Initialization of reference member requires a temporary variable C++

Question

struct Div
{
   int i;
   int j;
};   

class A
{
public:
    A();
    Div& divs;
};

In my constructor definition, I have the following implementation

A::A(): divs(NULL)
{}

I get the following error:

Error72 error C2354: 'A::divs' : initialization of reference member requires a temporary variable

Answer 1

A reference must be initialised to refer to something; it can't refer to nothing, so you can't default-construct a class that contains one (unless, as others suggest, you define a global "null" value). You will need a constructor that is given the Div to refer to:

explicit A(Div &d) : divs(d) {}

If you want it to be able to be "null", then you need a pointer, not a reference.