D语言静态函数成员

import std.stdio;

class Box { 
   public: 
      static int objectCount = 0; 

      // Constructor definition 
      this(double l = 2.0, double b = 2.0, double h = 2.0) { 
         writeln("Constructor called."); 
         length = l; 
         breadth = b; 
         height = h; 

         // Increase every time object is created 
         objectCount++; 
      }

      double Volume() {
         return length * breadth * height; 
      }

      static int getCount() { 
         return objectCount; 
      } 

   private: 
      double length;     // Length of a box 
      double breadth;    // Breadth of a box 
      double height;     // Height of a box 
};

void main() { 
   // Print total number of objects before creating object. 
   writeln("Inital Stage Count: ",Box.getCount());  

   Box Box1 = new Box(3.3, 1.2, 1.5);    // Declare box1 
   Box Box2 = new Box(8.5, 6.0, 2.0);    // Declare box2 

   // Print total number of objects after creating object. 
   writeln("Final Stage Count: ",Box.getCount()); 
}