Apparently unsigned types really are necessary

[Martin Nowak]

On Sun, 22 Jan 2012 13:49:37 +0100, Jonathan M Davis <jmdavisProg at gmx.com>  
wrote:

> One issue with unsigned integers right off the bat is for loops.
> for(size_t i = a.length; i > 0; --i) {}
> is not going to work.

What's not working with this?

Besides a neat idiom for reverse array indexing
     for (size_t i = a.length; i--; )
         writeln(a[i]);