code:

class MyButtClass;

class make_a_butt
{
private:
    friend class MyButtClass;
    int a_value, b_value;
    
public:
    make_a_butt() : a_value(0), b_value(0)
    {
        return;
    }

    make_a_butt& a(int value)
    {
        a_value = value;
        return *this;
    }
    
    make_a_butt& b(int value)
    {
        b_value = value;
        return *this;
    }
};

class MyButtClass
{
public:
    MyButtClass(const make_a_butt& params)
    {
        return;
    }
};

int main(int argc, char** argv)
{
    MyButtClass a_butt = make_a_butt().a(1).b(2);
    return 0;
}