Re: Casting ctype lookups

[Alan Barrett <apb%cequrux.com@localhost>]

On Wed, 14 Nov 2012, D'Arcy J.M. Cain wrote:
> Would this be safer?
>
> #define toupper(c)\
>  ((int)((_toupper_tab_ + 1)[(int)(unsigned char)(c)]))

No.  That would break when the caller passes the int value EOF.

I believe that there's nothing wrong with NetBSD's definitions of 
these functions and macros.  If the caller gets a warning about 
them, then there's a problem in the caller's code.

The only improvement that I can think of would be to abort with a 
descriptive message if the value is out of range, but to do so in 
a way that does not hurt performance for non-buggy callers.

--apb (Alan Barrett)