const/volatile integrity violation

This time I am going to point you at two short, interesting articles on const integrity violation which is also applicable to volatile modifier.

Basically it talks about the following feature of C++:

GIVEN
int *i;

const int *p = i; // is allowed
BUT
const int** p = &i; // is not allowed !!
AND
const int*& p = i; // is also not allowed !!

How to fix it?

GIVEN
int *i;

const int *p = i; // is allowed
BUT
const int* const * p = &i; // is allowed !!
AND
const int* const & p = i; // is also allowed !!


FAQ:
http://www.parashift.com/c++-faq-lite/const-correctness.html#faq-18.17
AND
http://www.gimpel.com/html/bugs/bug1561.htm