Method put_dth

src/strings/tries.rs:140–161

(
        &mut self,
        x: Option<NonNull<Node<T>>>,
        key: &str,
        val: Option<T>,
        d: usize,
    )

    }

    unsafe fn put_dth(
        &mut self,
        x: Option<NonNull<Node<T>>>,
        key: &str,
        val: Option<T>,
        d: usize,
    ) -> Option<NonNull<Node<T>>> {
        let mut x = x.unwrap_or_else(|| Node::new(None));

        if d == key.len() {
            if x.as_ref().val.is_none() {
                self.n += 1;
            }
            x.as_mut().val = val;
        } else {
            let i = common::util::byte_at(key, d);
            let next = x.as_ref().next[i];
            x.as_mut().next[i] = self.put_dth(next, key, val, d + 1);
        }

        Some(x)
    }

    unsafe fn delete_dth(
        &mut self,