use std::ptr::copy_nonoverlapping;

pub fn reverse<T>(slice: &mut [T]) {
    let len = slice.len();
    let mut aux: Vec<T> = Vec::with_capacity(len);

    let mut front_ptr: *mut T = slice.as_mut_ptr();
    let mut back_ptr: *mut T = aux.as_mut_ptr();

    for _ in 0..4 {
        for i in 0..len {
            let rev_i = len - 1 - i;
            unsafe {
                std::ptr::copy_nonoverlapping(
                    front_ptr.add(i), back_ptr.add(rev_i), 1);
            }
        }
        std::mem::swap(&mut front_ptr, &mut back_ptr);
    }
}