D语言类访问修饰符

import std.stdio;

class Line { 
   public:
      double length; 

      double getLength() { 
         return length ; 
      }

      void setLength( double len ) { 
         length = len; 
      } 
} 

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

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

   // set line length without member function 
   line.length = 10.0; // OK: because length is public 
   writeln("Length of line : ", line.length); 
}