/*============================================================================= Copyright (c) 2001-2003 Joel de Guzman Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) ==============================================================================*/ #include <vector> #include <algorithm> #include <iostream> #include <boost/spirit/include/phoenix_core.hpp> #include <boost/spirit/include/phoenix_function.hpp> using namespace boost::phoenix; using namespace boost::phoenix::arg_names; using namespace std; struct factorial_impl { template <typename Arg> struct result { typedef Arg type; }; template <typename Arg> Arg operator()(Arg n) const { return (n <= 0) ? 1 : n * this->operator()(n-1); } }; function<factorial_impl> factorial; int main() { int i = 4; cout << factorial(arg1)(i) << endl; return 0; }