How to get a pointer from a reference?

Question

There seems to be many relavent questions talking about pointer vs. reference, but I couldn\'t find what I want to know. Basically, an object is passed in by a reference:

Answer 1

Any operator applied to a reference will actually apply to the object it refers to (§5/5 [expr]); the reference can be thought of as another name for the same object. Taking the address of a reference will therefore give you the address of the object that it refers to.

It as actually unspecified whether or not a reference requires storage (§8.3.2/4 [dcl.ref]) and so it wouldn't make sense to take the address of the reference itself.

As an example:

int x = 5;
int& y = x;
int* xp = &x;
int* yp = &y;

In the above example, xp and yp are equal - that is, the expression xp == yp evaluates to true because they both point to the same object.