类中私有数据成员的可访问性

#include<iostream.h>
class date
{ //默认情况下，成员是私有的
 int day;
 int month;
 int year;
};
void main()
{
 date today;
 today.day=10;
 today.month=8;
 today.year=1999;
 cout<<"/nThe date is"<<today.day<<"/";
 cout<<today.month<<"/"<<today.year<<endl;
}

将出现以下错误信息：
date::day is not accessible
date::month is not accessible
date::year is not accessible

－－《面向对象编程：C++》