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//-----------------------------------------------------------------------------
// boost variant/detail/element_index.hpp header file
// See http://www.boost.org for updates, documentation, and revision history.
//-----------------------------------------------------------------------------
//
// Copyright (c) 2014-2015 Antony Polukhin
//
// 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)
#ifndef BOOST_VARIANT_DETAIL_ELEMENT_INDEX_HPP
#define BOOST_VARIANT_DETAIL_ELEMENT_INDEX_HPP
#include "boost/config.hpp"
#include "boost/variant/recursive_wrapper_fwd.hpp"
#include "boost/variant/variant_fwd.hpp"
#include "boost/mpl/find_if.hpp"
namespace boost { namespace detail { namespace variant {
template <class VariantElement, class T>
struct variant_element_functor :
boost::mpl::or_<
boost::is_same<VariantElement, T>,
boost::is_same<VariantElement, boost::recursive_wrapper<T> >,
boost::is_same<VariantElement, T& >
>
{};
template <class Types, class T>
struct element_iterator_impl :
boost::mpl::find_if<
Types,
boost::mpl::or_<
variant_element_functor<boost::mpl::_1, T>,
variant_element_functor<boost::mpl::_1, typename boost::remove_cv<T>::type >
>
>
{};
template <class Variant, class T>
struct element_iterator :
element_iterator_impl< typename Variant::types, T>
{};
template <class Variant, class T>
struct holds_element :
boost::mpl::not_<
boost::is_same<
typename boost::mpl::end<typename Variant::types>::type,
typename element_iterator<Variant, T>::type
>
>
{};
}}} // namespace boost::detail::variant
#endif // BOOST_VARIANT_DETAIL_ELEMENT_INDEX_HPP
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