boost/multi_index/detail/promotes_arg.hpp
/* Copyright 2003-2017 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_PROMOTES_ARG_HPP #define BOOST_MULTI_INDEX_DETAIL_PROMOTES_ARG_HPP #if defined(_MSC_VER) #pragma once #endif #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */ #include <boost/detail/workaround.hpp> /* Metafunctions to check if f(arg1,arg2) promotes either arg1 to the type of * arg2 or viceversa. By default, (i.e. if it cannot be determined), no * promotion is assumed. */ #if BOOST_WORKAROUND(BOOST_MSVC,<1400) namespace boost{ namespace multi_index{ namespace detail{ template<typename F,typename Arg1,typename Arg2> struct promotes_1st_arg:mpl::false_{}; template<typename F,typename Arg1,typename Arg2> struct promotes_2nd_arg:mpl::false_{}; } /* namespace multi_index::detail */ } /* namespace multi_index */ } /* namespace boost */ #else #include <boost/mpl/and.hpp> #include <boost/mpl/bool.hpp> #include <boost/mpl/not.hpp> #include <boost/multi_index/detail/is_transparent.hpp> #include <boost/type_traits/is_convertible.hpp> namespace boost{ namespace multi_index{ namespace detail{ template<typename F,typename Arg1,typename Arg2> struct promotes_1st_arg: mpl::and_< mpl::not_<is_transparent<F,Arg1,Arg2> >, is_convertible<const Arg1,Arg2>, is_transparent<F,Arg2,Arg2> > {}; template<typename F,typename Arg1,typename Arg2> struct promotes_2nd_arg: mpl::and_< mpl::not_<is_transparent<F,Arg1,Arg2> >, is_convertible<const Arg2,Arg1>, is_transparent<F,Arg1,Arg1> > {}; } /* namespace multi_index::detail */ } /* namespace multi_index */ } /* namespace boost */ #endif #endif