error: unrecognized repr on struct that implements RefCast
 --> tests/ui/unrecognized-repr.rs:4:19
  |
4 | #[repr(packed, C, usize, usize(0), usize = "0")]
  |                   ^^^^^

error: unrecognized repr on struct that implements RefCast
 --> tests/ui/unrecognized-repr.rs:4:26
  |
4 | #[repr(packed, C, usize, usize(0), usize = "0")]
  |                          ^^^^^^^^

error: unrecognized repr on struct that implements RefCast
 --> tests/ui/unrecognized-repr.rs:4:36
  |
4 | #[repr(packed, C, usize, usize(0), usize = "0")]
  |                                    ^^^^^^^^^^^

error[E0552]: invalid representation hint: `usize` does not take a parenthesized argument list
 --> tests/ui/unrecognized-repr.rs:4:26
  |
4 | #[repr(packed, C, usize, usize(0), usize = "0")]
  |                          ^^^^^^^^

error[E0552]: invalid representation hint: `usize` does not take a value
 --> tests/ui/unrecognized-repr.rs:4:36
  |
4 | #[repr(packed, C, usize, usize(0), usize = "0")]
  |                                    ^^^^^^^^^^^

error[E0517]: attribute should be applied to an enum
 --> tests/ui/unrecognized-repr.rs:4:19
  |
4 |   #[repr(packed, C, usize, usize(0), usize = "0")]
  |                     ^^^^^
5 | / struct Test {
6 | |     s: String,
7 | | }
  | |_- not an enum