const引用与非const引用

void print1(int a)
{
    cout<<a<<endl;
}

void print2(const int& a)
{
    cout<<a<<endl;
}


void print3(int& a)
{
    cout<<a<<endl;
}

int main()
{
    int a = 10;
    int& b = a;
    const int& c = a;

    print1(a);
    print1(b);
    print1(c);

    print2(a);
    print2(b);
    print2(c);

    print3(a);
    print3(b);
    print3(c);

    return 0;
}