old c-style casts should generally be avoided. use of std::static_cast is generally preferred. [ref](http://books.google.com/books?id=L5ZbzVnpkXAC&pg=PA102&lpg=PA102&dq=c%2B%2B+gotchas+%2340&source=bl&ots=Rm88SmQhfi&sig=8lY_Qr_Ix96mOSkw3GTuf01mE4I&hl=en&sa=X&ei=OfjvUcqcF6OEyAHo34HgAw&ved=0CC8Q6AEwAA#v=onepage&q=c%2B%2B%20gotchas%20%2340&f=false)