calloc (actually NULL =?= 0)

[Henry Spencer]

In article <987 at atanasoff.cs.iastate.edu> hascall at atanasoff.cs.iastate.edu (John Hascall) writes:
>>>I always thought a pointer consisting of zero bits is NULL. 
> 
>>Nope.  No such guarantee was ever made by any C language spec.
>
>   What about the following taken from K&R, Appendix A, section 7.14,
>   "Assignment operator":
>
>       However, it is guaranteed that assignment of the
>       constant 0 to a pointer will produce a null pointer...

"Produce" a null pointer.  And note that it says *constant*.  An integer
constant 0 in a pointer context is C's odd way of writing the null pointer
as a constant.  This is purely a *notation*; it does not necessarily have
anything to do with the actual representation.  On seeing this curious
bit of notation, the compiler generates whatever bits are needed.
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