Universal reference producing different instances with the same address

I was experimenting with Universal references inspired by Scott Meyers article on the subject.

So I tried the following:

#include <iostream>
#include <cassert>

template<typename T>
T& f(T&& var){
    std::cout<< &var << std::endl;
    return var;
}

int main() {
    int& j = f(10);
    std::cout<< &j << ", " << j << std::endl;
    int& k = f(20);
    std::cout<< &k << ", " << k << std::endl;

    if( &j == &k ){
        std::cout<< "This is peculiar." <<std::endl;
    }

    return 0;
}

With the output:

0x7ffff8b957ac
0x7ffff8b957ac, 10
0x7ffff8b957ac
0x7ffff8b957ac, 20
This is peculiar.

I was under the impression that &j == &k would guarantee that j==k.

What is happening here?

Edit, post answer:

Anecdotal reflection: Outputting j instead of k in the second printout makes the program output nothing at all. I guess I should be happy there were no Chesterfield sofas or whales involved.

You are using references bound to temporary objects after the lifetimes of those temporary objects have ended. In most cases, a temporary only lives until the end of the statement or other full-expression; and this program doesn't have any of the exceptions that would extend its lifetime. Since the lifetimes of the objects don't overlap, the compiler is allowed to use the same address for both. And your cout statements, using those dead objects, are Undefined Behavior - anything could happen.