boost/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/is_union.hpp>
  15 #   include <boost/type_traits/detail/ice_and.hpp>
  16 #   include <boost/type_traits/detail/ice_not.hpp>
  17
  18 #ifdef BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
  19 #   include <boost/type_traits/detail/yes_no_type.hpp>
  20 #else
  21 #   include <boost/type_traits/is_scalar.hpp>
  22 #   include <boost/type_traits/is_array.hpp>
  23 #   include <boost/type_traits/is_reference.hpp>
  24 #   include <boost/type_traits/is_void.hpp>
  25 #   include <boost/type_traits/is_function.hpp>
  26 #endif
  27
  28 #ifdef __EDG_VERSION__
  29 #   include <boost/type_traits/remove_cv.hpp>
  30 #endif
  31
  32 // should be the last #include
  33 #include <boost/type_traits/detail/bool_trait_def.hpp>
  34
  35 namespace boost {
  36
  37 namespace detail {
  38
  39 #ifdef BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
  40
  41 // This is actually the conforming implementation which works with
  42 // abstract classes.  However, enough compilers have trouble with
  43 // it that most will use the one in
  44 // boost/type_traits/object_traits.hpp. This implementation
  45 // actually works with VC7.0, but other interactions seem to fail
  46 // when we use it.
  47
  48 // is_class<> metafunction due to Paul Mensonides
  49 // (leavings@attbi.com). For more details:
  50 // http://groups.google.com/groups?hl=en&selm=000001c1cc83%24e154d5e0%247772e50c%40c161550a&rnum=1
  51 #if defined(__GNUC__)  && !defined(__EDG_VERSION__)
  52
  53 template <class U> ::boost::type_traits::yes_type is_class_tester(void(U::*)(void));
  54 template <class U> ::boost::type_traits::no_type is_class_tester(...);
  55
  56 template <typename T>
  57 struct is_class_impl
  58 {
  59
  60     BOOST_STATIC_CONSTANT(bool, value =
  61         (::boost::type_traits::ice_and<
  62             sizeof(is_class_tester<T>(0)) == sizeof(::boost::type_traits::yes_type),
  63             ::boost::type_traits::ice_not< ::boost::is_union<T>::value >::value
  64         >::value)
  65         );
  66 };
  67
  68 #else
  69
  70 template <typename T>
  71 struct is_class_impl
  72 {
  73     template <class U> static ::boost::type_traits::yes_type is_class_tester(void(U::*)(void));
  74     template <class U> static ::boost::type_traits::no_type is_class_tester(...);
  75
  76     BOOST_STATIC_CONSTANT(bool, value =
  77         (::boost::type_traits::ice_and<
  78             sizeof(is_class_tester<T>(0)) == sizeof(::boost::type_traits::yes_type),
  79             ::boost::type_traits::ice_not< ::boost::is_union<T>::value >::value
  80         >::value)
  81         );
  82 };
  83
  84 #endif
  85
  86 #else
  87
  88 template <typename T>
  89 struct is_class_impl
  90 {
  91 #   ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  92     BOOST_STATIC_CONSTANT(bool, value =
  93     (::boost::type_traits::ice_and<
  94         ::boost::type_traits::ice_not< ::boost::is_union<T>::value >::value,
  95         ::boost::type_traits::ice_not< ::boost::is_scalar<T>::value >::value,
  96         ::boost::type_traits::ice_not< ::boost::is_array<T>::value >::value,
  97         ::boost::type_traits::ice_not< ::boost::is_reference<T>::value>::value,
  98         ::boost::type_traits::ice_not< ::boost::is_void<T>::value >::value,
  99         ::boost::type_traits::ice_not< ::boost::is_function<T>::value >::value
 100         >::value));
 101 #   else
 102     BOOST_STATIC_CONSTANT(bool, value =
 103     (::boost::type_traits::ice_and<
 104         ::boost::type_traits::ice_not< ::boost::is_union<T>::value >::value,
 105         ::boost::type_traits::ice_not< ::boost::is_scalar<T>::value >::value,
 106         ::boost::type_traits::ice_not< ::boost::is_array<T>::value >::value,
 107         ::boost::type_traits::ice_not< ::boost::is_reference<T>::value>::value,
 108         ::boost::type_traits::ice_not< ::boost::is_void<T>::value >::value
 109         >::value));
 110 #   endif
 111 };
 112
 113 # endif // BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION
 114
 115 } // namespace detail
 116
 117 # ifdef __EDG_VERSION__
 118 BOOST_TT_AUX_BOOL_TRAIT_DEF1(
 119     is_class,T, detail::is_class_impl<typename boost::remove_cv<T>::type>::value)
 120 # else
 121 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_class,T,::boost::detail::is_class_impl<T>::value)
 122 # endif
 123
 124 } // namespace boost
 125
 126 #include <boost/type_traits/detail/bool_trait_undef.hpp>
 127
 128 #endif // BOOST_TT_IS_CLASS_HPP_INCLUDED