ceph/src/boost/boost/type_traits/detail/composite_member_pointer_type.hpp

   1 #ifndef BOOST_TYPE_TRAITS_DETAIL_COMPOSITE_MEMBER_POINTER_TYPE_HPP_INCLUDED
   2 #define BOOST_TYPE_TRAITS_DETAIL_COMPOSITE_MEMBER_POINTER_TYPE_HPP_INCLUDED
   3
   4 //
   5 //  Copyright 2015 Peter Dimov
   6 //
   7 //  Distributed under the Boost Software License, Version 1.0.
   8 //  See accompanying file LICENSE_1_0.txt or copy at
   9 //  http://www.boost.org/LICENSE_1_0.txt
  10 //
  11
  12 #include <boost/type_traits/detail/composite_pointer_type.hpp>
  13 #include <boost/type_traits/remove_pointer.hpp>
  14 #include <boost/type_traits/is_base_of.hpp>
  15 #include <boost/type_traits/conditional.hpp>
  16 #include <boost/config.hpp>
  17 #include <cstddef>
  18
  19 namespace boost
  20 {
  21
  22 namespace type_traits_detail
  23 {
  24
  25 template<class T, class U> struct composite_member_pointer_type;
  26
  27 // nullptr_t
  28
  29 #if !defined( BOOST_NO_CXX11_NULLPTR )
  30
  31 #if !defined( BOOST_NO_CXX11_DECLTYPE ) && ( ( defined( __clang__ ) && !defined( _LIBCPP_VERSION ) ) || defined( __INTEL_COMPILER ) )
  32
  33 template<class C, class T> struct composite_member_pointer_type<T C::*, decltype(nullptr)>
  34 {
  35     typedef T C::* type;
  36 };
  37
  38 template<class C, class T> struct composite_member_pointer_type<decltype(nullptr), T C::*>
  39 {
  40     typedef T C::* type;
  41 };
  42
  43 template<> struct composite_member_pointer_type<decltype(nullptr), decltype(nullptr)>
  44 {
  45     typedef decltype(nullptr) type;
  46 };
  47
  48 #else
  49
  50 template<class C, class T> struct composite_member_pointer_type<T C::*, std::nullptr_t>
  51 {
  52     typedef T C::* type;
  53 };
  54
  55 template<class C, class T> struct composite_member_pointer_type<std::nullptr_t, T C::*>
  56 {
  57     typedef T C::* type;
  58 };
  59
  60 template<> struct composite_member_pointer_type<std::nullptr_t, std::nullptr_t>
  61 {
  62     typedef std::nullptr_t type;
  63 };
  64
  65 #endif
  66
  67 #endif // !defined( BOOST_NO_CXX11_NULLPTR )
  68
  69 template<class C1, class C2> struct common_member_class;
  70
  71 template<class C> struct common_member_class<C, C>
  72 {
  73     typedef C type;
  74 };
  75
  76 template<class C1, class C2> struct common_member_class
  77 {
  78     typedef typename boost::conditional<
  79
  80         boost::is_base_of<C1, C2>::value,
  81         C2,
  82         typename boost::conditional<boost::is_base_of<C2, C1>::value, C1, void>::type
  83
  84     >::type type;
  85 };
  86
  87 //This indirection avoids compilation errors on some older
  88 //compilers like MSVC 7.1
  89 template<class CT, class CB>
  90 struct common_member_class_pointer_to_member
  91 {
  92     typedef CT CB::* type;
  93 };
  94
  95 template<class C1, class T1, class C2, class T2> struct composite_member_pointer_type<T1 C1::*, T2 C2::*>
  96 {
  97 private:
  98
  99     typedef typename composite_pointer_type<T1*, T2*>::type CPT;
 100     typedef typename boost::remove_pointer<CPT>::type CT;
 101
 102     typedef typename common_member_class<C1, C2>::type CB;
 103
 104 public:
 105
 106     typedef typename common_member_class_pointer_to_member<CT, CB>::type type;
 107 };
 108
 109 } // namespace type_traits_detail
 110
 111 } // namespace boost
 112
 113 #endif // #ifndef BOOST_TYPE_TRAITS_DETAIL_COMPOSITE_MEMBER_POINTER_TYPE_HPP_INCLUDED