[Boost-users] Is it a good style about boost::format( format-string ) % arg1 % arg2 % ... % argN

Hi, First, I am a new user of boost. I wonder of the style of 'boost::format( format-string ) % arg1 % arg2 % ... % argN'. I think it, format(...), as a function, but it seems not function in C or C++ style. % arg1 % ... seems like a group of parameters, if so, why not use '(' and ')' to wrap them? As it works, there must be something I don't know. Please feel free to point out what I am wrong. I'm very glade to know them. Thanks! -- Sincerely yours, William