| Attempted to cast to/from a pointer with an unknown kind. | |
| Erroneous code example: | |
| ```compile_fail,E0641 | |
| let b = 0 as *const _; // error | |
| ``` | |
| Type information must be provided if a pointer type being cast from/into another | |
| type which cannot be inferred: | |
| ``` | |
| // Creating a pointer from reference: type can be inferred | |
| let a = &(String::from("Hello world!")) as *const _; // ok! | |
| let b = 0 as *const i32; // ok! | |
| let c: *const i32 = 0 as *const _; // ok! | |
| ``` |