Pointer to rvalue reference illegal?

Consider the following code:

#include <iostream>

int main() {

    int a1 = 1;
    int a2 = 2;

    int&& r = a1 + a2; // rvalue reference
    r++;
    std::cout << r << std::endl;

    int* p = &r; // what is this if not pointer to reference?
    std::cout << &r << " " << p << " " << *p << std::endl;

    *p++;
    std::cout << &r << " " << p << " " << *p << std::endl;

}

cppreference.com claims:

> Because references are not objects, there are no arrays of references,
> no pointers to references, and no references to references

However what is int* p = &r if not a pointer to reference?

You misunderstand and mixed 2 separate concepts here - one is the type of an object and another is the value of that object. In this line:

int *p = &r;

you define p to have type pointer to int and there is no way in C++ to declare/define a type pointer to reference to int which what cppreference.com means.

Value it holds is an address of object in memory to which reference r refers, but it is irrelevant though to that statement.

> However what is int* p = &r if not a pointer to reference?

It's a pointer to int. That is, int *. It points to whatever the reference points to, not to the reference itself.

A pointer to reference would be int &* - and this doesn't compile.

You can also test it like this:

#include <iostream>

template <typename T>
void PrintType()
{
    std::cout <<
    #ifdef _MSC_VER
    __FUNCSIG__
    #else
    __PRETTY_FUNCTION__
    #endif
    << '\n';
}

Then PrintType<decltype(&r)>() prints something like void PrintType() [T = int *]. Note, no &.