Paolo Carlini wrote:
chris jefferson wrote:
Right, but that's the point. "doing arithmetic on arbitrary pointer"
values is
not defined, it is not even defined to compare two pointers pointing
to two
different objects.
While that is true according to the standard, I believe that on most
systems you can compare any two pointers. In particular, the C++
standard does require a total ordering on pointers, and at the moment
that is implemented for all systems by just doing "a < b" on the two
pointers.
Humpf! Can people please cite exact paragraphs of the relevant
Standards? Otherwise, I think we are just adding to the confusion. For
example, in my reading of C99 6.5.9 and C++03 5.10 pointers *can* be
compared for equality and discussing separately and correctly relational
operators and equality operators is not a language-lawyer-ism, is *very*
important for its real world implications. But this is only an example...
Paolo.
Surely pointers can be compared for equality (it is fine to see if a
pointer is pointing
to something). The discussion about pointer comparison across objects is wrt
expecting any kind of ordering relationshiop.
