support/traits/tuple_traits.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2014 Joel de Guzman
0003
0004     Distributed under the Boost Software License, Version 1.0. (See accompanying
0005     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 ================================================_==============================*/
0007 #if !defined(BOOST_SPIRIT_X3_TUPLE_TRAITS_JANUARY_2012_1132PM)
0008 #define BOOST_SPIRIT_X3_TUPLE_TRAITS_JANUARY_2012_1132PM
0009
0010 #include <boost/fusion/include/is_sequence.hpp>
0011 #include <boost/fusion/include/is_view.hpp>
0012 #include <boost/fusion/include/size.hpp>
0013 #include <boost/mpl/bool.hpp>
0014 #include <boost/mpl/and.hpp>
0015
0016 namespace boost { namespace spirit { namespace x3 { namespace traits
0017 {
0018     template <typename A, typename B>
0019     struct has_same_size
0020       : mpl::bool_<(
0021             fusion::result_of::size<A>::value ==
0022             fusion::result_of::size<B>::value
0023         )>
0024     {};
0025
0026     template <typename T, std::size_t N>
0027     struct has_size
0028       : mpl::bool_<(fusion::result_of::size<T>::value == N)>
0029     {};
0030
0031     template <typename A, typename B>
0032     struct is_same_size_sequence
0033       : mpl::and_<
0034             fusion::traits::is_sequence<A>
0035           , fusion::traits::is_sequence<B>
0036           , has_same_size<A, B>
0037         >
0038     {};
0039
0040     template <typename Seq>
0041     struct is_size_one_sequence
0042       : mpl::and_<
0043             fusion::traits::is_sequence<Seq>
0044           , has_size<Seq, 1>
0045         >
0046     {};
0047
0048     template <typename View>
0049     struct is_size_one_view
0050       : mpl::and_<
0051             fusion::traits::is_view<View>
0052           , has_size<View, 1>
0053         >
0054     {};
0055 }}}}
0056
0057 #endif