4 Aug
2008
4 Aug
'08
1:46 p.m.
>>>> "Fred" == Fred Cisin
<cisin at xenosoft.com> writes:
> > address 0 be NULL was not around on the
micros, and putting it
> at the
Fred> On Mon, 4 Aug 2008, Tony Duell wrote:
> I wasn't aware that this was a requirement of
C, or any other
> language.
Fred> C actually insists that address 0 is an invalid address!
Pedantically: not quite. It says that 0 is the token representing a
null address. It doesn't say that the encoding of such a pointer is
the same as that of the integer 0.
In practice that's probably the case in all platforms -- certainly all
current ones. I'm not 100% sure about the PDP-10, never mind the
Cyber 6600... both of which have oddball pointers.
paul