/* Copyright 2003-2008 Joaquin M Lopez Munoz. * 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) * * See http://www.boost.org/libs/multi_index for library home page. */ #ifndef BOOST_MULTI_INDEX_DETAIL_HASH_INDEX_ARGS_HPP #define BOOST_MULTI_INDEX_DETAIL_HASH_INDEX_ARGS_HPP #if defined(_MSC_VER)&&(_MSC_VER>=1200) #pragma once #endif #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */ #include <boost/functional/hash.hpp> #include <boost/mpl/aux_/na.hpp> #include <boost/mpl/eval_if.hpp> #include <boost/mpl/identity.hpp> #include <boost/mpl/if.hpp> #include <boost/multi_index/tag.hpp> #include <boost/static_assert.hpp> #include <boost/type_traits/is_same.hpp> #include <functional> namespace boost{ namespace multi_index{ namespace detail{ /* Hashed index specifiers can be instantiated in two forms: * * (hashed_unique|hashed_non_unique)< * KeyFromValue, * Hash=boost::hash<KeyFromValue::result_type>, * Pred=std::equal_to<KeyFromValue::result_type> > * (hashed_unique|hashed_non_unique)< * TagList, * KeyFromValue, * Hash=boost::hash<KeyFromValue::result_type>, * Pred=std::equal_to<KeyFromValue::result_type> > * * hashed_index_args implements the machinery to accept this * argument-dependent polymorphism. */ template<typename KeyFromValue> struct index_args_default_hash { typedef ::boost::hash<typename KeyFromValue::result_type> type; }; template<typename KeyFromValue> struct index_args_default_pred { typedef std::equal_to<typename KeyFromValue::result_type> type; }; template<typename Arg1,typename Arg2,typename Arg3,typename Arg4> struct hashed_index_args { typedef is_tag<Arg1> full_form; typedef typename mpl::if_< full_form, Arg1, tag< > >::type tag_list_type; typedef typename mpl::if_< full_form, Arg2, Arg1>::type key_from_value_type; typedef typename mpl::if_< full_form, Arg3, Arg2>::type supplied_hash_type; typedef typename mpl::eval_if< mpl::is_na<supplied_hash_type>, index_args_default_hash<key_from_value_type>, mpl::identity<supplied_hash_type> >::type hash_type; typedef typename mpl::if_< full_form, Arg4, Arg3>::type supplied_pred_type; typedef typename mpl::eval_if< mpl::is_na<supplied_pred_type>, index_args_default_pred<key_from_value_type>, mpl::identity<supplied_pred_type> >::type pred_type; BOOST_STATIC_ASSERT(is_tag<tag_list_type>::value); BOOST_STATIC_ASSERT(!mpl::is_na<key_from_value_type>::value); BOOST_STATIC_ASSERT(!mpl::is_na<hash_type>::value); BOOST_STATIC_ASSERT(!mpl::is_na<pred_type>::value); }; } /* namespace multi_index::detail */ } /* namespace multi_index */ } /* namespace boost */ #endif