1 files changed, 27 insertions, 26 deletions
diff --git a/tests/ui/derives/deriving-with-repr-packed.rs b/tests/ui/derives/deriving-with-repr-packed.rs
index 3884e3977..58be45197 100644
--- a/tests/ui/derives/deriving-with-repr-packed.rs
+++ b/tests/ui/derives/deriving-with-repr-packed.rs
@@ -1,45 +1,46 @@
-#![deny(unaligned_references)]
-
 // Check that deriving certain builtin traits on certain packed structs cause
-// errors. This happens when the derived trait would need to use a potentially
-// misaligned reference. But there are two cases that are allowed:
-// - If all the fields within the struct meet the required alignment: 1 for
-//   `repr(packed)`, or `N` for `repr(packed(N))`.
-// - If `Default` is the only trait derived, because it doesn't involve any
-//   references.
+// errors. To avoid potentially misaligned references, field copies must be
+// used, which involves adding `T: Copy` bounds.
 
 #[derive(Copy, Clone, Default, PartialEq, Eq)]
-//~^ ERROR `Clone` can't be derived on this `#[repr(packed)]` struct with type or const parameters
-//~| hard error
-//~^^^ ERROR `PartialEq` can't be derived on this `#[repr(packed)]` struct with type or const parameters
-//~| hard error
 #[repr(packed)]
 pub struct Foo<T>(T, T, T);
 
+// This one is fine because the fields all impl `Copy`.
 #[derive(Default, Hash)]
-//~^ ERROR `Hash` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
-//~| hard error
 #[repr(packed)]
 pub struct Bar(u32, u32, u32);
 
-// This one is fine because the field alignment is 1.
-#[derive(Default, Hash)]
-#[repr(packed)]
-pub struct Bar2(u8, i8, bool);
-
-// This one is fine because the field alignment is 2, matching `packed(2)`.
-#[derive(Default, Hash)]
-#[repr(packed(2))]
-pub struct Bar3(u16, i16, bool);
-
 // This one is fine because it's not packed.
 #[derive(Debug, Default)]
 struct Y(usize);
 
+// This one has an error because `Y` doesn't impl `Copy`.
+// Note: there is room for improvement in the error message.
 #[derive(Debug, Default)]
-//~^ ERROR `Debug` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
-//~| hard error
 #[repr(packed)]
 struct X(Y);
+//~^ ERROR cannot move out of `self` which is behind a shared reference
+
+// This is currently allowed, but will be phased out at some point. From
+// `zerovec` within icu4x-0.9.0.
+#[derive(Debug)]
+#[repr(packed)]
+struct FlexZeroSlice {
+    width: u8,
+    data: [u8],
+    //~^ WARNING byte slice in a packed struct that derives a built-in trait
+    //~^^ this was previously accepted
+}
+
+// Again, currently allowed, but will be phased out.
+#[derive(Debug)]
+#[repr(packed)]
+struct WithStr {
+    width: u8,
+    data: str,
+    //~^ WARNING string slice in a packed struct that derives a built-in trait
+    //~^^ this was previously accepted
+}
 
 fn main() {}