It's an idiom - obviously very little known, likely less known than comparing floats to themselves being a NaN check. The standard idiom for doing a reverse lo

It's an idiom - obviously very little known, likely less known than comparing floats to themselves being a NaN check. The standard idiom for doing a reverse loop would be: "for (int i = size; i-- > 0; ) ...". As a side benefit it has lower registry pressure. Some folks have issues reading that one as well. Saying all that not being 'unsigned fan', just the popularity of the idioms comes with their use frequency, and given that 'unsigned; is not popular at all...