call by value

/* p67
#include <iostream>

using std::cout;
using std::endl;

int main()
{

 int val=10;
 int &ref=val;

 val++;
 cout<<"ref:"<<ref<<endl;
 cout<<"cal"<<val<<endl;

 ref++;// 발갑에 영향을 미칠까?
 cout<<"ref:"<<ref<<endl;
 cout<<"val:"<<val<<endl;

 return 0;
}

*/