TITLE: referencing beyond the end of an array

(Newsgroups: comp.lang.c++, 15 Jan 97)


DEWAR: dewar@merv.cs.nyu.edu (Robert Dewar)

>>equally if you do something like
>>
>>   (x = p; x < &p[10]; p += 3)
>>
>>you can find you have an infinite loop, all quite in accordance with the
>>C semantics, although somewhat surprising.


KENNER: kenner@lab.ultra.nyu.edu (Richard Kenner)

>This case must work.  Such a reference to the end of an object is required
>to be treated like a reference within the object.

HENDERSON: fjh@mundook.cs.mu.OZ.AU (Fergus Henderson)

No, you missed the subtle point of Robert Dewar's example.
(Robert could obviously get a job advertising PC-LINT if he wanted ;-)
If it was `p++' rather than `p += 3', you would be right, but
since it is `p += 3', the behaviour is undefined -- ANSI/ISO C
only allows a reference to one past the end of an object, not
two past the end.