// Copyright (C) 2001-2003 // William E. Kempf // // Permission to use, copy, modify, distribute and sell this software // and its documentation for any purpose is hereby granted without fee, // provided that the above copyright notice appear in all copies and // that both that copyright notice and this permission notice appear // in supporting documentation. William E. Kempf makes no representations // about the suitability of this software for any purpose. // It is provided "as is" without express or implied warranty. #include <boost/thread/thread.hpp> #include <boost/ref.hpp> #include <iostream> class factorial { public: factorial(int x) : x(x), res(0) { } void operator()() { res = calculate(x); } int result() const { return res; } private: int calculate(int x) { return x <= 1 ? 1 : x * calculate(x-1); } private: int x; int res; }; int main() { factorial f(10); boost::thread thrd(boost::ref(f)); thrd.join(); std::cout << "10! = " << f.result() << std::endl; }