Attempted to cast to/from a pointer with an unknown kind.
Erroneous code example:
let b = 0 as *const _; // errorType 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!