/*============================================================================= | |
Copyright (c) 2001-2006 Joel de Guzman | |
Copyright (c) 2006 Dan Marsden | |
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) | |
==============================================================================*/ | |
#if !defined(FUSION_VALUE_OF_IMPL_20060124_2147) | |
#define FUSION_VALUE_OF_IMPL_20060124_2147 | |
#include <boost/fusion/container/vector/convert.hpp> | |
#include <boost/fusion/algorithm/transformation/transform.hpp> | |
#include <boost/fusion/iterator/value_of.hpp> | |
#include <boost/mpl/placeholders.hpp> | |
#include <boost/fusion/support/unused.hpp> | |
#include <boost/mpl/eval_if.hpp> | |
#include <boost/mpl/identity.hpp> | |
#include <boost/type_traits/is_same.hpp> | |
namespace boost { namespace fusion | |
{ | |
struct zip_view_iterator_tag; | |
namespace detail | |
{ | |
struct poly_value_of | |
{ | |
template<typename T> | |
struct result; | |
template<typename It> | |
struct result<poly_value_of(It)> | |
: mpl::eval_if<is_same<It, unused_type>, | |
mpl::identity<unused_type>, | |
result_of::value_of<It> > | |
{}; | |
}; | |
} | |
namespace extension | |
{ | |
template<typename Tag> | |
struct value_of_impl; | |
template<> | |
struct value_of_impl<zip_view_iterator_tag> | |
{ | |
template<typename Iterator> | |
struct apply | |
{ | |
typedef typename result_of::transform< | |
typename Iterator::iterators, | |
detail::poly_value_of>::type values; | |
typedef typename result_of::as_vector<values>::type type; | |
}; | |
}; | |
} | |
}} | |
#endif |