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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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