In the member initializer list, can I create a reference to a member variable not in the list?

Question

Consider:

#include 
#include 

class Foo
{
     public:
         Foo( char const * msg ) : x( y ) 
         {
             y =          


        

Answer 1

Can I safely create references to them as showcased?

Yes, you can. The storage address of the member y is known regardless initialized it or not, so x(y) reference initialization is legal.