Example of null ptr not = 0 ?

[Peter Eriksson]

DXB132 at psuvm.psu.edu (Dan Babcock) writes:

>I just read through the first section of the regular posting (common questions
>and answers) (it's about 'null pointers') and I have a down-to-earth question:

>Does there exist a C compiler for any "modern", commercial, 32-bit
>(or more :-)) machine (i.e. a machine like you and I use) that uses something
>other than zero (real binary zero) to mean "null pointer"? Why not just say in
>the spec "a null pointer is zero!" and be done with the whole matter?
>It just seems like a trivial academic exercise to talk about it any other way.
>(My humble opinion, of course :-))

Well... all Prime 50-series computers can use non-zero null pointers. They are
32 bit machines and not very uncommon. And there is a rather good C compiler
available for them too. (They run an operating system called PRIMOS, normally).

/Peter

--
Peter Eriksson                                              pen at lysator.liu.se
Lysator Computer Club                             ...!uunet!lysator.liu.se!pen
University of Linkoping, Sweden                               "Seize the day!"