Method empty

include/libfork/core/impl/stack.hpp:258–261

* @brief Test if the stack is empty (has no allocations). */

   * @brief Test if the stack is empty (has no allocations).
   */
  [[nodiscard]] auto empty() -> bool {
    LF_ASSERT(m_fib && m_fib->is_top());
    return m_fib->empty() && m_fib->m_prev == nullptr;
  }

  /**
   * @brief Release the underlying storage of the current stack and re-initialize this one.