On Fri, 12 Aug 2011 23:31:39 +0200 (CEST) [email protected] (Karl Hammar) wrote:
> Andrew Poelstra: > > On Thu, Aug 11, 2011 at 09:30:34PM +0200, Karl Hammar wrote: > ... > > > -#define LARGE_VALUE (LONG_MAX / 2 - 1) /* maximum > > > extent of board and elements */ +#define LARGE_VALUE > > > LONG_MAX /* (LONG_MAX / 2 - 1) maximum extent of board and > > > elements */ > ... > > > Why do you want to use only half the range? > > > > So that the width of a "max width" box can be calculated as > > LARGE_VALUE - (-LARGE_VALUE) without overflow, > > Hmm, wouldn't it be better to use unsigned here? IMHO, the many subtle pitfalls that crop up when unsigned arithmetic is used throughout a large C program far outweigh the benefit of the extra half-scale range. Compiler warnings from gcc can catch some problems (certainly not all) and usually it takes tons of effort to make the code “warning-clean” when you enable all the signed-unsigned type warnings. In my experience, I've found that, it is best to avoid unsigned arithmetic as much as possible. Regards, Colin _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
