>> Hmm, given Bruno's recent point that C89 didn't require ?: support >> in constant expressions
I'm skeptical of that. I can't find my copy of the official C89 standard, but the draft <http://flash-gordon.me.uk/ansi.c.txt> says that constant expressions can contain ?:. In fact, the grammar in section 3.4 looks like this: constant-expression: conditional-expression and until this discussion I've never heard of the claim that one cannot use ?: in constant expressions. Given that (X ? 1 : -1) captures the concept more clearly than (2 * X - 1), we're better off using the former notation than the latter.
