C++ standard: dereferencing NULL pointer to get a reference?

Question

(This question already has answers here): question from:https://stackoverflow.com/questions/2727834/c-standard-dereferencing-null-pointer-to-get-a-reference

Answer 1

Dereferencing a NULL pointer is undefined behavior.

In fact the standard calls this exact situation out in a note (8.3.2/4 "References"):

Note: in particular, a null reference cannot exist in a well-defined program, because the only way to create such a reference would be to bind it to the “object” obtained by dereferencing a null pointer, which causes undefined behavior.

---

As an aside: The one time I'm aware of that a NULL pointer can be "dereferenced" in a well-defined way is as the operand to the sizeof operator, because the operand to sizeof isn't actually evaluated (so the dereference never actually occurs).