The Size class is a small class holding the width and height:

Size.h

namespace SmallWindows { 

The ZeroSize object is an object with its width and height set to zero:

  class Size; 
  extern const Size ZeroSize;  
  class Size { 
    public: 

The default constructor initializes the width and height to zero. The size can be initialized by, and assigned to, another size. The Size class uses the assignment operator to assign a size to another size:

      Size(); 
      Size(int width, int height); 
      Size(const Size& size); 
      Size& operator=(const Size& size); 

A Size object can be initialized and assigned to a value of the Win32 API SIZE structure, and a Size object can be converted to a SIZE:

      Size(const SIZE& size); 
      Size& operator=(const SIZE& size); 
      operator SIZE() const; 

When comparing two sizes, the widths are compared first. If they are equal, the heights are then...