Modifying reference member from const member function in C++

Question

I am working on const-correctness of my code and just wondered why this code compiles:

class X
{
    int x;
    int& y;
public:
    X(int& _y):y(_y)
         


        

Answer 1

Because you are not changing any variable in X. Actually, you are changing _y which is an outsider with respect to your class. Don't forget that:

y = newY;

Is assigning the value of newY to the variable pointed by y, but not the references them selves. Only on initialization the references are considered.