Chris@102: /*=============================================================================
Chris@102:     Copyright (c) 2014 Christoph Weiss
Chris@102: 
Chris@102:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@102:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@102: ==============================================================================*/
Chris@102: #if !defined(FUSION_HASH_23072014_1017)
Chris@102: #define FUSION_HASH_23072014_1017
Chris@102: 
Chris@102: #include <boost/functional/hash.hpp>
Chris@102: #include <boost/fusion/algorithm/iteration/fold.hpp>
Chris@102: #include <boost/fusion/support/is_sequence.hpp>
Chris@102: #include <boost/utility/enable_if.hpp>
Chris@102: 
Chris@102: namespace boost { namespace fusion
Chris@102: {
Chris@102:     namespace hashing
Chris@102:     {
Chris@102:         struct hash_combine_fold
Chris@102:         {
Chris@102:             typedef std::size_t result_type;
Chris@102:             template<typename T>
Chris@102:             inline std::size_t operator()(std::size_t seed, T const& v)
Chris@102:             {
Chris@102:                 boost::hash_combine(seed, v);
Chris@102:                 return seed;
Chris@102:             }
Chris@102:         };
Chris@102: 
Chris@102:         template <typename Seq>
Chris@102:         inline typename
Chris@102:         boost::enable_if<traits::is_sequence<Seq>, std::size_t>::type
Chris@102:         hash_value(Seq const& seq)
Chris@102:         {
Chris@102:             return fold(seq, 0, hash_combine_fold());
Chris@102:         }
Chris@102:     }
Chris@102: 
Chris@102:     using hashing::hash_value;
Chris@102: }}
Chris@102: 
Chris@102: #endif