>> Does GCC consider an 'int' and a 'volatile int' (or 'int*' and a >> 'volatile int*') almost the same? > > It's not symmetrical. > > The rules are the rules of the C standard. I don't think there's any > intention to use GCC-specific rules.... Yes, correct. > ... > If an attempt is made to refer to an object defined with a > volatile-qualified type through use of an lvalue with > non-volatile-qualified type, the behavior is undefined. >>> > > It's OK to cast a pointer to int to a pointer to volatile int and then > dereference that pointer, but not vice versa. So, GCC must assume > that a pointer to volatile int may point to a non-volatile int object. > But the reverse is not true: GCC need not assume that a pointer to int > may point to a volatile int. One last question, and then I will be done. Is it OK to do in C++03 and above. Sorry to ask. I have a heck of a time locating the relevant parts and then parsing the standard _correctly_ at times (emphasis on correctly). Jeff
