use std::cell::UnsafeCell;

pub fn evil_foo<'bytes, T>(bytes: &'bytes mut [u8]) -> &'bytes mut [u8] {
        // Dear borrow checker, please go out of the way for a second
        //  let bytes_alias: &'bytes UnsafeCell<[u8]> = std::mem::transmute(bytes);

        // Now, we're going to need a scope to contain some evil deeds
        {
            // This is a perfect copy of the original "bytes"
            // let bytes: &'bytes mut [u8] = &mut *bytes_alias.get();

            // The borrow checker can borrow it as long as it likes...
            deserialize2::<T>(bytes);
            // ...because we're just going to drop it anyhow.
        }

        // What we will return is... a _different_ clone of "bytes"
        // let bytes: &'bytes mut [u8] = &mut *bytes_alias.get();
        bytes

}

fn deserialize2<T>(bytes: &mut [u8]) -> &mut T {
    unsafe {
        &mut *(bytes as *mut [u8] as *mut T)
    }
}

#[repr(C)]
struct AlignTo<T, U>(T, [U;0]);

fn main() {
    let mut x = AlignTo::<_, u32>([0; 10], []);
    evil_foo::<u32>(&mut x.0);
}