Friend Function Access

#include<iostream>
#include<cstdint>
using namespace std;

class Register8
{
private:
uint8_t value;
public:
Register8():value(0){}
void setValue(uint8_t v)
{
    this->value = v;
}

friend void printRegister(const Register8 &r);
};

void printRegister(const Register8 &r)
{
    cout<<"Register value = "<<static_cast<int>(r.value);
}

int main()
{
    Register8 R;
    R.setValue(170);
    printRegister(R);
}