http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49048
--- Comment #8 from Cecilio <s.cecilio at gmail dot com> 2011-05-19 17:01:15 UTC --- Thanks again, Paolo and Jackub, for your help and explanations. Believe it or not, I a have a PhD and had to learn a lot of complex mathematics, but I never heard about so many types of 'rounding' methods. To me, rounding had always meant round-half-up (banker's rounding): 5.5 rounds up to 6 and 6.5 rounds up to 7. As this is also the normally required method for financial calculations, I can not understand the usefulness of printf sometimes rounding up and others rounding down, as it is the behaviour of round-half-even method. But once I've learn that (thanks for this) I know that I can no longer rely on setprecision or printf, and that I have to implement my rounding methods to get the banker's rounding behaviour. I'm wondering how many financial programs are there relying on setprecision without having noticed its 'problematic' rounding behaviour, caused by printf and blessed by ISO c++ standard. ;-) It's been a pleasure taking to both and learning with your help. With my best regards, Cecilio
