Chris@102: //-----------------------------------------------------------------------------
Chris@102: // boost variant/detail/element_index.hpp header file
Chris@102: // See http://www.boost.org for updates, documentation, and revision history.
Chris@102: //-----------------------------------------------------------------------------
Chris@102: //
Chris@102: // Copyright (c) 2014-2015 Antony Polukhin
Chris@102: //
Chris@102: // Distributed under the Boost Software License, Version 1.0. (See
Chris@102: // accompanying file LICENSE_1_0.txt or copy at
Chris@102: // http://www.boost.org/LICENSE_1_0.txt)
Chris@102: 
Chris@102: #ifndef BOOST_VARIANT_DETAIL_ELEMENT_INDEX_HPP
Chris@102: #define BOOST_VARIANT_DETAIL_ELEMENT_INDEX_HPP
Chris@102: 
Chris@102: #include "boost/config.hpp"
Chris@102: #include "boost/variant/recursive_wrapper_fwd.hpp"
Chris@102: #include "boost/variant/variant_fwd.hpp"
Chris@102: 
Chris@102: #include "boost/mpl/find_if.hpp"
Chris@102: 
Chris@102: namespace boost { namespace detail { namespace variant {
Chris@102: 
Chris@102: template <class VariantElement, class T>
Chris@102: struct variant_element_functor :
Chris@102:     boost::mpl::or_<
Chris@102:         boost::is_same<VariantElement, T>,
Chris@102:         boost::is_same<VariantElement, boost::recursive_wrapper<T> >,
Chris@102:         boost::is_same<VariantElement, T& >
Chris@102:     >
Chris@102: {};
Chris@102: 
Chris@102: template <class Types, class T>
Chris@102: struct element_iterator_impl :
Chris@102:     boost::mpl::find_if<
Chris@102:         Types,
Chris@102:         boost::mpl::or_<
Chris@102:             variant_element_functor<boost::mpl::_1, T>,
Chris@102:             variant_element_functor<boost::mpl::_1, typename boost::remove_cv<T>::type >
Chris@102:         >
Chris@102:     >
Chris@102: {};
Chris@102: 
Chris@102: template <class Variant, class T>
Chris@102: struct element_iterator :
Chris@102:     element_iterator_impl< typename Variant::types, T>
Chris@102: {};
Chris@102: 
Chris@102: template <class Variant, class T>
Chris@102: struct holds_element :
Chris@102:     boost::mpl::not_<
Chris@102:         boost::is_same<
Chris@102:             typename boost::mpl::end<typename Variant::types>::type,
Chris@102:             typename element_iterator<Variant, T>::type
Chris@102:         >
Chris@102:     >
Chris@102: {};
Chris@102: 
Chris@102: 
Chris@102: }}} // namespace boost::detail::variant
Chris@102: 
Chris@102: #endif // BOOST_VARIANT_DETAIL_ELEMENT_INDEX_HPP