Sorry, I forgot to change that. My example Obsolete was a function, so I used the parentheses. Your Obsolete is a bool variable, so you should remove the parentheses:
The reason ++i is preferred over i++ is that in general, when you use i++, the code must make a copy of i, then increment it, then return the copy. Even if you don't use the returned value, the code that figures it out might still be run. When you use ++i, i is incremented first, and then returned without a copy being made. Since you are ignoring the return value, you don't care what is returned, the pre-incremented value or the post-incremented value. Since you don't care, it is better to go with the one that won't require an unnecessary copy. It is possible that the extra copy is optimized away, but I wouldn't count on it and there is no reason to since there is really no difference to you in writing one or the other. This isn't a big deal, just another suggested good habit.