Here's a link to a good reference:
Try looking on your compiler's documentation/help for setiosflags. If that doesn't help, try doing a search at Dinkumware.com. (Click-on the footprints to get-to the free reference.) Dinkumware is the most complete C++ reference that I've found. ...But, I'm not saying that it's the easiest reference to understand. :(
In order to understand how the the flags actually work, you need to understand binary numbers, bit-weights (1, 2, 4, 8, 16...) and bitwise operations.