Method volume

Examples/NoModules/Chapter 13/Ex13_01/Box.h:11–11

  Box(double l, double w, double h) : m_length{l}, m_width{w}, m_height{h} {}

  double volume() const { return m_length * m_width * m_height; }

  // Accessors
  double getLength() const { return m_length; }