1 files changed, 79 insertions, 0 deletions
diff --git a/src/test/ui/specialization/non-defaulted-item-fail.stderr b/src/test/ui/specialization/non-defaulted-item-fail.stderr
new file mode 100644
index 000000000..8b7d67972
--- /dev/null
+++ b/src/test/ui/specialization/non-defaulted-item-fail.stderr
@@ -0,0 +1,79 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/non-defaulted-item-fail.rs:1:12
+   |
+LL | #![feature(specialization, associated_type_defaults)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+
+error[E0520]: `Ty` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/non-defaulted-item-fail.rs:30:5
+   |
+LL | impl<T> Foo for Box<T> {
+   | ---------------------- parent `impl` is here
+...
+LL |     type Ty = Vec<()>;
+   |     ^^^^^^^^^^^^^^^^^^ cannot specialize default item `Ty`
+   |
+   = note: to specialize, `Ty` in the parent `impl` must be marked `default`
+
+error[E0520]: `CONST` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/non-defaulted-item-fail.rs:32:5
+   |
+LL | impl<T> Foo for Box<T> {
+   | ---------------------- parent `impl` is here
+...
+LL |     const CONST: u8 = 42;
+   |     ^^^^^^^^^^^^^^^^^^^^^ cannot specialize default item `CONST`
+   |
+   = note: to specialize, `CONST` in the parent `impl` must be marked `default`
+
+error[E0520]: `foo` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/non-defaulted-item-fail.rs:34:5
+   |
+LL | impl<T> Foo for Box<T> {
+   | ---------------------- parent `impl` is here
+...
+LL |     fn foo(&self) -> bool { true }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot specialize default item `foo`
+   |
+   = note: to specialize, `foo` in the parent `impl` must be marked `default`
+
+error[E0520]: `Ty` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/non-defaulted-item-fail.rs:46:5
+   |
+LL | impl<T> Foo for Vec<T> {}
+   | ---------------------- parent `impl` is here
+...
+LL |     type Ty = Vec<()>;
+   |     ^^^^^^^^^^^^^^^^^^ cannot specialize default item `Ty`
+   |
+   = note: to specialize, `Ty` in the parent `impl` must be marked `default`
+
+error[E0520]: `CONST` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/non-defaulted-item-fail.rs:48:5
+   |
+LL | impl<T> Foo for Vec<T> {}
+   | ---------------------- parent `impl` is here
+...
+LL |     const CONST: u8 = 42;
+   |     ^^^^^^^^^^^^^^^^^^^^^ cannot specialize default item `CONST`
+   |
+   = note: to specialize, `CONST` in the parent `impl` must be marked `default`
+
+error[E0520]: `foo` specializes an item from a parent `impl`, but that item is not marked `default`
+  --> $DIR/non-defaulted-item-fail.rs:50:5
+   |
+LL | impl<T> Foo for Vec<T> {}
+   | ---------------------- parent `impl` is here
+...
+LL |     fn foo(&self) -> bool { true }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot specialize default item `foo`
+   |
+   = note: to specialize, `foo` in the parent `impl` must be marked `default`
+
+error: aborting due to 6 previous errors; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0520`.