Implementing NULL trapping

[Doug Gwyn]

In article <423 at minya.UUCP> jc at minya.UUCP (John Chambers) writes:
>I've also used this on occasion to illustrate the Old Engineer's
>maxim that you can't guarantee the correct functioning of a system
>by guaranteeing correctness of all its parts.

Sure you can, if the design is also correct.

However, in this particular example, the C implementation was
clearly NOT correct, since the implementors assigned an object
an address such that it was not distinguishable from a null
pointer.

There is no way to guarantee that one's application will not
break due to bugs in the implementation of the target system.