized type
 
-error[E0277]: the size for value values of type `PathHelper3 + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn PathHelper3 + 'static)` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:57:15
    |
 LL |     VK(isize, Path3),
    |               ^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Path3`, the trait `std::marker::Sized` is not implemented for `PathHelper3 + 'static`
+   = help: within `Path3`, the trait `std::marker::Sized` is not implemented for `(dyn PathHelper3 + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: required because it appears within the type `Path3`
    = note: no field of an enum variant may have a dynamically sized type
 
-error[E0277]: the size for value values of type `PathHelper4 + 'static` cannot be known at compilation time
+error[E0277]: the size for value values of type `(dyn PathHelper4 + 'static)` cannot be known at compilation time
   --> $DIR/unsized-enum2.rs:59:18
    |
 LL |     VL{u: isize, x: Path4},
    |                  ^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Path4`, the trait `std::marker::Sized` is not implemented for `PathHelper4 + 'static`
+   = help: within `Path4`, the trait `std::marker::Sized` is not implemented for `(dyn PathHelper4 + 'static)`
    = note: to learn more, visit <https://doc.rust-lang.org/book/second-edition/ch19-04-advanced-types.html#dynamically-sized-types--sized>
    = note: required because it appears within the type `Path4`
    = note: no field of an enum variant may have a dynamically sized type