(char *)(-1)

[david Fridley]

In article <1063 at tukki.jyu.fi>, tarvaine at tukki.jyu.fi (Tapani Tarvainen) writes:
> In article <118 at psitech.UUCP> david at psitech.UUCP (david Fridley) writes:
> 
> If -1 isn't safe, is there any other value (besides NULL) that can
> safely be returned from a (any *) function to indicate error?
> -- 
> Tapani Tarvainen    (tarvaine at jyu.fi, tarvainen at finjyu.bitnet)

On some systems, even NULL can accidently be a valid pointer.  The environment
has to take precautions to prevent this, like starting virtual data sections at
100 instead of 0, etc.  But since NULL is written in K&R and (-1) is not, it
is not garanteed to be portable.  I have not had any problems though, and it
sure is convenient to be able to return more than one fail code from a function
that returns a pointer.  Does any body have an environment where they think
this will not work? 


-- 
david.
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