boost/type_traits/is_class.hpp

   1 //  (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes, Howard
   2 //  Hinnant & John Maddock 2000-2003.
   3 //  Use, modification and distribution are subject to the Boost Software License,
   4 //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 //  http://www.boost.org/LICENSE_1_0.txt).
   6 //
   7 //  See http://www.boost.org/libs/type_traits for most recent version including documentation.
   8
   9
  10 #ifndef BOOST_TT_IS_CLASS_HPP_INCLUDED
  11 #define BOOST_TT_IS_CLASS_HPP_INCLUDED
  12
  13 #include <boost/type_traits/config.hpp>
  14 #include <boost/type_traits/intrinsics.hpp>
  15 #ifndef BOOST_IS_CLASS
  16 #   include <boost/type_traits/is_union.hpp>
  17 #   include <boost/type_traits/detail/ice_and.hpp>
  18 #   include <boost/type_traits/detail/ice_not.hpp>
  19
  20 #ifdef BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
  21 #   include <boost/type_traits/detail/yes_no_type.hpp>
  22 #else
  23 #   include <boost/type_traits/is_scalar.hpp>
  24 #   include <boost/type_traits/is_array.hpp>
  25 #   include <boost/type_traits/is_reference.hpp>
  26 #   include <boost/type_traits/is_void.hpp>
  27 #   include <boost/type_traits/is_function.hpp>
  28 #endif
  29
  30 #endif // BOOST_IS_CLASS
  31
  32 #ifdef __EDG_VERSION__
  33 #   include <boost/type_traits/remove_cv.hpp>
  34 #endif
  35
  36 // should be the last #include
  37 #include <boost/type_traits/detail/bool_trait_def.hpp>
  38
  39 namespace boost {
  40
  41 namespace detail {
  42
  43 #ifndef BOOST_IS_CLASS
  44 #ifdef BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
  45
  46 // This is actually the conforming implementation which works with
  47 // abstract classes.  However, enough compilers have trouble with
  48 // it that most will use the one in
  49 // boost/type_traits/object_traits.hpp. This implementation
  50 // actually works with VC7.0, but other interactions seem to fail
  51 // when we use it.
  52
  53 // is_class<> metafunction due to Paul Mensonides
  54 // (leavings@attbi.com). For more details:
  55 // http://groups.google.com/groups?hl=en&selm=000001c1cc83%24e154d5e0%247772e50c%40c161550a&rnum=1
  56 #if defined(__GNUC__)  && !defined(__EDG_VERSION__)
  57
  58 template <class U> ::boost::type_traits::yes_type is_class_tester(void(U::*)(void));
  59 template <class U> ::boost::type_traits::no_type is_class_tester(...);
  60
  61 template <typename T>
  62 struct is_class_impl
  63 {
  64
  65     BOOST_STATIC_CONSTANT(bool, value =
  66         (::boost::type_traits::ice_and<
  67             sizeof(is_class_tester<T>(0)) == sizeof(::boost::type_traits::yes_type),
  68             ::boost::type_traits::ice_not< ::boost::is_union<T>::value >::value
  69         >::value)
  70         );
  71 };
  72
  73 #else
  74
  75 template <typename T>
  76 struct is_class_impl
  77 {
  78     template <class U> static ::boost::type_traits::yes_type is_class_tester(void(U::*)(void));
  79     template <class U> static ::boost::type_traits::no_type is_class_tester(...);
  80
  81     BOOST_STATIC_CONSTANT(bool, value =
  82         (::boost::type_traits::ice_and<
  83             sizeof(is_class_tester<T>(0)) == sizeof(::boost::type_traits::yes_type),
  84             ::boost::type_traits::ice_not< ::boost::is_union<T>::value >::value
  85         >::value)
  86         );
  87 };
  88
  89 #endif
  90
  91 #else
  92
  93 template <typename T>
  94 struct is_class_impl
  95 {
  96 #   ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  97     BOOST_STATIC_CONSTANT(bool, value =
  98     (::boost::type_traits::ice_and<
  99         ::boost::type_traits::ice_not< ::boost::is_union<T>::value >::value,
 100         ::boost::type_traits::ice_not< ::boost::is_scalar<T>::value >::value,
 101         ::boost::type_traits::ice_not< ::boost::is_array<T>::value >::value,
 102         ::boost::type_traits::ice_not< ::boost::is_reference<T>::value>::value,
 103         ::boost::type_traits::ice_not< ::boost::is_void<T>::value >::value,
 104         ::boost::type_traits::ice_not< ::boost::is_function<T>::value >::value
 105         >::value));
 106 #   else
 107     BOOST_STATIC_CONSTANT(bool, value =
 108     (::boost::type_traits::ice_and<
 109         ::boost::type_traits::ice_not< ::boost::is_union<T>::value >::value,
 110         ::boost::type_traits::ice_not< ::boost::is_scalar<T>::value >::value,
 111         ::boost::type_traits::ice_not< ::boost::is_array<T>::value >::value,
 112         ::boost::type_traits::ice_not< ::boost::is_reference<T>::value>::value,
 113         ::boost::type_traits::ice_not< ::boost::is_void<T>::value >::value
 114         >::value));
 115 #   endif
 116 };
 117
 118 # endif // BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
 119 # else // BOOST_IS_CLASS
 120 template <typename T>
 121 struct is_class_impl
 122 {
 123     BOOST_STATIC_CONSTANT(bool, value = BOOST_IS_CLASS(T));
 124 };
 125 # endif // BOOST_IS_CLASS
 126
 127 } // namespace detail
 128
 129 # ifdef __EDG_VERSION__
 130 BOOST_TT_AUX_BOOL_TRAIT_DEF1(
 131    is_class,T, boost::detail::is_class_impl<typename boost::remove_cv<T>::type>::value)
 132 # else
 133 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_class,T,::boost::detail::is_class_impl<T>::value)
 134 # endif
 135
 136 } // namespace boost
 137
 138 #include <boost/type_traits/detail/bool_trait_undef.hpp>
 139
 140 #endif // BOOST_TT_IS_CLASS_HPP_INCLUDED