D语言构造函数

import std.stdio;

class Line { 
   public: 
      void setLength( double len ) {
         length = len; 
      }
      double getLength() { 
         return length; 
      }
      this() { 
         writeln("Object is being created"); 
      }

   private: 
      double length; 
} 

void main( ) { 
   Line line = new Line(); 

   // set line length 
   line.setLength(6.0); 
   writeln("Length of line : " , line.getLength()); 
}