3rdparty/boost/boost/type_traits/is_virtual_base_of.hpp

   1 //  (C) Copyright Daniel Frey and Robert Ramey 2009.
   2 //  Use, modification and distribution are subject to the Boost Software License,
   3 //  Version 1.0. (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/type_traits for most recent version including documentation.
   7
   8 #ifndef BOOST_TT_IS_VIRTUAL_BASE_OF_HPP_INCLUDED
   9 #define BOOST_TT_IS_VIRTUAL_BASE_OF_HPP_INCLUDED
  10
  11 #include <boost/type_traits/is_base_of.hpp>
  12 #include <boost/type_traits/is_same.hpp>
  13
  14 namespace boost {
  15 namespace detail {
  16
  17
  18 #ifdef BOOST_MSVC
  19 #pragma warning( push )
  20 #pragma warning( disable : 4584 4250 4594)
  21 #elif defined(__GNUC__) && (__GNUC__ >= 4)
  22 #pragma GCC system_header
  23 #endif
  24
  25 template<typename Base, typename Derived, typename tag>
  26 struct is_virtual_base_of_impl
  27 {
  28     BOOST_STATIC_CONSTANT(bool, value = false);
  29 };
  30
  31 template<typename Base, typename Derived>
  32 struct is_virtual_base_of_impl<Base, Derived, true_type>
  33 {
  34    union max_align
  35    {
  36       unsigned u;
  37       unsigned long ul;
  38       void* v;
  39       double d;
  40       long double ld;
  41 #ifndef BOOST_NO_LONG_LONG
  42       long long ll;
  43 #endif
  44    };
  45 #ifdef __BORLANDC__
  46     struct boost_type_traits_internal_struct_X : public virtual Derived, public virtual Base
  47     {
  48        boost_type_traits_internal_struct_X();
  49        boost_type_traits_internal_struct_X(const boost_type_traits_internal_struct_X&);
  50        boost_type_traits_internal_struct_X& operator=(const boost_type_traits_internal_struct_X&);
  51        ~boost_type_traits_internal_struct_X()throw();
  52        max_align data[4];
  53     };
  54     struct boost_type_traits_internal_struct_Y : public virtual Derived
  55     {
  56        boost_type_traits_internal_struct_Y();
  57        boost_type_traits_internal_struct_Y(const boost_type_traits_internal_struct_Y&);
  58        boost_type_traits_internal_struct_Y& operator=(const boost_type_traits_internal_struct_Y&);
  59        ~boost_type_traits_internal_struct_Y()throw();
  60        max_align data[4];
  61     };
  62 #else
  63     struct boost_type_traits_internal_struct_X : public Derived, virtual Base
  64     {
  65        boost_type_traits_internal_struct_X();
  66        boost_type_traits_internal_struct_X(const boost_type_traits_internal_struct_X&);
  67        boost_type_traits_internal_struct_X& operator=(const boost_type_traits_internal_struct_X&);
  68        ~boost_type_traits_internal_struct_X()throw();
  69        max_align data[16];
  70     };
  71     struct boost_type_traits_internal_struct_Y : public Derived
  72     {
  73        boost_type_traits_internal_struct_Y();
  74        boost_type_traits_internal_struct_Y(const boost_type_traits_internal_struct_Y&);
  75        boost_type_traits_internal_struct_Y& operator=(const boost_type_traits_internal_struct_Y&);
  76        ~boost_type_traits_internal_struct_Y()throw();
  77        max_align data[16];
  78     };
  79 #endif
  80     BOOST_STATIC_CONSTANT(bool, value = (sizeof(boost_type_traits_internal_struct_X)==sizeof(boost_type_traits_internal_struct_Y)));
  81 };
  82
  83 template<typename Base, typename Derived>
  84 struct is_virtual_base_of_impl2
  85 {
  86    typedef boost::integral_constant<bool, (boost::is_base_of<Base, Derived>::value && ! boost::is_same<Base, Derived>::value)> tag_type;
  87    typedef is_virtual_base_of_impl<Base, Derived, tag_type> imp;
  88    BOOST_STATIC_CONSTANT(bool, value = imp::value);
  89 };
  90
  91 #ifdef BOOST_MSVC
  92 #pragma warning( pop )
  93 #endif
  94
  95 } // namespace detail
  96
  97 template <class Base, class Derived> struct is_virtual_base_of : public integral_constant<bool, (::boost::detail::is_virtual_base_of_impl2<Base, Derived>::value)>{};
  98
  99 template <class Base, class Derived> struct is_virtual_base_of<Base&, Derived> : public false_type{};
 100 template <class Base, class Derived> struct is_virtual_base_of<Base, Derived&> : public false_type{};
 101 template <class Base, class Derived> struct is_virtual_base_of<Base&, Derived&> : public false_type{};
 102
 103 } // namespace boost
 104
 105 #endif