ceph/src/boost/libs/multi_index/include/boost/multi_index/detail/promotes_arg.hpp

   1 /* Copyright 2003-2014 Joaquin M Lopez Munoz.
   2  * Distributed under the Boost Software License, Version 1.0.
   3  * (See accompanying file LICENSE_1_0.txt or copy at
   4  * http://www.boost.org/LICENSE_1_0.txt)
   5  *
   6  * See http://www.boost.org/libs/multi_index for library home page.
   7  */
   8
   9 #ifndef BOOST_MULTI_INDEX_DETAIL_PROMOTES_ARG_HPP
  10 #define BOOST_MULTI_INDEX_DETAIL_PROMOTES_ARG_HPP
  11
  12 #if defined(_MSC_VER)
  13 #pragma once
  14 #endif
  15
  16 #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
  17 #include <boost/mpl/bool.hpp>
  18 #include <boost/type_traits/intrinsics.hpp>
  19
  20 /* Metafunctions to check if f(arg1,arg2) promotes either arg1 to the type of
  21  * arg2 or viceversa. By default, (i.e. if it cannot be determined), no
  22  * promotion is assumed.
  23  */
  24
  25 #if !defined(BOOST_IS_CONVERTIBLE)
  26
  27 namespace boost{
  28
  29 namespace multi_index{
  30
  31 namespace detail{
  32
  33 template<typename F,typename Arg1,typename Arg2>
  34 struct promotes_1st_arg:mpl::false_{};
  35
  36 template<typename F,typename Arg1,typename Arg2>
  37 struct promotes_2nd_arg:mpl::false_{};
  38
  39 } /* namespace multi_index::detail */
  40
  41 } /* namespace multi_index */
  42
  43 } /* namespace boost */
  44
  45 #else
  46
  47 #include <boost/mpl/and.hpp>
  48 #include <boost/mpl/not.hpp>
  49 #include <boost/multi_index/detail/is_transparent.hpp>
  50 #include <boost/type_traits/is_convertible.hpp>
  51
  52 namespace boost{
  53
  54 namespace multi_index{
  55
  56 namespace detail{
  57
  58 template<typename F,typename Arg1,typename Arg2>
  59 struct promotes_1st_arg:
  60   mpl::and_<
  61     mpl::not_<is_transparent<F,Arg1,Arg2> >,
  62     is_convertible<const Arg1,Arg2>,
  63     is_transparent<F,Arg2,Arg2>
  64   >
  65 {};
  66
  67 template<typename F,typename Arg1,typename Arg2>
  68 struct promotes_2nd_arg:
  69   mpl::and_<
  70     mpl::not_<is_transparent<F,Arg1,Arg2> >,
  71     is_convertible<const Arg2,Arg1>,
  72     is_transparent<F,Arg1,Arg1>
  73   >
  74 {};
  75
  76 } /* namespace multi_index::detail */
  77
  78 } /* namespace multi_index */
  79
  80 } /* namespace boost */
  81
  82 #endif /* defined(BOOST_IS_CONVERTIBLE) */
  83 #endif