RE: signed vs unsigned pointer warning

[terra at gnome dot org (Morten Welinder)]

Dave Korn writes:

> Until you try indexing an array with an 8-bit high ASCII char, of course.
> Then things become radically different.  I've known buggy ctype
> implementations that have failed on this (ASCII > 127 being signed negative
> and the ctype function accidentally indexing memory space before an array
> full of ctype result flags).

[/me gathers soapbox]

I bet you have.  In fact *ALL* ctype implementations will fail.[*]
That includes glibc

What glibc does is to *mostly* work around buggy programs that send
(explicitly or implicitly) signed characters to, say, isprint.  It does
not always work, though, so glibc really did you a disservice.  It is
really hard to get people to fix their programs.

It does not work for (signed char)-1 if EOF==-1.  It cannot work as two
different results are required for the same argument value.

Solaris does the array[arg] thing you speak about.  It isn't buggy.  The
caller is, and, IMHO the standard is.

Morten


[*] Assuming (char)EOF==EOF, which it will be with signed characters and
EOF==-1.