Reference to Reference, Pointer to Reference....

I have read on wiki, they say that:

There shall be no references to references, no arrays of references, and no pointers to references.

on page Reference (C++) - Wikipedia, the free encyclopedia
I don't know why they say that, because I have do them (referencees to references, pointers to references, references to pointers and see that no error.)
this is my code:

Code:

int a=6;
int& ref_a=a;  //reference to variable
int* ptr_a=&ref_a; //pointer to reference
int& ref_a2=ref_a; //reference to reference
cout<<ref_a<<endl<<*ptr_a<<endl<<ref_a2<<endl;

And no problem appears, it will prints 6 at all.
So, who can explain why wiki said that, am I understand wrong ? Talk to me, please.

thanks

Originally Posted by hqt

int* ptr_a=&ref_a; //pointer to reference
int& ref_a2=ref_a; //reference to reference

No, ptr_a is a pointer to an int; ref_a2 is a reference to an int.

@:laserlight: Oh, I see, I'm very sorry because I have a basic mistake here
As you know: Pointer to Pointer look like:

Code:

int a=5;
int*p=&a;
int**p=&p;

Because above code, may I have this question: if C++ agree have <Pointer to reference> and <reference to reference>, So does It looks like:

Code:

int a=5;
int &ref=a;
int*&  ptr=&ref; //pointer to reference
int&& ref_ref=ref;//reference to reference

I know above code is very funny, but I still want to know: if my supposition is true, so pointer to ref and ref to ref looks like that, huh :-?

Thanks for all

Originally Posted by hqt

int*& ptr=&ref; //pointer to reference

ptr is a reference to a pointer, which is valid.

Originally Posted by hqt

int&& ref_ref=ref;//reference to reference

ref_ref is an rvalue reference.

ptr is a reference to a pointer, which is valid.

@laserlight: sorry, but as you say, so my code is true, huh ? But when I compiled, there two errors in line 3 and line 4
that is:invalid initialization of non-const reference of type 'int*&' from a temporary of type 'int* and error: expected unqualified-id before '&&' token.

Can you teach me more about this problem, please.
thanks

Originally Posted by hqt

invalid initialization of non-const reference of type 'int*&' from a temporary of type 'int*

Pay attention to the word "temporary" to understand why

Originally Posted by hqt

error: expected unqualified-id before '&&' token.

Your compiler does not conform to the 2011 edition of the C++ standard.