#[derive(Debug)]
struct Complex {
    re: f32,
    im: f32
}

fn main() { unsafe {
    let v = vec![1_f32, 2., 3., 4.];
    let len = v.len();
    assert_eq!(len % 2, 0);

    let mut s = v.into_boxed_slice();
    let ptr = s.as_mut_ptr();
    std::mem::forget(s);

    let ptr = ptr as *mut Complex;
    let v = Vec::from_raw_parts(ptr, len / 2, len / 2);
    println!("{:?}", v);
} }