Method getHeight

Exercises/NoModules/Chapter 13/Soln13_08/Box.h:22–22

  double getLength() const { return m_length; }
  double getWidth() const  { return m_width; }
  double getHeight() const { return m_height; }

  // Functions that add full support for comparison operators
  std::partial_ordering operator<=>(const Box& aBox) const;