Best SC++L Reference Book

There's a competition that my school enters every year and we're allowed to bring a language reference book for every language we use. For Java we'll just bring whatever we brought last time, but what is a good reference book for C++? I'm mainly looking for something with excellent detail on the standard library, including minor tweaks and quirks that one doesn't use every day. For example, if a problem asked for an output with exactly 7 decimal places, I'd do:

std::cout.setf(std::ios::fixed, std::ios::floatfield);
std::cout.precision(7);

However, if that wasn't exactly on the top of my head, it'd be nice to be able to quickly look up std::ostream (or just std::cout if there's a specific section on it or something) and see "oh, precision() and setf() is what I need."