ceph/src/boost/libs/multi_index/include/boost/multi_index/detail/is_transparent.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_IS_TRANSPARENT_HPP
  10 #define BOOST_MULTI_INDEX_DETAIL_IS_TRANSPARENT_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 namespace boost{
  21
  22 namespace multi_index{
  23
  24 namespace detail{
  25
  26 /* Metafunction that checks if f(arg,arg2) executes without argument type
  27  * conversion. By default (i.e. when it cannot be determined) it evaluates to
  28  * true.
  29  */
  30
  31 template<typename F,typename Arg1,typename Arg2,typename=void>
  32 struct is_transparent:mpl::true_{};
  33
  34 } /* namespace multi_index::detail */
  35
  36 } /* namespace multi_index */
  37
  38 } /* namespace boost */
  39
  40 #if !defined(BOOST_NO_SFINAE)&&!defined(BOOST_NO_SFINAE_EXPR)&& \
  41     !defined(BOOST_NO_CXX11_DECLTYPE)&& \
  42     (defined(BOOST_NO_CXX11_FINAL)||defined(BOOST_IS_FINAL))
  43
  44 #include <boost/mpl/and.hpp>
  45 #include <boost/mpl/not.hpp>
  46 #include <boost/mpl/or.hpp>
  47 #include <boost/type_traits/function_traits.hpp>
  48 #include <boost/type_traits/is_class.hpp>
  49 #include <boost/type_traits/is_final.hpp>
  50 #include <boost/type_traits/is_function.hpp>
  51 #include <boost/type_traits/is_same.hpp>
  52 #include <boost/type_traits/remove_pointer.hpp>
  53 #include <boost/utility/declval.hpp>
  54 #include <boost/utility/enable_if.hpp>
  55
  56 namespace boost{
  57
  58 namespace multi_index{
  59
  60 namespace detail{
  61
  62 struct not_is_transparent_result_type{};
  63
  64 template<typename F,typename Arg1,typename Arg2>
  65 struct is_transparent_class_helper:F
  66 {
  67   using F::operator();
  68   template<typename T,typename Q>
  69   not_is_transparent_result_type operator()(const T&,const Q&)const;
  70 };
  71
  72 template<typename F,typename Arg1,typename Arg2,typename=void>
  73 struct is_transparent_class:mpl::true_{};
  74
  75 template<typename F,typename Arg1,typename Arg2>
  76 struct is_transparent_class<
  77   F,Arg1,Arg2,
  78   typename enable_if<
  79     is_same<
  80       decltype(
  81         declval<const is_transparent_class_helper<F,Arg1,Arg2> >()(
  82           declval<const Arg1&>(),declval<const Arg2&>())
  83       ),
  84       not_is_transparent_result_type
  85     >
  86   >::type
  87 >:mpl::false_{};
  88
  89 template<typename F,typename Arg1,typename Arg2>
  90 struct is_transparent<
  91   F,Arg1,Arg2,
  92   typename enable_if<
  93     mpl::and_<
  94       is_class<F>,
  95       mpl::not_<is_final<F> > /* is_transparent_class_helper derives from F */
  96     >
  97   >::type
  98 >:is_transparent_class<F,Arg1,Arg2>{};
  99
 100 template<typename F,typename Arg1,typename Arg2,typename=void>
 101 struct is_transparent_function:mpl::true_{};
 102
 103 template<typename F,typename Arg1,typename Arg2>
 104 struct is_transparent_function<
 105   F,Arg1,Arg2,
 106   typename enable_if<
 107     mpl::or_<
 108       mpl::not_<mpl::or_<
 109         is_same<typename function_traits<F>::arg1_type,const Arg1&>,
 110         is_same<typename function_traits<F>::arg1_type,Arg1>
 111       > >,
 112       mpl::not_<mpl::or_<
 113         is_same<typename function_traits<F>::arg2_type,const Arg2&>,
 114         is_same<typename function_traits<F>::arg2_type,Arg2>
 115       > >
 116     >
 117   >::type
 118 >:mpl::false_{};
 119
 120 template<typename F,typename Arg1,typename Arg2>
 121 struct is_transparent<
 122   F,Arg1,Arg2,
 123   typename enable_if<
 124     is_function<typename remove_pointer<F>::type>
 125   >::type
 126 >:is_transparent_function<typename remove_pointer<F>::type,Arg1,Arg2>{};
 127
 128 } /* namespace multi_index::detail */
 129
 130 } /* namespace multi_index */
 131
 132 } /* namespace boost */
 133
 134 #endif
 135 #endif