Forget lifetimes, do this. It's a bug. It's in the safe code. You fix it in the safe code, because it misused unsafe code.

  let vec: Vec<i32> = vec![1, 2, 3, 4, 5];
  let ptr = vec.as_ptr();
  let len = vec.len();
  
  let slice_ref = unsafe {slice::from_raw_parts(ptr, len)};
  
  drop(vec);
  
  println!("{:?}", slice_ref);