# Deref

Alright! We've got a decent minimal stack implemented. We can push, we can pop, and we can clean up after ourselves. However there's a whole mess of functionality we'd reasonably want. In particular, we have a proper array, but none of the slice functionality. That's actually pretty easy to solve: we can implement `Deref<Target=[T]>`. This will magically make our Vec coerce to, and behave like, a slice in all sorts of conditions.

All we need is `slice::from_raw_parts`. It will correctly handle empty slices for us. Later once we set up zero-sized type support it will also Just Work for those too.

    use std::ops::Deref;

    impl<T> Deref for Vec<T> {
        type Target = [T];
        fn deref(&self) -> &[T] {
            unsafe {
                ::std::slice::from_raw_parts(self.ptr.as_ptr(), self.len)
            }
        }
    }

And let's do DerefMut too:

    use std::ops::DerefMut;

    impl<T> DerefMut for Vec<T> {
        fn deref_mut(&mut self) -> &mut [T] {
            unsafe {
                ::std::slice::from_raw_parts_mut(self.ptr.as_ptr(), self.len)
            }
        }
    }

Now we have `len`, `first`, `last`, indexing, slicing, sorting, `iter`, `iter_mut`, and all other sorts of bells and whistles provided by slice. Sweet!