c++友元类

#include <iostream>


using namespace std;


class Tv
{
friend class Tel;
public:
Tv(int volume,int change):voiume_(volume),changel_(change)
{


}
private:
int voiume_;
int changel_;
};


class Tel
{
public:
void VoumeUp(Tv& tv)
{
tv.voiume_+=1;
}
void VoumeDown(Tv& tv)
{
tv.voiume_-=1;
}
void changeUp(Tv& tv)
{
tv.changel_+=1;
}
void changeDown(Tv& tv)
{
tv.changel_-=1;
}
};






int main(void)
{






return 0;
}