Method printVolume

Examples/Modules/Chapter 12/Ex12_11/Box.cpp:19–24

Modify mutable member variable from a const member function

// Modify mutable member variable from a const member function 
void Box::printVolume() const
{
  // Count how many times printVolume() is called using a mutable member in a const function
  std::cout << "The volume of this box is " << volume() << std::endl;
  std::cout << "printVolume() has been called " << ++m_count << " time(s)" << std::endl;
}