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- /*=============================================================================
- 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/phoenix/core.hpp>
- #include <boost/phoenix/function.hpp>
- struct factorial_impl
- {
- template <typename Sig>
- struct result;
-
- template <typename This, typename Arg>
- struct result<This(Arg)>
- : result<This(Arg const &)>
- {};
- template <typename This, typename Arg>
- struct result<This(Arg &)>
- {
- typedef Arg type;
- };
- template <typename Arg>
- Arg operator()(Arg n) const
- {
- return (n <= 0) ? 1 : n * this->operator()(n-1);
- }
- };
- int
- main()
- {
- using boost::phoenix::arg_names::arg1;
- boost::phoenix::function<factorial_impl> factorial;
- int i = 4;
- std::cout << factorial(i)() << std::endl;
- std::cout << factorial(arg1)(i) << std::endl;
- return 0;
- }
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