| A literal was used in a built-in attribute that doesn't support literals. | |
| Erroneous code example: | |
| ```compile_fail,E0565 | |
| #[repr("C")] // error: meta item in `repr` must be an identifier | |
| struct Repr {} | |
| fn main() {} | |
| ``` | |
| Literals in attributes are new and largely unsupported in built-in attributes. | |
| Work to support literals where appropriate is ongoing. Try using an unquoted | |
| name instead: | |
| ``` | |
| #[repr(C)] // ok! | |
| struct Repr {} | |
| fn main() {} | |
| ``` |