Error code E0606

An incompatible cast was attempted.

Erroneous code example:

#![allow(unused)]
fn main() {
let x = &0u8; // Here, `x` is a `&u8`.
let y: u32 = x as u32; // error: casting `&u8` as `u32` is invalid
}

When casting, keep in mind that only primitive types can be cast into each other. Example:

#![allow(unused)]
fn main() {
let x = &0u8;
let y: u32 = *x as u32; // We dereference it first and then cast it.
}

For more information about casts, take a look at the Type cast section in The Reference Book.